Effects of Transcranial Magnetic Stimulation (TMS) on Somatosensory Perception
Condition: Healthy Volunteer
Study type: Observational

Summary: 
      Background:

      - Different parts of the brain are involved in feeling touch. Researchers want to study
      whether repetitive magnetic stimulation (rTMS) to the sensory cortex affects how sensation
      feels. rTMS is a repeated magnetic pulse that interferes with brain activity. It affects a
      small part of the brain beneath the scalp. Researchers want to find out the role of sensory
      cortex in sensing different types of touch.

      Objectives:

      - To find out the role of sensory cortex, a brain area, in sensing different types of touch.

      Eligibility:

      - Healthy adults ages 18 45.

      Design:

        -  Participants will be pre-screened with a telephone interview. Then they will be screened
           with physical and psychological exams and a urine test.

        -  In Session 1, participants will have an MRI brain scan and fill out questionnaires.

        -  For MRI, a magnetic field and radio waves take pictures of the brain. Participants will
           lie on a table that slides in and out of a metal cylinder. A coil will be placed over
           their head. They will perform a task during the scan. The scanner makes loud knocking
           noises. Participants will get earplugs. They will be in the scanner for up to 60
           minutes.

        -  In Sessions 2 and 3, participants will take urine tests. Their perception of touch will
           be measured. Then rTMS will be used to stimulate their sensory cortex and scalp for
           about 20 minutes. Their perception of touch will be measured again.

        -  For rTMS, a wire coil is held on the scalp. A brief electrical current passes through
           the coil and creates a magnetic pulse that affects activity in the brain.
    

Detailed description: 
      This study will test how parts of sensory cortex relate to different aspects of touch
      sensation. Healthy male and female adults (ages 18-45) will be enrolled. We will use low
      frequency repetitive transcutaneous magnetic stimulation (rTMS) to temporarily reduce
      activation in parts of the sensory cortex and will examine the effect of this procedure on
      perception of touch stimuli. After screening, participants will undergo three testing
      sessions. Session 1 will involve questionnaires and anatomical and functional MRI scans
      (non-invasive brain imaging) that will be used for localizing the correct regions to
      stimulate with the rTMS. Sessions 2 and 3 will involve active and control rTMS and testing of
      gentle (non-painful) touch sensation.
    

Intervention name(s): Transcranial magnetic stimulation (TMS); MRI
Intervention type(s): Device; Device
Intervention description(s): 1 Hz rTMS for 20 minutes. TMS sessions were separated by at least 24 hours.; Anatomical MRI, resting state MRI and functional MRI using gentle brushing and finger movement
Time perspective: Prospective
Keywords: Emotion; Tactile Discrimination; Transcranial Magnetic Stimulation (TMS); Somatosensory; Somatosensory Cortex