Study of the causal role of Locus-Coeruleus in perceptual decision-making across varying levels of difficulty

Details

Supervisors

Duque, Julie

Faculty

Faculté des sciences de la motricité

Degree label

Master [60] en kinésithérapie et réadaptation

Abstract

enThe Locus Coeruleus is a small brainstem nucleus that is the primary source of norepinephrine in the brain, forming the Locus Coeruleus-Norepinephrine (LC-NE) system. Transcutaneous vagus nerve stimulation (tVNS) is a specific method previously described to increase LC-NE activity, which leads to a pupil dilation, used therefore as a marker of LC-NE activity. In a previous study, it was found that tVNS can enhance accuracy without any changes in the reaction time, during a perceptual decision-making task. More interestingly, data pointed to a selective contribution of the tVNS for participants who are prone to show declined accuracy in trials following errors. However, our understanding of the LC-NE role depending on trial specificity remains unclear and needs further research. Therefore, in the current study, using tVNS during a perceptual decision-making task, a total of 13 subjects underwent trials in blocks with 3 different difficulty levels, in order to elucidate the specific causal role of LC on performance through increasing difficulty. Preliminary results suggest greater decision accuracy under tVNS compared to SHAM stimulation especially in difficult blocks leading to a low accuracy rate. However, tVNS had no significant impact on reaction time. These findings suggest that LC-NE activation might be a protective system against low performance, by energizing behavior when it occurs alongside a difficulty to decide accurately during a perceptual decision-making task.