Brain Stimulation and Visually-guided Navigation

Emory University

Status: Terminated

Conditions: Healthy Participants

Treatments: Behavioral: Computer-based Test; Behavioral: Behavioral-based Test; Device: Repetitive Transcranial Magnetic Stimulation (rTMS)

Study type: Interventional

Funder types: Other; NIH

Identifiers

NCT04961645

5R01EY029724 (U.S. NIH Grant/Contract)

STUDY00002512

Details and patient eligibility

About

This study investigates the neural mechanisms causally involved in how people navigate through their immediately visible environment (e.g., walking around one's bedroom flawlessly and effortlessly, not bumping into the walls or furniture). To investigate whether particular neural mechanisms are causally involved in "visually-guided navigation", repetitive transcranial magnetic stimulation (rTMS) is used to temporarily disrupt the functioning of particular brain regions in healthy adults while they are shown simple visual stimuli of places (e.g., bedrooms, kitchens, and living rooms) and asked to perform simple computer tasks or to complete simple behavioral tasks.

Full description

Human ability to navigate through the immediately visible environment is crucial for survival. However, the representations and computations underlying this remarkable ability are not well understood, and current computer vision algorithms (robots) still lag far behind human performance. One promising strategy for attempting to understand "visually-guided navigation" is to characterize the neural systems that accomplish it. The results from functional magnetic resonance (fMRI) on adult humans have begun to elucidate the cortical regions involved in visually-guided navigation, with the central finding that there is at least one visual cortical region - called the occipital place area (OPA) that may play a central role in the ability to navigate through currently visible places (e.g., walking around our bedroom flawlessly and effortlessly, not bumping into the walls or furniture our bedroom). However, fMRI is a correlational method, and research still needs to determine if this functionally specific brain region is causally involved in visually-guided navigation. Understanding the causal involvement of this region will provide important clues about how humans navigate their world, and also perhaps someday be harnessed to help those individuals who devastatingly lose the ability to navigate, as a result of eye diseases, brain surgery, stroke, neurodegenerative diseases, or developmental disorders.

The use of rTMS to investigate the causal involvement of particular brain regions in particular human abilities is not novel, having been used to investigate face recognition, scene recognition, and object recognition. The general question for this research is to determine, using rTMS, the causal involvement of OPA in visually-guided navigation.

Participants will have an fMRI scan to identify the OPA location in each individual participant. Once the OPA location is known, participants will receive the rTMS study intervention.

Enrollment: 11 patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Normal or corrected-to-normal vision

Exclusion criteria

• Metal in the body
• Personal or first-degree family history of epileptic seizure
• A known brain injury
• Claustrophobia
• Taking certain medications that may increase the risk of seizures (e.g., bupropion, varenicline, chlorpromazine, theophylline) or reduce the effects of rTMS, such as benzodiazepines
• Adults who are unable to consent, pregnant women, and prisoners

Trial design

Primary purpose: Basic Science

Allocation: Non-Randomized

Interventional model: Sequential Assignment

Masking: None (Open label)

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11 participants in 2 patient groups

Repetitive Transcranial Magnetic Stimulation (rTMS) During Computer-based Task

Experimental group

Description:

Participants receiving rTMS while they perform computer-based tests to examine the causal involvement of OPA in visually-guided navigation. The study visit lasts approximately 90 minutes.

Treatment:

Device: Repetitive Transcranial Magnetic Stimulation (rTMS)

Behavioral: Computer-based Test

Repetitive Transcranial Magnetic Stimulation (rTMS) During Behavioral-based Task

Experimental group

Description:

Participants receiving rTMS while they perform behavioral-based tests to examine the causal involvement of OPA in visually-guided navigation. The study visit lasts approximately 90 minutes.

Treatment:

Device: Repetitive Transcranial Magnetic Stimulation (rTMS)

Behavioral: Behavioral-based Test