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CompletedNCT04155333Updated Jan 25, 2022

Effects of Non-Invasive Brain Stimulation on Soldiers' Cognitive and Functional Performance

An interventional study of Transcranial direct current stimulation in Performance Enhancement, sponsored by United States Army Aeromedical Research Laboratory. Completed at 1 site in United States. Open to participants aged 18 Years to 40 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2022-01-25.

Sponsored by United States Army Aeromedical Research Laboratory · Not applicable, Interventional, and Basic science

Phase
Not applicable
Study type
Interventional
Enrollment
28
Allocation
Randomized
Ages
18 Years to 40 Years
Sex
All
01

Study summary

Non-invasive brain stimulation has been shown to alter performance in both clinical and healthy populations on cognitive tasks. While the performance alterations have generally been shown to result in enhancement, mixed results remain in the literature. Much of the mixed results within the literature have been attributed to the use of different stimulation parameters, targeting of different brain areas, and using a variety of performance measures or assessing different constructs. However, non-invasive brain stimulation is a desirable method for enhancing Soldier performance given the ease of administration and minimal side effects as compared to other forms of performance enhancement (e.g., pharmaceuticals, caffeine). The objective of the current study is to evaluate the effects of non-invasive brain stimulation to the left dorsolateral prefrontal cortex in enhancing Soldier cognitive skills and performance on military tasks. A double blind within-subjects design will be used with healthy, rested Soldiers who will receive non-invasive brain stimulation and perform basic cognitive and operationally relevant tasks.

02

Conditions studied

  • Performance Enhancement
03

In context

Lead sponsor

United States Army Aeromedical Research Laboratory is the lead sponsor of 5 studies on the registry; none are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 40 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  1. Must be 18 (if active duty), 19 (if non-active duty) up to 40 years old.
  2. Must have normal hearing, vision or corrected to normal vision, and cognitive function as determined by self-report and screening by study physician
  3. Must have obtained at minimum 6 hours of sleep prior to data collection, as assessed by actigraphy data and self-report.
  4. Must have refrained from consumption of caffeine, 16 hours, nicotine, 2 hours, and alcohol, 24 hours, prior to the study, assessed by self-report.

Exclusion criteria

Exclusion Criteria:

  1. The following medically-related exclusionary criteria will be used, as assessed and verified by the study physician:

    1. Haven taken any medications which induce drowsiness, such as over-the-counter antihistamines within 24 hours of participation in the study. Any self-medication will be assessed through self-report
    2. No current medical conditions or medications affecting cognitive function or attention.
    3. Any history of any attention deficit condition requiring medication.
    4. Any history of psychological/psychiatric disorder.
    5. Any history of seizures, migraines, or neurological disorders.
    6. History of a head injury involving loss of consciousness.
    7. Any metal implanted within the head (e.g., shrapnel, surgical clips) or any implanted devices (e.g., cardiac pacemaker, brain stimulator, hydrocephalic shunt).
    8. Skin condition on the scalp, such as psoriasis or eczema, or wounds on the head.
    9. Currently receiving hormonal therapy treatments, other than or as determined by physicians.
    10. Potential for caffeine withdrawal symptoms that will impede cognitive testing.
  2. Females with a known pregnancy, who test positively for pregnancy, or refuse the test will be excluded, given the lack of available research regarding the effects of tDCS during pregnancy. Known pregnancy will be assessed during screening, females without a known pregnancy will be requested to provide a urine sample during the screening procedures to ensure the absence of pregnancy.
Terms in these criteria, in plain language(1)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

05

Study design

Phase
Not applicable
Primary purpose
Basic science
Allocation
Randomized
Intervention model
Crossover assignment
Masking
Single (Investigator)
Enrollment
28 participants (actual)

Study arms

  • Experimental
    Active anodal stimulation

    active anodal stimulation at F3, cathode placed on contralateral bicep

    Device: Transcranial direct current stimulation

  • Experimental
    Active cathodal stimulation

    active cathodal stimulation at F3, anode placed on contralateral bicep

    Device: Transcranial direct current stimulation

  • Sham comparator
    Sham stimulation

    sham stimulation that will be counterbalanced between subjects such that half will receive sham stimulation configured as condition 1 (anode F3, cathode bicep) and half will receive condition 2 (cathode F3, anode bicep)

