Cerebral Differences in Explicit and Implicit Emotional Processing – An fMRI Study

Abstract

The processing of emotional facial expression is a major part of social communication and understanding. In addition to explicit processing, facial expressions are also processed rapidly and automatically in the absence of explicit awareness. We investigated 12 healthy subjects by presenting them with an implicit and explicit emotional paradigm. The subjects reacted significantly faster in implicit than in explicit trials but did not differ in their error ratio. For the implicit condition increased signals were observed in particular in the thalami, the hippocampi, the frontal inferior gyri and the right middle temporal region. The analysis of the explicit condition showed increased blood-oxygen-level-dependent signals especially in the caudate nucleus, the cingulum and the right prefrontal cortex. The direct comparison of these 2 different processes revealed increased activity for explicit trials in the inferior, superior and middle frontal gyri, the middle cingulum and left parietal regions. Additional signal increases were detected in occipital regions, the cerebellum, and the right angular and lingual gyrus. Our data partially confirm the hypothesis of different neural substrates for the processing of implicit and explicit emotional stimuli.

Hidden sources of joy, fear, and sadness: Explicit versus implicit neural processing of musical emotions

“…Interestingly, activity in the inferior parietal lobule is consistent with explicit processing of emotional vocal and visual stimuli (Wildgruber et al, 2005;Scheuerecker et al, 2007) and with the implicit processing of prosody (Bach et al, 2008;Wildgruber et al, 2005). The right inferior parietal lobule has also been associated with musical emotion processing, particularly with respect to exciting pleasant versus relaxing pleasant music (Flores-Gutierrez et al, 2007) and with music performer expressivity (Chapin et al, 2010).…”

“…The experiment is comprised of two tasks, implicit and explicit, each presented in a unique block as in previous studies using voices (e.g., Bach et al, 2008;Frühholz et al, 2012) or faces (e.g., Critchley et al, 2000;Scheuerecker et al, 2007). In the implicit processing task, we sought to mirror the non-affective (typically gender) task in studies of visual and vocal emotions.…”

“…On the other hand, explicit face processing activates cortical areas along the temporal, occipital, and frontal lobes. These regions include the inferior/middle temporal gyri (Critchley et al, 2000;Scheuerecker et al, 2007), related to processing facial expressions and movements (Puce et al, 1998), and limbic areas such as the dorsal anterior cingulate cortex (Scheuerecker et al, 2007;Williams et al, 2006), involved in the regulation of emotion responses (Etkin et al, 2011), and the medial prefrontal cortex (Fusar-Poli et al, 2009;Scheuerecker et al, 2007;Williams et al, 2006]), related to selfreflective thought and appraisal (Smithz & Johnson, 2007). In addition, a number of visual association areas, such as the fusiform gyrus, the inferior and middle occipital gyri, and the lingual gyri (Fusar-Poli et al, 2009;Scheuerecker et al, 2007), show increased activation in explicit compared with implicit emotion processing.…”

“…These regions include the inferior/middle temporal gyri (Critchley et al, 2000;Scheuerecker et al, 2007), related to processing facial expressions and movements (Puce et al, 1998), and limbic areas such as the dorsal anterior cingulate cortex (Scheuerecker et al, 2007;Williams et al, 2006), involved in the regulation of emotion responses (Etkin et al, 2011), and the medial prefrontal cortex (Fusar-Poli et al, 2009;Scheuerecker et al, 2007;Williams et al, 2006]), related to selfreflective thought and appraisal (Smithz & Johnson, 2007). In addition, a number of visual association areas, such as the fusiform gyrus, the inferior and middle occipital gyri, and the lingual gyri (Fusar-Poli et al, 2009;Scheuerecker et al, 2007), show increased activation in explicit compared with implicit emotion processing. Subcortically, the explicit processing of facial expressions or other emotional pictures activates the hippocampus (Critchley et al, 2000;Fusar-Poli et al, 2009) and in one study also the bilateral amygdala (Fusar-Poli et al, 2009;Scheuerecker et al, 2007; but for the opposite finding, showing a larger involvement of the amygdala during implicit processing, see Critchley et al, 2000).…”

“…In addition, a number of visual association areas, such as the fusiform gyrus, the inferior and middle occipital gyri, and the lingual gyri (Fusar-Poli et al, 2009;Scheuerecker et al, 2007), show increased activation in explicit compared with implicit emotion processing. Subcortically, the explicit processing of facial expressions or other emotional pictures activates the hippocampus (Critchley et al, 2000;Fusar-Poli et al, 2009) and in one study also the bilateral amygdala (Fusar-Poli et al, 2009;Scheuerecker et al, 2007; but for the opposite finding, showing a larger involvement of the amygdala during implicit processing, see Critchley et al, 2000).…”