Has Modern Experience Changed The Human Brain?

May 19, 2017

The brain has evolved over evolutionary time scales of millions of years. So, what is the likelihood that the relatively recent advent of reading and writing, or motorized transport, or the Internet, could have changed our brains?

On the other hand, we know that modernity, which we can think of as the emergence of psychologically modern human beings some 50,000 years ago or more, is the history of ever-evolving ways of doing things, ever-changing technologies and systems for coping — from pictures to systems of writing to instruments for building to practices of exchange and cooperation among groups. And with all these changes and development, we acquire not only new things to think about, but new styles of thinking.

How could this not change our brains?

A study out of India, still undergoing peer review, in which scientists look at EEG measures in diverse populations across India may shed some light on the question.

It has long been known that awake subjects with eyes closed show a pattern of neural oscillation in the so-called alpha band (8-15 Hz) and this has been taken to be a fundamental cerebral rhythm that may be tied to attention, learning ability, and working memory. Understanding the meaning and mechanisms of this dominant rhythm of the human brain has been of interest to science since the discovery of alpha-band oscillation in the early 20th century.

For the study, Indian scholars Dhanya Parameshwaran and Tara Thiagarajan performed EEG measurements on 402 subjects from 38 different settlements across India — ranging from remote hamlets to large cities. Participants in the study had incomes ranging from $300 a year to $150,000 a year, and they had wildly divergent levels of formal education and access to technology.

The findings of the study are dramatic. The existence of alpha-band activity was basically undetectable in people who lack wealth, education and knowledge of modern technology.

In the words of the scientists, the upshot: "Here we have shown that alpha oscillation, thought to be a fundamentally ubiquitous feature of brain activity, widely diverges across humanity in its presence in the EEG."

Moreover, they find no basis for making claims about "normal" or average when it comes to alpha oscillation and consider the possibility that it may not exist. Unlike the heart, say, the brain can only be understood in relation to the "specific context of human experience."

But the most important finding, they argue, is that in those populations that do exhibit the alpha dynamics, it appears that this is due to exposure to "modern experience" — that is, to education and technology (and, by association, wealth). Alpha oscillation, which is not present in children, is an experience-dependent phenomenon.

All this has serious policy implications, they mention in conclusion.

Can the world afford to confine alpha rhythms to the 15-20 percent who, by the criteria of this study, enjoy the income, education and technology conducive to cognitive and neurological development?

There is also a fascinating methodological upshot. The vast majority of cognitive science has been done on WEIRD subjects — that is, subjects sampled from Western, Educated, Industrialized, Rich, Democratic societies. But recent scholarship suggests that this fact may conceal real variation across human communities. For decades it's been jokingly acknowledged that so many studies coming out of psychology laboratories around the world use the readily available population of undergraduates as a subject pool.

Could it be that our understanding of what it is to be human will be transformed when we widen our test pool? How could it not be?

Special thanks to Evan Thompson for alerting me to the work of Parameshwaran and Thiagarajan — and for helpful discussion.

Alva Noë is a philosopher at the University of California, Berkeley, where he writes and teaches about perception, consciousness and art. He is the author of several books, including his latest, Strange Tools: Art and Human Nature (Farrar, Straus and Giroux, 2015). You can keep up with more of what Alva is thinking on Facebook and on Twitter: @alvanoe

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