Fear but not awareness predicts enhanced sensory processing in fear conditioning

Authors: Moratti, Stephan¹; Keil, Andreas¹; Miller, Gregory A.²

Source: Psychophysiology, Volume 43, Number 2, March 2006 , pp. 216-226(11)

Buy & download fulltext article:

Price: $48.00 plus tax (Refund Policy)

Abstract:

It is not clear whether enhanced cortical processing of reinforced stimuli as reported by neuroimaging studies is due to expectancy of an aversive event alone or to activation of the fear system. The present study investigated cortical and autonomic responses of aware participants using an instructed fear conditioning design. Steady-state visual evoked fields (ssVEF) and heart rate change were recorded to assess sensory processing and activation of the fear system by reinforced (CS+) and nonreinforced stimuli (CS−). Participants who showed heart rate acceleration demonstrated increased ssVEFs in visual and parietal cortex during CS+ in acquisition trials. Heart rate decelerators did not show enhanced cortical activation with respect to the CS+. Participants in both groups reported awareness of CS–US contingencies. Awareness of stimulus contingency in fear conditioning seems not to be sufficient to elicit enhanced visual cortical processing.

Keywords: Fear conditioning; Fear system; MEG; Heart rate; Steady-state visual evoked field potentials; Awareness

Document Type: Research article

DOI: http://dx.doi.org/10.1111/j.1464-8986.2006.00386.x

Affiliations: 1: Department of Psychology, University of Konstanz, Konstanz, Germany 2: Department of Psychology and Beckman Institute Biomedical Imaging Center, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA

Publication date: 2006-03-01