Neural Mechanisms of Spatial Representations Beyond the Self

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

Interventions

BEHAVIORAL

Self-navigation task

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.

BEHAVIORAL

Observation task

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.

Sponsors & Collaborators

• National Institute of Neurological Disorders and Stroke (NINDS)

  collaborator NIH

• National Institutes of Health (NIH)

  collaborator NIH

• Boston Medical Center

  collaborator OTHER

• Boston University Charles River Campus

  lead OTHER

Principal Investigators

• Matthias Stangl · Boston University

Study Design

Allocation

NA

Purpose

BASIC_SCIENCE

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Max Age

70 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2022-08-06

Primary Completion

2027-04-30

Completion

2027-04-30

Countries

• United States

Study Locations