Skip to main content
Clinical Trials/NCT05853939
NCT05853939CompletedNot Applicable

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

University of California, San Francisco2 sites in 1 country106 target enrollmentStarted: July 1, 2023Last updated:
Conditions
Interventions

Trial Snapshot

Phase
Not Applicable
Status
Completed
Enrollment
106
Locations
2
Primary Endpoint
post-rTMS change in ssVEP Response Amplitude

Study Overview

Brief Summary

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.

Study Design

Study Type
Interventional
Allocation
Randomized
Intervention Model
Crossover
Primary Purpose
Basic Science
Masking
Single (Participant)

Masking Description

Participant is blind to the rTMS target hemisphere, the rTMS stimulation parameters, and the objective of the study

Eligibility Criteria

Ages
18 Years to 65 Years (Adult, Older Adult)
Sex
All
Accepts Healthy Volunteers
Yes

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

Arms & Interventions

Visual Cortex, 1 Hz rTMS, Attended

Experimental

Intervention: repetitive transcranial magnetic stimulation (Device)

Visual Cortex, 1 Hz rTMS, Unattended

Experimental

Intervention: repetitive transcranial magnetic stimulation (Device)

Visual Cortex, 10 Hz rTMS, Attended

Experimental

Intervention: repetitive transcranial magnetic stimulation (Device)

Visual Cortex, 10 Hz rTMS, Unattended

Experimental

Intervention: repetitive transcranial magnetic stimulation (Device)

Visual Cortex, Sham, Attended

Sham Comparator

Intervention: repetitive transcranial magnetic stimulation (Device)

Visual Cortex, Sham, Unattended

Sham Comparator

Intervention: repetitive transcranial magnetic stimulation (Device)

Outcomes

Primary Outcomes

post-rTMS change in ssVEP Response Amplitude

Time Frame: 60 minutes

Change in ssVEP contrast-response amplitude after rTMS

post-rTMS change in visual contrast perceptual sensitivity

Time Frame: 60 minutes

change in visual psychometric threshold across contrasts after rTMS

Secondary Outcomes

No secondary outcomes reported

Investigators

Sponsor Class
Other
Responsible Party
Sponsor
Principal Investigator

Ryan T. Ash MD, PhD

Instructor

Stanford University

Study Sites (2)

Loading locations...

Similar Trials