Effects of Sensory Flicker and Electrical Flicker Stimulation
Neurophysiological and Behavioral Effects of Sensory Flicker and Electrical Flicker Stimulation
Study Overview
Status
Status
Conditions
Conditions
Intervention / Treatment
Intervention / Treatment
Detailed Description
Clinical trials have explored the modulation of brain circuits to treat several brain disorders, including Parkinson's Disease, Alzheimer's Disease (AD), depression, and Obsessive-Compulsive Disorder (OCD). However, current means to non-invasively modulate brain activity are limited.
The study will evaluate whether sensory flicker can modulate neural activity of deep brain regions in humans, and whether it can have relevant effects on behavior. Moreover, it will compare those effects to the gold-standard method of modulating brain circuits, direct electrical stimulation of the brain (the same mechanism as deep brain stimulation), using a powerful within-subjects design.
Study Type
Study Type
Enrollment (Actual)
Enrollment
Phase
Phase
- Not Applicable
Contacts and Locations
Study Locations
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Georgia
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Atlanta, Georgia, United States, 30322
- Emory University Hospital
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Participation Criteria
Eligibility Criteria
Eligibility Criteria
Ages Eligible for Study
Accepts Healthy Volunteers
Description
Inclusion Criteria:
- Adult (>18 years, regardless of gender, race or ethnicity).
- To be implanted with intracranial depth or grid/strip electrodes for surgical evaluation.
- Patient was not shown, during phase I seizure monitoring, to exhibit abnormal EEG activity in response to photic stimulation, and is not clinically suspected to be susceptible to photic-induced seizures.
- Patient has no pre-existing diagnosis of autism.
- Patient is not considered at risk for psychogenic nonepileptic seizures (PNES) triggered by sensory stimulation.
- Fluent in English.
- Able to understand an informed consent (comprehend potential risks and benefits).
- Give written and verbal informed consent to all experiments patient would participate in.
Exclusion Criteria:
- Failure to meet any one inclusion criteria.
Study Plan
How is the study designed?
Design Details
- Primary Purpose: Basic Science
- Allocation: Non-Randomized
- Interventional Model: Crossover Assignment
- Masking: None (Open Label)
Number of Arms
Arms and Interventions
Participant Group / ArmParticipant Group / Arm |
Intervention / TreatmentIntervention / Treatment |
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Experimental: Sensory Flicker Stimulation
Participants will be exposed for about 10 to 60 minutes at a time, to a sequence of sensory flicker trials each lasting a few seconds to 5 minutes, while their eyes are open or closed. Each trial may include the following modalities and frequencies of flicker:
Additionally, subjects may be exposed to individual pulses of light and/or sound, i.e. around or less than 1 pulse /second, for up to 20 minutes at a time. |
A customized version of the DAVID device will be used to expose participants to sensory flicker.
The device consists of opaque glasses containing LEDs to present flickering light, as well as earbuds or headphones to present flickering sound.
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Active Comparator: Electrical Flicker Stimulation
Participants will be exposed to direct electrical brain stimulation with low-amplitude current, at given flicker frequencies. Participants will be exposed to frequencies ranging from 5-100Hz, for up to 10 seconds at a time. Initially, frequencies of 5.5Hz and 40Hz will be tested. During brain stimulation sessions, bipolar electrical stimulation will be applied to one or more areas of the brain at a time either with or without associated memory tasks. Stimulation in the absence of any memory task will be applied to assess the subject's neurophysiological response to stimulation and to identify the optimal stimulation parameters for use during memory tasks. Stimulation during behavioral tasks will be applied in an attempt to affect the subject's memory. |
The Blackrock CereStim is a fully programmable neurostimulator.
The current pulses generated by the Blackrock CereStim are intended to stimulate neurons in proximity to a set of electrodes.
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What is the study measuring?
Primary Outcome Measures
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
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Fold-change in Oscillatory Activity (Power Spectral Density) in Response to Exposure to Sensory Flicker: Comparing Mean Power Spectral Density at the Frequency of Flicker Being Presented Between Flicker and Baseline Periods
Time Frame: During experiment session (up to 2 hours) during hospital admission (up to 2 weeks)
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The power spectral density of the LFP will be measured across stimulus frequencies and modalities of sensory flicker stimuli in visual areas, auditory areas, hippocampus, and prefrontal cortex.
To evaluate the effects of sensory flicker on brain activity in various brain regions, researchers compared the average increase in oscillatory neural activity of given recorded brain regions during sensory stimulation, among the total number of recording locations that showed a significant response to sensory stimulation compared to baseline.
In participants in whom a condition was repeated across multiple experimental sessions.
If a location showed a significant response in multiple sessions, the data point that showed the highest level of response was kept.
The average fold-change increase in oscillatory activity, 25th and 75th percentiles, within a region of interest is reported.
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During experiment session (up to 2 hours) during hospital admission (up to 2 weeks)
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Secondary Outcome Measures
Secondary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
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Effect of Sensory Flicker on the Rate of Interictal Epileptiform Discharges (IEDs) Which Represent Pathological Activity Often Observed in Epilepsy
Time Frame: During experiment session (up to 2 hours) during hospital admission (up to 2 weeks)
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The change of of the sensory flicker effect will be evaluated by the comparison of the whole-brain rate of IEDs between sensory flicker stimulation and baseline (no stimulation).
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During experiment session (up to 2 hours) during hospital admission (up to 2 weeks)
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Collaborators and Investigators
Sponsor
Sponsor
Collaborators
Collaborators
Investigators
Investigators
- Principal Investigator: Joseph Manns, PhD, Emory University
Publications and helpful links
Study record dates
Study Major Dates
Study Start (Actual)
Study Start
Primary Completion (Actual)
Primary Completion
Study Completion (Actual)
Study Completion
Study Registration Dates
First Submitted
First Submitted
First Submitted That Met QC Criteria
First Submitted That Met QC Criteria
First Posted (Actual)
First Posted
Study Record Updates
Last Update Posted (Actual)
Last Update Posted
Last Update Submitted That Met QC Criteria
Last Update Submitted That Met QC Criteria
Last Verified
Last Verified
More Information
Terms related to this study
Keywords
Additional Relevant MeSH Terms
Other Study ID Numbers
Other Study ID Numbers
- IRB00107577
Plan for Individual participant data (IPD)
Plan to Share Individual Participant Data (IPD)?
IPD Plan Description
IPD Sharing Time Frame
IPD Sharing Access Criteria
IPD Sharing Supporting Information Type
- STUDY_PROTOCOL
- SAP
- ANALYTIC_CODE
Drug and device information, study documents
Studies a U.S. FDA-regulated drug product
Studies a U.S. FDA-regulated device product
product manufactured in and exported from the U.S.
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