Human Intracranial Electrophysiology

This study will enroll patients with epilepsy who are being evaluated for epilepsy surgery and have electrodes implanted in the brain and/or have electrodes on the scalp. Additionally, this study will recruit normal and online controls (participants who do not have epilepsy). Participants will be asked to participate in 1 to 2 (30-90 minutes) daily sessions designed to test aspects of human cognition such as memory, speech, language, feeling, movement, attention, sound perception, and emotions. Generally, this will involve working on a computer, looking at pictures or watching videos, and answering questions. Additionally, participants may be asked to be hooked up to additional equipment such as eye tracker, electrical stimulator, heart rate monitor, sweat monitor or other non-invasive equipment. The overall aim of this study is to use human intracranial electrophysiology (the recording of the electrical activity of the human brain) to study localization and function of the human brain.

Study Overview

• Status: Recruiting
• Conditions: Epilepsy
• Intervention / Treatment: Other: Memory Tasks; Other: Attention/arousal tasks; Other: Language tasks; Other: Visuospatial tasks; Procedure: Brain Stimulation; Other: Social Emotional Task; Other: Recording of facial expressions; Other: Auditory Tasks; Other: Judgement/Impulsivity Task

Detailed Description

This project aims to study the mechanisms of brain function by using Human Intracranial Electrophysiology (HIE) methods and is a continuation of the "Localization of Human Brain Function" study done at Dartmouth-Hitchcock Medical Center (DHMC). HIE refers to the recording of brain signals using electrodes which are surgically inserted into the human brain for the clinical purpose of localizing the origins of epileptic seizures.

Secondary to clinical goals, such patients with intracranial EEG electrodes can be safely recruited to participate in research studies, i.e. the research "piggybacks" on procedures that are performed strictly for a clinical purpose. Brain signals obtained using HIE methods during performance of specific tasks have unique properties rich with insight into the inner workings of the human brain. HIE methods can be used together with electrical brain stimulation (EBS) techniques to better understand relationship between brain and behavior. Furthermore, HIE methods can be recorded together with other non-invasive bio-physiological data streams such as pupillometry, electrodermal activity (EDA), cardiac monitoring, and respiratory monitoring to understand the relationship between the brain and many aspects of human physiology.

• Study Type: Interventional
• Enrollment (Estimated): 175
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Krzysztof A Bujarski, MD; Phone Number: 603-650-5104; Email: krzysztof.a.bujarski@hitchcock.org
• Study Contact Backup: Name: Gina Kersey; Phone Number: (603) 650-0260; Email: Gina.E.Kersey@Hitchcock.ORG

Study Locations

• United States
  • New Hampshire
    • Lebanon, New Hampshire, United States, 03776
      • Recruiting
      • Dartmouth-Hitchcock Medical Center
      • Principal Investigator: Krzysztof A Bujarski, MD
      • Contact: Krzysztof A Bujarski, MD; Phone Number: 603 650-5104; Email: krzysztof.a.bujarski@hitchcock.org
      • Contact: Gina Kersey; Phone Number: (603) 650-0260; Email: Gina.E.Kersey@Hitchcock.ORG

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Patients with Intracranial EEG: Inclusion Criteria

• Patients must be age 18 years or older. There is no upper age limit.
• Patients must have a diagnosis of refractory epilepsy undergoing intracranial EEG recording for clinical purposes.

Patients with Intracranial EEG: Exclusion Criteria

• Patient has additional neurological condition (such as stroke or dementia) or a psychiatric condition (such as active psychosis or suicidal ideation) and are deemed inappropriate for the study
• Patients are not able to provide informed consent for any reason (e.g. encephalopathic, experiencing a seizure)

Patients with Scalp EEG: Inclusion Criteria

• Patients must be age 18 years or older. There is no upper age limit.
• Patients must have a probable diagnosis of epilepsy.

Patients with Scalp EEG: Exclusion Criteria

• Patient has additional neurological condition (such as stroke or dementia) or a psychiatric condition (such as active psychosis or suicidal ideation) and are deemed inappropriate for the study
• Patients are not able to provide informed consent for any reason (e.g. encephalopathic, experiencing a seizure)

Normal Controls: Inclusion Criteria

• Participants must be age 18 years or older. There is no upper age limit.
• Participants must be able to provide informed consent for themselves.

