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.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
100
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.
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.
Vanderbilt University Medical Center
Nashville, Tennessee, United States
RECRUITINGLocal 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
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
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
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