accounts of our memories are like meticulously made reports in laboratory notebooks of carefully observed results obtained by using poorly calibrated apparatus designed for a different type of experiment. They may faithfully reproduce information, but that information is not entirely reliable.
Is remembering something a sufficent reason to believe it happended?
I came to the realisation that something I had remembered, was not actually something that had happened. I had experienced it as a genuine memory – but on reflection soon afterwards I knew full well it was not the case (indeed, could not have been the case). This could have been rather disconcerting in other circumstances. That is, if this had occurred during what we consider a normal state of consciousness. Even so, it gave me pause for thought.
Memories and false beliefs about memory
Memory is one of these things we all know about, but tends to be generally poorly understood. Nomenclature such as 'remember', 'recall', and 'forget', are part of the mental register – the set of terms that are used in everyday discourse to talk about mental experience and related phenomena (Taber, 2013). Our familiarity with this kind of talk probably encourages most of us to feel we have a pretty good handle on the basis of what memory is; what remembering is; and what it means to forget.
Yet, actually, this is not generally so. Research shows that even when people recall events with clarity and are confident in the accuracy of these recollections, their memories may not be trustworthy. Certainly much of what we remember is basically sound (though I am not sure anyone has a good estimate of just how much!) But details often get changed. And sometimes, more than just details.
We represent experience in memory but this is not usually akin to making a video record (even if some people experience their memories as if watching a recording). Memory (the faculty) seems to have evolved to give us an abstracted, generalised impression of past experience. From an evolutionary perspective, we have inherited the kind of memory that was selected for in the context of how our ancestors lived.
Related experiences are often represented without proper discrimination. So, if you regularly get the train to work, you have a memory of this – but not discrete memories of each separate occasion. At least, not unless you are one of those rare people who have been gifted, or perhaps cursed (Luria, 1987), with an eidetic memory. Arguably, for most purposes, a generalised memory of a much repeated scenario is more useful than a large set of records of similar events distinguished by variations in incidental detail. There is value in remembering how to make a cup of tea or unlock a door: less so in having a record of each time one has made tea or unlocked doors.
Memory as a reconstruction
Research shows that memories are often in part constructed – representations ('in memory') activated in remembering offer a partial account, which is filled-in with feasible details BEFORE the memory is presented to consciousness. The person reporting the memory does not know which elements were actually recalled, and which then added.
This has been shown, for example, by testing people a few days after they have been told an unfamiliar story. Typically, people get some points correct, forget some details, but also change details, or even add material that was never in the original. But the person 'remembering' (actually, reconstructing) the story does not necessarily have any less confidence in the fabricated elements, as they have been integrated into the account pre-consciously: 'out of mind' so to speak. Reports of memories are usually honest – it is just that they are honest reports of imperfect memories. Eye witness testimony is famously unreliable, but not because most people lie.
In this way, accounts of our memories are like meticulously made reports in laboratory notebooks of carefully observed results obtained by using poorly calibrated apparatus designed for a different type of experiment. They may faithfully reproduce information, but that information is not entirely reliable. We cannot trust such results just because someone provides an honest report of what was noted down in the record.
Memories are somewhat like those historical reconstructions based on incomplete accounts filled in by a dramatist to offer a full narrative for the viewer, perhaps with some scenes moved to locations that seem to be more keeping with the overall progression of the storyline (or are just considered more visually compelling). Crick and Watson may not have had those specific conversations as portrayed when walking across the backs, or in The Eagle, but there is a sense in which the story has greater coherence and truth if shown that way. Not a strict, historical, truth, of course – but perhaps it creates a better mythology, or acts as more effective pedagogy, or just offers a better aesthetic?
"Look, according to the script here, they are going to film us having this conversation on the tennis court." (Tim Pigott-Smith as Francis Crick and Jeff Goldblum as Jim Watson in a still from the 1987 Horizon special docudrama, 'Life Story' {a.k.a. 'The Race for the Double Helix'}.)
Memories are not fixed. Each time you activate a memory you change the trace. It is therefore possible to 'plant' memories. The first time you are asked to recall the crime scene you are asked if you saw a knife and report not. But when asked again at a later date, you may now associate a knife with the scene (as you had been invited to think about it in that context previously, the image has got linked to the memory). This can be done deliberately, but criminal investigators have to be very careful of accidentally planting memories.
People sometimes recall events from very early in their lives at an age research suggests is before distinct autobiographical memories can be laid down. Presumably, what is actually being remembered is having previously imagined the scene years before when told about it.
I can picture myself in my pram telling enquiring passers-by my name and address – but that is actually my memory of a report of someone else's memory. I almost believe I recall escaping from my playpen by emptying out the toy box and turning it upside down to act as step. But that could be a fabrication I have been fed. I do know these are memories ofstories about me and not actual memories of the events, but perhaps some of my actual early memories of events were also 'planted' without my being aware of this?
It is all in the mind
After all, what we actually recall is a representation ofour experience, which is effectively mental. We have mental experiences when we are out acting on the environment (e.g., walking in the woods) – but also when watching a film, or listening to a story, or simply daydreaming. And, indeed, we also have mental experiences when we sleep.
Researchers have found children giving convincing and committed accounts of how when they were younger
they had to attend hospital for a minor emergency, or
when they drifted away from caregivers at the shops and got lost
although these were imaginary events which the researchers themselves had previously planted, and which parents confirmed did not reflect any actual event the child had experienced. (Such research raises ethical issues – now we know memories can be suggested by researchers, is it ethical for investigators to continue to carry out such studies? If so, what are the limits on the kinds of memories it is acceptable to try and plant?)
False memory syndrome
A very serious consequence of this phenomenon has been the recognition that accusations against parents and teachers and other caregivers of child abuse can arise from the inadvertent planting of false memories when children are questioned. Careful probing of the children's memories may be needed over sequences of interviews. Unfortunately, that very scenario also provides suitable conditions for leading questions to plant false memories.
Identifying cases of child abuse can be especially challenging as young children may not understand what has happened to them (especially in cases of sexual assaults) and/or may be traumatised. Young children are also less able to distinguish memories of real and imaginary events.
Recalling previous mental states
There is a procedure undertaken in psychology where a youngster is shown a biscuit box, say, and asked to guess its contents. For example:
Cookies.
The child is then shown that the box actually contains something incongruous:
Pebbles!
They are then asked what they had thought was in the box when first shown it, before they saw inside:
Pebbles, of course.
This is normal behaviour. The child gives what for them is a genuine response – but it is false. It is not a lie – it would hardly be convincing if it was. With maturation a child becomes able to distinguish what I think now from what I thought before – but below a certain age this distinction is simply not available.
That particular result is specific to young children, but a degree of memory distortion is normal for the rest of us – indeed the best of us, according to the historian/philosopher of science Thomas Kuhn,
"Not always, but quite usually, scientists will strenuously resist recognising that their discoveries were the product of beliefs and theories incompatible with those to which the discoveries themselves gave rise."
Kuhn was not suggesting that scientists were seeking to claim a prescience they did not have, but simply that they too are effected by the difficulty of returning to an earlier state of ignorance before they slowly built a more nuanced and deeper understanding of a field. The instrument they used to expand their understanding – their prior understanding – was the very thing that was being modified. That is something teachers need to bear in mind – many of those things that now seem obvious and straightforward to the expert were obscure and complex when met as a novice.
The dilemma of 'recovered' memories of abuse
It is obviously imperative to detect and stop sexual abuse, but it became clear that in some communities there seemed to be an inordinate amount of such child abuse going on, often involving strange rituals more at home in a Hammer Horror film. Children who were perfectly happy at home were being separated from their families on the basis of an investigative methodology which unfortunately created the 'evidence' of abuse (and made it indistinguishable from any real memories of actual abuse).
Some adults in therapy also found they gradually uncovered (or perhaps, actually, gradually constructed) previously undetected memories of childhood abuse, and consequently became estranged from parents that they now labelled abusers. Of course, such 'recovered' memories could be real, but sometimes they were not, and unfortunately recall does not come with metadata tags to tell us how and when what is being recalled was first represented in memory.
How is it possible that adults might live for decades without any conscious awareness that their parents had abused them as children, only for this to come to light when they entered into a psychoanalytic relationship with a therapist? Supposedly, the memories of something so awful, and often inconsistent with an otherwise happy family life, had been repressed.
There are different views on whether false memory syndrome leading to fabricated accusations of abuse is very widespread as has sometimes been claimed (an 'epidemic'), or is just an occasional aberration (Goodman, Gonzalves & Wolpe, 2019; Otgaar, Howe & Patihis, 2022). The challenge is that when there is nothing to corroborate memory with, then all we have is the memory; and memory is fallible and susceptible to distortion.
Memories are like conceptions
The research into student conceptions in science makes it clear that a learners' knowledge of a topic does not exist on a single dimension from ignorance to knowledge – they can have knowledge that is more or less complete, but also alternative conceptions that are more or less canonical. In a similar way, memories can also be more or less complete, but also more or less accurate – indeed, more or less fabricated.
Memory and sleep
We know that sleep is essential to good health and, indeed, that healthy sleep must include dreaming. It is normal to dream every night, although we may only remember dreams if they occur just before waking. Clearly, sleep must be physiologically important as sleeping involves taking the significant risk of losing awareness of our environment when, for example, predators may be around.
Sleeping leaves us vulnerable. Of course, some creatures are less vulnerable than others when they nod off. (Image by PublicDomainPictures from Pixabay)
One of the areas that sleep is considered to support is memory consolidation. That is, without good sleep, our ability to update and maintain our memories suffers. I do not think the details of this are well understood – but the effects of sleep deprivation are well known (such that it can be used as a form of torture).
