Transcranial direct current stimulation modulates primate brain dynamics across states of consciousness.
Elife October 13, 2025 Guylaine Hoffner, Pablo Castro, Lynn Uhrig et al.
Transcranial direct current stimulation (tDCS) applied to the prefrontal cortex alters the dynamic organization of functional connectivity in the primate brain, with effects depending on the state of consciousness. In awake macaques, cathodal tDCS disrupted the repertoire of connectivity patterns, increased structure-function correlation, decreased Shannon entropy, and favored transitions toward anatomically based patterns. Under deep sedation, anodal tDCS significantly altered brain pattern distribution and reduced structure-function correlation. The stimulation also modified dynamic connectivity arrangements typically associated with consciousness and unconsciousness. These findings suggest that prefrontal tDCS can modulate brain dynamics differently in conscious and unconscious states, offering insights into mechanisms relevant to disorders of consciousness.