Neural Basis of Human Working Memory

Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age18+
SponsorVanderbilt University Medical Center

About this trial

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.

Eligibility criteria

This trial does not accept healthy volunteers

Qualifiers

Undergoing SEEG monitoring at Vanderbilt University Medical Center

Age >18

English speaking

Disqualifiers

Age <18

Not able to complete questionnaires (unable to comprehend instructions or follow directions)

Trial design

Design model

Single group

Treatments tested in this trial

  • 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.

  • 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.

Treatment groups

100 Participants
are divided into 1 treatment group
Group A: Epilepsy patientsOther 2 interventions

Trial outcomes

Primary outcomes

1

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.

Time frame
During patient's epilepsy monitoring stay, approximately 20-30 minutes
2

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.

Time frame
During patient's epilepsy monitoring stay, approximately 20-30 minutes
3

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.

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

Secondary outcomes

Other outcomes

Sponsors and contacts

Click on the lead sponsor to view all of their trials.

Vanderbilt University Medical Center

Lead sponsor

National Institute of Mental Health (NIMH)

Collaborator