No one really knows for sure the function of dreams, or whether, perhaps, dreams are just an epiphenomenon, a kind of by-product of the maintenance processes going on in the brain during sleep. There is a very long tradition of trying to read meaning in (or into!) dreams (the story of Daniel in the Bible Old Testament for example) and the interpretation of dreams was a key part of Sigmund Freud's psychoanalysis. Dreams are such a part of our lives, it often seems they must have significance – but there is no strong scientific support to suggest this is so. Given the nature of most of my dreams, I find this reassuring.
Autobiographical and semantic memory
Our memories represent both autobiographical and semantic material. That is, we recall specific events in our lives as well as abstract material such as Ohm's law, the theory of natural selection, or the molecular structure of benzene.
So, if our sleeping brains are maintaining memory function and this involves activating memory traces, and we experience – or make sense of – some of this as dreaming, then why do my dreams involve me in 'social' situations, but I do not (that I can recall) dream about, say, molecular shapes or circuit configurations? After all, August Kekulé supposedly discovered the structure of benzene when he was drifting into sleep.
Does this reflect my lack of genius – would an AlbertEinstein or a Richard Feynman dream in abstract mathematical symbols? I do not, at least, not that I notice. Generally my dreams are very mundane, which is why one of last night's dream's seemed out of place.
A dream party (no teaching involved)
I was at a kind of Hollywood-type party – a party attended by many of those who would be labelled by the general public as 'stars'. To be fair, I did not recognise (or perhaps, better, actually notice) who most of the people there were: rather I just had the impression that these were 'stars'.
I should point out that I do not tend to go to those kinds of parties (obviously, I do not tend to be invited to them), and indeed I am not really one for parties. So, I am not sure why I was dreaming about being at one.
More typically, my dreams involve teaching situations. Yet, I never actually teach anything substantial in these dreams – more often I am
getting myself ready to teach a class,
organising a class to get ready to work, or
on my way to teach a class (which for various reasons never gets started)
as if my dreaming brain has access to autobiographical material, but does not know any chemistry or physics or research methodology or anything I might actually teach. It seems as if I do not have access to my semantic knowledge for use in my dreams. This raises an interesting question.
If dreaming is considered to support the processes of memory consolidation – why do we not dream about the material we are learning?
(And although I am not taking any formal classes – I read books and listen to podcasts which would provide plenty of subject matter.)
Is it just that this processing happens at a more abstract level that we cannot picture directly in dreams?
Why are dreams not more realistic?
What has long intrigued me about dreams is that although I do sometimes dream about my late wife or close family: in general the people in my dreams seem to be made up, like characters in a fiction. I do not dream about students or classes I have taught but rather populate my dreams with fictional people. This seems odd, as when I am awake I can remember many students I have taught and it would seem more economical for my brain to use their images than construct people de novo. 1 Why are my dreams so 'CGI-heavy' (as in 'computer generated imagery') when it is known that requires a lot of processing?
And this is not just people. In my dreams I am in buildings or in streets, etcetera – but when I awake and can recall a dream I realise that the house I was living in, in the dream, is not my house, or any other house I have ever lived in. Or know. (And when there is an exception, the house seems to have been moved! 3)
The classroom in a dream is not one where I taught, even though there are several very familiar classrooms where I taught a great number of lessons over a period of years. The same applies with the teaching institutions more generally – when I move around these buildings in my dreams I use hallways, go to canteens, and the like; pass thought entrance areas. All these things are experienced as familiar to me – in my dreams, the people, rooms and buildings and sometimes even streets and town centres all seem familiar – but only till I wake up. Then it is immediately clear they were constructed – in effect imagined – and not recalled from real life. Perhaps they are sometimes recalled from a previous dream, but not recalled from my actual 'awake' life. They are familiar in sleep – but not known from my waking life.
[There is a theory that we live to dream. Our real lives, the lives that really matter, are the lives we have in sleep when we dream. In order to maintain these meaningful lives we need the support period when we are awake and eat and, so forth. From this perspective, the question of why we dream disappears. Instead we might ask why we need to be conscious when awake: presumably this makes it easier to find sustenance, mates, shelter and the other things that allows us to continue the human lineage, and to regularly settle down for a good night's sleep.]
There are exceptions. Once when younger and at my parents house, I dreamt that I flew out of their house down the road, turning into the adjoining road then right at a junction into another road that led to the local shops, over the roundabout and headed down to town. I will not bore you with the details except to say the flight was exhilarating rather than scary…and was (certainly, subjectively seemed) detailed. I saw the roads and buildings in detail, and, as far as I could tell when I awoke, accurately. This seemed to me more memory than imagination…with one obvious caveat. In the dream I was seeing everything from maybe 10 metres above the ground looking down. I had walked along those roads hundreds of times, but only from a vantage point of less than two metres above ground level.
Maybe there is a good reason we do not dream realistically too often. When I have had dreams where I interact with real people then I have sometimes become confused later. I have had to realise that 'no, that was just a dream'. If one does not realise on waking, perhaps one would never know of the mistake – but that could have consequences. ("You told me to give the house to Marxist anarchists!")
And awaking from a conversation with a loved one, only to then realise that must have been a dream because the person is no longer with us, is difficult: waking up and realising that was not a real experience, and it could not have been, tends to ratchet the grief process back up a few notches. Spending time with the loved one, only to wake and realise – again – she is gone offers a bitter-sweet counterpoint and reprise to the old adage that it is better to have loved and lost…
All the same, it does suggest that if dreaming is largely a constructive process that requires the brain to design and simulate new but realistic-seeming environments and populate them with convincing androids, then that is an awful lot of mental work. Perhaps it calls upon 'memories' at some level, but it seems largely the work of imagination.
Transitioning to sleep
I had slept for about four hours, but then awoke wishing to use the bathroom. That is not unusual, and more often than not I crawl back into bed and straight back to sleep. On this occasion I just lay there waiting to drop off again. I can often tell when I am about to go to sleep as my visual cortex does its version of the iTunes visualiser and I see various shapes and colours gradually appear and then start moving around. Sometimes, not. But I have a strategy to avoid lying awake worrying that I am not asleep. I go on adventures.
So, I take sea voyages, and spend time relaxing on my private tropical island with its bananas, coconuts and pineapples – I have built quite a repertoire of scenarios I slowly develop knowing that usually the story does not get very far before I drift off somewhere else. (That is, I have represented in memory my previous imagined experiences of my repertoire of getting ready for sleep scenarios.)
However, this time my body did not seem to want to go back to sleep, and I seemed to still be lying awake waiting for sleep hours later. This went on so long I could eventually hear the voices of others in the house, now up to start the day; and eventually they were even leaning over me in bed to try and get access to the breakfast things. (That should have been a clue, even if my sleeping self had forgotten there was no one else in the house.)
Then, I was at the party.
I 'remembered' (…in my dream…) that Elton and I go back a long way (Elton publicity shot accessed from Wikimedia, with apologies to Bernie)
My friend, the superstar
I did not really know the people there – I do not mix in these circles.
But then I saw Sir Elton John, and realised there was someone at the party that I did know well. Elton greeted me, and at that moment I recalled how we regularly engaged in repartee on the morning radio show. In that instant, Elton being there and acknowledging me, fitted with a long-standing and familiar part of my life.
Except, of course, this was completely fabricated. I have never met Sir Elton, and the Elton in my dream was for some reason Elton from the 1980s. And I certainly do not appear on any morning radio show, with or without him. Elton (I am pretty sure) does not know I exist, and would not be seeking me out at the kind of parties that I do not in any case go to, and that I would not be invited to (and that I would not really want to go to even if I was invited. Though meeting Elton would be cool.)
So what? This is just a dream – so, it is not real. I do not usually dream of celebrities. (Though Joe Root tuned up in a dream a while back.2)
Why Elton? I have no idea. I do have a lot of his records and rate him highly as a songwriter/singer/pianist. But my dreams would be pretty crowded if all the musicians who moved me made an appearance. 4 Perhaps I just associate Elton with glitzy parties – and I did not spot Freddie was over the far side of the room.
But that was not the point that really struck me. It was rather a phenomenon that I have noticed before about dreams: that one is in a scenario where something needs explaining (here, Elton greeting me as a friend) and there is an immediate in-fill of backstory which is experienced in the dream as authentic recall. Our brains (i.e., we) are able to make up stuff, and present it to us, and convince us that it is what we have previously experienced: here regular jovial exchanges with Elton on a non-existent radio show. In the waking world (where I am well aware that I do not move in those kinds of circles) I immediately saw through this, but in the context of the dream I simply accepted the false memory as being a genuine, recalled, experience.
So, what is to say something similar is not happening regularly in my waking life?
Almost a century ago, the experimental psychologist Frederic Bartlett (1932/1995) concluded from his empirical studies on memory that the three phenomena we consider separately as perceiving, remembering, and imagining, were not so discrete and separate at all.
Perception, imagination, and memory are generally considered separate mental faculties – but are probably not as distinct as we tend to think
What we think we see or hear is strongly framed by (memory of) previous experiences. What we can imagine is resourced by (memory traces of) what we have experienced – what we have seen and heard in the past. What we think we remember is often fragmentary data filled-out with imaginary components that seem (on the basis of our general experience of the world, i.e., a kind of memory) feasible. What we remember may be based on what we have experienced, or what we have previously imagined we have experienced, or even what has been suggested to us in the past as something we have experienced. The memory that seems so genuine and convincing may be filled-in by guesswork, and may indeed be a memory of something other than a real experience.
