Differential modulation of sensorimotor network between temporal interference and high-definition direct current stimulation

Objective.Temporal interference stimulation's (TISs) efficacy in modulating brain networks remains unexplored. We aimed to evaluate the differential impact of TIS and high-definition transcranial direct current stimulation (HD-tDCS) on resting-state functional connectivity (FC) and the topological properties of brain networks, particularly the sensorimotor network (SMN).Approach.In a randomized, double-blind, crossover study, 40 healthy adults underwent both TIS and HD-tDCS targeting the left primary motor cortex (M1). Resting-state functional magnetic resonance imaging data were collected before, during, and after stimulation. Brain networks were constructed using the Dosenbach atlas and the Yeo seven-network parcellation, with a focus on 29 regions of interests within the SMN. Network analysis included FC calculations using Pearson correlations and graph-theoretical measures of global and local efficiency. A two-way repeated measures analysis of variance was used to assess the effects of stimulation on network connectivity properties.Main results.(1) Both stimulation methods enhanced SMN connectivity, with TIS demonstrating greater efficacy than HD-tDCS (FC increase: 31.25% vs 22.58%). (2) TIS significantly improved SMN global and local efficiencies by 15.44% and 18.85%, respectively, while HD-tDCS increased these measures by 11.97% and 12.5%, respectively (allp< 0.05). (3) While both methods enhanced within-network connections of the SMN, TIS additionally strengthened the connections within the visual network, dorsal attention network (DAN), and frontoparietal network, as well as multiple between-network connections. In contrast, HD-tDCS only improved connections between SMN-DAN and SMN-default mode network.Significance.Both TIS and HD-tDCS enhanced SMN FC, with TIS demonstrating superior efficacy. Under specific parameter configurations, TIS exhibited broader effects, improving both network efficiency and extensive within- and between-network connections, whereas HD-tDCS had a limited impact on the selection of network connections. These findings establish TIS as a potentially more effective neuromodulation technique for enhancing brain network properties compared to HD-tDCS.