Citation

Kruse O, León IT, Stalder T, Stark R, Klucken T. Neuroimage 2018; 171: 15-25.

Affiliation

Bender Institute for Neuroimaging (BION), Justus Liebig University Giessen, Otto-Behaghel-Str. 10H, 35394 Giessen, Germany; Department of Clinical Psychology, University of Siegen, Adolf-Reichwein-Str. 2a, 57076 Siegen, Germany. Electronic address: Tim.Klucken@uni-siegen.de.

Copyright

(Copyright © 2018, Elsevier Publishing)

DOI

10.1016/j.neuroimage.2017.12.076

PMID

29288866

Abstract

Acute stress has a profound influence on learning, as has been demonstrated in verbal learning or fear conditioning. However, its effect on appetitive conditioning is still unclear. Fear conditioning research suggests the possibility of overgeneralization of conditioning to the CS- under acute stress due to its effect on prefrontal and hippocampal processing). In this study, participants (N = 56 males) were subjected to the Trier Social Stress Test, or a placebo version. After that, all participants underwent an appetitive conditioning paradigm in the fMRI, in which one neutral cue (CS+) was repeatedly paired with reward, while another (CS-) was not. Importantly, the stress-group revealed overgeneralization of conditioning to the CS- on the behavioral level. On the neural level, stressed participants showed increased connectivity between the hippocampus and amygdala, vACC, and OFC, which maintain specificity of conditioning and also showed reduced differential activation. The results indicate overgeneralization of appetitive conditioning promoted by maladaptive balancing of pattern separation and pattern completion in the hippocampus under acute stress and are discussed with respect to clinical implications.

Copyright © 2017. Published by Elsevier Inc.

Language: en

Keywords

Acute stress; Conditioning; Hippocampus; Overgeneralization; Reward; fMRI