Interactions of time of day and sleep with between-session habituation and extinction memory in young adult males.
Within-session habituation and extinction learning co-occur as do subsequent consolidation of habituation (i.e., between-session habituation) and extinction memory. We sought to determine whether, as we predicted: (1) between-session habituation is greater across a night of sleep versus a day awake; (2) time-of-day accounts for differences; (3) between-session habituation predicts consolidation of extinction memory; (4) sleep predicts between-session habituation and/or extinction memory. Participants (N = 28) completed 4-5 sessions alternating between mornings and evenings over 3 successive days (2 nights) with session 1 in either the morning (N = 13) or evening (N = 15). Twelve participants underwent laboratory polysomnography. During 4 sessions, participants completed a loud-tone habituation protocol, while skin conductance response (SCR), blink startle electromyography (EMG), heart-rate acceleration and heart-rate deceleration (HRD) were recorded. For sessions 1 and 2, between-session habituation of EMG, SCR and HRD was greater across sleep. SCR and HRD were generally lower in the morning. Between-session habituation of SCR for sessions 1 and 2 was positively related to intervening (first night) slow wave sleep. In the evening before night 2, participants also underwent fear conditioning and extinction learning phases of a second protocol. Extinction recall was tested the following morning. Extinction recall was predicted only by between-session habituation of SCR across the same night (second night) and by intervening REM. We conclude that: (1) sleep augments between-session habituation, as does morning testing; (2) extinction recall is predicted by concurrent between-session habituation; and (3) both phenomena may be influenced by sleep.
Department of Psychiatry, Harvard Medical School, Massachusetts General Hospital, Boston, MA, USA, epace-schott@mgh.harvard.edu.
Edward F
EF
Pace-Schott
Lauren E
LE
Tracy
Zoe
Z
Rubin
Adrian G
AG
Mollica
Jeffrey M
JM
Ellenbogen
Matt T
MT
Bianchi
Mohammed R
MR
Milad
Roger K
RK
Pitman
Scott P
SP
Orr
D000328:Adult; D000704:Analysis of Variance; D002940:Circadian Rhythm / Q000502:physiology*; D003213:Conditioning, Psychological; D004576:Electromyography; D005108:Extinction, Psychological / Q000502:physiology*; D005239:Fear / Q000502:physiology; D005712:Galvanic Skin Response; D006185:Habituation, Psychophysiologic / Q000502:physiology*; D006339:Heart Rate; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology*; D017286:Polysomnography; D057566:Self Report; D012890:Sleep / Q000502:physiology*; D013997:Time Factors; D014851:Wakefulness / Q000502:physiology*; D055815:Young Adult