TY  - JOUR
A1  - Wendt, Julia
A1  - Loew, Andreas
A1  - Weymar, Mathias
A1  - Lotze, Martin
A1  - Hamm, Alfons O.
T1  - Active avoidance and attentive freezing in the face of approaching threat
T2  - NeuroImage : a journal of brain function
N2  - Defensive behaviors in animals and humans vary dynamically with increasing proximity of a threat and depending upon the behavioral repertoire at hand. The current study investigated physiological and behavioral adjustments and associated brain activation when participants were exposed to dynamically approaching threat that was either inevitable or could be avoided by motor action. When the approaching threat was inevitable, attentive freezing was observed as indicated by fear bradycardia, startle potentiation, and a dynamic increase in activation of the anterior insula and the periaqueductal grey. In preparation for active avoidance a switch in defensive behavior was observed characterized by startle inhibition and heart rate acceleration along with potentiated activation of the amygdala and the periaqueductal grey. Importantly, the modulation of defensive behavior according to threat imminence and the behavioral option at hand was associated with activity changes in the ventromedial prefrontal cortex. These findings improve our understanding of brain mechanisms guiding human behavior during approaching threat depending on available resources.
KW  - Defensive response patterns
KW  - Active avoidance
KW  - Freezing
KW  - Psychophysiology
KW  - fMRI
Y1  - 2017
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/46384
SN  - 1053-8119
SN  - 1095-9572
VL  - 158
SP  - 196
EP  - 204
PB  - Elsevier
CY  - San Diego
ER  -