Normal Controls: Exclusion Criteria

• Determined not to be appropriate normal control for the study population

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Invasive EEG (electrodes are implanted in a participant's brain); Patients with intracranial electrodes (electrodes are implanted in a participant's brain) undergoing pre-surgical evaluation for clinical reasons will be asked to participate in various study tasks with the recording of intracranial EEG (recording of brain waves via electrodes implanted in a participant's brain) during these tasks.	Other: Memory Tasks; Participants will be asked to view pictures and videos presented on a computer screen and will be asked to recall the details of presented pictures or videos sometime later.; Other: Attention/arousal tasks; Participants will be asked to perform a continuous performance task, such as continuous addition of numbers. Additionally, participants may be presented with images and may be asked to rate the significance or arousal values for each image.; Other: Language tasks; Participants will be asked to view pictures of actions or things and will be asked to name them. Participants may also be asked to read words or passages.; Other: Visuospatial tasks; Participants will be asked to copy 3 dimensional designs or make judgements of angle size.; Procedure: Brain Stimulation; A brain stimulator will be used to understand new functions of the brain. Participants will be presented with pictures on a computer screen and may be asked to tell researchers what is seen or remembered by participants. As pictures are viewed by the participants, the brain stimulator may be activated, which would not be something that would be felt by an individual participant.; Other: Social Emotional Task; Participants will be asked to view presented pictures and videos of people engaged in social interaction. Additionally, participants will be presented with the standardized tasks that are designed to help the researchers with understanding the nature of emotions. Some of these images may be emotionally disturbing. If participants are not comfortable viewing such images, they will be asked to refrain from participation in this study.; Other: Recording of facial expressions; Some participants may be asked permission to record the video of their facial expressions during performance of a research task. Generally, this will include only research tasks investigating brain representation of social/emotional information. Automated analysis of facial expression may be used in certain experiments to provide information on experience of emotional states such as happiness and sadness related to the images being presented.; Other: Auditory Tasks; Participants will be presented with short, approximately 8-minute clips of music from various genres ( i.e. classical, country, rock, etc.) with an attention task (modified sustained attention to response task) nested within each trial. Participants will receive approximately 8 music stimuli and 1 control stimulus (pink noise) twice over the course of two testing sessions ( 90 mins each). Additionally, participants will be asked to answer questions about their hearing, music preferences/training, and certain demographic information (age, handedness, and language proficiency).; Other: Judgement/Impulsivity Task; Certain study participants may be enrolled into research tasks designed to activate regions important for judgment and impulse control. These tasks will present participants with choices of varying monetary rewards and ask them to make judgements to measure one's tendency to prefer immediate over delayed rewards.
Experimental: Scalp EEG (electrodes are placed on a participant's scalp); Patients with non-invasive scalp electrodes who are admitted to the hospital for clinical reasons will be asked to participate in various study tasks with the recording of their EEG (recording of brain waves via electrodes attached to a participant's scalp) during these tasks.	Other: Memory Tasks; Participants will be asked to view pictures and videos presented on a computer screen and will be asked to recall the details of presented pictures or videos sometime later.; Other: Attention/arousal tasks; Participants will be asked to perform a continuous performance task, such as continuous addition of numbers. Additionally, participants may be presented with images and may be asked to rate the significance or arousal values for each image.; Other: Language tasks; Participants will be asked to view pictures of actions or things and will be asked to name them. Participants may also be asked to read words or passages.; Other: Visuospatial tasks; Participants will be asked to copy 3 dimensional designs or make judgements of angle size.; Other: Social Emotional Task; Participants will be asked to view presented pictures and videos of people engaged in social interaction. Additionally, participants will be presented with the standardized tasks that are designed to help the researchers with understanding the nature of emotions. Some of these images may be emotionally disturbing. If participants are not comfortable viewing such images, they will be asked to refrain from participation in this study.; Other: Recording of facial expressions; Some participants may be asked permission to record the video of their facial expressions during performance of a research task. Generally, this will include only research tasks investigating brain representation of social/emotional information. Automated analysis of facial expression may be used in certain experiments to provide information on experience of emotional states such as happiness and sadness related to the images being presented.; Other: Auditory Tasks; Participants will be presented with short, approximately 8-minute clips of music from various genres ( i.e. classical, country, rock, etc.) with an attention task (modified sustained attention to response task) nested within each trial. Participants will receive approximately 8 music stimuli and 1 control stimulus (pink noise) twice over the course of two testing sessions ( 90 mins each). Additionally, participants will be asked to answer questions about their hearing, music preferences/training, and certain demographic information (age, handedness, and language proficiency).; Other: Judgement/Impulsivity Task; Certain study participants may be enrolled into research tasks designed to activate regions important for judgment and impulse control. These tasks will present participants with choices of varying monetary rewards and ask them to make judgements to measure one's tendency to prefer immediate over delayed rewards.
