A functional MRI study of human amygdala responses to facial expressions of fear versus anger.

Abstract

Functional magnetic resonance imaging (fMRI) of the human brain was used to compare changes in amygdala activity associated with viewing facial expressions of fear and anger. Pictures of human faces bearing expressions of fear or anger, as well as faces with neutral expressions, were presented to 8 healthy participants. The blood oxygen-level dependent (BOLD) fMRI signal within the dorsal amygdala was significantly greater to Fear versus Anger, in a direct contrast. Significant BOLD signal changes in the ventral amygdala were observed in contrasts of Fear versus Neutral expressions and, in a more spatially circumscribed region, to Anger versus Neutral expressions. Thus, activity in the amygdala is greater to fearful facial expressions when contrasted with either neutral or angry faces. Furthermore, directly contrasting fear with angry faces highlighted involvement of the dorsal amygdaloid region.

Individual differences in structural and functional connectivity predict speed of emotion discrimination

“…Fearful faces additionally engaged the amygdala and fusiform gyrus, which is in line with previous findings and suggests increased processing of fearful compared to angry facial expressions within regions of the core and extended emotional faces processing systems (Whalen et al, 2001). Perception of fearful faces further engaged the left globus pallidum, which might be related to the initiation of a fight-or-flight response (Korzeniewska, Kasicki & Zagrodzka, 1997;Grèzes & Dezecache, 2014).…”

“…As an indicator of behaviour, we measured reaction times of emotion discrimination. Based on previous studies, which show that angry and fearful faces are identified equally fast and that processing of both emotions engages the core and extended face-processing networks (De Sonneville et al, 2002;Whalen et al, 2001), we hypothesized that, as a group, participants would (i) be equally fast to match angry and fearful faces and (ii) engage the core and extended face processing networks for both facial expressions. Based on the assumption that the discrimination of different emotional expressions requires the interaction between the amygdala and fusiform gyrus (Herrington et al, 2011;Wang et al, 2016), we further hypothesized that (iii) M A N U S C R I P T…”

“…Those faster individuals engaged more regions outside of the face processing network related to attention and visual processing, suggesting that the processing speed of facial expressions signalling indirect threat profits from the recruitment of additional visual-attentional systems, which are engaged in searching for novel cues that help reduce the ambiguity associated with indirect threat expressions (Whalen et al, 2001;Phelps, Ling, & Carrasco, 2005). In contrast to direct threat, the rapid recognition of indirect threat, therefore, seems to depend less on the cortical face-processing network and instead might rely more on a subcortical pathway (Villeumier et al, 2003).…”

Amygdala–Prefrontal Disconnection in Borderline Personality Disorder

“…Whalen et al (2001) suggest that the human dorsal vs ventral designation within the amygdala provides a means for incorporating numerous results from the animal literature offering compelling evidence that the BLC (located ventrally in the human) can be dissociated behaviorally from the central nucleus (located dorsally in the human) and is the component of the amygdala predominantly involved in emotion modulation. Further, they note that whereas expressions of fear appear to activate the BLC and CN (ie ventral and dorsal amygdala), anger may involve the CN to a lesser degree (than the BLC) because less additional information concerning the stimulus is required (Whalen et al, 2001). Furthermore, fMRI studies by this group have shown that specifically the ventral amygdala is in response to emotional stimuli (Kim et al, 2003.…”

The Effect of Citalopram Pretreatment on Neuronal Responses to Neuropsychological Tasks in Normal Volunteers: An fMRI Study

“…The amygdala has been one of the most consistently activated areas in studies relating to fearful faces (eg Morris et al, 1996;Hariri et al, 2000;Phillips et al, 2001), a response that is lateralized in some studies (eg Morris et al, 1996), possibly relating to different rates of habituation with one study finding faster habituation in the right than left amygdala to repeated exposure (Morris et al, 2001). There are less consistent findings with other emotions such as anger (eg Blair et al, 1999;Hariri et al, 2002) and disgust (Phillips et al, 1997;Winston et al, 2003), perhaps reflecting a stronger reaction to fear than other emotions rather than a truly selective response (Whalen et al, 2001). Previous imaging studies using emotional face stimuli have also shown activation of medial and orbital prefrontal cortices, including anterior cingulate, insula and regions of the occipital cortex, particularly the fusiform gyrus (Sprengelmeyer et al, 1998;Blair et al, 1999;Surguladze et al, 2003;Abel et al, 2003;Keightley et al, 2003).…”