Brain Stimulation and Visually-guided Navigation

Brain Stimulation Study of Human Visually-guided Navigation Using Repetitive Transcranial Magnetic Stimulation (rTMS)

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.

Study Overview

• Status: Terminated
• Conditions: Healthy Participants
• Intervention / Treatment: Device: Repetitive Transcranial Magnetic Stimulation (rTMS); Behavioral: Computer-based Test; Behavioral: Behavioral-based Test

Detailed 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.

• Study Type: Interventional
• Enrollment (Actual): 11
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Georgia
    • Atlanta, Georgia, United States, 30322
      • Emory University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Non-Randomized
• Interventional Model: Sequential Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Repetitive Transcranial Magnetic Stimulation (rTMS) During Computer-based Task; 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.	Device: Repetitive Transcranial Magnetic Stimulation (rTMS); TMS is a safe and noninvasive method for affecting brain function relying on the properties of electromagnetic induction. Action potentials are triggered in neurons, along with a subsequent period of deactivation. Normal ongoing brain activity is disrupted providing a way for investigators to produce a transient and reversible period of brain disruption.; Behavioral: Computer-based Test; Participants will be seated comfortably in a chair and asked to complete a simple computer-based task where they imagine walking through a room and press a button indicating if they can leave through a door on the left, center, or right wall. During or just before each of these tasks, participants will receive rTMS. In rTMS, a small plastic coil is placed next to the participant's head. The coil will be placed over the relevant brain region identified during the participant's fMRI scan. The coil will then generate a magnetic pulse, and stimulation will occur.
Experimental: Repetitive Transcranial Magnetic Stimulation (rTMS) During Behavioral-based Task; 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.	Device: Repetitive Transcranial Magnetic Stimulation (rTMS); TMS is a safe and noninvasive method for affecting brain function relying on the properties of electromagnetic induction. Action potentials are triggered in neurons, along with a subsequent period of deactivation. Normal ongoing brain activity is disrupted providing a way for investigators to produce a transient and reversible period of brain disruption.; Behavioral: Behavioral-based Test; Participants will be asked to complete a simple behavioral task that will require them to walk around in a small room and search for hidden objects. During or just before each of these tasks, participants will receive rTMS. In rTMS, a small plastic coil is placed next to the participant's head. The coil will be placed over the relevant brain region identified during the participant's fMRI scan. The coil will then generate a magnetic pulse, and stimulation will occur.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Accuracy During Visually-guided Navigation Computer-based Task	To assess performance during the visually-guided navigation computer-based task, rTMS is applied to to the control vertex site, which is not implicated in visually-guided navigation, as well as the occipital place area (OPA) site. While participants are shown simple visual stimuli of places (e.g., bedrooms, kitchens, and living rooms) they are asked to perform simple computer-based tasks (e.g., imagine they are walking through the room, and respond via button press whether they can leave through a door on the left, center, or right wall, as indicated by a continuous path on the floor). Performance is measured in task accuracy (the percentage of tasks performed correctly). A decrease in performance on the visually-guided navigation task only after rTMS is applied to OPA (but not vertex) indicates causal involvement of OPA in visually-guided navigation.	During rTMS of control site and during rTMS of OPA, on Day 1
Reaction Time During Visually-guided Navigation Computer-based Task	To assess performance during the visually-guided navigation computer-based task, rTMS is applied to to the control vertex site, which is not implicated in visually-guided navigation, as well as the occipital place area (OPA) site. While participants are shown simple visual stimuli of places (e.g., bedrooms, kitchens, and living rooms) they are asked to perform simple computer-based tasks (e.g., imagine they are walking through the room, and respond via button press whether they can leave through a door on the left, center, or right wall, as indicated by a continuous path on the floor). Performance is measured in the time (in milliseconds) that it takes to complete the task correctly. A decrease in performance on the visually-guided navigation task only after rTMS is applied to OPA (but not vertex) indicates causal involvement of OPA in visually-guided navigation.	During rTMS of control site and during rTMS of OPA, on Day 1
Accuracy During Visually-guided Navigation Behavioral-based Task	To assess performance during the visually-guided navigation behavior-based task, rTMS is applied to to the control vertex site, which is not implicated in visually-guided navigation, as well as the occipital place area (OPA) site. Participants are asked to complete simple behavioral-based tasks (e.g., actually walk around a small room and search for hidden objects). Performance is measured in task accuracy (the percentage of tasks performed correctly). A decrease in performance on the visually-guided navigation task only after rTMS is applied to OPA (but not vertex) indicates causal involvement of OPA in visually-guided navigation.	During rTMS of control site and during rTMS of OPA, on Day 1
Reaction Time During Visually-guided Navigation Behavioral-based Task	To assess performance during the visually-guided navigation behavioral-based task, rTMS is applied to to the control vertex site, which is not implicated in visually-guided navigation, as well as the occipital place area (OPA) site. Participants are asked to complete simple behavioral tasks (e.g., actually walk around a small room and search for hidden objects). Performance is measured as the time (in milliseconds) that it takes to complete the task correctly. A decrease in performance on the visually-guided navigation task only after rTMS is applied to OPA (but not vertex) indicates causal involvement of OPA in visually-guided navigation.	During rTMS of control site and during rTMS of OPA, on Day 1

Collaborators and Investigators

• Sponsor: Emory University
• Collaborators: National Eye Institute (NEI)
• Investigators: Principal Investigator: Daniel Dilks, PhD, Emory University

Study record dates

Study Major Dates

• Study Start (Actual): March 3, 2023
• Primary Completion (Actual): May 17, 2023
• Study Completion (Actual): May 17, 2023

Study Registration Dates

• First Submitted: July 5, 2021
• First Submitted That Met QC Criteria: July 5, 2021
• First Posted (Actual): July 14, 2021

Study Record Updates

• Last Update Posted (Actual): April 24, 2025
• Last Update Submitted That Met QC Criteria: April 8, 2025
• Last Verified: April 1, 2025

More Information

Terms related to this study

• Keywords: Visually-guided navigation
• Other Study ID Numbers: STUDY00002512; 5R01EY029724 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes