Early research asked whether cats dream

Excerpt from the May 29, 1965, issue of Science News Letter


DREAMING OF MICE?  Cats go through REM sleep but researchers still don’t know exactly why.

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Dream phase necessary — Dreaming sleep, which seems to be a necessity for man, may also be crucial for cats.… Scientists do not know exactly what function [REM sleep] periods serve in animals. For this reason, they call the phase paradoxical sleep.… [Researchers] have found that a group of cats deprived of paradoxical sleep for a number of days will react the same way humans do. The longer the cats were kept from paradoxical sleep, the more they tried to enter it.
— Science News Letter, May 29, 1965


The need for REM sleep – in people as in animals – remains mysterious, even though the tools for studying the slumbering brain have increased greatly in sophistication (SN: 10/24/09, p. 16). Some researchers argue that REM sleep helps solidify memories. Mammals from platypuses to sloths to giraffes go through REM sleep. Some animals experimentally prevented from REM sleep have learning deficits; others do not.

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