Modulating Behavior in Humans by Entrainment With Rhythmic Transcranial Magnetic Stimulation

Background:

• The brain has natural rhythms called brain waves. An electroencephalogram (EEG) can record these rhythms. When people identify the picture of a familiar object shown on a computer screen, the communication between certain regions of the brain increases. An EEG can detect these communication brain waves. Transcranial magnetic stimulation (TMS) can affect these brain waves by slightly changing the brain s rhythms. Researchers want to see if changing brain rhythms with TMS interferes with the ability to identify pictures of familiar objects. This study will provide more information about how TMS can affect brain waves and behavior.

Objectives:

• To see if TMS can interfere with the brain s ability to identify pictures of familiar objects.

Eligibility:

• Healthy volunteers between 18 and 70 years of age.

Design:

• This study requires two visits to the clinical center. The first visit will last about 2 hours. The second visit will last about 4 hours.
• Participants will be screened with a physical exam and medical history.
• At the first visit, participants will have an object recognition test. Participants will look at pictures of several objects on a computer screen. They will then have to state whether the objects they see on the screen are familiar. The object recognition test will be done along with TMS.
• At the second visit, participants will have an EEG while taking the object recognition test. Brain waves will be monitored during the test. They will then repeat the test while having repetitive TMS to study its effect on object recognition. The participants will then take the object recognition test alone for a final time. This will make sure that TMS effects (if any) on the ability to identify familiar object images are no longer present.