Probably, we all live with false memories that we never have reason to question and discard. (Perhaps some of them even do a great deal of good work in supporting our self-esteem and self-worth? Or, perhaps, the opposite?)
Based on past experience, at least as I remember it(!), the Elton dream was atypical, as it involved a real person rather than the usual rolling cast of fictional characters. (But see notes 2 and 4) Perhaps that is just as well, as we are less likely to misconstrue recollections of dreams involving imaginary people in imaginary places as being memories from our waking lives. So, I probably will not meet any stars in my dreams tonight. However, just in case, I wonder if Kate Bush is free?
See you in my dreams?
Work cited:
Bartlett, F. C. (1932/1995) Remembering. A study in experimental and social psychology. Cambridge; Cambridge University Press.
Goodman, G. S., Gonzalves, L., & Wolpe, S. (2019). False memories and true memories of childhood trauma: Balancing the risks. Clinical Psychological Science, 7(1), 29-31.
Kuhn, T. S. (1984/1887) Afterword: Revisiting Planck, in Black-Body Theory and the Quantum Discontinuity, 1894-1912. With a new afterword (pp.349-370). The University of Chicago Press.
Luria, A. R. (1987).The Mind of a Mnemonist: a little book about a vast memory.Harvard University Press.
Otgaar, H., Howe, M. L., & Patihis, L. (2022). What science tells us about false and repressed memories. Memory, 30(1), 16-21.
Schacter, D. L. (Ed.). (1995). Memory Distortion. How minds, brains, and societies reconstruct the past. Harvard University Press.
1 This question vexes me when I also consider that I believe that, in a sense, I do not directly interact any other real people. By that, I mean, that although I seem to be, say, talking to a person in the external world, I only have direct experience of a simulation of them constructed in my brain based on sensory data and past experience. We all (I assume?) have mental conversations with people we know well when they are not present: we think we know what they would say in a situation: how they would react; what they might suggest. When they are [actually, physically] present we are surely engaging the same simulation, just with a modest drip feed of sensory data blending in.
(Does that sound strange? I think it would be more strange that if you have been married for 20 years you would assume that you base your interaction with a spouse primarily on transient and likely incomplete immediate sensory data rather than the detailed mental simulation of them that you have incrementally and iteratively built up over hundred of hours of past experience.)
If I call upon those simulations deliberately when asking myself "what would X think about this?", why not in my dreams? (Perhaps, I suggest above, as realistic dreams that are remembered would too readily be confused with waking experience.)
If my simulation argument seems unconvincing, ask yourself why you feel you are engaging with the same person
when you meet them under different conditions (lighting, background noise);
when you only see a two-dimensional image on a small flat screen; or even
when you only have a low quality reproduction of their voice coming from a tiny speaker?
It is not because the sensory data matches well in these different situations.
2 This is my note of my dream involving cricketer Joe Root
I awoke 3 from a dream where I'd been watching sport – football, and switched to cricket [at this point I seem to be watching television], there was a run out call. English bowler, never seen before, seemed to hesitate as he picked up the ball, but direct hit on wicket – awaiting replays to see if it was a run out.
Joe Root was watching next to me on the grass (this was just after it had been announced he was standing down as test team captain) but seemed fidgety – he was moving about and taking up yoga-like positions. [Note, I am now actually at the cricket match, not watching TV.]
There were two young women, girls really, wearing Summer gear (shorts, top tied up high so bare stomach area). They were exchanging glances, and edging closer to Joe. Eventually he did some kind of flip, and landed on one of the girls who had moved up close behind him.
Giggles.
I joked that this was a litigation issue and he might be sued for millions.
Report of a dream [this is a purely imaginary account and in no way reflects any real (waking!) event involving Joe Root that I am aware of!]
Why Joe Root? Just because he had been mentioned in the news? Perhaps. However Root was involved in two of my own alternative conceptions (we have them in all areas of knowledge, not just science), and in both cases I had sensed there was something I was missing in the particular situation – so, perhaps it might be said I felt some 'cognitive dissonance' until I realised my misunderstandings.
One of these misconceptions concerned advertising for pet insurance* that often featured Root alongside a dog, by a company who sponsored some of the cricket highlights on television. It struck me as odd that this company could afford to air so many adverts employing a leading sportsman when I could not imagine the market for pet insurance was especially lucrative. It eventually dawned on me (many months later) that the company were advertising insurance for people – not pets. Perhaps the dog was meant to represent health (rather than, as I had assumed, a creature likely to soon need veterinary attention). [* Note, my clear memories of regularly seeing advertisements for pet insurance turned out to be unreliable as I had misconstrued the sensory data that became represented in memory.]
The other misconception concerned the regular occurrence of booing of Root on the cricket field. Generally cricket crowds do not boo – although fast bowler Stuart Broad had incurred the wrath of Australian supporters who had taken to booing him. But Root, an English international cricketer, seemed to get booed at English grounds whenever he went out to bat, or when he hit a boundary, even though I was not aware of anything he had done or said likely to offend. And, indeed, from after-match interviews I had seen, I thought he did not seem like a person who would offend a large proportion of spectators. Indeed, he was always polite, and sensible, and modest. Again, it took quite a while before I realised that what I was hearing as "bo:o" was actually the crowd calling out an extended "ro:ot".
3 Actually, this is part of a longer account I noted down because it involved a dream within a dream. The account continues:
I woke up, and went downstairs, and went to the table I use as a desk at the front of the house. Looking out I saw the house opposite [which should have been obscured by my garden hedge] had no door and looked like they were having workers in to put in a new door. Then I realised that the house as a whole (which was much larger than usual, and all red brick [unlike the actual house opposite]) was not finished, and looking around I realised that none of the houses in the street were finished yet. I noticed there was no computer on my desk. I went to look out of the back of the house and saw rolling hills and countryside – it look like the West Country around Bristol. I realised I must still be asleep, and found some paper to write down the dream so I could have a record when I really wake (!). Found a pen but it did not seem to work very well.
So, if I can wake up from one dream within another dream, perhaps I am not actually awake now?
4 I have a note of the guitarist/composer Steve Hackett appearing in one dream that was part of a sequence of scenes I recalled when I awoke,
2. Hackett was in an office with charts/manuscripts for music he intended to play for a concert, and in discussion over whether to bring in a second guitarist to play some parts. A person advising – 'manager'(?) of the venue – was going to play some of the music there in the office.
I am not sure what triggered that, although the previous scene that I recalled was unusual (for me) in that it was an auditory dream5:
listening to the first Genesis album ('From Genesis to Revelation') and noticing atmospheric instrumental passages with subtle electric guitar parts I'd never noticed before
I had not noticed these passages before, because – of course- they are not actually on the album! Steve Hackett did not join Genesis till after that album, but perhaps my sleeping brain was thinking that these were contributions he might have made if he had been in the band then?
5 Again, it seems odd that as much of my waking life is accompanied by music, I seldom dream of music. Indeed the first time I recall this happening I was so struck by the dream that I still recall the occasion over 40 years later. I was about 17 and I had fallen asleep one Sunday afternoon, after a having been up late the night before as someone in the sixth form had had a party. (No, Elton was not there – at least, as far as I recall!) I dreamed what seemed to me at the time a very vivid and detailed rendition of 'Shine on you crazy diamond' by Pink Floyd.
Of course, that is just my recollecti0n of my subjective experience on waking from sleep (that is, the waking memory of the dream) – but the music had (at least) seemed so real and intense and deep that, all these years later, I still remember the effect such a detailed dream had on me when I awoke.
"why the brain can't multitask is still very much a topic of considerable debate"
Prof. Paul Dux
Is it true that brains cannot multitask? I think mine can. (Image by Gerd Altmann from Pixabay)
The podcast was an episode of the ABC radio programme All in the Mind (not to be confused with the BBC radio programme All in the Mind, of course) entitled 'Misadventures in multitasking'
"All in the Mind is an exploration of the mental: the mind, brain and behaviour — everything from addiction to artificial intelligence." An ABC radio programme and podcast.
The argument against multitasking
Now mutlitasking is doing several things at once – such as perhaps having a phone conversation whilst reading an unrelated email. Some aspects of the modern world seem to encourage this – such as being queued on the telephone (as when I was kept on hold for over an hour waiting to get an appointment at my doctor's surgery – I was not going to just sit by the phone in the hope I would eventually get to the top of the queue). Similarly 'notifications' that seek to distract us from what we are doing on the computer, as if anything that arrives is likely to be important enough for us to need immediate alerting, add little to the sum of human happiness.1
Now I have heard the argument against multitasking before. The key is attention. We may think we are doing several things at once, but instead of focusing on one activity, completing, it, then shifting to another, what multitaskers actually do is continuously interrupt their focus on one activity to refocus attention on the another. The working memory has limited capacity (this surely is what limits our ability to reflectively multitask?), and we can only actually focus on one activity at a time, so multitasking is a con – we may think we are being more productive but we are not.
Now, people do tire, and after, say 45 minutes at one task it may be more effective to break, do something unrelated, and come back to your work fresh. If you are writing, and you break, and take the washing out of the machine and hang it up to dry, and make a cup of tea, and then come back to your writing fifteen or twenty minutes later, this is likely to be ultimately more productive than just ploughing on. You have been busy, not just resting, but a very different kind of activity, and your mind (hopefully) is refreshed. If you have been at your desk for 90 minutes without a break, then go for a walk, or even a quick lie down.
