How To Think About Those Brain Scan Pictures

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NYU psychologist Gary Marcus has an interesting piece on the New Yorker website about how we should think about brain science. Yes, he says, neuroscientific findings are often overhyped, but that’s no reason to dismiss the whole field:

“Neuroscience has already told us lot, just not the sort of things we may think it has. What gets play in the daily newspaper is usually a study that shows some modest correlation between a sexy aspect of human behavior, with headlines like “FEMALE BRAIN MAPPED IN 3D DURING ORGASM” and “THIS IS YOUR BRAIN ON POKER.”

But a lot of those reports are based on a false premise: that neural tissue that lights up most in the brain is the only tissue involved in some cognitive function. The brain, though, rarely works that way.   Most of the interesting things that the brain does involve many different pieces of tissue working together. Saying that emotion is in the amygdala, or that decision-making is the prefrontal cortex, is at best a shorthand, and a misleading one at that.

Different emotions, for example, rely on different combinations of neural substrates. The act of comprehending a sentence likely involves Broca’s area (the language-related spot on the left side of the brain that they may have told you about in college), but it also draws on the parts of the brain in the temporal lobe that analyze acoustic signals, and part of sensorimotor cortex and the basal ganglia become active as well. (In congenitally blind people, some of the visual cortex also plays a role.)   It’s not one spot, it’s many, some of which may be less active but still vital, and what really matters is how vast networks of neural tissue work together . . .

The real problem with neuroscience today isn’t with the science—though plenty of methodological challenges still remain—it’s with the expectations. The brain is an incredibly complex ensemble, with billions of neurons coming into—and out of—play at any given moment.   There will eventually be neuroscientific explanations for much of what we do; but those explanations will turn out to be incredibly complicated. For now, our ability to understand how all those parts relate is quite limited, sort of like trying to understand the political dynamics of Ohio from an airplane window above Cleveland.

Which may be why the best neuroscientists today may be among those who get the fewest headlines, like researchers studying the complex dynamics that enter into understanding a single word. As [neuroscientific pioneer David] Poeppel says, what we need now is ‘the meticulous dissection of some elementary brain functions, not ambitious but vague notions like brain-based aesthetics, when we still don’t understand how the brain recognizes something as basic as a straight line.’

The sort of short, simple explanations of complex brain functions that often make for good headlines rarely turn out to be true. But that doesn’t mean that there aren’t explanations to be had, it just means that evolution didn’t evolve our brains to be easily understood.” (Read more here.)

An interesting and important takeaway here: “The real problem with neuroscience today isn’t with the science, it’s with the expectations.”

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One Response to “How To Think About Those Brain Scan Pictures”

  1. Michael says:

    I must say that I compare using MRI for neuroscience as earlier astronomers. Many of them made good deductions and some other didn’t. I think it’s a matter of time until we get useful interpretations, but we have to be patient, something difficult in an era that demands immediate results.

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