Measuring rTMS-induced Neuroplasticity With EEG Steady-state Visual-evoked Potentials

Inducing and Measuring Visual-evoked Potential Plasticity in Humans With Repetitive Transcranial Magnetic Stimulation

The goals of this study are to 1) use EEG steady-state visual evoked potentials as a noninvasive measure of the neuroplasticity induced by repetitive transcranial magnetic stimulation (rTMS), 2) use visual contrast detection paradigms as a behavioral measure of rTMS effects, and 3) to investigate how visual spatial attention augments or suppresses the neuroplastic impact of rTMS. Participants will observe visual stimuli on a screen while allocating their attention to different parts of the visual field and making responses when they observe changes in the visual stimuli. rTMS is performed to visual cortex using MRI-retinotopy neuronavigation. Then the visual task paradigm is performed again.

Inclusion Criteria:

• Men and women, ages 18 to 65
• Must comprehend English well to ensure adequate comprehension of the EEG and TMS instructions, and of clinical scales
• Left- or Right-handed
• No current or history of neurological disorders
• No seizure disorder or risk of seizures

Exclusion Criteria:

• Those with a contraindication for MRIs (e.g. implanted metal)

  • Any unstable medical condition
  • History of head trauma with loss of consciousness
  • History of seizures
  • Neurological or uncontrolled medical disease
  • Active substance abuse
  • Diagnosis of psychotic or bipolar disorder
  • Currently taking medications that substantially reduce seizure threshold (e.g., bupropion, olanzapine, chlorpromazine, lithium)
  • Currently pregnant or breastfeeding