That however, is very different from doing your writing, as you check your email inbox, and keep an eye on a social media feed, and shop online. You can only really do one of those things at a time and if you try to multitask you are likely to quickly tire, and make mistakes as you keep interrupting your flow of concentration. (So, if you have been doing your writing, and you feel the need to do something else, give yourself a definite period of time to completely change activity, and then return fully committed to the writing.)
Now, I find that line of argument very convincing and in keeping my with own experience. (Which is not to say I always follow my own advice, of course.) Yet, I still thought Prof. Dux was wrong. And, indeed, there is one sense in which I would like to think deliberate reflective multitasking is not counterproductive.
If your brain cannot multitask you'd perhaps better hope it focuses on breathing
The brain is complex…
This is a short extract from the programme,
Paul Dux: Why the brain can't multitask is still very much a topic of considerable debate because we have these billions of neurons, trillions of synaptic connections, so why can't we do two simple things at once?
Sana Qadar: This is Professor Paul Dux, he's a psychologist and neuroscientist at the University of Queensland. He takes us deeper into what's going on in the brain.
Paul Dux: A lot of people would say it's because we have these capacities for attention. The brain regions that are involved in things like attention are our lateral prefrontal cortex. You have these populations of neurons that respond to lots of different tasks and multiple demands. That of course on one hand could be quite beneficial because it means that we are able to learn things quickly and can generalise quickly, but maybe the cost of that is that if we are doing two things at once in close temporal proximity, they try to draw on the same populations of neurons, and as a result leads to interference. And so that's why we get multitasking costs.
Sana Qadar: Right, so that's why if you are doing dishes while chatting to a friend, a dish might end up in the fridge rather than the cupboard where it's supposed to go.
Paul Dux: That's right, exactly.
Paul Dux talking to Sana Qadar who introduces 'All in the mind'
Now I imagine that Prof. Dux is an expert, and he certainly seemed authoritative. Yet, I sensed a kind of concept-creep, that led to a category error, here.
A category error
A category error is where something is thought of or discussed as though a member of an inappropriate class or category. A common example might be gender and sex. At one time it was widely assumed that gender (feminine-masculine) was directly correlated to biological sex (female-male) so terms were interchangeable. It is common to see studies in the literature which have looked for 'sex differences' when it seems likely that the researchers have collected no data on biological sex.
Models that suggest that the 'particles' (molecules, ions, atom) in a solid are touching encourage category errors among learners: that such quanticles are like tiny marbles that have a definite surface and diameter. This leads to questions such as whether on expansion the particles get larger or just further apart. (Usually the student is expected to think that the particles get further apart, but it is logically more sensible to say they get larger. But neither answer is really satisfactory.)
If someone suggested that a mushroom must photosynthesise because that is how plants power their metabolism then they would have made a category error. (Yes, plants photosynthesise. However, a mushroom is not a plant but a fungus, and fungi are decomposers.)
The issue here, to my mind (so to speak) was the distinction between brain (a material object) and conscious mind (the locus of subjective experience). Whilst it is usually assumed that mind and brain are related (and that mind may arise, emerge from processes in the brain) they may be considered to relate to different levels of description. So, mind and brain are not just different terms for the same thing.
Mind might well arise from brain, but it is not the same kind of thing. So, perhaps the notion of 'tasks' applies to minds, not brains? (Figure from Taber, 2013)
So, it is one thing to claim that the mind can only be actively engaged in one task at a time, but that is not equivalent to suggesting this is true of the brain that gives rise to that mind.2
Prof. Dax seemed to be concerned with the brain:
"the brain…billions of neurons, trillions of synaptic connections… brain regions…lateral prefrontal cortex…populations of neurons"
Yet it seems completely unfounded to claim that human brains do not multitask as we surely know they do. Our brains are simultaneously processing information from our eyes, our ears, our skin, our muscles, etc. This is not some kind of serial process with the brain shifting from one focus to another, but is parallel processing, with different modules doing different things at the same time. Certainly, we cannot give conscious attention to all these inputs at once, so the brain is filtering and prioritising which signals are worth notifying to head office (so to speak). We are not aware of most of this activity – but then that is generally the case with our brains.
The brain controls the endocrine system. The brain stem has various functions, including regulating breathing and heart rate and balance. If the brain cannot multitask we had perhaps better hope it focuses on breathing, although even then I doubt we would survive for long based on that activity alone.
Like the proverbial iceberg, most of our brain activity takes place below the waterline, out of conscious awareness. This is not just the physiological regulation – but a lot of the cognitive processing. So, we consolidate memories and develop intuitions and have sudden insights because our brains are constantly (but preconsciously) processing new data in the light of structures constructed through past experience.
If you are reading, you may suddenly notice that the room has become cold, or that the doorbell is ringing. This is because although you were reading (courtesy of your brain), your brain was also monitoring various aspects of the environment to keep alert for a cue to change activity. You (as in a conscious person, a mind if you like) may not be able to do two things at once, so your reading is interrupted by the door bell, but only because your brain was processing sensory information in the background whilst it was also tracking the lines of text in your book, and interpreting the symbols on the page, and recalling relevant information to provide context (how that term was defined, what the author claimed she was going to demonstrate at the start of the chapter…). Your mind as the locus of your conscious experience cannot multi-task, certainly, and certainly "brain regions that are involved in…attention" are very relevant to that, but your brain itself is still a master of multitasking.
Me, mybrain, and I
So, if the brain can clearly multitask, can we say that the person cannot multitask?
That does not seem to work either. The person can thermoregulate, digest food, grow hair and nails, blink to moisten the eye etc., etc as they take an examination or watch a film. These are automatic functions. So, might we say that it is the body, not the person carrying out those physiological functions? (The body of the person, but not the person, that is.)
Yet, most people (i.e., persons) can hold a conversation as they walk along, and still manage to duck under an obstruction. The conversation requires our direct attention, but walking and swerving seem to be things which we can do on 'autopilot' even if not automatic like our heartbeat. But if there was a complex obstruction which required planning to get around, then the conversation would likely pause.
So, it is not the brain, the body, or even the person that cannot multitask, but more the focus of attention, the stream of consciousness, the conscious mind. Perhaps confusion slips in because these distinctions do not seem absolute as our [sic] sense of identify and embodiment can shift. I kick out (with my leg), but it is my leg which hurts, and perhaps my brain that is telling me it is hurting?
There is also one sense in which I regularly multitask. I listen to music a lot. This includes, usually, when I am reading. And, usually, when I am writing. I like to think I can listen to music and work. (But Prof. Dux may suggest this is just another example of how humans "are not actually good at knowing our own limitations".)
I like to think it usually helps. I also know this is not indiscriminate. If I am doing serious reading I do not play music with lyrics as that may distract me from my reading. But sometimes when I am writing I will listen to songs (and, unfortunately for anyone in earshot, may even find I am singing along). I also know that for some activities I need to have familiar music and not listen to something new if the music is to support rather than disturb my activity.
Perhaps I am kidding myself, and am actually shifting back and forth between
being distracted from my work by my music
and
focusing on my work and ignoring the music.
I know that certainly sometimes is the case, but my impression is that usually I am aware of the music at a level that does not interfere with my work, and sometimes the music both seems to screen out extraneous noise and even provides a sense of flow and rhythm to my thinking.
The human brain has two somewhat self-contained, but connected, hemispheres. (Image by Gerd Altmann from Pixabay)
I suspect this has something to do with brain lateralisation and how, in a sense, we all have two brains (as the hemispheres are to some extent autonomous). Perhaps one of my hemispheres is quietly (sic) enjoying my music whilst the other is studiously working. I even fancy that my less verbal hemisphere is being kept on side by being fed music and so does not get bored (and so perhaps instigate a distracting daydream) whilst it waits for the other me, its conjoined twin, to finish reading or writing.
I may well be completely wrong about that.
Perhaps I am just as hopeless at multitasking with my propensity to attempt simultaneous scholarship and music appreciation as those people who think they can monitor social media whilst effectively studying.3 Perhaps it is just an excuse to listen to music when I should be working.
But even if that is so, I am confident my brain can multitask, even if I cannot.
Another email has arrived inviting me to talk at some medical conference on a specialism I cannot even pronounce?
A fiend of a friend of a friend has posted some update on social media that I can put into Google translate if I can be bothered?
Someone I do not recall seems to have a job anniversary?
Someone somewhere seems to have read something I once wrote (and I can find out who and where for a fee)?
Luckily I have been notified immediately as now I know this I will obviously no longer wish to complete the activity I was in the middle of.
2 One could argue that when a person is conscious (be that awake, or dreaming) one task the brain is carrying out is supporting that conscious experience. So, anything else a brain of a conscious person is doing must be an additional task. Perhaps, the problem is that minds carry out tasks (which suggests an awareness of purpose), but brains are just actively processing?
3 As a sporting analogy for the contrast I am implying here, there is a tradition in England of attending international cricket matches, and listening to the 'test match special' commentary (i.e., verbal) on the radio while watching (i.e. visual) the match. This seems to offer complementary enhancement of the experience. But I have also often seen paying spectators on televised football matches looking at their mobile phones rather than watching the match.
Is the work of cognition like the work of a palaeontologist? (Image by Brenda Geisse from Pixabay)
I like the reflexive nature of this account – of someone reconstructing an analogy
abouthow cognition reconstructs coherent wholes from partial, fragmented data
froma partial, fragmented memory representation.
