Inhibitory control is a fundamental component of executive functioning, enabling the suppression of one's own cognitive and behavioral responses. Although inhibitory control exerts substantial effects on everyday life and clinical settings, its neural underpinnings and relationship with other higher-order cognitive functions remain poorly understood. The right inferior frontal gyrus (rIFG) has been proposed as a potential target for neuromodulation, given its putative role in the inhibition of premature or maladaptive motor responses. In this study, we applied transcranial direct current stimulation (tDCS) over the rIFG in thirty one healthy participants, each undergoing two experimental sessions—one with active stimulation and one with sham stimulation. Prior to stimulation, participants completed the Metacognitions Questionnaire-30 and a Monetary Intertemporal Choice Task (MICT) to assess delay discounting. During stimulation, subjects performed the Go/NoGo and the Stop-Signal tasks to evaluate inhibitory control. Following stimulation, they repeated the MICT. Our results show that anodal tDCS over the rIFG enhances inhibitory control compared to sham stimulation. Significant interaction effects on inhibitory control were also observed between tDCS protocol and baseline measures of metacognitive beliefs and delay discounting. Although rIFG stimulation did not steeply reduce delay discounting, significant time-by-protocol and metacognition-by-protocol interactions were detected. These findings not only suggest that tDCS effects on inhibitory control are affected by subjects' cognitive profiles but also pave the way for future research on the efficacy of tDCS in enhancing inhibitory control and reducing delay discounting in psychological conditions where these higher-order cognitive functions are impaired, such as mood disorders and substance addiction.
Anodal transcranial direct current stimulation over the right inferior frontal gyrus enhances inhibitory control, with modulation by individual differences in metacognition and delay discounting
de Bartolo, Paola;
2025-01-01
Abstract
Inhibitory control is a fundamental component of executive functioning, enabling the suppression of one's own cognitive and behavioral responses. Although inhibitory control exerts substantial effects on everyday life and clinical settings, its neural underpinnings and relationship with other higher-order cognitive functions remain poorly understood. The right inferior frontal gyrus (rIFG) has been proposed as a potential target for neuromodulation, given its putative role in the inhibition of premature or maladaptive motor responses. In this study, we applied transcranial direct current stimulation (tDCS) over the rIFG in thirty one healthy participants, each undergoing two experimental sessions—one with active stimulation and one with sham stimulation. Prior to stimulation, participants completed the Metacognitions Questionnaire-30 and a Monetary Intertemporal Choice Task (MICT) to assess delay discounting. During stimulation, subjects performed the Go/NoGo and the Stop-Signal tasks to evaluate inhibitory control. Following stimulation, they repeated the MICT. Our results show that anodal tDCS over the rIFG enhances inhibitory control compared to sham stimulation. Significant interaction effects on inhibitory control were also observed between tDCS protocol and baseline measures of metacognitive beliefs and delay discounting. Although rIFG stimulation did not steeply reduce delay discounting, significant time-by-protocol and metacognition-by-protocol interactions were detected. These findings not only suggest that tDCS effects on inhibitory control are affected by subjects' cognitive profiles but also pave the way for future research on the efficacy of tDCS in enhancing inhibitory control and reducing delay discounting in psychological conditions where these higher-order cognitive functions are impaired, such as mood disorders and substance addiction.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
