Where does fear originate in the brain? A coordinate-based meta-analysis of explicit and implicit fear processing

Common and distinct neurofunctional representations of core and social disgust in the brain: Coordinate-based and network meta-analyses

“…Examining regions specifically engaged during the two disgust processing domains revealed stronger activity of several regions of the left hemispheric disgust network during core disgust processing including e.g., occipital visual, limbic, inferior frontal and parietal regions. These regions mainly mirror the results of the core disgust processing network, suggesting that exposure to potentially dangerous stimuli engages core nodes of the defensive-avoidance circuits, including the amygdala engaged in threat detection (Whalen, 2007), interoceptive and emotional awareness (Critchley et al, 2004) as well as regions engaged in attentional and contextual processes such as inferior parietal and parahippocampal regions (Behrmann, Geng, & Shomstein, 2004; Caspers et al, 2012; Tao et al, 2021). In contrast, for the social disgust processing a right lateralized network encompassing inferior frontal gyrus, superior temporal gyrus as well as anterior cingulate regions was stronger activity.…”

“…The identified left fusiform gyrus network comprised a limbic-occipital network encompassing the amygdala, parahippocampal gyrus, putamen and inferior occipital regions. The functional interplay between these regions has been demonstrated in several previous studies (Amting, Greening, & Mitchell, 2010;Fairhall & Ishai, 2007;Herrington, Taylor, Grupe, Curby, & Schultz, 2011;Molapour, Golkar, Navarrete, Haaker, & Olsson, 2015;Turk-Browne, Norman-Haignere, & McCarthy, 2010) and plays an important role in early threat detection (Tao et al, 2021), suggesting that this network may facilitate detection of potential threats across core and social disgust processes.…”

“…The identified network for general disgust processing largely resembles regions that have been consistently engaged in disgust-related processes (Fusar-Poli et al, 2009; Kirby & Robinson, 2017; Vytal & Hamann, 2010; Wager et al, 2015) and may reflect the multifaceted nature of the disgust response. The identified regions may support the engagement of different simultaneous processes which allow a concerted disgust reaction, ranging from initial detection of biologically salient stimuli in occipital visual regions (Tao et al, 2021), early threat detection and implementation of the defensive motor response by the amygdala, globus pallidus, fusiform and cerebellar regions (e.g., Phelps & LeDoux, 2005; Surguladze et al, 2003; Yao, Zhao, et al, 2018), as well as salience allocation and interoceptive awareness of the emotional state in the insula cortex (Craig, 2009; Li et al, 2019; Uddin, 2015), and the subjective experience and interpretation of the emotional state in prefrontal regions (LeDoux & Pine, 2016).…”

“…For single study analyses (within-group analyses, i.e., general disgust processing, core disgust processing, and social disgust, respectively), the ALE statistics were calculated at each voxel, and cluster-level family-wise error correction (cluster-FWE) (Eickhoff et al, 2016) was applied to the ALE results to control for multiple comparisons. The voxel-level threshold was set at p < 0.001 (uncorrected cluster forming), and the cluster-level threshold was set at p < 0.05 (Eickhoff, Laird, Fox, Lancaster, & Fox, 2017; Eickhoff et al, 2016; Müller et al, 2018), p values in our analyses were generated by 5,000 permutations (Laird et al, 2010; Tao et al, 2021).…”

“…In line with the observations from the separate analyses, the right anterior insula extending into the adjacent inferior frontal gyrus and the left fusiform gyrus specifically exhibited convergent engagement during core and social disgust processing. Together with the anterior insula the inferior frontal cortex plays an important role in general emotional processes such as evaluation of biological significant stimuli (Rolls, 2000a(Rolls, , 2004, interoception (Critchley, Wiens, Rotshtein, Öhman, & Dolan, 2004), multimodal representation emotion salient stimuli (Yamasaki, LaBar, & McCarthy, 2002), and emotion recognition (Sprengelmeyer et al, 1998) while the fusiform gyrus plays a role in higher order visual processing (Fusar-Poli et al, 2009) and emotional reactivity towards negative and threatening stimuli (Kirby & Robinson, 2017;Tao et al, 2021). Further meta-analytic network decoding via MACM demonstrated that the identified anterior insula cortex region coupled with a bilateral network encompassing the insula and ventrolateral prefrontal regions as well as anterior cingulate and medial frontal regions.…”