I was reading something about memory function that piqued my interest in an analogy:
"Neisser, using an analogy initially developed by Hebb (1949) to characterize [sic] perception, likened the rememberer to a paleontologist who attempts to reconstruct a dinosaur from fragmentary remains: 'out of a few stored bone chips, we remember a dinosaur'…"
Schacter, 1995, p.10
I was interested enough to look up the original use of this analogy (as I report below).
This links to three things that have separately interested me:
using analogies in teaching and comunicating science
The nature of our memories
I have long been interested in what memory is and how it works – and its role in academic learning (Taber, 2003). In part this perhaps derives from the limits of my own memory – I have been reasonably successful academically, but have never felt I had a good memory (and I seem to get more 'absent minded' all the time). This interest grew as it became clearer to me that our memory experiences seem to be quite different – my late wife Philippa would automatically and effortlessly remember things in a way that that seemed to me to be a kind of superpower. (She was once genuinely surprised that I could not picture what a family member had been wearing on arriving at a family event years before, whereas I thought I was doing pretty well to even remember I had been there.) Now that neurodiversity is widely recognised, it seems less surprising that we do not all experience memory in the same way.
A lot of people, however, understand memory in terms of a kind of folk-model (that is, a popular everyday account which does not match current scientific understanding) – along the lines that we put information into a memory store, where – unless it gets lost and we forget – we can later access it and so remember what it was that we committed to memory. Despite the ubiquity of that notion, research suggests that is not really how memory functions. We might say that this is a common alternative conception of how memory works.
Schacter was referring back to a tradition that began a century ago when Bartlett carried out a series of studies on memory. Bartlett (1932/1995) would, for example, expose people to a story that was unfamiliar to his study participants, and then later ask them to retell as much of the story as they could remember. As might be expected, some people remembered more details than others.
What perhaps was less predictable at the time was the extent to which people included in their retelling details that had not been part of the original story at all. These people were not deliberately embellishing or knowingly guessing, but reporting, as best they could, what their memory suggested had been part of the original story.
People who habitually exhibit this 'confabulation' to an pathological degree (perhaps remembering totally fantastic things that clearly could not be true) are recognised as having some kind of problem, but it transpires this is just an extreme of something that is normal behavior. Remembering is not the 'pulling something out of storage' that we may experience it as – as actually what we remember is more like a best guess based on insufficient data (but a guess made preconsciously, so it appears in our conscious minds as definitive) than a pristine copy of an original experience. Memory is often more a matter of constructing an account from the materials at hand than simply reading it out from something stored.
Thus the analogy. Here is some wider context for the quote presented above:
"The publication of Neisser's (1967) important monograph on cognitive psychology rekindled interest in Bartlett's ideas about schemas and reconstructive memory. According to Neisser, remembering the past is not a simple matter of reawakening a dormant engram or memory trace; past events are constructed by using preexisting knowledge and [schemata] to piece together whatever fragmentary remains of the initial episode are available in memory. Neisser, using an analogy initially developed by Hebb (1949) to characterize [sic] perception, likened the rememberer to a paleontologist who attempts to reconstruct a dinosaur from fragmentary remains: 'out of a few stored bone chips, we remember a dinosaur' (1967, p.285). In this view, all memories are constructions because they include general knowledge that was not part of a specific event, but is necessary to reconstruct it. The fundamentally constructive nature of memory in turn makes it susceptible to various kinds of distortions and inaccuracies. Not surprisingly, Neisser embraced Bartlett's observations and ideas about the nature of memory."
Schacter, 1995, p.10
These ideas will not seem strange to those who have studied science education, a field which has been strongly influenced by a 'constructivist' perspective on learning. Drawing on learning science research, the constructivist perspective focuses on how each learner has to build up their own knowledge incrementally: it is not possible for a teacher to take some complex technical knowledge and simply transfer it (or copy it) to a learner's mind wholesale.
Excavating the analogy: what did Hebb actually say?
Hebb is remembered for his work on understanding the brain in terms of neural structures – neurons connected into assemblies through synapses. His book 'The Organization of Behavior' has been described as "one of the most influential books in Psychology and Neuroscience" (Brown, 2020: 1).
The analogy referred to by Schacter was used by Hebb in describing perception. He discussed studies using a tachistoscope, an instrument for displaying images for very brief periods. This could be used to show an image to a person with an exposure insufficient for them to take in all the details,
"…the pattern is perceived, first, as a familiar one, and then with something missing or something added. The something, also, is familiar; so the total perception is a mélange of the habitual.
The subject's reports [make it] clear that the subject is not only responding to the diagram as a whole; he perceives its parts as separate entities, even though presentation is so brief. Errors are prominent, and such as to show that all the subject really perceives–and then only with rough accuracy–is the slope of a few lines and their direction and distance from one another"
Hebb, 1949: pp.46-47
That is, the cognitive system uses the 'clues' available from the incomplete visual data to build (in effect) a hypothesis of what was seen, based on correspondences between the data actually available and familiar images that match that limited data. What the person becomes consciously aware of 'seeing' is not actually a direct report from the visual field of the presented image, but a constructed image that is a kind of conjecture of what might have been seen – 'filling-in' missing data with what seems most likely based on past visual experiences.
Cognitive scientist Annette Karmiloff-Smith developed the concept of 'representational redescription' as a way of describing how initially tacit knowledge could eventually become explicit. She suggested that "intra-domain and inter-domain representational relations are the hallmark of a flexible and creative cognitive system" (Karmiloff-Smith,1996: 192). The gist was that the brain is able to re-represent its own internal representations in new forms with different affordances.
An loose analogy might be someone who takes a screenshot when displaying an image from the JPEG photo collection folder on the computer, opens the screenshot as a pdf file, and then adds some textual annotations before exporting the file to a new pdf. The representation of the original image is unchanged in the system, but a new representation has been made of it in a different form, which has then been modified and 'stored' (represented) in a different folder.
Hebb was describing how a representation of visual data at one level in the cognitive system has been represented elsewhere in the system (representational redescription?) at a level where it can be mentipulated by 'filling-in'.
"A drawing or a report of what is seen tachistoscopically is not unlike a paleontologist's reconstruction of early man from a tooth and a rib. There is a clear effect of earlier experience, filling in gaps in the actual perception, so that the end result is either something familiar or a combination of familiar things–a reconstruction on the basis of experience."
Hebb, 1949: p.47
Teaching analogies
Hebb was writing a book that can be considered as a textbook, so this can be seen as a teaching analogy, although such analogies are also used in communicating science in other contexts.
Teaching is about making the unfamiliar familiar, and one way we do that is by saying that 'this unfamiliar thing you need to learn about is a bit like this other thing that you already know about'. Of course, when teaching in this way we need to say in what way there is an analogy, and it may also be important to say in what ways the two things are not alike if we do not want people to map across irrelevant elements (i.e., to develop 'associative' learning impediments).
Hebb is saying that visual perception is often not simply the detection of a coherent and integral image, but is rather a construction produced by building upon the available data to construct a coherent and integral image. In extremis, a good deal may be made of very little scraps of input – akin to a scientist reconstructing a model of a full humanoid body based on a couple of bits of bone or tooth.
There are examples where palaeontologists or anthropologists have indeed suggested such complete forms based on a few fossil fragments as data. This is only possible because of their past experiences of meeting many complete forms, and the parts of which they are made. (And of course, sometimes other scientists completely disagree about their reconstructions!)
An exscientific analogy?
Often in teaching science we use teaching analogies that compare an unfamiliar scientific concept to some familiar everyday phenomenon – perhaps a reaction profile is a bit like a roller-coaster track. Perhaps we could call these adscientific analogies as the meaning is transferred to the scientific concept from the everyday.
Sometimes, however, familiar scientific phenomena or ideas are used as the source – as here. Perhaps these could be called exscientific analogies as the meaning is taken from the science concept and applied elsewhere.
Developing the palaeontology analogy
So, Hebb had originally used the palaeontology analogy in the context of discussing perception. When I looked into how Neisser had used the comparison in his "important monograph on cognitive psychology" I found he had developed the analogy, returning to it at several points in his book.
Do we analyse what we attend to?
Neisser's first reference was also in relation to perception, rather than memory. Neisser argued that before we can attend to part of a scene there must already have been the operation of "preattentive mechanisms, which form segregated objects" from which we can select what to attend to. These processes might be referred to as analyses:
"…the detailed properties and features that we ordinarily see in an attended figure…arise…only because part of the input was selected for attention and certain operations then performed on it. Neither the object of analysis nor the nature of the analysis is inevitable, and both may vary in different observers and at different times."
Neisser, 1967, p.94
But Neisser was not sure this really was 'analysis', which he understood as drawing on another (what I labelled above) exscientific analogy:
"The very word 'analysis' may not be apt. It suggests an analogy with chemistry: a chemist 'analyses' unknown substances to find out what they 'really' are."
Neisser, 1967, p.94
Rather than refer to analysis, we could draw on Hebb's palaeontological analogy:
"More appropriate…is Hebb's (1949, p.47) comparison of the perceiver with a paleontologist, who carefully extracts a few fragments of what might be bones from a mass of irrelevant rubble and 'reconstructs' the dinosaur that will eventually stand in the Museum of Natural History. In this sense it is important to think of focal attention as a constructive, synthetic activity rather than as purely analytic. One does not simply examine the input and make a decision; one builds an appropriate visual object."
