About the SA Blog Network

Illusion Chasers

Illusion Chasers

Illusions, Delusions, and Everyday Deceptions
Illusion Chasers HomeAboutContact

To sleep perchance to learn

The views expressed are those of the author and are not necessarily those of Scientific American.

Email   PrintPrint

From the Sleights of Mind archives.

When I was 11 or 12, my geography teacher in Spain announced that every student needed to learn the capital of each country in the world, in addition to all the major geographical features of every continent: rivers, mountain ranges, capes, gulfs, and archipelagos. I stuck a large world map to my bedroom wall and tried to memorize the textbook in front of the poster, without success. I was out of options: I didn’t see how I could hold the copious, tedious details in my head.  With the date of the test quickly approaching, panic set in, and then inspired me. I pulled out my tape recorder and read aloud  as I recorded from the hated textbook for hours on end. I  then played back the recording as I slept, for the  remaining 3 nights leading to my date with doom.  The outcome was disappointing. I wish I could tell you that I aced the exam, but alas, none of the  information seemed to absorbed as I slept. Though I continued to struggle with geography through high school, I never attempted to study in my sleep again. So I guess I did learnsomething useful from my experience after all.  High school procrastinators of future generations may be more fortunate, however. A recent study published in Nature Neuroscience shows that humans can acquire entirely new information while they sleep. The researchers paired pleasant and unpleasant odors with different tones during sleep, and measured the subjects’ sniffs to tones alone when they were awake. Tones associated with pleasant smells produced stronger sniffs, and tones associated with disgusting smells produced weaker sniffs, despite the subjects’ lack of awareness of the learning process. So it may not  help today,  or even tomorrow, but perhaps  this a first step towards fulfilling our dreams of learning through osmosis.

Susana Martinez-Conde About the Author: Susana Martinez-Conde and Stephen L. Macknik are laboratory directors at SUNY Downstate Medical Center. Follow on Twitter @illusionchasers.

The views expressed are those of the author and are not necessarily those of Scientific American.

Rights & Permissions

Comments 1 Comment

Add Comment
  1. 1. hoamingin 2:19 am 05/25/2013

    Osmosis is exactly how the brain evolved to learn. For millions of years of human evolution from apes in Africa and many tens of millions of years back to our mammalian roots the brain that modern humans inherited evolved in ancestors who could not speak. They learned by observing and absorbing. What their brains evolved to learn were not facts or information, they evolved to learn behaviours – how to respond to different situations. Responses that worked survived because the individuals who used them survived and passed those behaviours on to the next generation. Individuals who had learned behaviours that did not work in new or changing conditions were eliminated, along with those behaviours.
    Brains did not evolve to think. They evolved to store responses to specific situations. Humans evolved the large brain to learn the responses appropriate to a large number of situations so their brains could produce fast, automatic responses without the need to think.
    Mammalian brains have a small conscious memory which is used to intercept the fast, automatic response and modify it to better fit the specific circumstances. This mechanism has been observed with wires connected to individual neurons in the brains of macaques and can probably be observed with scans of human brains.
    As has often been observed by many eminent biologists, the human brain evolved as a visual brain. That suggests that it evolved to memorise situations as images – ie. as contexts without differentiating the contents.
    The reson that there was almost no innovation for millions of years was that the brain evolved to do the opposite of innovation – to preserve past behaviours that worked because they had kept alive the people from whom they were being learned.
    The reason that the first signs of consciousness – jewellery, body paint, ceremonial burying of the dead – have been observed about 170,000 years ago is that speech inevitably requires differentiation of individuals and objects that were the contents of the contexts the brain evolved to memorise.
    So consciousness was not the result of any physical change in the brain. It resulted from a different way of using the brain – specifically in how language obliged brains to interconnect objects. “I” and “YOU” and “THEY” defined individuals as separate entities. Speech required language, which amay have created the first concept in evolutionary history of the individual independent of the context.
    Cognitive scientists have long been puzzled why the brain evolved such a large long term (non-conscious) memory and such a tiny short term conscious memory which George Miller described as a bottle neck on the brain – a bottle neck on how modern humans use it, but not on how the brain evolved to be used. That means that humans now use the brain in ways it did not evolve to be used, which may explain why cognitive scientists have defined long lists of automatic errors of the brain and puzzle over why the brain evolved to get things so wrong.
    So osmosis is how the brain evolved to learn. Watch babies and young children doing exactly that as they observe and absorb like littel sponges.

    Link to this

Add a Comment
You must sign in or register as a member to submit a comment.

More from Scientific American

Email this Article