Sleep facilitates long-term face adaptation

Adaptation is an automatic neural mechanism supporting the optimization of
visual processing on the basis of previous experiences. While the short-term
effects of adaptation on behaviour and physiology have been studied extensively,
perceptual long-term changes associated with adaptation are still
poorly understood.Here,we showthat the integration of adaptation-dependent
long-term shifts in neural function is facilitated by sleep. Perceptual shifts
induced by adaptation to a distorted image of a famous person were larger in
a group of participants who had slept (experiment 1) or merely napped for
90 min (experiment 2) during the interval between adaptation and test compared
with controls who stayed awake. Participants’ individual rapid eye
movement sleep duration predicted the size of post-sleep behavioural adaptation
effects. Our data suggest that sleep prevented decay of adaptation in a
way that is qualitatively different from the effects of reduced visual interference
known as ‘storage’. In the light of the well-established link between
sleep and memory consolidation, our findings link the perceptual mechanisms
of sensory adaptation—which are usually not considered to play a relevant
role in mnemonic processes—with learning and memory, and at the same
time reveal a new function of sleep in cognition.