Active Comparator: Normal Controls; Normal controls will be recruited from family members of patients, from advertisements, or from online tools. There will be no EEG recordings obtained from these participants.	Other: Memory Tasks; Participants will be asked to view pictures and videos presented on a computer screen and will be asked to recall the details of presented pictures or videos sometime later.; Other: Attention/arousal tasks; Participants will be asked to perform a continuous performance task, such as continuous addition of numbers. Additionally, participants may be presented with images and may be asked to rate the significance or arousal values for each image.; Other: Language tasks; Participants will be asked to view pictures of actions or things and will be asked to name them. Participants may also be asked to read words or passages.; Other: Visuospatial tasks; Participants will be asked to copy 3 dimensional designs or make judgements of angle size.; Other: Social Emotional Task; Participants will be asked to view presented pictures and videos of people engaged in social interaction. Additionally, participants will be presented with the standardized tasks that are designed to help the researchers with understanding the nature of emotions. Some of these images may be emotionally disturbing. If participants are not comfortable viewing such images, they will be asked to refrain from participation in this study.; Other: Recording of facial expressions; Some participants may be asked permission to record the video of their facial expressions during performance of a research task. Generally, this will include only research tasks investigating brain representation of social/emotional information. Automated analysis of facial expression may be used in certain experiments to provide information on experience of emotional states such as happiness and sadness related to the images being presented.; Other: Judgement/Impulsivity Task; Certain study participants may be enrolled into research tasks designed to activate regions important for judgment and impulse control. These tasks will present participants with choices of varying monetary rewards and ask them to make judgements to measure one's tendency to prefer immediate over delayed rewards.
Active Comparator: Online Controls; Certain control subjects will be recruited through Amazon Mechanical Turk. These participants will be given their task on the online platform using Qualtric survey function. The task design will be identical to normal controls who are recruited in-person, with the exception of identifiers. There will be no EEG recordings obtained from these participants.	Other: Memory Tasks; Participants will be asked to view pictures and videos presented on a computer screen and will be asked to recall the details of presented pictures or videos sometime later.; Other: Attention/arousal tasks; Participants will be asked to perform a continuous performance task, such as continuous addition of numbers. Additionally, participants may be presented with images and may be asked to rate the significance or arousal values for each image.; Other: Language tasks; Participants will be asked to view pictures of actions or things and will be asked to name them. Participants may also be asked to read words or passages.; Other: Visuospatial tasks; Participants will be asked to copy 3 dimensional designs or make judgements of angle size.; Other: Social Emotional Task; Participants will be asked to view presented pictures and videos of people engaged in social interaction. Additionally, participants will be presented with the standardized tasks that are designed to help the researchers with understanding the nature of emotions. Some of these images may be emotionally disturbing. If participants are not comfortable viewing such images, they will be asked to refrain from participation in this study.; Other: Recording of facial expressions; Some participants may be asked permission to record the video of their facial expressions during performance of a research task. Generally, this will include only research tasks investigating brain representation of social/emotional information. Automated analysis of facial expression may be used in certain experiments to provide information on experience of emotional states such as happiness and sadness related to the images being presented.; Other: Judgement/Impulsivity Task; Certain study participants may be enrolled into research tasks designed to activate regions important for judgment and impulse control. These tasks will present participants with choices of varying monetary rewards and ask them to make judgements to measure one's tendency to prefer immediate over delayed rewards.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Using scalp and intracranial EEG, measure changes in electrical activity of the human brain associated with memory.	Primary objective is to use human intracranial electrophysiology to study localization and function of the human brain. With continuous recording of the electrical activity in participants' brain, study participants will be asked to take part in research tasks involving memory. The researchers will use the information to further the understanding of the exact location of cognitive functions.	Evaluated for each patient during monitoring period of approximately 2 weeks.
Using scalp and intracranial EEG, measure changes in electrical activity of the human brain associated with language.	Primary objective is to use human intracranial electrophysiology to study localization and function of the human brain. With continuous recording of the electrical activity in participants' brain, study participants will be asked to take part in research tasks involving language. The researchers will use the information to further the understanding of the exact location of cognitive functions.	Evaluated for each patient during monitoring period of approximately 2 weeks.
