Thread by @fortelabs

1/ My summary/interpretation of the remarkable book by @NickJChater The Mind is Flat: The Remarkable Shallowness of the Improvising Brain

Affiliate link: amzn.to/2KBEZJd

2/ I LOVE books that make extreme, hyper-reductionist statements because they are bolder and more interesting, and force everyone to take a side. And this one is a doozy:

3/ “The inner, mental world, and the beliefs, motives and fears it is supposed to contain is a work of the imagination... It is not hard to plumb our mental depths because they are so deep and so murky, but because there are no mental depths to plumb.”

4/ You read that right. There are no such things as:

Hidden motives
Unconscious beliefs
Secret desires
Subliminal perceptions
Permanent values
Inner agents/selves
Intuitive introspections
Underlying mental principles
Subconscious preferences
Mental depths
Moral convictions

5/ As you read that list, your mind might readily jump to examples of each of them, so effortlessly that they seem pre-formed in some vast internal archive, ready to be “read off” at a moment’s notice

6/ But your mind is making each of those up in the moment, the same way the next tweet seems to exist pre-made just off the edge of the screen, but is actually being generated on demand right at the instant you scroll up

7/ Much of the book is dedicated to detailed explanations of a long series of experiments that support these assertions, from perception to memory to visual acuity to emotion to logic to physiology

8/ In AI, it was long attempted to “excavate our mental depths, and to bring to the surface as much of this supposed inner storehouse of beliefs as we can.” But the knowledge, insights and strategies that top human players claim they are using turn out to be totally contradictory

9/ Instead, huge strides in machine learning have been made by completely bypassing human knowledge extraction, and creating algorithms that directly confront the problem to be solved and learn from experience

10/ “Chess grandmasters can’t really explain how they play chess; doctors can’t explain how they diagnose patients; & none of us can remotely explain how we understand the everyday world of ppl & objects.”

11/ “What we say sounds like explanation – but really it is a terrible jumble that we are making up as we go along... analysis of these streams of verbal description, however long they continue, shows that they are little more than a series of loosely connected fragments.”

12/ This is called the Illusion of Explanatory Depth: “the bizarre contrast between our feeling of understanding and our inability to produce cogent explanations, whether explaining how a fridge works, how to steer a bicycle, or the origin of the tides...”

13/ In linguistics, Noam Chomsky’s generative grammar tried to systematize structure of language, but it turns out that even the structural patterns observed in language – not just its meaning – are a jumble of inconsistent regularities, sub-regularities and outright exceptions

14/ In economics, assumption that consumers and companies have a complete and consistent understanding of their own preferences has also foundered

15/ Countless experiments in psychology and behavioural economics have shown just how spectacularly ill-defined and self-contradictory our beliefs and preferences are (not as a rare “cognitive bias,” but as a pervasive default)

16/ Ppl routinely supply wildly different answers to exactly the same question, provide inconsistent answers, or act in direct contradiction to their stated beliefs. Not because those beliefs contradict each other, but because they don’t exist

17/ Only the very center of our vision can see in color, yet we seem to perceive a full color world. We can only perceive 10-15 characters at a time on a page, and won’t notice if all the rest turn to x’s, yet the whole page seems to be coherent text wherever we look

18/ The brain perceives only fragments and snippets, but stitches them together so seamlessly that it fools us into thinking it is one coherent landscape. And it does this internally as well, stitching together beliefs, opinions, preferences, motives just in time

19/ “The world around us seems sharp and colourful and full of objects, words and faces because, as soon as we wonder about any aspect of that world, our eyes can almost instantly flick across to the relevant part, fixate it and, apparently in an instant, provide an answer.”

20/ “The very fluency with which answer follows question gives us the impression that all the answers were already stored up, ready for use – that we have a full and precise mental representation of the world around us, to be consulted at any moment.”

But we don’t.

21/ Here’s an experiment: imagine a tiger. How many stripes does it have?