    Device: Transcranial direct current stimulation

Interventions

  • DeviceTranscranial direct current stimulation

    Transcranial direct current stimulation (tDCS) is a form of non-invasive brain stimulation that stimulates the brain through the application of a low-intensity electrical current, typically ranging from 1 to 2 milliamps (mA), via electrodes placed on an individual's scalp. During the active stimulation sessions, 2 mA of stimulation will be applied for 30 minutes. During the sham stimulation session, 2 mA of stimulation will be applied over the course of 90 sec, the electrodes will remain in place for the 30 minute duration.

06

What researchers measure

Primary outcomes

  1. Military task performance

    Patrol exertion multitask

    Time frame: Folllowing stimulation; task lasts approximately 20 min

  2. Military task performance

    Target acquisition

    Time frame: Folllowing stimulation; task lasts approximately 40 min

  3. Cognitive function - Selective Attention

    Stroop test

    Time frame: Approximately 3 minutes during stimulation

  4. Cognitive function - Multitasking/Working Memory

    Dual n-back

    Time frame: Approximately 5 minutes during stimulation

  5. Cognitive function - Working Memory

    Digit span task

    Time frame: Approximately 2 minutes during stimulation

  6. Cognitive function - Sustained attention

    Rapid Visual Information Processing Task

    Time frame: Approximately 7 minutes during stimulation

  7. Cognitive function - Executive function

    Shifting Attention Task: Digit symbol substitution task

    Time frame: Approximately 2 minutes during stimulation

Secondary outcomes

  1. Cognitive function - Impulsivity/Motor Control

    Stop signal task - response inhibition

    Time frame: Approximately 3 minutes after stimulation

  2. Cognitive function - Risk Taking/ Decision Making

    Delayed Discounting Task

    Time frame: Approximately 1 minute after stimulation

  3. Cognitive function - Cognitive Flexibility

    Uses Task

    Time frame: Approximately 5 minutes after stimulation

Other outcomes

  1. Confounding factor - Sleepiness

    Karolinska Sleepiness Scale

    Time frame: Approximately 1 minute, before and after stimulation

  2. Confounding factor - Circadian typology

    Morningness-Eveningness Questionnaire

    Time frame: Approximately 15 minutes during intake

  3. Moderator variable - Intelligence

    Shipley's Institute of Living Scale

    Time frame: Approximately 15 minutes during intake

  4. Moderator variable - Trait motivation

    Behavioral Avoidance/ Inhibition Scales

    Time frame: Approximately 10 minutes during intake

  5. Side effects - mood symptoms

    Profile of Mood States - Short Form

    Time frame: Approximately 3 minutes before and after stimulation

  6. Side effects - Physical side effects

    Symptom Checklist

    Time frame: Approximately 2 minutes before and after stimulation

  7. Side effects - Physiology/health

    Welch Allyn Connex 6000

    Time frame: Approximately 5 minutes before and after stimulation

07

Study locations

1 site
  • U.S. Army Aeromedical Research Laboratory
    Fort Rucker, Alabama 36362, United States
08

References and documents

Study documents

PDFs hosted by the registry, ClinicalTrials.gov.

Individual participant data

Plan to share: No

09

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reached

Ran from Dec 2019 to primary completion in Jun 2021, 17 months.

How these figures are worked out, and which studies are left out of them.

Registered
Nov 5, 2019
First posted
Nov 7, 2019
StartActual
Dec 12, 2019
Primary completionActual
Jun 1, 2021
CompletionActual
Sep 30, 2021
Last update
Jan 25, 2022
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Jan 25, 2022, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT04155333
Lead sponsor
United States Army Aeromedical Research Laboratory
Responsible party
Sponsor
First posted
Nov 7, 2019
Start date
Dec 12, 2019
Primary completion
Jun 1, 2021
Completion
Sep 30, 2021
Last update
Jan 25, 2022

Study contacts

Katie Feltman, PhD
principal investigator · US Army Aeromedical Research Laboratory

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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