Using scalp and intracranial EEG, measure changes in electrical activity of the human brain associated with emotions.	Primary objective is to use human intracranial electrophysiology to study localization and function of the human brain. With continuous recording of the electrical activity in participants' brain, study participants will be asked to take part in research tasks involving emotions. The researchers will use the information to further the understanding of the exact location of cognitive functions.	Evaluated for each patient during monitoring period of approximately 2 weeks.
Using scalp and intracranial EEG, measure changes in electrical activity of the human brain associated with movement.	Primary objective is to use human intracranial electrophysiology to study localization and function of the human brain. With continuous recording of the electrical activity in participants' brain, study participants will be asked to take part in research tasks involving movement. The researchers will use the information to further the understanding of the exact location of cognitive functions.	Evaluated for each patient during monitoring period of approximately 2 weeks.
Using scalp and intracranial EEG, measure changes in electrical activity of the human brain associated with attention and executive function.	Primary objective is to use human intracranial electrophysiology to study localization and function of the human brain. With continuous recording of the electrical activity in participants' brain, study participants will be asked to take part in research tasks involving attention and executive function. The researchers will use the information to further the understanding of the exact location of cognitive functions.	Evaluated for each patient during monitoring period of approximately 2 weeks.
Using scalp and intracranial EEG, measure changes in electrical activity of the human brain associated with sound perception.	Primary objective is to use human intracranial electrophysiology to study localization and function of the human brain. With continuous recording of the electrical activity in participants' brain, study participants will be asked to take part in research tasks involving sound perception. The researchers will use the information to further the understanding of the exact location of cognitive functions.	Evaluated for each patient during monitoring period of approximately 2 weeks.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The degree of correlation between the brain activation and respiratory activity.	Researchers will investigate the degree of correlation (correlation coefficient or how similar the measurements are) between the human intracranial EEG signals and respiratory activity. The respiratory activity (e.g. breathing rate, oxygen level, etc.) will be measured with non-invasive sensors such as respiratory belt worn around a participant's chest and abdomen as well as a small sensor under their nose.	Evaluated for each patient during monitoring period of approximately 2 weeks.
The degree of correlation between the brain activation and electrodermal activity.	Researchers will investigate the degree of correlation between the human intracranial EEG signals and electrodermal activity (electrical characteristics of human skin). The electrodermal activity will be measured with non-invasive electrodermal sensors such as wrist or ankle sensors and expressed as a variation in electrical characteristics of participants' skin.	Evaluated for each patient during monitoring period of approximately 2 weeks.
Measure the degree of correlation between the brain activation and sweat variations.	Researchers will investigate the degree of correlation between the human intracranial EEG signals and sweat volume. The researchers will use use a Q-SWEAT system to noninvasively measure the sweat volume produced during specific study tasks. The Q-SWEAT system has a multicompartmental capsule, which is placed tightly on the skin, often in four standard locations (the dorsal foot, distal leg, proximal leg, and forearm), though any flat, area of skin can be used. Nitrogen gas flows through the inner compartment, and the system detects sweat volume by measuring changes in the relative humidity of returning nitrogen during the recording period.	Evaluated for each patient during monitoring period of approximately 2 weeks.
Measure the degree of correlation between the brain activation and cardiac physiology.	Researchers will use a CNAP machine (finger sensor) to record heart-rate variability. The CNAP machine will measure the waveform and pressure continuously, which will allow for detection of changes in blood pressure without using an arterial line or other invasive methods. Researchers will investigate the degree of correlation between the human intracranial EEG signals and heart-rate variability, including changes in blood pressure during the performance of study tasks.	Evaluated for each patient during monitoring period of approximately 2 weeks.

Collaborators and Investigators

• Sponsor: Dartmouth-Hitchcock Medical Center
• Collaborators: Dartmouth College
• Investigators: Principal Investigator: Krzysztof A Bujarski, MD, Dartmouth-Hitchcock Medical Center

Study record dates

Study Major Dates

• Study Start (Actual): January 17, 2023
• Primary Completion (Estimated): August 1, 2027
• Study Completion (Estimated): August 1, 2032

Study Registration Dates

• First Submitted: August 22, 2022
• First Submitted That Met QC Criteria: September 1, 2022
• First Posted (Actual): September 7, 2022

Study Record Updates

• Last Update Posted (Actual): January 15, 2026
• Last Update Submitted That Met QC Criteria: January 13, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Epilepsy; Therapeutics; Surgical Procedures, Operative; Electric Stimulation Therapy; Deep Brain Stimulation
• Other Study ID Numbers: STUDY02001606

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No