A meta-analysis of instructed fear studies: implications for conscious appraisal of threat.

TY - JOUR

T1 - A meta-analysis of instructed fear studies: implications for conscious appraisal of threat.

AU - Mechias, Marie-Luise

AU - Etkin, Amit

AU - Kalisch, Raffael

PY - 2010

Y1 - 2010

N2 - In classical Pavlovian fear conditioning, a neutral stimulus (conditioned stimulus, CS) comes to be evaluated as threatening due to its association with an aversive stimulus (unconditioned stimulus, UCS), and elicits fear. In a subtype of fear conditioning paradigms, called instructed fear or anticipatory anxiety, subjects are made aware of the CS-UCS association prior to actually experiencing it. Initial fear elicitation during this type of conditioning results from the negative evaluation of the CS as a consequence of CS-UCS contingency awareness. Prior reports have suggested that this conscious appraisal process is mediated by a variety of brain regions, including rostral dorsomedial prefrontal/dorsal anterior cingulate cortex (dmPFC/dACC), lateral prefrontal cortex (lPFC), posterior cingulate, hippocampus/parahippocampus, and nucleus accumbens, but there is little overlap between results. We reasoned that a formal meta-analysis of existing instructed fear studies should help narrow down the search for conscious appraisal areas in fear conditioning to those consistently activated across studies. We found consistent activation in rostral dmPFC but not in the other candidate areas. These results allow for maintaining the theory that the rostral dmPFC is involved in conscious threat appraisal. We also report a meta-analysis of uninstructed (classical) fear conditioning studies in which we found notable activation in more posterior parts of the dmPFC/dACC that overlapped with some of the instructed fear activations. These data suggest that mid regions of the dmPFC/dACC are part of a "core" fear network that is activated irrespective of how fear was learnt.

AB - In classical Pavlovian fear conditioning, a neutral stimulus (conditioned stimulus, CS) comes to be evaluated as threatening due to its association with an aversive stimulus (unconditioned stimulus, UCS), and elicits fear. In a subtype of fear conditioning paradigms, called instructed fear or anticipatory anxiety, subjects are made aware of the CS-UCS association prior to actually experiencing it. Initial fear elicitation during this type of conditioning results from the negative evaluation of the CS as a consequence of CS-UCS contingency awareness. Prior reports have suggested that this conscious appraisal process is mediated by a variety of brain regions, including rostral dorsomedial prefrontal/dorsal anterior cingulate cortex (dmPFC/dACC), lateral prefrontal cortex (lPFC), posterior cingulate, hippocampus/parahippocampus, and nucleus accumbens, but there is little overlap between results. We reasoned that a formal meta-analysis of existing instructed fear studies should help narrow down the search for conscious appraisal areas in fear conditioning to those consistently activated across studies. We found consistent activation in rostral dmPFC but not in the other candidate areas. These results allow for maintaining the theory that the rostral dmPFC is involved in conscious threat appraisal. We also report a meta-analysis of uninstructed (classical) fear conditioning studies in which we found notable activation in more posterior parts of the dmPFC/dACC that overlapped with some of the instructed fear activations. These data suggest that mid regions of the dmPFC/dACC are part of a "core" fear network that is activated irrespective of how fear was learnt.

M3 - SCORING: Zeitschriftenaufsatz

VL - 49

SP - 1760

EP - 1768

JO - NEUROIMAGE

JF - NEUROIMAGE

SN - 1053-8119

IS - 2

M1 - 2

ER -