Related Experiment Video
Updated: Aug 5, 2026
Measuring and Manipulating Functionally Specific Neural Pathways in the Human Motor System with Transcranial Magnetic Stimulation
Published on: February 23, 2020
Timing and circuit engagement shape state-dependent plasticity in the ventral premotor-motor pathway
Sonia Turrini1, Anastasia Amadori1, Sara Zago2
1Centro studi e ricerche in Neuroscienze Cognitive, Dipartimento di Psicologia "Renzo Canestrari", Alma Mater Studiorum Università di Bologna, Campus di Cesena 47521 Cesena, Italy.
Objective:
Brain state-dependency shapes the outcomes of non-invasive brain stimulation. We previously showed that cortico-cortical paired associative stimulation (ccPAS) targeting the ventral premotor-to-primary motor cortex (PMv-to-M1) circuit during a visuomotor response selectively strengthens the association between a visual cue and its movement. This study determined whether ccPAS-induced plasticity in this pathway depends on brain state at the time of stimulation.
Methods:
Eighty participants performed a visuomotor mapping task, associating two visual cues with two finger movements, while receiving PMv-to-M1 ccPAS during movement execution (Movement group), movement preparation (Preparation group), passive viewing (Vision group), or with stimulation confined to PMv (PMv group). CSE was assessed at baseline, T-0, and T-40.
Results:
ccPAS during movement execution induced a selective, sustained CSE increase in the target muscle for the cue active at stimulation (Δ = .415 mV; p = 0.008; r = 0.74), with target-versus-control specificity (Δ = .100 mV; p = 0.003; r = 0.72). No changes emerged in the Preparation or PMv groups. The Vision group showed a transient, non-specific CSE increase (all Δ > .573 mV; all p < 0.008; all r > 0.75), absent by T-40 (all p > 0.16), indicating that passive viewing alone cannot explain the Movement group's selective, lasting effects.
Conclusions:
Effective circuit engagement during movement execution favors selective and persistent ccPAS-induced plasticity.
Significance:
Stimulation timing relative to ongoing brain states, not just the targeted circuit, determines whether paired stimulation produces functionally specific, lasting plasticity, refining the state-dependent framework and informing tailored interventions.
