Cog ergo sum

Reading Matthew Cobb’s The Idea of the Brain for New Scientist 15 April 2020

Ask a passer-by in 2nd-century Rome where consciousness resided — in the heart or in the head — and he was sure to say, in the heart. The surgeon-philosopher Galen of Pergamon had other ideas. During one show he had someone press upon the exposed brain of a pig, which promptly (and mercifully) passed out. Letting go brought the pig back to consciousness.

Is the brain one organ, or many? Are our mental faculties localised in the brain? 1600 years after, Galen a Parisian gentleman tried to blow his brains out with a pistol. Instead he shot away his frontal bone, while leaving the anterior lobes of his brain bare but undamaged. He was rushed to the Hôpital St. Louis, where Ernest Aubertin spent a few vain hours trying to save his life. Aubertin discovered that if he pressed a spatula on the patient’s brain while he was speaking, his speech “was suddenly suspended; a word begun was cut in two. Speech returned as soon as pressure was removed,” Aubertin reported.

Does the brain contain all we are? Eighty years after Aubertin, Montreal neurosurgeon Wilder Penfield was carrying out hundreds of brain operations to relieve chronic temporal-lobe epilepsy. Using delicate electrodes, he would map the safest cuts to make — ones that would not excise vital brain functions. For the patient, the tiniest regions, when stimulated, accessed the strangest experiences. A piano being played. A telephone conversation between two family members. A man and a dog walking along a road. They weren’t memories, so much as dreamlike glimpses of another world.

Cobb’s history of brain science will fascinate readers quite as much as it occasionally horrifies. Cobb, a zoologist by training, has focused for much of his career on the sense of smell and the neurology of the humble fruit fly maggot. The Idea of the Brain sees him coming up for air, taking in the big picture before diving once again into the minutiae of his profession.

He makes a hell of a splash, too, explaining how the analogies we use to describe the brain both enrich our understanding of that mysterious organ, and hamstring our further progress. He shows how mechanical metaphors for brain function lasted well into the era of electricity. And he explains why computational metaphors, though unimaginably more fertile, are now throttling his science.

Study the brain as though it were a machine and in the end (and after much good work) you will run into three kinds of trouble.

First you will find that reverse engineering very complex systems is impossible. In 2017 two neuroscientists, Eric Jonas and Konrad Paul Kording employed the techniques they normally used to analyse the brain to study the Mos 6507 processor — a chip found in computers from the late 1970s and early 1980s that enabled machines to run video games such as Donkey Kong, Space Invaders or Pitfall. Despite their powerful analytical armoury, and despite the fact that there is a clear explanation for how the chip works, they admitted that their study fell short of producing “a meaningful understanding”.

Another problem is the way the meanings of technical terms expand over time, warping the way we think about a subject. The French neuroscientist Romain Brette has a particular hatred for that staple of neuroscience, “coding”, an term first invoked by Adrian in the 1920s in a technical sense, in which there is a link between a stimulus and the activity of the neuron. Today almost everybody think of neural codes as representions of that stimulus, which is a real problem, because it implies that there must be an ideal observer or reader within the brain, watching and interpreting those representations. It may be better to think of the brain as constructing information, rather than simply representing it — only we have no idea (yet) how such an organ would function. For sure, it wouldn’t be a computer.

Which brings us neatly to our third and final obstacle to understanding the brain: we take far too much comfort and encouragement from our own metaphors. Do recent advances in AI bring us closer to understanding how our brains work? Cobb’s hollow laughter is all but audible. “My view is that it will probably take fifty years before we understand the maggot brain,” he writes.

One last history lesson. In the 1970s, twenty years after Penfield electrostimulation studies, Michael Gazzaniga, a cognitive neuroscientist at the University of California, Santa Barbara, studied the experiences of people whose brains had been split down the middle in a desperate effort to control their epilepsy. He discovered that each half of the brain was, on its own, sufficient to produce a mind, albeit with slightly different abilities and outlooks in each half. “From one mind, you had two,” Cobb remarks. “Try that with a computer.”

Hearing the news brought veteran psychologist William Estes to despair: “Great,” he snapped, “now we have two things we don’t understand.”

All fall down

Talking to Scott Grafton about his book Physical Intelligence (Pantheon), 10 March 2020.

“We didn’t emerge as a species sitting around.”

So says University of California neuroscientist Scott Grafton in the introduction to his provoking new book Physical Intelligence. In it, Grafton assembles and explores all the neurological abilities that we take for granted — “simple” skills that in truth can only be acquired with time, effort and practice. Perceiving the world in three dimensions is one such skill; so is steadily carrying a cup of tea.

At UCLA, Grafton began his career mapping brain activity using positron emission tomography, to see how the brain learns new motor skills and recovers from injury or neurodegeneration. After a career developing new scanning techniques, and a lifetime’s walking, wild camping and climbing, Grafton believes he’s able to trace the neural architectures behind so-called “goal-directed behavior” — the business of how we represent and act physically in the world.

Grafton is interested in all those situations where “smart talk, texting, virtual goggles, reading, and rationalizing won’t get the job done” — those moments when the body accomplishes a complex task without much, if any, conscious intervention.. A good example might be bagging groceries. Suppose you are packing six different items into two bags. There are 720 possible ways to do this, and — assuming that like most people you want heavy items on the bottom, fragile items on the top, and cold items together — more than 700 of the possible solutions are wrong. And yet we almost always pack things so they don’t break or spoil, and we almost never have to agonise over the countless micro-decisions required to get the job done.

