Eye model simulations of saccadic impairment through transcranial magnetic stimulation (TMS

Abstract

Simulations of predictive experimental saccades that were impaired through transcranial magnetic stimulation (TMS) of the frontal or parietal cortex demonstrated that dynamics of small saccades were highly influenced resulting in a significant decrease of acceleration and amplitude, up to an almost complete inhibition. The impact of inhibition through TMS was critically dependent on timing: early TMS (-70 msec) led to large inhibition, late TMS (-20 msec) led to small inhibition of experimental saccades. Differential timing of TMS in influencing the cortical control signal was paralleled by empirically determined changes in eye movement dynamics after real TMS. Hence there was a reasonable match between the model and the experimental data. The authors conclude that the inhibitory action of a presaccadic inhibitory disturbance like a TMS pulse on saccadic programming is inversely related to timing and amplitude of the predicted saccade.

Key Words:

• transcranial magnetic stimulation
• eye movements
• eye model simulations
• inhibition of saccades