Cognitive Demands and Electrical Stimulation in Memory Function Research

Enrolling by invitation at 1 trial location

Overseen By Robert Baudo, PhD

Age: 18 - 65

Sex: Any

Trial Phase: Academic

Sponsor: University of Chicago

Disqualifiers: Non-epilepsy, Under 18, Non-English, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: Unknown

Duration: 1.5 hours per session, multiple sessions

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial examines how the brain, particularly the hippocampus, aids in forming memories by observing how people view objects and scenes. It tests various memory and visual tasks while applying gentle electrical stimulation (a technique using a small electrical current to the brain) to understand these interactions. Participants must be adults who speak English fluently, have normal vision, and are undergoing epilepsy treatment, which includes special brain activity recordings. The research aims to enhance understanding of memory disruptions in various brain disorders. As an unphased trial, this study allows participants to contribute to groundbreaking research that could lead to improved treatments for memory-related issues.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Studies have shown that using intracranial EEG (iEEG) to monitor brain activity provides researchers with a clear view of real-time brain function. This method is safe and aids in understanding thought and memory processes. When individuals perform tasks, iEEG captures detailed signals specific to different brain areas.

Research into electrical stimulation, like that used in this study, has safely explored brain functions. Experts adhere to guidelines to ensure the electrical stimulation is well-tolerated. This method often identifies brain areas involved in seizures in epilepsy patients. Safety studies suggest that the stimulation is generally safe when performed correctly.

Overall, both the cognitive tasks and electrical stimulation used in the study have proven safe in similar settings. The research methods prioritize participants' safety while exploring how the brain processes memories. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about this trial because it explores how cognitive demands and electrical stimulation can enhance memory function, especially for individuals with epilepsy undergoing iEEG recordings. Unlike traditional medications or therapies that might target symptoms, this approach involves tracking eye movements and applying electrical stimulation directly to specific brain areas like the hippocampus and amygdala. This innovative method could uncover new ways to boost memory by directly interacting with brain circuits, potentially leading to more precise and effective treatments for memory-related challenges.

What evidence suggests that this trial's treatments could be effective for memory function?

Research has shown that different mental tasks affect how people process and remember information. Tasks requiring more mental effort can impact memory, highlighting the link between mental effort and memory. In this trial, participants will engage in various cognitive and memory tasks to explore these effects. Additionally, electrical stimulation has shown promise in boosting brain functions. For example, studies have found that certain types of electrical stimulation can improve memory and thinking skills. This trial will also investigate different electrical stimulation parameters during these tasks. These findings suggest that both mental tasks and electrical stimulation influence memory, providing a strong basis for studying their effects in this trial. ^{6 7 8 9 10}

Who Is on the Research Team?

Joel Voss, PhD

Principal Investigator

University of Chicago

Are You a Good Fit for This Trial?

This study is for adults over 18 with normal or corrected vision who speak English natively. It's designed for individuals with epilepsy undergoing neurosurgical procedures, allowing researchers to record and stimulate brain activity directly.

Inclusion Criteria

I am a native English speaker.

My vision is normal or corrected to normal.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants perform eye-tracking memory tasks with iEEG recordings and electrical stimulation in various experimental conditions

1.5 hours per session, multiple sessions

Multiple visits (inpatient)

Follow-up

Participants are monitored for memory task performance and iEEG outcomes

5 minutes post-intervention

What Are the Treatments Tested in This Trial?

Interventions

• Different cognitive and memory demands during the memory experiment
• Different electrical stimulation parameters during cognitive and memory demands

Trial Overview The trial investigates how the hippocampus influences memory formation and visual processing. Participants will perform eye-tracking tasks while receiving different cognitive challenges and electrical stimulations to their brains.

How Is the Trial Designed?

Group I: Experiment 6 Experimental Treatment 1 Intervention

The same group of 20 iEEG subjects that are included in Study Experiment Condition 5 will perform the same eye-tracking memory task as described for Study Experiment Condition 2. This experiment condition will be performed on a different day of the inpatient visit than participation in Study Experiment Condition 5.

