Henderson, L., Stathis, A., James, C., et al (2012). Real-time imaging of cortical areas involved in the generation of increases in skin sympathetic nerve activity when viewing emotionally charged images. NeuroImage. doi:10.1016/j.neuroimage.2012.04.049 Details
Customer study highlights
Do particular extremes of emotions generate signature autonomic changes? Some recent studies have suggested this may be the case.
To explore this further, Henderson et al (2012) measured skin sympathetic nerve activity (SSNA) while simultaneously measuring brain activity using functional magnetic resonance imaging (fMRI). The aim was to define brain regions responsible for emotionally-induced increases in SSNA.
To provoke emotional reactions, images of erotica (positively-charged) and mutilation (negatively-charged) were presented to thirteen adult subjects. Neutral images served as control stimuli.
During image viewing, microneurography was used to monitor SSNA in the common peroneal nerve using a NeuroAmp amplifier, PowerLab and LabChart. Additional, indirect measures of autonomic tone included: pulse rate and amplitude (recorded using LabChart Cyclic Measurements), electrodermal skin responses (measured across the sole of the foot using a BioAmp), and respiratory rate (tracked using a piezo-electric respiratory belt).
Similar increases in SSNA burst frequency and amplitude were found during exposure to positively- and negatively-charged emotional images. These similarities in SSNA responses argue against a ‘signature autonomic signal’ evoked by different emotions, and dispute the theory that the ANS is most reactive to stimuli that represent a threat to survival.
Imaging with fMRI showed activation of areas involved in emotional arousal, such as the amygdala and nucleus accumbens, which correlated well with emotionally-induced SSNA bursts. In summary, this study finds that autonomic responses tend to be non-specific rather than characteristic for particular emotions.