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Has Modern Experience Changed The Human Brain? (NPR):

“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?…

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…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…

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…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.”

The Study

Modernization, Wealth And The Emergence Of Strong Alpha Oscillations In The Human EEG (not peer-reviewed yet). Abstract:

Oscillations in the alpha range (8-15 Hz) have been found to appear prominently in the EEG signal when people are awake with their eyes closed, and since their discovery have been considered a fundamental cerebral rhythm. While the mechanism of this oscillation continues to be debated, it has been shown to bear positive relation to memory capacity, attention and a host of other cognitive outcomes. Here we show that this feature is largely undetected in the EEG of adults without post-primary education and access to modern technologies. Furthermore, we show that the spatial extent and energy of the oscillation have wide variation, with energy ranging over a thousand fold across the breath of humanity with no centralizing mean. This represents a divergence in a fundamental functional characteristic of an organ demonstrating both that modernization has had a profound influence on brain dynamics and that a meaningful average human brain does not exist in a dynamical sense.

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