Modulating the Interplay Between Impulsivity and Interoception Through HD-tDCS to the Right Insula and Anterior...

Area of Science:

• Neuroscience
• Cognitive Psychology
• Psychiatry

Background:

• Interoception is linked to impulsive behaviors like maladaptive eating.
• Brain mechanisms of interoception-impulsivity interaction across reward types are unclear.

Purpose of the Study:

• Investigate how modulating the right insula and dorsal anterior cingulate cortex (dACC) with HD-tDCS affects interoceptive accuracy and impulsivity.
• Examine reward-specific effects on impulsive decision-making.

Main Methods:

• Used model-based HD-tDCS to target right insula and dACC.
• Administered heartbeat detection task (HBD) for interoceptive accuracy and delay discounting (DD) tasks for impulsivity (food/monetary rewards).
• Recorded heart rate variability (HRV); HD-tDCS delivered online during HBD, DD tasks offline in a within-subject design.

Main Results:

• Insula and dACC stimulation impaired heartbeat detection but improved exteroceptive accuracy.
• Insula stimulation increased discounting rates.
• HD-tDCS effects on DD performance differed based on reward type (food vs. monetary).

Conclusions:

• Suggests distinct roles for dACC and insula in interoceptive/exteroceptive processing.
• Supports HD-tDCS combined with interoceptive tasks for modulating impulsivity.
• Highlights reward-specific effects crucial for interventions targeting impulsive eating.