Group II: Experiment 5 Experimental Treatment 1 Intervention

Subjects with iEEG electrodes implanted will perform the same eye-tracking memory task as described for Study Experiment Condition 1. This is a different group of iEEG subjects selected based on having iEEG electrodes implanted in the hippocampus as well as in at least one location of the Dorsal Attention Network (DAN), which is a region of interest for the experiment condition. 20 subjects undergoing iEEG recordings as part of epilepsy treatment will be assigned to this study experiment condition.

Group III: Experiment 4 Experimental Treatment 2 Interventions

The same 20 subjects with iEEG electrodes implanted who perform Study Experiment Condition 1 will perform the same eye-tracking memory task described for Study Experiment Condition 2. For these subjects, high-frequency electrical stimulation will be delivered through the iEEG electrodes on a subset of study trials, with half of stimulated trials receiving stimulation of the hippocampus and the other half receiving stimulation of the amygdala. This memory task will take about 1.5 hours to complete and will be performed on a different day of their inpatient visit than the procedures for Study Experiment Condition 1.

Group IV: Experiment 3 Experimental Treatment 2 Interventions

The same 20 subjects with iEEG electrodes implanted who perform Study Experiment Condition 2 will perform the same eye-tracking memory task described for Study Experiment Condition 1. For these subjects, high-frequency electrical stimulation will be delivered through the iEEG electrodes on a subset of study trials, with half of stimulated trials receiving stimulation of the hippocampus and the other half receiving stimulation of the amygdala. This memory task will take about 1.5 hours to complete and will be performed on a different day of their inpatient visit than the procedures for Study Experiment Condition 2.

Group V: Experiment 2 Experimental Treatment 1 Intervention

Subjects with iEEG electrodes implanted will perform an eye-tracking memory task in which they view arrays of everyday objects arranged as a grid and later undergo memory testing for these object image arrays. Half of the object-image arrays are studied actively (subjects view objects in any order they wish) and half are studied passively (viewing patterns are predetermined and subjects must follow along). For the memory test, subjects attempt to pick studied objects from among novel (foil) objects and replace them at studied locations using the computer mouse. Eye movements will be remotely (noninvasively) tracked using a camera during the study phases. This memory task will take about 1.5 hours to complete. 20 subjects undergoing iEEG recordings as part of epilepsy treatment will be assigned to this study experiment condition.

Group VI: Experiment 1 Experimental Treatment 1 Intervention

Subjects with iEEG electrodes implanted will perform an eye-tracking memory task in which they view pictures of naturalistic scenes and later undergo memory testing for these scene pictures. For the memory test, studied scenes will be repeated and presented along with novel (foil) scenes. Subjects will attempt to discriminate studied from novel scenes using button press responses. Eye movements will be remotely (noninvasively) tracked using a camera during both study and test. This memory task will take about 1.5 hours to complete. 20 subjects undergoing iEEG recordings as part of epilepsy treatment will be assigned to this study experiment condition.

Who Is Running the Clinical Trial?

University of Chicago

Lead Sponsor

Trials

1,086

Recruited

844,000+

National Institute of Mental Health (NIMH)

Collaborator

Trials

3,007

Recruited

2,852,000+

Published Research Related to This Trial

In a study involving 22 patients, direct electrical stimulation of specific brain regions (hippocampus, parahippocampal region, neocortex, prefrontal cortex, and lateral temporal cortex) was shown to modulate high γ activity during verbal memory tasks, particularly affecting memory performance.

The modulation of high γ activity correlated with memory outcomes: stimulation in some areas decreased memory performance, while stimulation in the lateral temporal cortex enhanced memory, suggesting that high γ activity could serve as a biomarker for optimizing brain stimulation therapies.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Electrical Stimulation Modulates High γ Activity and Human Memory Performance. Kucewicz, MT., Berry, BM., Kremen, V., et al.[2019]

The review emphasizes the need for standardized guidelines in intracranial stimulation studies of human memory to improve consistency and comparability across research, which currently suffers from methodological inconsistencies.

It outlines important technical and safety considerations for researchers, including electrode placement and behavioral task design, to enhance the reliability of findings in future studies on memory modulation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Reporting Guidelines and Issues to Consider for Using Intracranial Brain Stimulation in Studies of Human Declarative Memory. Suthana, N., Aghajan, ZM., Mankin, EA., et al.[2022]

Citations

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