Partial and Total Sleep Deprivation Interferes With Neural Correlates of Consolidation of Fear Extinction Memory.

Background: We assessed the impact of total and partial sleep loss on neural correlates of fear conditioning, extinction learning, and extinction recall in healthy young adults.

Methods: Participants (56.3% female, age 24.8 ± 3.4 years) were randomized to a night of normal sleep (NS) (n = 48), sleep restriction (SR) (n = 53), or sleep deprivation (SD) (n = 53). All completed fear conditioning and extinction learning phases the following morning. Extinction recall was tested in the evening of the same day. Task-based contrasts were modeled at the beginning of, at the end of, and across the fear conditioning and extinction learning phases, and at the beginning of extinction recall. These contrasts were compared among the 3 groups by means of analysis of variance. Nonparametric permutation corrected analyses using a cluster-determining threshold of p < .005 and a familywise error of p < .05.

Results: At the end of fear conditioning, NS activated medial prefrontal regions, SR activated motor areas, and participants in the SD group showed no significant activations. Across extinction learning, only NS activated both salience (fear) and extinction (regulatory) areas. For extinction recall, SD activated similar regions as NS across extinction learning, while SR activated salience and motor areas. During early fear conditioning, compared with NS, SD activated more medial prefrontal and SR activated more salience network areas. For extinction recall, NS activated more prefrontal areas and SD activated more of both salience- and extinction-related areas than SR.

Conclusions: Relative to NS, SR may enhance fear-related and diminish extinction-related activity, whereas SD may delay engagement of extinction learning. Findings may have clinical implications for populations and occupations in which sleep loss is common.