Citation

Stout DM, Glenn DE, Acheson DT, Simmons AN, Risbrough VB. Brain Res. 2019; 1719: 225-234.

Affiliation

Center of Excellence for Stress and Mental Health, VA San Diego Healthcare System, San Diego, CA 92161 USA; Department of Psychiatry, University of California San Diego, San Diego, CA 92093 USA.

Copyright

(Copyright © 2019, International Brain Research Organization, Publisher Elsevier Publishing)

DOI

10.1016/j.brainres.2019.06.003

PMID

31173725

Abstract

Contextual threat learning is often associated with twoprocesses: elemental and configural learning. Few studies have examined configural learning where subjects form a representation of the threat-related context as a gestalt whole from the individual features in the environment. The goal of the current study was to compare and contrast neural circuitry recruited by variation in demands placed on configural threat encoding. Subjects (N=25) completed a configural threat learning task, where we manipulated the amount of configural encoding required to learn the threat association (low demand: changes to a discrete element of the context; and high demand: rearrangement of elements). US expectancy ratings, skin conductance responses (SCR), and functional magnetic resonance imaging (fMRI) were collected. Subjects successfully learned the configural threat association as measured by US expectancy ratings, SCR, and BOLD activity. Hippocampal and amygdala region of interest analyses indicated differential configural threat learning and predicted SCR measures of learning. Furthermore, whole brain analyses identified four circuits that were impacted by the amount of differential configural encoding required, but none correlated with SCR. These results set the stage for a more detailed understanding of how configural threat learning is instantiated in the brain-an important mechanism associated with PTSD and other fear-related disorders.

Copyright © 2019. Published by Elsevier B.V.

Language: en

Keywords

Configural learning; Contextual fear; Fear conditioning; Threat processing; fMRI