Thu, 21 Aug 2008 14:57:37 BST CiteULike: jeep's Ohrmann http://www.citeulike.org/user/jeep/author/Ohrmann CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/jeep/article/1434468 <i>Exp Brain Res (3 July 2007)</i><br /><br />It has been argued that the amygdala represents an integral component of a vigilance system that is primarily involved in the perception of ambiguous stimuli of biological relevance. The present investigation was conducted to examine the relationship between automatic amygdala responsivity to fearful faces which may be interpreted as an index of trait-like threat sensitivity and spatial processing characteristics of facial emotions. During 3T fMRI scanning, pictures of human faces bearing fearful, angry, and happy expressions were presented to 20 healthy volunteers using a backward masking procedure based on neutral facial expressions. Subsequently, a computer-based face-in-the-crowd task using schematic face stimuli was administered. The neural response of the (right) amygdala to masked fearful faces correlated consistently with response speed to negative and neutral faces. Neither amygdala activation during the masked presentation of angry faces nor amygdala activation during the presentation of happy faces was correlated with any of the response latencies in the face-in-the-crowd task. Our results suggest that amygdala responsivity to masked facial expression is differentially related to the general visual search speed for facial expression. Neurobiologically defined threat sensitivity seems to represent an important determinant of visual scanning behaviour. Threat sensitivity as assessed by automatic amygdala response to fearful faces predicts speed of visual search for facial expression. Patricia Ohrmann Astrid Rauch Jochen Bauer Harald Kugel Volker Arolt Walter Heindel Thomas Suslow doi:10.1007/s00221-007-1022-0 Exp Brain Res (3 July 2007) 2007-07-05T02:46:59-00:00 2007 Exp Brain Res 0014-4819 amygdala attention expression face visual_search http://www.citeulike.org/user/jeep/article/831527 <i>Brain and Cognition, Vol. 61, No. 3. (August 2006), pp. 243-248.</i><br /><br />It has been argued that critical functions of the human amygdala are to modulate the moment-to-moment vigilance level and to enhance the processing and the consolidation of memories of emotionally arousing material. In this functional magnetic resonance study, pictures of human faces bearing fearful, angry, and happy expressions were presented to nine healthy volunteers using a backward masking procedure based on neutral facial expression. Activation of the left and right amygdala in response to the masked fearful faces (compared to neutral faces) was significantly correlated with the number of fearful faces detected. In addition, right but not left amygdala activation in response to the masked angry faces was significantly related to the number of angry faces detected. The present findings underscore the role of the amygdala in the detection and consolidation of memory for marginally perceptible threatening facial expression. Amygdala activation during masked presentation of emotional faces predicts conscious detection of threat-related faces. Thomas Suslow Patricia Ohrmann Jochen Bauer Astrid Rauch Wolfram Schwindt Volker Arolt Walter Heindel Harald Kugel doi:10.1016/j.bandc.2006.01.005 Brain and Cognition, Vol. 61, No. 3. (August 2006), pp. 243-248. 2006-09-05T19:31:00-00:00 2006 Brain and Cognition 61 3 243 248 amygdala emotion expression face fmri masked http://www.citeulike.org/user/jeep/article/1291045 <i>Psychiatry Res, Vol. 154, No. 1. (15 January 2007), pp. 13-20.</i><br /><br />The amygdala is a key structure in a limbic circuit involved in the rapid and unconscious processing of facial emotions. In the present study, the role of the amygdala in automatic, involuntary appraisal processes, which are believed to be a crucial component of emotion processing, was investigated in 23 healthy subjects. Amygdala activity was recorded in response to masked displays of angry, sad, and happy facial expressions using functional magnetic resonance imaging (fMRI). In a subsequent experiment, the subjects performed a masked affective priming task that characterizes automatic emotion processing by investigating the biasing effect of subliminally presented emotional faces on evaluative ratings to subsequently presented neutral stimuli. In the affective priming task, significant valence-congruent evaluation manipulation was observed. Subjects rated neutral targets more positively if they were primed by happy faces. Significant correlations were found between amygdala responses to masked negative facial expressions and negative evaluation shifts elicited by the corresponding emotion quality in the affective priming task. Spontaneous amygdala reactivity to facial emotions appears to be a determinant of automatic negative evaluative response tendencies. This finding might shed some light on how amygdala hyperresponsivity contributes to negative cognitive biases commonly observed in affective disorders. Amygdala reactivity predicts automatic negative evaluations for facial emotions. U Dannlowski P Ohrmann J Bauer H Kugel V Arolt W Heindel T Suslow doi:10.1016/j.pscychresns.2006.05.005 Psychiatry Res, Vol. 154, No. 1. (15 January 2007), pp. 13-20. 2007-05-12T04:20:14-00:00 2007 Psychiatry Res 0165-1781 154 1 13 20 amygdala emotion expression face fmri