NEURAL HACKING FOR HEALTHY EATING: INVESTIGATING THE POTENTIAL OF TRANSAURICULAR VAGUS NERVE STIMULATION IN THE FOOD-PICTURES STROOP TASK

Non-invasive brain stimulation (NIBS) may represent innovative approach to address dysregulated eating behaviors, by modulating maladaptive response toward food. Among NIBS, the transauricular vagus nerve stimulation (taVNS) specifically targets the vagus nerve that plays a crucial role in energy homeostasis, influencing food intake and body weight. Additionally, vagal afferent signals modulate cognitive dimensions of eating behaviors, such as reward processing, inhibitory control, attention. This preliminary study aimed to evaluate the effect of taVNS on attentional response toward food, exploring its potential application in dysregulated eating. The study included four females in condition of overweight and four females in condition of Normal Weight. The experimental procedure consisted of two counterbalanced sessions: active and sham taVNS stimulation. Heart rate variability (HRV) was assessed as index of vagal-mediated autonomic activation. Attentional responses to food stimuli (hypercaloric; hypocaloric) were evaluated via Food-Pictures Stroop Task. The results indicated an increase of autonomic activation in active (t=-3.14; p=0.01) and in sham (t=- 4.56; p=0.003) compared to resting condition, suggesting an effect of the task-related cognitive load on autonomic system. Furthermore, the Hypercaloric Stroop Effect (difference in reaction times between neutral and hypercaloric trials) as an index of attentional conflict, was greater in the Overweight compared to the Normal weight group only in the sham condition (t=2.81; p=0.03). No significant between-group differences were found during the active tavns. These findings suggest that taVNS may reduce the attentional bias towards hypercaloric stimuli in overweight, indicating its promising role as mitigator of the attractiveness of food in dysregulated eating.