(Do this now)

22/ Clear images of the number of stripes may spring instantly to mind, as will details of its teeth, eyes, paws, and whiskers as I mention them. This may lead you to believe you have a mental model of a tiger stored in the recesses of your mind, ready to be accessed

23/ But as we question further, it becomes clear you don’t. Do the stripes continue the same direction all over the body? How about on its underbelly? Face and neck? The further we dive in the less coherent the image gets

24/ As further detailed in How Emotions Are Made, even our interpretations of our own emotions are being improvised on the spot

https://twitter.com/fortelabs/status/1123316547064254464?s=21

25/ We can’t measure risk preferences, trade offs between present against the future; how altruistic we are and to whom; how far we display prejudice on gender or race, etc. because there is nothing stable to measure

26/ The brain cannot think about more than one thing at a time, because it works as one interconnected network that solves problems through cooperative computation across most or all of the network at the same time

27/ This means there is no “background processing,” because this network makes one giant, coordinated step at a time rather than, as in a conventional computer, a myriad of almost infinitesimally tiny information-processing steps that can be timeshared across problems

28/ This means there are no sub or unconscious thoughts, no hidden motives, and no battle between multiple “selves” (e.g. Freud’s id, ego and superego).

29/ Anatomical support: consciousness seems to be routed through a bottleneck in sub-cortical structures like the thalamus (removing entire sections of the overlying cortex causes no disturbance in consciousness, while shocking thalamus leads to coma/seizure)

30/ “Our brain is fully engaged w/ making sense of the info it is confronted w/ at each moment. Consciousness appears to be guided, sequentially, thru the narrow bottleneck: deep, sub-cortical structures coordinate patterns in sensory input, memory & motor output, one at a time”

32/ More bluntly: “our only conscious experience is our interpretation of sensory information.” You can’t imagine the abstract number 7 in your mind, only sensory images and words and situations that relate to the number 7

33/ The idea that our brains can unconsciously “work on” a problem over time, suddenly sparking a solution, is challenged: in a study, ppl who had long breaks showed no improvement over those who just kept working on the problem continuously

34/ The possible advantage of stepping away is that you unload unproductive approaches and start afresh with a new perspective. But that doesn’t require background processing. It actually requires the problem to be forgotten

35/ The brain is particularly well adapted to solving problems in which large numbers of constraints must be satisfied simultaneously, but it does this in one big coordinated step, which we may think must involve many separate strands of thought

36/ What does remain somewhat consistent is our memories, which groove paths in our thinking over time and form the raw material for later improvisations

37/ We feel like we have immediate access to vast repository of general knowledge, autobiography, likes/dislikes, moral/religious convictions, etc. But in truth we impose meaning on them with the same flexibility and urgency that applies in perception

38/ “The memories themselves are not thoughts: they are not, for example, beliefs, choices or preferences...Instead, they consist of mere fragments of past thoughts, to be reused, reconstituted and transformed by the cycle of thought”

39/ “Each momentary interpretation draws on and adapts our previous attempts to understand the world. So each cycle of thought may be viewed as creating, over time, mental channels along which our thoughts most easily flow”

40/ “Over a lifetime, the flow of thought shapes, and is shaped into, complex patterns: our habits of mind, our mental repertoire. These past patterns of thought, and their traces in memory, underpin our remarkable mental abilities, shape how we behave and make each of us unique”

41/ “Our natural ‘mode’ of thinking is wildly flexible – we only think of discipline and control as the essence of thought because these require our conscious and careful attention. The sheer ubiquity of our imaginative flexibility renders it invisible.”

42/ “the secret of human intelligence is the ability to find patterns in the least structured, most unexpected, hugely variable of streams of information... Watching the mind at play is our best guide to its natural mode of operation”

43/ “Each fresh improvisation is built from the fragments of past improvisations – so each of us is a unique history, together with a wonderfully creative machine for redeploying that history to create new perceptions, thoughts, emotions and stories.“

44/ “we are astonishingly inventive ad hoc reasoners, creative metaphor-machines, continually welding together scattered scraps of information into momentarily coherent wholes. We are very different from the image we create for ourselves, and much more remarkable.”

45/ “How, then, are perceptual reorganizations, sudden insights, religious conversions and conceptual and political revolutions possible? One answer is that memory is fragile; so that we can often end up starting again from scratch, and coming up with a different answer”

46/ “If the mind is flat – if we imagine our minds, our lives and our culture – we have the power to imagine an inspiring future, and to make it real.”