Neural Basis of Human Working Memory

NCT07617506 | Recruiting DMC FDA Device

• 2 other identifiers: 2512311R21MH139624-01
• Study Type: interventional
• Target: 100
• Locations: 1 country
• Sites: 1

Brief Summary

This ClinicalTrials.gov entry corresponds to the Neural Basis of Human Working Memory protocol approved under Vanderbilt University Medical Center IRB #251231. This study investigates the neural activity underlying human working memory, via local field potential changes (macro level) and/or single neuronal spiking changes (micro level) from depth electrodes placed for invasive seizure monitoring. Subjects will complete neurocognitive tasks while neural recordings are collected. Some patients will complete neurocognitive tasks while stimulation is applied via depth electrodes. Further understanding the neural activity changes underlying normal and impaired working memory may help to identify novel diagnostic methods and treatments for impaired working memory and may support the use of stimulation for treatment of memory disorders.

Conditions

Memory Disorders

Keywords

Neural stimulation; Memory disorders; Working Memory; Stereo Electroencephalography (SEEG)

Outcome Measures

Primary Outcomes (3)

• Local field potential changes in response to working memory tasks

  Local field potential changes are from intracranial neural recordings taken while patients complete spatial working memory tasks. In the manual remember 1 remember 2 task, patients are instructed to hold down a cursor on a central location box colored one color or another on screen, while two boxes in locations sequentially flash on screen. Depending on the central location box color, the patient will drag their cursor to the first or second location box shown, after the central box has disappeared from screen. In the retro remember 1 remember 2 task, the color of the central box color is not shown until both location boxes have flashed onscreen. In the manual version, the central location box color is constant throughout the trial.

  During patient's epilepsy monitoring stay, approximately 20-30 minutes

• Single unit neuronal spiking changes in response to memory tasks

  Single neuron spiking activity is recorded through SEEG micro neural recordings while patients complete working memory tasks.

  During patient's epilepsy monitoring stay, approximately 20-30 minutes

• Behavioral performance changes with stimulation

  Bipolar stimulation through pre-selected SEEG electrodes in the prefrontal cortex and surrounding areas will occur during the remember 1 remember 2 working memory tasks. Stimulation will be performed via the Ripple Neuromed Summit system. Stimulation will be tested with each patient prior to task to determine safety and tolerability, while patient is monitored by a neurosurgeon or neurologist.

  During patient's epilepsy monitoring stay, approximately 20-30 minutes

Study Arms (1)

Epilepsy patients

OTHER

All participants will be patients with medically refractory epilepsy who have undergone depth electrode placement for stereo EEG monitoring for seizure localization. Participants will complete working memory tasks and EEG recordings will be concurrently collected from their depth electrodes. Some subjects will undergo macro-micro electrode implantation as a part of their SEEG implantation procedure for the purpose of EEG macro (local activity) and micro (single-unit) recordings. Some subjects will complete working memory tasks with stimulation applied during task completion.

Behavioral: Neurocognitive Tasks; Device: Ripple Neuromed Summit System

Interventions

Neurocognitive Tasks BEHAVIORAL

Participants complete computerized neurocognitive tasks assessing working memory, response inhibition, decision-making, reward processing, and other related cognitive functions during sEEG monitoring. Tasks may include the stop signal reaction time task, the n-back working memory task, the delayed response task, the match/nonmatch task, the gambling task, the card guessing task, and the emotional stop signal reaction time task. Intracranial neural activity is recorded during task performance, and select tasks may include research electrical stimulation delivered through the implanted sEEG electrodes.

Epilepsy patients

Ripple Neuromed Summit System DEVICE

Neurophysiology system designed to allow recording of neural signals as well as delivery of neural stimulation. The system is a portable unit which is connected to cables connected to the clinical electrodes. Neurophysiology signals from the electrodes can be recorded, amplified, and processed by the unit. The unit also has the ability to deliver electrical stimulation through the electrodes according to programmed parameters.

Epilepsy patients

Eligibility Criteria

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

You may qualify if:

• Undergoing SEEG monitoring at Vanderbilt University Medical Center
• Age \>18
• English speaking

You may not qualify if:

• Age \<18
• Not able to complete questionnaires (unable to comprehend instructions or follow directions)

Sponsors & Collaborators

• Vanderbilt University Medical Center: lead
• National Institute of Mental Health (NIMH): collaborator

Study Sites (1)

Vanderbilt University Medical Center

Nashville, Tennessee, 37232, United States

RECRUITING

MeSH Terms

Conditions

Memory Disorders

Condition Hierarchy (Ancestors)

Neurobehavioral Manifestations; Neurologic Manifestations; Nervous System Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Central Study Contacts

Lucas Chang, BS

CONTACT

615-421-3046; lucas.m.chang@vumc.org

Christos Constantinidis, PhD

CONTACT

+1 (615) 936-2020; christos.constantinidis.1@Vanderbilt.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: Professor of Biomedical Engineering, Principal Investigator

Study Record Dates

• First Submitted: May 23, 2026
• First Posted: June 1, 2026
• Study Start: June 4, 2025
• Primary Completion (Estimated): April 1, 2027
• Study Completion (Estimated): April 1, 2027
• Last Updated: July 31, 2026

Record last verified: 2026-06

Locations

US (1)