Enhancing anger perception in older adults by stimulating inferior frontal cortex with high frequency transcranial random noise stimulation

Abstract

Extensive behavioural evidence has shown that older people have declined ability in facial emotion perception. Recent work has begun to examine the neural mechanism that contribute to this, and potential tools to support emotion perception during aging. The aim of this study was to investigate whether high frequency tRNS applied to the inferior frontal cortex would enhance facial expression perception in older adults. Healthy aged adults (60+ years) were randomly assigned to receive active high-frequency or sham tRNS targeted at bilateral inferior frontal cortices. Each group completed tests of facial identity perception, facial happiness perception and facial anger perception. These tasks were completed before and after stimulation. The results showed that, compared to the sham group, the active tRNS group showed greater gains in performance after stimulation in anger perception (relative to performance before stimulation). The same tRNS stimulation did not significantly change performance on the two other face perception tasks assessing facial identity and facial happiness perception. Examination of how inter-individual variability related to changes in anger perception following tRNS indicated that the degree of performance change in anger perception following active tRNS to inferior frontal cortex was predicted by baseline ability and gender of older adult participants. The findings suggest that high frequency tRNS may be a potential tool to aid anger perception in typical aging, but flag that performance variability and gender may interact with stimulation leading to different outcomes.

Emotion perception improvement following high frequency transcranial random noise stimulation of the inferior frontal cortex

“…Error scores were summed to determine the total number of errors and this was converted into percentage of correct responses. This approach is consistent with prior work using CFPT measures 9 , 10 , 15 , 21 . Chance performance is 36% 21 .…”

“…Recent work has demonstrated the utility of tES to aid social perception [e.g. refs 9 – 15 ]. One example is facial emotion perception.…”

“…empathy). Prior work has suggested that some forms of non-invasive brain stimulation can be useful to aid emotion perception skills 10 – 15 , but whether tRNS can or cannot aid emotion perception abilities has rarely been addressed in the literature.…”

“…ref. 18 ], while high frequency tRNS to IFC has been shown to enhance anger perception abilities in older adult participants 15 . These findings highlight the importance of the IFC in emotion processing, but key questions remain.…”

Anodal transcranial direct-current stimulation over the left dorsolateral prefrontal cortex and perception of emotional faces

“…Stimulation of the l-DLPFC by means of anodal tDCS has been shown to facilitate attentional disengagement away from emotional faces (happy, disgusted and sad expressions), whereas active stimulation of the r-DLPFC slowed gaze disengagement to the same emotional stimuli (11). Yang et al (12) have recently reported that anodal tDCS over the r-DLPFC improved correct detection of schematic emotional faces, but only during the tDCS session, with no effect when tests were done immediately after 15 min of tDCS at 1.5 mA. Moreover, the improvement was only seen for faces expressing positive emotions.…”