Exploring how the brain processes visual information

TMS Investigations of the Human Visual System

This study is testing how different parts of the brain help us recognize objects and understand where things are in space by having healthy adults do visual tasks while their brain activity is monitored.

Quick facts

• Study type: Observational
• Enrollment: 665 (estimated)
• Ages: 18 Years to 50 Years
• Sex: All
• Sponsor: National Institutes of Health Clinical Center (CC) (nih)
• Locations: 1 site (Bethesda, Maryland)
• Trial ID: NCT01617408 on ClinicalTrials.gov

What this trial studies

This study investigates the brain's two visual processing pathways: the ventral pathway for object recognition and the dorsal pathway for spatial awareness. Using techniques like functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS), researchers aim to understand how these pathways contribute to cognitive tasks such as object recognition and attention. Healthy volunteers aged 18 to 50 will participate in experiments that involve both brain stimulation and visual tasks to observe changes in brain activity. The goal is to gain insights into the neural mechanisms underlying visual processing.

Who should consider this trial

Good fit: Ideal candidates for this study are healthy individuals aged 18 to 50 who are fluent in English.

Not a fit: Patients with neurological conditions, visual impairments, or those who cannot safely undergo MRI or TMS procedures will not benefit from this study.

Why it matters

Potential benefit: If successful, this research could enhance our understanding of visual processing, potentially leading to improved treatments for visual and cognitive disorders.

How similar studies have performed: Other studies using TMS and fMRI have shown promise in understanding brain function, suggesting that this approach may yield valuable insights.

Eligibility criteria

* INCLUSION CRITERIA:

Healthy

Ages 18-50 years (inclusive)

Able to read and write in English to guarantee understanding of all written and spoken instructions, which are in English

EXCLUSION CRITERIA:

Individuals with conditions that could pose a risk relating to the safety of the MRI procedure, the TMS procedure or the combined TBS and fMRI procedure will be excluded from the protocol such as:

* Those with ferromagnetic metal in the cranial cavity or eye, e.g. aneurysm clip, implanted neural stimulator, cochlear implant, ocular foreign body.
* Those with an abnormality on a structural MRI.
* Those with an implanted cardiac pacemaker or auto-defibrillator
* Those with an insulin pump.
* Those with an irremovable body piercing
* Pregnant women
* Those with a visual impairment that will prevent them from performing the task
* Those without consent capacity will not be enrolled
* Those who do not understand the study instructions
* Those with a history of neurological problems. Neurological problems include, but are not limited to; family history of epilepsy, history of seizures and recurrent migraines.
* Those using medicines that can lower the seizure threshold. These can include but are not limited to; imipramine, amitriptyline, doxepine, nortriptyline, maprotiline, chlorpromazine, clozapine, foscarnet, ganciclovir, ritonavir, amphetamines.
* Those with a visual impairment that will prevent them from performing the task
* Those who have a significant psychiatric illness or have a history of psychiatric illness.
* NIMH staff/employees/family members

Where this trial is running

Bethesda, Maryland

• National Institutes of Health Clinical Center — Bethesda, Maryland, United States (RECRUITING)

Study contacts

• Principal investigator: Christopher I Baker, Ph.D. — National Institute of Mental Health (NIMH)
• Study coordinator: NIMH LBC Volunteer

Conditions: fMRI, Dorsal Pathway, Ventral Pathway, Theta Burst Stimulation, Transcranial Magnetic Stimulation, Visual Cortex, Visual Processing, Natural History