Neisser draws upon the analogy repeatedly in developing his account of perception:
"Such emotion-flooded experiences [as 'physiognomic' perception: 'Everyone has perceived such traits as suppressed anger in a face, gaiety in a movement, or peaceful harmony in a picture'] can be thought of as the result of particular kinds of construction. The same fragments of bone that lead one paleontologist to make an accurate model of an unspectacular creature might lead another, perhaps more anxious or more dramatic, to 'reconstruct' a nightmarish monster." (pp.96-97)
"To 'direct attention' to a figure is to attempt a more extensive synthesis of it. Of course, synthesis presupposes some prior analysis, as the paleontologist must have some fragments of bone before he can build his dinosaur…" (p.103)
"Recognition, whether of spelling patterns or words as wholes, must be mediated by relevant features, as meaningless in themselves as the bone chips of the paleontologist." (p.114)
"The process of figural synthesis does not depend only on the features extracted from the input, just as the dinosaur constructed by a paleontologist is not based only on the bone chips he has found. Equally important is the kind of perceptual object the perceiver is prepared to construct. The importance of set and context on the perception of words has been demonstrated in a great many experiments." (pp.115-116)
Neisser, 1967
And as with perception, so memory…
When Neisser discusses memory he uses a kind of double analogy – suggesting that memory is a bit like perception, which (as already established) is a bit like the work of the palaeontologist:
"Perception is constructive, but the input information often plays the largest single role in determining the constructive process. A very similar role, it seems to me, is played by the aggregate of information stored in long-term memory.
This is not to say that the stimuli themselves are copied and stored; far from it. The analogy being offered asserts only that the role which stored information plays in recall is like the role which stimulus information plays in perception….The model of the paleontologist, which was applied to perception and focal attention in Chapter 4, applies also to memory: out of a few stored bone chips, we remember a dinosaur….one does not recall objects or responses simply because traces of them exist in the mind, but after an elaborate process of reconstruction, (which usually makes use of relevant stored information).
What is the information – the bone chips – on which reconstruction is based? The only plausible possibility is that it consists of traces of prior processes of construction. There are no stored copies of finished mental events, like images or sentences, but only traces of earlier constructive activity."
Neisser, 1967, p.285
Fleshing-out the metaphor
Neisser then pushes the analogy one step further, by pointing out that the 'fleshed-out' model of a dinosaur in the museum may be constructed in part based on the fossil fragments of bones, but those fragments themselves do not form part of the construction (the model). The bones are used as referents in building the skeletal framework (literally, the skeleton) around which the model will be built, but the model is made from other materials (wood, steel, fibreglass, whatever) and the fossil fragments themselves will be displayed separately or perhaps filed away in a drawer in the museum archives. (As in the representational redescription model – the original representation is redescribed at another level of the system.)
"The present proposal is, therefore, that we store traces of earlier cognitive acts, not of the products of those acts. The traces are not simply 'revised' or 'reactivated' in recall; instead, the stored fragments are used as information to support a new construction. It is as if the bone fragments used by the paleontologist did not appear in the model he builds at all – as indeed they need not, if it to represent a fully fleshed-out skin-covered dinosaur. The bones can be thought of, somewhat loosely, as remnants of the structure which created and supported the original dinosaur, and thus as sources of information about how to reconstruct it."
A final reference to the analogy is used when Neisser addresses the question of the cognitive executive: the notion that somewhere in the cognitive system there is something akin to an overseer who direct operations:
"Who does the turning, the trying, and the erring" Is there a little man in the head, a homonculus, who acts the part of the paleontologist vis-à-vis the dinosaur? p.293
Neisser, 1967, p.293
The homonculus can be pictured as a small person sitting in the brain's control room, for example, viewing the images being projected from the visual input.
It is usually considered this is a flawed model (potentially lading to an infinite regress), a failure to take a systemic view of the cognitive system. It is the system which functions and leads to our conscious experience of perceiving, attending, making decisions, planning, remembering, and so forth. Whilst there are specialist components (modules) including for the coordination of the system, there is not a discrete controller overlaying the system as a whole who is doing the seeing, hearing, thinking, etcetera based on outputs from processing by the system.
Here the homonculus would like an authority that the palaeontologist turned to in order to decide how to build her model: raising the question of how does that expert know, and who would they, in turn, ask?
Why change Hebb's orignal analogy?
Altohugh Neisser refers to the analogy as being that used by Hebb, he modifies it. A tooth and rib become fragments of bone, and the early man becomes a dinosaur. Whether the shift from the reconstruction of an early hominid to the reconstruction of a terrible lizard was a deliberate one (for greater effect? because Neisser thought it would be more familiar to his readers?) or not I do not know. The phrasing suggests that Neisser thought he was applying Hebb's original comparison – so I suspect this is how he recalled the analogy.
Perhaps Neisser had regularly used the analogy in his teaching, in which case it may have become so familiar to him that he did not feel the need to check the original version. That is, perhaps he was correctly remembering how he had previously misremembered the original analogy. That is not fanciful, as memory researchers suggest this is something that is very common. Each time we access a memory the wider representational context becomes modified by engagement with it.
That is, if what is represented (in 'long-term memory'*) is indeed "traces of prior processes of construction…traces of earlier constructive activity" then each time a 'memory' is experienced, by being constructed based on what is represented ('in memory'*), new traces of that process of constructing the memory are left in the system.
It is possible over the years to be very convinced about the accuracy of a distorted memory that has been regularly reinforced. (The extent to which this may in part be the origin of many wars, feuds, and divorces might be a useful focus for research?)
So perhaps Neisser had represented in his long-term memory the analogy of a palaeontologist with a few fossil fragments, and when he sought to access the analogy, perhaps in a classroom presentation, the other elements were filled-in: the 'tooth and rib' became 'a few fragments of what might be bones' and the 'early man' become 'a dinosaur' – details that made sense of the analogy in terms familiar to Neisser.
The account of cognition that Hebb, Neisser and Schater were presenting would suggest that if this had been the case then for Neisser there would be no apparent distinction between the parts of Hebb's analogy that Neisser was remembering accurately, and the parts his preconscious mind had filled-in to construct a coherent analogy. I like the reflexive nature of this account – of someone reconstructing an analogy about how cognition reconstructs coherent wholes from partial, fragmented data – from a partial, fragmented memory representation.
Sources cited:
Bartlett, F. C. (1932/1995). Remembering: A study in experimental and social psychology Cambridge: Cambridge University Press.
Brown, R. E. (2020). Donald O. Hebb and the Organization of Behavior: 17 years in the writing. Molecular Brain, 13(1), 55. doi:10.1186/s13041-020-00567-8
Hebb, D. O. (1949). The Organisation of Behaviour. A neuropsychological theory. New York: John Wiley & Sons, Inc.
Karmiloff-Smith, A. (1996). Beyond Modularity: A developmental perspective on cognitive science. Cambridge, Massachusetts: MIT Press.
Neisser, U. (1967). Cognitive Psychology. New York: Appleton-Century-Crofts.
Schacter, D. L. (1995). Memory distortion: history and current status. In D. L. Schacter (Ed.), Memory Distortion. How minds, brains, and societies reconstruct the past (pp. 1-43). Cambridge, Massachusetts: Harvard University Press.
* terms like 'in memory' and 'in long-term memory' may bring to mind the folk-notion of memory as somewhere in the brain where things are stored away, whereas it is probably better to think of the brain as a somewhat plastic processing system which is constantly being modified by its own functioning. The memory we experience is simply the outcome of active processing** in part of the system that has previously been modified by earlier mental activity (** active processing which is in turn itself further modifying the system).
Umar was a participant in the Understanding Chemical Bonding project. When I spoke to him in the first term of his course he was unsure whether tetrachloromethane (CCl4) would have ionic or covalent bonding.
When I spoke to him near the start of his second term, I asked him again about this. Umar then thought this compound would have polar bonding, however he seemed to have difficulty explaining what this meant ⚗︎ . Given his apparently confused notion about the C-Cl bond I decided to turn the conversation to a covalent bond which I knew, well certainly believed, was more familiar to him.
Is it possible for chlorine to form a bond with another chlorine?
[Pause, c.2s]
Yeah.
What substance would you get if two chlorine atoms formed a bond?
[Pause, c.2s]
You get, it still, you get, if you had like two chlorines it depends what groups are attached to it, to see how electronegative or electropositive they are.
What about if you just had two chlorine atoms joined together and nothing else, is that possible?
[Pause, c.3s]
No.
No?
On their own.
Not on their own?
No.
Umar's response here rather surprised me, as I was pretty confident that Umar had met chlorine as an element, and would know it was comprised of diatomic molecules: Cl2.
So you couldn’t have sort of Cl2, a molecule of Cl2?
[Pause, c.1s]
Yeah, you could do.
Could you?
[Pause, c.2s]
They might be just, they might be like, be covalently bonded.
Perhaps the earlier context of talking about polar bonds and the trichloroethane molecule somehow acted as a kind of impediment to Umar remembering about the chlorine molecule. It seemed that my explicit reference to the formula, Cl2, (eventually) activated his knowledge of the molecule bringing to mind something he had forgotten. Although he suggested the bond was (actually "might be") covalent, this seemed less something that he confidently recalled, than something he was inferring from what he could remember – or perhaps even guessing at what seemed reasonable: "they might be just, they might be like, be covalently bonded".
As often happens in talking to learners in depth about their ideas it becomes clear that thinking of students 'knowing' or 'not knowing' particular things is a fairly inadequate way of conceptualising their cognition, which is often nuanced and context-dependent. This suggests that what students respond in written tests should be considered only as what they were triggered to write on that day in response to those particular questions, and may not fully reflect their knowledge and understanding of science topics. Other slightly different questions may well have cued the elicitation of different knowledge. Now Umar had recalled that chlorine comprises of covalent molecules, I asked him about the nature of the bond:
So what would that be, covalently bonded?
