# Ventral striatum temporal interference brain stimulation enhances the reward positivity event-related potential and reduces anxiety

## TL;DR

This study shows that a new brain stimulation method, when combined with meditation, can improve reward processing and reduce anxiety by targeting the ventral striatum.

## Contribution

The study demonstrates the feasibility of temporal interference stimulation to target the ventral striatum and enhance emotion regulation.

## Key findings

- Active TI stimulation increased the reward positivity (RewP) event-related potential during meditation.
- Participants who received active TI showed sustained RewP increases in a follow-up session.
- Active TI was associated with reduced negative emotionality compared to sham stimulation.

## Abstract

Temporal interference (TI) electrical stimulation is a novel neuromodulation method that can target deep brain structures to enhance the impact of behavioral techniques. We tested the feasibility of TI in targeting the ventral striatum (VS) in concert with an emotion regulation practice (breath-focused mindfulness meditation). As an assay of target engagement, we used electroencephalography (EEG) to measure amplitude of the reward positivity potential (RewP), an event-related potential ERP associated with VS function.

Nineteen healthy adults (age range: 18–36 years) received an MRI scan and two stimulation sessions during meditation: one active 8 Hz TI stimulation and one 0 Hz sham TI. Before and after meditation, they completed a reward task during EEG recording.

A significant time by stimulation type effect was observed with the RewP win-loss difference (p<.001; ηp2 = .61), but not an unrelated ERP, the Cue-N200 (p=.93). Active TI, but not sham, led to a RewP increase to win trials from pre- to post-stimulation, with evidence of a sustained RewP win amplitude increase at visit 2 in participants who received active TI at visit 1 (p < .001). Decreased negative emotionality was observed for active TI; emotion changes corresponded with increased RewP amplitude to win trials for only active TI.

Findings show support for TI targeting of VS in conjunction with meditation to elicit self-reported and neural change in emotion-regulation and reward processing. Although replication is warranted, our data indicate the precision and short-term continued effects of TI on the VS and reward-related functioning.