Preliminary Investigations of Transcranial Electrical Stimulation Effects on Neurophysiology and Behavior
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Enrollment
- 44
- Locations
- 1
- Primary Endpoint
- ROBoT-r Task Performance Score (During Stimulation)
Study Overview
Brief Summary
The objective of this randomized, double-blind, sham-controlled, crossover study is to evaluate the effects of transcranial electrical stimulation (tES) on complex cognitive task performance in healthy adult volunteers.
The primary questions this study aims to answer are:
- Does tES improve task performance, including speed, accuracy, and overall success, during a computerized track-and-capture task?
- Do different stimulation targets produce differential effects on performance?
- Are there short-term post-stimulation effects on task performance (up to 48 hours)?
Participants will:
- Complete two testing sessions under either active or sham stimulation conditions.
- Perform a complex operational task involving dual-hand controllers while undergoing tES or sham stimulation, and immediately after.
- Return for follow-up task performance assessments at 24 and 48 hours post-stimulation to evaluate after-effects.
Detailed Description
Transcranial electrical stimulation (tES) is a non-invasive neuromodulation technique that delivers low-intensity electrical currents (e.g., <2 mA) through scalp electrodes to modulate brain activity. Numerous studies have shown that tES can enhance cognitive functions such as learning, memory, attention, and decision-making in healthy individuals, as well as provide therapeutic benefits in psychiatric and neurological populations. Despite these findings, substantial knowledge gaps remain regarding the effects of tES, particularly in the context of complex, operationally relevant tasks.
Existing research has primarily focused on the effects of tES on simple cognitive tasks, with limited investigation into task that require multiple cognitive domain to operate simultaneously. Performance on complex tasks, such as those involving motor coordination, visual-spatial process, decision-making, and rapid response, may respond differently to tES than simple, isolated tasks. Understanding these effects could have broad applications in optimizing cognitive performance across various high-demand settings.
This study is designed to address several key uncertainties:
- Inter-individual variability in behavioral and neurophysiological responses to tES.
- the impact of stimulation parameters (location, type, intensity) on task performance.
- The magnitude and duration of both immediate and post-stimulation effects on behavior.
To investigate these questions, healthy adults perform a computerized track-and-capture task requiring real-time motor control and decision-making using dual-hand controllers. Participants undergo both active and sham stimulation in a randomized, double-blind, crossover design. Stimulation will target either the left dorsolateral prefrontal cortex or the left anterior insula, guided by current flow modeling software. Performance is assessed during stimulation, immediately after, and at 24 and 48 hours post-stimulation to evaluate both immediate and short-term after-effects.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Crossover
- Primary Purpose
- Basic Science
- Masking
- Double (Participant, Investigator)
Masking Description
Participants and investigators were blinded to stimulation conditions (active vs. sham) and to which pre-programmed stimulation protocol (A or B) corresponded to active stimulation. The investigator was aware of the assigned stimulation location (DLPFC or L-aINS), but not whether stimulation protocol A or B was active or sham. The tES device was operated in double-blind model, with stimulation order randomized.
Eligibility Criteria
- Ages
- 25 Years to 55 Years (Adult)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •Age 25 to 55 years
- •Master's or Doctorate degree, or equivalent relevant experience
- •No history of head injury or neurological or psychiatric disorders
- •No history of cardiac disease
- •No metal implants in the head
- •No implanted electronic devices
- •Not taking medication affecting neural or cardiovascular function
- •Able to provide written, dated informed consent
Exclusion Criteria
- •Smoking within the past year
- •Current illegal drug use
- •Alcohol abuse
- •Pregnancy (confirmed by urine test)
- •Participation in another brain stimulation protocol within the past month
Arms & Interventions
Anterior Insula Stimulation Group
Participants receive transcranial electrical stimulation (tES) targeting the left anterior insula and perform a complex cognitive-motor task using the Robotic On-Board Trainer for Research (ROBoT-r) under both active and sham stimulation in a randomized, crossover design.
Intervention: Active Transcranial Electrical Stimulation (Device)
DLPFC Stimulation Group
Participants receive transcranial electrical stimulation (tES) targeting the left dorsolateral prefrontal cortex (DLPFC) and perform a complex cognitive-motor task using the Robotic On-Board Trainer for Research (ROBoT-r) under both active and sham stimulation in a randomized, crossover design.
Intervention: Active Transcranial Electrical Stimulation (Device)
DLPFC Stimulation Group
Participants receive transcranial electrical stimulation (tES) targeting the left dorsolateral prefrontal cortex (DLPFC) and perform a complex cognitive-motor task using the Robotic On-Board Trainer for Research (ROBoT-r) under both active and sham stimulation in a randomized, crossover design.
Intervention: Sham Transcranial Electrical Stimulation (Device)
Anterior Insula Stimulation Group
Participants receive transcranial electrical stimulation (tES) targeting the left anterior insula and perform a complex cognitive-motor task using the Robotic On-Board Trainer for Research (ROBoT-r) under both active and sham stimulation in a randomized, crossover design.
Intervention: Sham Transcranial Electrical Stimulation (Device)
Outcomes
Primary Outcomes
ROBoT-r Task Performance Score (During Stimulation)
Time Frame: 5 minutes after stimulation onset
Performance on the ROBoT-r computerized track-and-capture task assessed using a weighted performance score that integrates accuracy, speed, and task success metrics. Scores are scaled from 0 to 100, with higher scores indicating better performance. Participants used dual-hand controllers to grapple a simulated spacecraft in a time-limited, physics-based environment. Performance was assessed during task execution concurrent with stimulation.
ROBoT-r Task Performance Score (Post-Stimulation)
Time Frame: 15 minutes post stimulation
Performance on the ROBoT-r task 15 minutes after completion of tES. Performance is quantified using a weighted composite score. Scores range from 0 to 100, with higher scores indicating better overall task performance.
ROBoT-r Task Performance Score (Post-Stimulation Follow-up)
Time Frame: 24 and 48 hours post-stimulation
Performance on ROBoT-r task at 24 and 48 hours after completion of tES. Performance is quantified using a weighted composite score. Scores range from 0 to 100, with higher scores indicating better overall task performance.
Secondary Outcomes
- tES Adverse Effects Questionnaire(Immediately following each stimulation session (active and sham), up to approximately 45 minutes per session.)
- fNIRS Data Availability(Throughout study sessions when fNIRS was collected (during stimulation and post-stimulation follow-ups).)
Investigators
Gary E. Strangman
Principle Investigator
Massachusetts General Hospital