Send to

Choose Destination
See comment in PubMed Commons below
Behav Neurosci. 2006 Dec;120(6):1196-203.

Fear conditioning and extinction: influence of sex and menstrual cycle in healthy humans.

Author information

Department of Psychiatry, Massachusetts General Hospital/Harvard Medical School, Boston, MA, USA.


Although sex differences have been demonstrated in behavioral paradigms of fear conditioning, the findings have been inconsistent, and fear extinction has been little studied. The present study investigated the influence of sex and menstrual cycle phase on the recall of fear extinction. Three groups of healthy adult participants were studied: women at 2 different phases of the menstrual cycle (early follicular [early cycle] and late follicular [midcycle]) and men. Participants underwent a 2-day fear conditioning and extinction protocol. The paradigm entailed habituation, fear conditioning, and extinction learning on Day 1 and extinction recall and fear renewal on Day 2. Skin conductance served as the dependent variable. During fear acquisition on Day 1, men showed significantly larger conditioned responses relative to women; early cycle and midcycle women did not differ. No significant group differences were found during extinction learning. On Day 2, men and early cycle women expressed greater extinction memory than midcycle women. These data confirm sex differences in conditioned fear acquisition and suggest that midcycle hormones attenuate extinction recall.

[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for American Psychological Association
    Loading ...
    Support Center