Neural Mechanisms of Spatial Representations Beyond the Self

NCT05406349 | Recruiting

• 2 other identifiers: 7450ER00NS126715
• Study Type: interventional
• Target: 60
• Locations: 1 country
• Sites: 1

Brief Summary

Spatial navigation is a fundamental human behavior, and deficits in navigational functions are among the hallmark symptoms of severe neurological disorders such as Alzheimer's disease. Understanding how the human brain processes and encodes spatial information is thus of critical importance for the development of therapies for affected patients. Previous studies have shown that the brain forms neural representations of spatial information, via spatially-tuned activity of single neurons (e.g., place cells, grid cells, or head direction cells), and by the coordinated oscillatory activity of cell populations. The vast majority of these studies have focused on the encoding of self-related spatial information, such as one's own location, orientation, and movements. However, everyday tasks in social settings require the encoding of spatial information not only for oneself, but also for other people in the environment. At present, it is largely unknown how the human brain accomplishes this important function, and how aspects of human cognition may affect these spatial encoding mechanisms. This project therefore aims to elucidate the neural mechanisms that underlie the encoding of spatial information and awareness of others. Specifically, the proposed research plan will determine how human deep brain oscillations and single-neuron activity allow us to keep track of other individuals as they move through our environment. Next, the project will determine whether these spatial encoding mechanisms are specific to the encoding of another person, or whether they can be used more flexibly to support the encoding of moving inanimate objects and even more abstract cognitive functions such as imagined navigation. Finally, the project will determine how spatial information is encoded in more complex real-world scenarios, when multiple information sources (e.g., multiple people) are present. To address these questions, intracranial medial temporal lobe activity will be recorded from two rare participant groups: (1) Participants with permanently implanted depth electrodes for the treatment of focal epilepsy through responsive neurostimulation (RNS), who provide a unique opportunity to record deep brain oscillations during free movement and naturalistic behavior; and (2) hospitalized epilepsy patients with temporarily implanted intracranial electrodes in the epilepsy monitoring unit (EMU), from whom joint oscillatory and single-neuron activity can be recorded.

Conditions

Epilepsy Intractable

Outcome Measures

Primary Outcomes (4)

• Oscillatory power

  It will be measured how the oscillatory power (measurement unit: microvolts-squared) of electrophysiological brain activity, as measured via intracranially implanted electrodes and an electroencephalography recording system, is modulated by task-related behavioral variables (such as the individual's spatial location, head direction, movement speed, or their distance/direction to environmental boundaries).

  Continuous measurement during task performance on day 1 and all subsequent measurement days (up to 14 days per participant)

• Oscillatory amplitude

  It will be measured how the oscillatory amplitude (measurement unit: microvolts) of electrophysiological brain activity, as measured via intracranially implanted electrodes and an electroencephalography recording system, is modulated by task-related behavioral variables (such as the individual's spatial location, head direction, movement speed, or their distance/direction to environmental boundaries).

  Continuous measurement during task performance on day 1 and all subsequent measurement days (up to 14 days per participant)

• Oscillatory frequency

  It will be measured how the frequency of an oscillation (measurement unit: Hertz), as measured via intracranially implanted electrodes and an electroencephalography recording system, is modulated by task-related behavioral variables (such as the individual's spatial location, head direction, movement speed, or their distance/direction to environmental boundaries).

  Continuous measurement during task performance on day 1 and all subsequent measurement days (up to 14 days per participant)

• Firing rate of single neurons

  It will be measured how the firing rate of single neurons (measurement unit: Hertz), as measured via intracranially implanted micro-electrodes and an electrophysiology recording system, is modulated by task-related behavioral variables (such as the individual's spatial location, head direction, movement speed, or their distance/direction to environmental boundaries).

  Continuous measurement during task performance on day 1 and all subsequent measurement days (up to 14 days per participant)

Other Outcomes (1)

• Eye movement speed

  Continuous measurement during task performance on day 1 and all subsequent measurement days (up to 14 days per participant)

Study Arms (1)

Electrophysiological recordings in participants with intracranially implanted electrodes

OTHER

All participants will perform behavioral tasks that test their spatial navigation and memory performance in self-navigation and observation tasks.

Behavioral: Self-navigation task; Behavioral: Observation task

Interventions

Self-navigation task BEHAVIORAL

Participants will perform a self-navigation task with two experimental conditions: Either they will be asked to walk towards a visible wall-mounted sign, or they will be asked to find and learn a hidden target location within the experimental room.

Electrophysiological recordings in participants with intracranially implanted electrodes

Observation task BEHAVIORAL

Participants will sit on a chair in a corner of the room (RNS participants) or watch a video that was recorded from the corner of the room (EMU participants). They will be asked to keep track of another person's location who is walking around the room, and to press a button whenever the other person crosses a previously-learned target location.

Electrophysiological recordings in participants with intracranially implanted electrodes

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Between 18 and 70 years of age
• Adequate visual and auditory acuity to allow neuropsychological testing
• Have undergone depth electrode placement for the purpose of epilepsy evaluation/treatment OR have NeuroPace RNS System implanted for epilepsy treatment

You may not qualify if:

• All DSM-V Axis I and II disorders other than nicotine-dependence
• History of brain damage

Sponsors & Collaborators

• Boston University Charles River Campus: lead
• National Institute of Neurological Disorders and Stroke (NINDS): collaborator
• National Institutes of Health (NIH): collaborator
• Boston Medical Center: collaborator

Study Sites (1)

Boston University

Boston, Massachusetts, 02215, United States

RECRUITING

MeSH Terms

Conditions

Drug Resistant Epilepsy

Condition Hierarchy (Ancestors)

Epilepsy; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases

Study Officials

• Matthias Stangl

  Boston University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Matthias Stangl

CONTACT

617-353-0879; mstangl@bu.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: May 25, 2022
• First Posted: June 6, 2022
• Study Start: August 6, 2022
• Primary Completion (Estimated): April 30, 2027
• Study Completion (Estimated): April 30, 2027
• Last Updated: March 14, 2025

Record last verified: 2025-03

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)