Less is more: Neural activity during very brief and clearly visible exposure to phobic stimuli.
Research on automatic processes in fear has emphasized the provocation of fear responses rather than their attenuation. We have previously shown that the repeated presentation of feared images without conscious awareness via backward masking reduces avoidance of a live tarantula in spider-phobic participants. Herein we investigated the neural basis for these adaptive effects of masked exposure. 21 spider-phobic and 21 control participants, identified by a psychiatric interview, fear questionnaire, and approaching a live tarantula, viewed stimuli in each of three conditions: (1) very brief exposure (VBE) to masked images of spiders, severely limited awareness; (2) clearly visible exposure (CVE) to spiders, full awareness; and (3) masked images of flowers (control), severely limited awareness. Only VBE to masked spiders generated neural activity more strongly in phobic than in control participants, within subcortical fear, attention, higher-order language, and vision systems. Moreover, VBE activated regions that support fear processing in phobic participants without causing them to experience fear consciously. Counter-intuitively, CVE to the same spiders generated stronger neural activity in control rather than phobic participants within these and other systems. CVE deactivated regions supporting fear regulation and caused phobic participants to experience fear. CVE-induced activations also correlated with measures of explicit fear ratings, whereas VBE-induced activations correlated with measures of implicit fear (color-naming interference of spider words). These multiple dissociations between the effects of VBE and CVE to spiders suggest that limiting awareness of exposure to phobic stimuli through visual masking paradoxically facilitates their processing, while simultaneously minimizing the experience of fear. Hum Brain Mapp 38:2466-2481, 2017. © 2017 Wiley Periodicals, Inc.
Purchase College, SUNY, Purchase, New York.
Paul
0000-0002-5815-8324
P
Siegel
Purchase College, SUNY, Purchase, New York.
Richard
R
Warren
New York State Psychiatric Institute, Columbia University, New York, New York.
Zhishun
Z
Wang
New York State Psychiatric Institute, Columbia University, New York, New York.
Jie
J
Yang
New York University, New York, New York.
Don
D
Cohen
University of California, Santa Barbara, California.
Jason F
JF
Anderson
Purchase College, SUNY, Purchase, New York.
Lilly
L
Murray
Children's Hospital Los Angeles & Keck School of Medicine, University of Southern California, Los Angeles, California.
Bradley S
BS
Peterson
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D000818:Animals; D001364:Awareness; D001921:Brain / Q000000981:diagnostic imaging*; D016022:Case-Control Studies; D005239:Fear; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007092:Imagination; D008279:Magnetic Resonance Imaging; D010698:Phobic Disorders / Q000473:pathology* / Q000523:psychology*; D010775:Photic Stimulation / Q000009:adverse effects*; D013112:Spiders; D013360:Subliminal Stimulation; D011795:Surveys and Questionnaires; D013997:Time Factors; D055815:Young Adult
automatic processing; exposure; fear; masking; phobia