They share the electrons.
So how many electrons would they have then?
They’ll have
[Pause, c.7s – n.b., quite a long pause]
like the one on it, the one of the chlorines shares electrons with the other chlorine to fill in its shell on the other one, and the same does it with the other.
In thinking about covalent bonding, Umar (in common with many students) drew upon the full shells explanatory principle that considered bonding to be driven by the needs of atoms to 'fill' their outer electron shells. (The outer shell of chlorine would only actually be 'full' with 18 electrons, but that complication is seldom recognised, as octets and full shells are usually considered synonymous by students).
So how many electrons does each chlorine have to start with?
In the outer shell, seven.
And how many have they got after this?
They’ve got seven, but they share one.
[Pause, c.1s]
Maybe.
So that’s a covalent bond, is it?
Yeah.
So how many electrons are involved in a covalent bond?
[Pause, c.3s]
Erm,
[Pause, c.3s]
Two.
Two electrons.
So where do those two electrons come from?
They like, one that fills up the gap, fills up the – last electron needed in one of the chlorine shells, and the other chlorine shell fills it up in the other one.
So where do they come from?
Each chlorine. Outer shell.
One from each chlorine?
Yeah.
Okay, and that’d be a covalent bond?
Yeah.
Here, again, Umar is using the full shells explanatory principle as the basis for explaining the bond in terms of electrons 'filling up the gaps' in the electron shells, rather than considering how electrical interactions can hold the structure together. Umar's suggestion that the sharing of electrons "fills up the – last electron needed in one of the chlorine shells" demonstrates the anthropomorphic language (e.g., what an atom wants or needs) commonly used when learners have acquired aspects of the common octet rule framework that is developed from the full shells explanatory principle and used by many learners to explain bonding reactions, chemical reactions, patterns in ionisation energy, and chemical stability.
It's covalent bonding where the electrons are shared to create a full outer shell
Keith S. Taber
Brian was a participant in the Understanding Chemical Bonding project. He was interviewed during the first year of his college 'A level' course (equivalent to Y12 of the English school system). Brian was shown, and asked about, a sequence of images representing atoms, molecules and other sub-microscopic structures of the kinds commonly used in chemistry teaching. He was shown a simple representation of a covalent molecule:
Focal figure ('2') presented to Brian
Any idea what that's meant to be, number 2?
Hydrogen molecule.
Why, how do you recognise that as being a hydrogen molecule?
Because there's two atoms with one electron in each shell.
Uh hm. Er, what, what's going on here, in this region here, where these lines seem to meet?
Bonding.
That's bonding. So there's some sort of bonding there is there?
Yeah.
Can you tell me anything about that bonding?
It's covalent bonding.
So, so what's covalent bonding, then?
The electrons are shared to create a full outer shell.
Okay, so that's an example of covalent bonding, so can you tell me how many bonds there are there?
One.
There's one covalent bond?
Yeah.
Right, what exactly is a covalent bond?
It's where electrons are shared, almost, roughly equally, between the two atoms.
So that's what we'd call a covalent bond?
Yeah.
So according to Brian, covalent bonding is where "the electrons are shared to create a full outer shell". The idea that a covalent bond is the sharing of electrons to allow atoms to obtain full electron shells is a very common way of discussing covalent bonding, drawing upon the full shells explanatory principle, where a 'need' for completing electron shells is seen as the impetus for bonding, reactions, ion formation etc. This principle is the basis of a common alternative conceptual framework, the octet rule framework.
For some students, such ideas are the extent of their ways of discussing bonding phenomena. However, despite Brian defining the covalent bond in this way, continued questioning revealed that he was able to think about the bond in terms of physical interactions
Okay. And why do they, why do these two atoms stay stuck together like that? Why don't they just pull apart?
Because of the bond.
So how does the bond do that?
(Pause, c.13s)
Is it by electrostatic forces?
Is it – so how do you think that works then?
I'm not sure.
The long pause suggests that Brian did not have a ready formed response for such a question. It seems here that 'electrostatic forces' is little more than a guess, if perhaps an informed guess because charges and forces had features in chemistry. A pause of about 13 seconds is quite a lacuna in a conversation. In a classroom context teachers are advised to give students thinking time rather than expecting (or accepting) immediate responses. Yet, in many classrooms, 13 seconds of 'dead air' (to borrow a phrase from broadcasting) from the teacher night be taken as an invitation to retune attention to another station.
Even in an interview situation the interviewer's instinct may be to move on to a another question, but in situations where a researcher is confident that waiting is not stressful to the participant, it is sometimes productive to give thinking time.
Another issue relating to interviewing is the use of 'leading questions'. Teachers as interviewers sometimes slip between researcher and teacher roles, and may be tempted to teach rather than explore thinking.
Yet, the very act of interviewing is an intervention in the learners' thinking, in that whatever an interviewer tells us is in the context of the conversation set up by the interviewer, and the participant may have ideas they would not have done without that particular context. In any case, learning is not generally a once off event, as school learning relies on physiological process long after the initial teaching event to consolidate learning, and this is supported by 'revision'. Each time a memory is reactivated it is strengthened (and potentially changed).
So the research interview is a learning experience no matter how careful the researcher is. Therefore the idea of leading questions is much more nuanced that a binary distinction between those questions which are leading and those that are not. So rather than completely avoiding leading questions, the researcher should (a) use open-ended questions initially to best understand the ideas the learner most easily beings to mind; (b) be aware of the degree of 'scaffolding' that Socratic questioning can contribute to the construction of a learners' answer. [Read about the idea of scaffolding learning here.] The interview continued:
Can you see anything there that would give rise to electrostatic forces?
The electrons.
Right so the electrons, they're charged are they?
Yeah. Negatively.
Negatively charged – anything else?
(Pause, c.8s)
The protons in the nucleus are positively charged.
Uh hm. And so would that give rise to any electronic interactions?
Yeah.
So where would there be, sort of any kind of, any kind of force involved here is there?
By the bond.
So where would there be force, can you show me where there would be force?
By the, in the bond, down here.
So the force is localised in there, is it?
The erm, protons would be repelling each other, they'd be attracted by the electrons, so they're keep them at a set distance.
It seemed that Brian could discuss the bond as due to electrical interactions, although his initial ('instinctive') response was to explain the bond in terms of electrons shared to fill electron shells. Although the researcher channelled Brian to think about the potential source of any electrical interactions, this was only after Brian had himself conjectured the role of 'electrostatic forces.'
Often students learn to 'explain' bonds as electron sharing in school science (although arguably this is a rather limited form of explanation), and this becomes a habitual way of talking and thinking by the time they progress to college level study.
So, for example, she found it strange that iron could be vaporised:
So which bits of that are you not convinced about then?
(Pause, c.3 seconds)
It just all … I don't, it's not that I'm not convinced about it, it's just sound strange, because it's like…
(Pause, c.2s)
… erm, well this sounds like ridiculous but, like but before today like none of the people in out class had thought about iron being turned into a gas, and it's little things like that which sound weird.
Okay, erm so if you said to people, can you turn water into a gas, most people would say.
Yeah.
Yeah, do it in the kettle all the time, sort of thing.
Yeah.
But if you said to people can you turn iron into a gas? – do people find that a strange idea?
Yeah.
Yeah?
Well we did. (She laughs)
Although Amy and her classmates had studied the states of matter years earlier at the start of secondary school, and would have learnt that substances can commonly be converted between solid, liquid and gaseous phases, their life-world (everyday) experience of iron – the metallic material – made the idea of iron vapour seem 'weird'.
Given the prevalence of grounded learning impediments where prior learning interferes with new learning, this did not seem as "ridiculous" to the interviewer as Amy suspected it may appear.
As science teachers we have spent many years thinking in terms of substances, and the common pattern that a substance can exist as a solid, liquid or gas – yet most people (even when they refer to 'substances') usually think in terms of materials, not substances. Iron, as a material, is a strong solid material suitable for use in building structures – thinking of iron the familiar material as becoming a gas requires a lot of imagination for someone who not habitually think in terms of scientific models.
Although Amy thought her classmates had found the idea of iron as gas as weird, they had not rejected it. Yet, if it is such a counter-intuitive idea, it may not be later readily brought to mind when it might be relevant, unless it is consolidated into memory by reinforcement through being revisited and reiterated. (Indeed the research interview provides one opportunity for rehearsing the idea: research suggests that whenever a memory is activated this strengthens it.)
Adrian was a participant in the Understanding Science Project. When I spoke to him during the his first year (Y12) of his 'A level' course he told me he had been studying quantum theory, and I asked him about the name 'quantum theory'. He suggested that a theory is an idea that can be proven, but struggled to suggest any other scientific theories.
What about the theory of evolution? Would you count that as a theory?
Yes, but I am not familiar with it. Was it e=mc²?
That's relativity.
Relativity.
I was thinking evolution?
I don't know that one.
Not sure about evolution at all?
No.
Of course there is more than one theory of evolution, but natural selection was a compulsory topic in the school curriculum, and widely referred to as 'the theory of evolution'. Adrian, however, seemed to have no recollection of hearing about evolution at all. It is inconceivable that he had not met the term in school or elsewhere, but it was not something he was bringing to mind in response to my questioning.
Memories from a pandemic: On recollection, confabulation, and verisimilitude!