The grocery-bagging example is trivial, but often, what’s at stake in a task is much more serious — crossing the road, for example — and sometimes the experience required to accomplish it is much harder to come by. A keen hiker and scrambler, Grafton studs his book with first-hand accounts, at one point recalling how someone peeled off the side of a snow bank in front of him, in what escalated rapidly into a ghastly climbing accident. “At the spot where he fell,” he writes, “all I could think was how senseless his mistake had been. It was a steep section but entirely manageable. Knowing just a little bit more about how to use his ice axe, he could have readily stopped himself.”

To acquire experience, we have to have experiences. To acquire life-saving skills, we have to risk our lives. The temptation, now that we live most of our lives in urban comfort, is to create a world safe enough that we don’t need expose ourselves to such risks, or acquire such skills.

But this, Grafton tells me, when we speak on the phone, would be a big mistake. “If all you ever are walking on is a smooth, nice sidewalk, the only thing you can be graceful on is that sidewalk, and nothing else,” he explains. “And that sets you up for a fall.”

He means this literally: “The number one reason people are in emergency rooms is from what emergency rooms call ‘ground-level falls’. I’ve seen statistics which show that more and more of us are falling over for no very good reason. Not because we’re dizzy. Not because we’re weak. But because we’re inept. ”

For more than 1.3 million years of evolutionary time, hominids have lived without pavements or chairs, handling an uneven and often unpredictable environment. We evolved to handle a complex world, and a certain amount of constant risk. “Very enriched physical problem solving, which requires a lot of understanding of physical relationships, a lot of motor control, and some deftness in putting all those understandings together — all the while being constantly challenged by new situations — I believe this is really what drives brain networks towards better health,” Grafton says.

Our chat turns speculative. The more we removed risks and challenges from our everyday environment, Grafton suggests, the more we’re likely to want to complicate and add problems to the environment, to create challenges for ourselves that require the acquisition of unusual motor skills. Might this be a major driver behind cultural activities like music-making, craft and dance?

Speculation is one thing; serious findings are another. At the moment, Grafton is gathering medical and social data to support an anecdotal observation of his: that the experience of walking in the wild not only improves our motor abilities, but also promotes our mental health.

“A friend of mine runs a wilderness programme in the Sierra Nevada for at-risk teenagers,” he explains, “and one of the things he does is to teach them how to get by for a day or two in the wilderness, on their own. It’s life-transforming. They come out of there owning their choices and their behaviour. Essentially, they’ve grown up.”

Elements of surprise

Reading Vera Tobin’s Elements of Surprise for New Scientist, 5 May 2018

How do characters and events in fiction differ from those in real life? And what is it about our experience of life that fiction exaggerates, omits or captures to achieve its effects?

Effective fiction is Vera Tobin’s subject. And as a cognitive scientist, she knows how pervasive and seductive it can be, even in – or perhaps especially in – the controlled environment of an experimental psychology lab.

Suppose, for instance, you want to know which parts of the brain are active when forming moral judgements, or reasoning about false beliefs. These fields and others rest on fMRI brain scans. Volunteers receive short story prompts with information about outcomes or character intentions and, while their brains are scanned, have to judge what other characters ought to know or do.

“As a consequence,” writes Tobin in her new book Elements of Surprise, “much research that is putatively about how people think about other humans… tells us just as much, if not more, about how study participants think about characters in constructed narratives.”

Tobin is weary of economists banging on about the “flaws” in our cognitive apparatus. “The science on this phenomenon has tended to focus on cataloguing errors people make in solving problems or making decisions,” writes Tobin, “but… its place and status in storytelling, sense-making, and aesthetic pleasure deserve much more attention.”

Tobin shows how two major “flaws” in our thinking are in fact the necessary and desirable consequence of our capacity for social interaction. First, we wildly underestimate our differences. We model each other in our heads and have to assume this model is accurate, even while we’re revising it, moment to moment. At the same time, we have to assume no one else has any problem performing this task – which is why we’re continually mortified to discover other people have no idea who we really are.

Similarly, we find it hard to model the mental states of people, including our past selves, who know less about something than we do. This is largely because we forget how we came to that privileged knowledge.

“Tobin is weary of economists banging on about the ‘flaws’ in our cognitive apparatus”
There are implications for autism, too. It is, Tobin says, unlikely that many people with autism “lack” an understanding that others think differently – known as “theory of mind”. It is more likely they have difficulty inhibiting their knowledge when modelling others’ mental states.

And what about Emma, titular heroine of Jane Austen’s novel? She “is all too ready to presume that her intentions are unambiguous to others and has great difficulty imagining, once she has arrived at an interpretation of events, that others might believe something different”, says Tobin. Austen’s brilliance was to fashion a plot in which Emma experiences revelations that confront the consequences of her “cursed thinking” – a cognitive bias making us assume any person with whom we communicate has the background knowledge to understand what is being said.

Just as we assume others know what we’re thinking, we assume our past selves thought as we do now. Detective stories exploit this foible. Mildred Pierce, Michael Curtiz’s 1945 film, begins at the end, as it were, depicting the story’s climactic murder. We are fairly certain we know who did it, but we flashback to the past and work forward to the present only to find that we have misinterpreted everything.

I confess I was underwhelmed on finishing this excellent book. But then I remembered Sherlock Holmes’s complaint (mentioned by Tobin) that once he reveals the reasoning behind his deductions, people are no longer impressed by his singular skill. Tobin reveals valuable truths about the stories we tell to entertain each other, and those we tell ourselves to get by, and how they are related. Like any good magic trick, it is obvious once it has been explained.