The role of the amygdala in human fear: Automatic detection of threat
Introduction
The purpose of this article is to review some of the recent literature on the role of the amygdala in fear with particular emphasis on my own work. After specifying what I mean by fear, I shall start out with some behavioral work that implicates the amygdala for human fear responses, and then I proceed to brain imaging studies that help to delineate the role of the amygdala in fear activation and attention capture.
Section snippets
A perspective on fear
Fear is an activated, aversive emotional state that serves to motivate the organism to cope with threatening events (Öhman, 2000). The coping attempts are more or less clearly focused on metabolically taxing defensive behaviors such as immobility (freezing), escape, or attack. Even though immobility refers to an apparently passive and quiescent organism, it involves an attentive stance associated with an active physiology, in some respects similar to the one seen in the more active flight and
Amygdala activation to masked and non-masked fear stimuli
Morris et al. (1998) examined regional cerebral blood flow responses assessed by positron emission tomography to masked facial stimuli whose emotional impact had been enhanced by Pavlovian conditioning. They reported specific activation of the right amygdala to masked conditioned angry faces as compared to masked non-conditioned angry faces.
To further elucidate the dynamics of fear activation in the human brain Carlsson et al. (2004) recruited participants that either were fearful of snakes or
Conclusions
Research on the neural basis of fear has made important headways during the last few decades. We have gained important knowledge about the factors that activate fear, including the role of non-conscious processes and the role of fear in guiding attention. Furthermore, we are beginning to come to grips with the neural mechanisms behind these behavioral effects. Fear stimuli engage a subcortical network of structures that is centered on the amygdala and that can activate fear responses via an
Acknowledgements
The author's research that is reviewed in this paper was supported by grants from the Swedish Research Council and the Bank of Sweden Tercentennial Foundation. He wishes to express his gratitude to his co-workers Katrina Carlsson, Ray Dolan, Francisco Esteves, Anders Flykt, Martin Ingvar, Pernilla Juth, Andreas Karlsson, Daniel Lundqvist, John Morris, and Karl-Magnus Petersson.
References (34)
- et al.
Effects of attention and emotion on faces processing in the human brain: an event-related fMRI study
Neuron
(2001) - et al.
Neural correlates of the automatic processing of threat facial signals
J. Neurosci.
(2003) - et al.
How danger is encoded: toward a systems, cellular, and computational understanding of cognitive-emotional interactions in fear
- et al.
Prefrontal cortical function and anxiety: controlling attention to threat related stimuli
Nat. Neurosci.
(2004) - et al.
State anxiety modulation of the amygdala response to unattended threat-related stimuli
J. Neurosci.
(2004) - et al.
Fear and the amygdala: manipulation of awareness generates differential cerebral responses to phobic and fear-relevant (but non-feared) stimuli
Emotion
(2004) - et al.
Separable components in the processing of black and white faces
Psychol. Sci.
(2004) - et al.
Dysfunction in the neural circuitry of emotion regulation—a possible prelude to violence
Science
(2000) - et al.
Behold the wrath: psychophysiological responses to facial stimuli
Motiv Emotion
(1996) - et al.
Fear appears fast: temporal course of startle reflex potentiation in animal fearful subjects
Psychophysiology
(1999)
Information flow from sensation to emotion: plasticity in the neural computation of stimulus value
The Emotional Brain
Emotion circuits in the brain
Ann. Rev. Neurosci.
Eye movements and behavioral responses to threatening and nonthreatening stimuli during visual search in phobic and nonphobic subjects
Emotion
Conscious and unconscious emotional learning in the human amygdala
Nature
A subcortical pathway to the right amygdala mediating ‘unseen’ fear
Proc. Natl Acad. Sci. USA
Differential extrageniculostriate and amygdala responses to presentation of emotional faces in a cortically blind field
Brain
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