Keith S. Taber
I had gone into the office to collect something. (My office is in the Science Education Centre of the University's Faculty of Education, located on the site of Homerton College Cambridge.) Due to the global pandemic, and government advice (and later instructions) the office had been in lock down for some time. I'd been away for so long that aspects of the room seemed unfamiliar! The room was something of an oblong, at the back of the building near the technician's area. It was rather cluttered: that was certainly familiar, but it struck me, having been away for some weeks, just how cluttered.
I was pretty sure I needed to collect a lead, but could not see the lead I wanted. I noticed some leads with very thick insulation connecting to the computer – were these SCART leads: I did not remember these being used in the office. But that was not what I was looking for.
I've been in this office quite a few years (well over a decade now) and whilst looking around I found some things I had rather forgotten about. There were some small toy cars – of the kind that that were used on some gravity powered racing tracks when I was a child. These were approx. 1:64 scale, and made to roughly replicate real models, and painted in various colours. It might seem an odd thing to have in an adult's (there may be an unjustified assumption there?) office, but for my first decade in the University I had largely worked in teacher education and led on the physics teaching component – so that provided a good excuse for having lots of different toys!
Another thing that was initially unfamiliar was a large card. This was about A3 size, or originally A2 but folded like a greetings card. Inside were various other post-card sized cards attached, as well as some confectionery wrappers! What was this? It was coming back to me. One year I'd sent a message out to all the students who had finished the course (this was presumably our one-year Educational Research course), and many had replied from all over the world, and I'd made this as a record. Had I sent them all chocolate, and they had returned the wrapper with a greeting? Or had they sent that the confectionery to me from different locations? I was not sure now – the details were bit hazy.
Coming back into the office, and indeed into Cambridge from the satellite town where I live, for the first time in a while was a little odd. I could see into the school next door to our site. There were not many children (most were now at home, with just key workers' children and vulnerable children being in school to be looked after) but those there seemed to be playing happily (both outside and inside classrooms – I could not see anyone supervising) and unperturbed by the current emergency. This seemed reassuring, if a little odd.
I could also see into a classroom of an adjacent college (not a college of the university, but one of the many independent sixth form colleges that allow, mostly overseas, students to study at Cambridge at university entrance level). There were a few young people visible studying. A teenage boy and girl were sitting next to each other working on something together. They were even touching I noticed – nothing inappropriate in normal times – but these are not normal times.
I'd been to the College Combination Room (a staff room for all those working in Homerton – whether academics, clerical, gardeners, or whatever). It was almost empty. I had a conversation there with a colleague I recognised. I think I had wanted to say something about the prime minister being in hospital, along the lines that if he were to die from COVID-19 that would be a terrible loss to his family and friends, but might do wonders for getting across the government's message about social distancing – his one death could save hundreds. But although this was a thought experiment along the lines of those 'trolley' dilemmas used to explore ethical reasoning, I thought it might come across as a little callous. (It is one thing to conjecture scenarios involving the deaths of unnamed imaginary people, but not a real, ill, human being.) [Since publishing this, I have learned this evening on the BBC Radio News that Mr Johnson's health has deteriorated, and he has been placed in intensive care. I do, of course, wish him well along with others suffering from the disease.]
I saw it was 14.00 (2 p.m.) and felt I should have gone to the main faculty building to take a class (although there are no classes now, so just force of habit there I suppose). I wanted to get a cup of coffee to take with me to the class (force of habit, again?), but I saw the coffee machine, and all the tea making paraphernalia, were gone. I assumed that this was because of the current emergency – having a place where people can come to get tea and coffee would encourage the social mixing that we need to avoid. The College must have taken all the refreshments away.
On leaving the Combination room I moved into a corridor (known as Pauper's Walk) but, as I entered the corridor, I saw another colleague enter from the far end. Current protocols suggested to me that I needed to stand back against the wall, and allow her to pass on the other side. However, she had not seen me for a while, and seemed to want to come up to me to talk.
Back in my office, I noticed that some things had been moved since I had been in regularly (pre-pandemic). Some filing cabinets had been shoved out of position, apparently to get access to some large cupboards built into the walls. I did know what was in those cupboards – actually I am not sure I had ever noticed them before. I assumed the technicians used them for storage and had been in to get something, and had needed to shift the cabinets across the floor.
I also noticed that the builders (who had been on site an interminable time, working on one project after another) had made a small hole in the floor in the corner of the room. Through that I was able to see the large, and very 'modern' looking, installation beneath the floor of the store room – presumably the new power plant to heat the building. I could see it was subject to a continuous, and quite extensive, waterfall. I wondered if this was necessary. If the building is closed at the moment, was this not wasting a good deal of water? Or, I wondered, was it a safety precaution that the core needed to be kept cooled even though we were not meant to be operating at the moment?
I had given up on finding the lead I was looking for, and decided I should head for home. I felt a little uneasy about this. The restrictions were still in place. If I was stopped by a police officer, could I really justify my going to work as essential if my main justification had been to look for a lead that I could manage to work at home perfectly well without? I was also uneasy about getting the bus back from the centre of Cambridge to my home – did I really want to be using public transport at this time?
It was then that I started to experience what might be considered cognitive dissonance. Why had I not been concerned about getting the bus into Cambridge? Actually, I did not recall having got the bus into work. The only other viable way I could have got there was cycling, which given the distance, my fitness, and my cargo trike, was, although certainly possible, not an undertaking I would likely have made and immediately forgotten. It was at this point that I released that I did not remember going into work because I had not done so. It was a dream, and, realising that, I woke up at home.
But it was a dream like so many of my dreams – experienced as real, and involving a lot of remembering of things that never happened. (I do not mean remembering the dream when awake, but the experience of remembering in the dream). There is an independent college just adjacent to our building where I often see students studying as I pass by. But no school. The combination room was a real (or at least realistic) memory, as was the colleague I talked to there and the corridor outside – but the other colleague who approached me in the corridor (although seen with clarity in my dream) was not someone I know, or as far as I know based on any real person.
The office I was in (in my dream) was not actually my office, or any office we have in the building (much more like an office I shared at the Institute of Education in London for a year when a visiting fellow there), and was in a different part of the building to my real office.
There is no power plant built under our store room (though last Summer something like this, sans waterfall, was built under the Homerton College lawn). I had left my laptop power lead in the office when I brought the laptop home, and I had considered whether I should go back for it (before we were officially banned from the University buildings) and see if there was anything else I needed before the lock-down: but had decided it was not necessary or a good use of time, or sensible in the circumstances. (But why could I not find the right lead in the dream?)
I have various things in the office from my days working on the PGCE teacher preparation course (a magnetic pendulum for example), but I am not sure if there are toy cars (perhaps there are, and I have forgotten them in my waking life). The large card displaying messages (and chocolate wrappings) from various students has no real counterpoint, but could perhaps be seen as a composite of various post cards and gifts I've been given or sent by students over the years.
Why bother writing about a dream at such length? Because it made me think about memory. In the dream I experienced things that are real, some that were realistic enough (the non-existent colleague in the corridor seemed as real as the real one in the Combination Room) and some that seem (now) fantastic distortions or syntheses of past experiences.
But what was most notable, to my mind, is the role of memory in the dream. When I found the cars, and the card, I was initially nonplussed, but then remembered them from years before (even though, in the case of the card at least, I could not have actually remembered something that never existed). When there was no coffee available in the Combination Room I remembered the current restrictions and inferred this was a precaution the College had taken.
When I found the hole in the floor of my office, I remembered that the builders have been excavating and installing equipment beneath the store room next door (they had not, and the store room was not next door to my actual office). However, a shiny new futuristic apparatus as part of the heating system had recently been open to incidental passer-by inspection as part of ongoing (and indeed interminable) works elsewhere on site – perhaps conflated in my dream with the ground source heat pump under the lawn. In my dream I recognised and remembered things that were real, imagined but possible, and fantastic (the waterfall installed in the excavated cave under our store room, even if not exactly where "the sacred river, ran, through caverns measureless to man"), with equal verisimilitude, as seeming equally likely and trustworthy. The imaginary colleague was as real to me as the remembered real one.
I had no doubts during my dream that I had been in my office, even if it seemed a lot narrower than I recalled. I did not remember having toy cars there, but immediately saw why they might have been useful in teaching. I was initially not at all sure what to make of the large card with the various additions attached inside – but then I 'remembered' (actually, constructed an account of) what I had done years before, and the responses this had initiated, and what I had then done to commemorate those response from past students. It seems a little odd that in my sleep I could 'remember' this unlikely object, but could not remember having gone into work (where there is much genuine experience on which to have constructed a recollection). Perhaps I was just reaching the point where I (my body) was ready to wake, and so my dream became lucid, initiating my awakening. (The thinking we do in dreaming seems worth the effort at the time, until we realise it is 'just' a dream.)
It is perhaps not surprising that in dreams we recognise, and even remember, things that are not real, things that are distorted, and things that are syntheses or different experiences, or that are actually post hoc justifications that enable us to make sense of otherwise confusing (dreamed) experiences. What struck me, though, was how this phenomenon – the way memory seems to cheat and fabricate during dreams – was actually no different from how research suggests memory works in our waking lives. When students tell me they have been taught something that I realise is incorrect in their science lessons, I am always aware they may be recalling correctly, but it is also quite possible that what they 'remember' being told was not what the teacher actually said at the time.
So we might readily dismiss as false things we thought we were remembering when dreaming. But we usually trust a memory we have when we are awake, although research has shown that the things we remember clearly in our waking lives can also be distortions – or even confabulations – as our mind guesses and fills-in what we infer must have happened in order to to make sense of current experience.
