Posterior Cingulate Cortex and Executive Control of Episodic Memory

NCT06540976 | Recruiting

• 1 other identifier: R01MH129439
• Study Type: interventional
• Target: 130
• Locations: 1 country
• Sites: 1

Brief Summary

This project will use intracranial recordings and stimulation of the human brain to understand the unique contributions of the posterior cingulate cortex (PCC) to episodic memory behavior. The goal is to test how distinct subregions of the PCC differentially contribute to memory-based decisions (e.g., have I seen this picture before?). The ability to perform invasive studies of the human brain is through routine clinical monitoring of brain activity which occurs during the neurosurgical treatment of epilepsy. However, this project only focuses on the basic science of PCC and memory behavior. Specifically, the investigators will use single-0cell and population measures of brain activity to test a new theory of PCC function which focuses on the executive processes needed to support memory retrieval and memory-based decisions. By studying the PCC, a convergence zone of memory and executive brain systems, progress can be made in elucidating how the failure to successfully leverage past experiences in daily behavior can occur as a common symptom of both neurodegenerative disease (e.g., Alzheimer's disease) and multiple psychiatric conditions (e.g., schizophrenia) implicating PCC dysfunction.

Conditions

Episodic Memory

Outcome Measures

Primary Outcomes (3)

• Episodic/Executive behavioral task performance accuracy

  Participants will perform three tasks each testing the accuracy of executive (reward) or episodic (memory strength) based decisions. Outcome measures will be decision accuracy (% correct).

  Outcome assessed 10 minutes after intervention

• Episodic/Executive behavioral task performance speed

  Participants will perform three tasks each testing the speed of executive (reward) or episodic (memory strength) based decisions. Outcome measures will be response/decision reaction time (milliseconds).

  Outcome assessed 10 minutes after intervention

• Changes in high-frequency electrophysiological brain response

  During behavioral task performance, electrophysiological signals recorded from the brain will be quantified for changes in the mean high-frequency activity (70-150 Hz) amplitude during correct and incorrect episodic/executive decisions. The goal is to track this electrophysiological activity to quantify if and when brain activity in the posterior cingulate cortex occurs during memory and non-memory based decisions.

  Outcome assessed 1 hour after intervention

Study Arms (3)

Experiment 1 - episodic / executive switch

EXPERIMENTAL

All enrolled participants will be asked to perform experiment 1, which is a cognitive task involving the switch between performing episodic memory decisions (e.g., "did you eat fruit yesterday?") and executive decisions (e.g. "...does 5+3+8 = 17?"). Participants will perform this computer-based task while electrical brain activity is recorded from the posterior cingulate cortex, hippocampus and prefrontal cortex. This task takes 18 minutes to complete.

Behavioral: Cognitive testing

Experiment 2 - executive decision task

EXPERIMENTAL

All enrolled participants will be asked to perform experiment 2, which is a cognitive task involving reward-based decisions between two options. For each decision, the two options will differ in their risk and reward (e.g., 100% chance of 10 points vs. 30% chance of 50 points). Participants will perform this computer-based task while electrical brain activity is recorded from the posterior cingulate cortex, hippocampus and prefrontal cortex. This task takes 15 minutes to complete.

Behavioral: Cognitive testing

Experiment 3 - episodic decision task

EXPERIMENTAL

All enrolled participants will be asked to perform experiment 3, which is a cognitive task involving memory-based decisions between two options (pictures of people). For each decision, the two pictures will differ in memory strength and reward (e.g., familiar picture for 10 points vs. unfamiliar picture 50 points). Memory strength for each picture will be defined by how many times the picture was previously shown (e.g., 2 vs. 10 presentations) prior to performing the memory decision task. Participants will perform this computer-based task while electrical brain activity is recorded from the posterior cingulate cortex, hippocampus and prefrontal cortex. This task takes 15 minutes to complete.

Behavioral: Cognitive testing

Interventions

Cognitive testing BEHAVIORAL

Cognitive tasks testing executive and episodic based decisions, and the switching between these processes.

Experiment 1 - episodic / executive switch; Experiment 2 - executive decision task; Experiment 3 - episodic decision task

Eligibility Criteria

• Age: 18 Years - 50 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• All participants are patients undergoing invasive brain monitoring for epilepsy and will be asked to consent to participation in this basic science protocol (which is focused on the patient group but is not focused on the study of epilepsy).

You may not qualify if:

• Individuals not undergoing invasive brain monitoring for epilepsy.
• Individuals outside of the age range (18-50 yrs).
• Individuals with cognitive impairment or intellectual difficulty.

Sponsors & Collaborators

• University of Pennsylvania: lead

Study Sites (1)

Hospital of the University of Pennsylvania - Pavilion

Philadelphia, Pennsylvania, 19104, United States

RECRUITING

MeSH Terms

Interventions

Neuropsychological Tests

Intervention Hierarchy (Ancestors)

Psychological Tests; Behavioral Disciplines and Activities

Central Study Contacts

Ilaina Edelstein

CONTACT

2156153525; Ilaina.Edelstein@Pennmedicine.upenn.edu

Brett Foster

CONTACT

2156153525; Brett.Foster@Pennmedicine.upenn.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 16, 2024
• First Posted: August 7, 2024
• Study Start: January 18, 2023
• Primary Completion (Estimated): March 2, 2027
• Study Completion (Estimated): April 30, 2027
• Last Updated: September 12, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will share
• Shared Documents: ANALYTIC CODE

Locations

US (1)