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Completed

NCT Number: NCT06390267

Effect of Transcutaneous Auricular Neurostimulation on Cognitive Performance in a Laboratory Model of Acute Stress Reaction

The objective of this study is to test the effects of transcutaneous auricular neurostimulation (tAN) in treating or preventing performance degradation after an acute stressor.

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Key information

Conditions

Acute Stress Reaction Cognitive Performance Mental Disorders Stress Disorders, Traumatic Stress Disorders, Traumatic, Acute Trauma and Stressor Related Disorders

Age range

18 year–41 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Battelle Memorial Institute

Columbus, Ohio, 43201, United States

About this study

This study is designed as a randomized, double-blind, sham-controlled trial. Sixty healthy, able-bodied participants will be randomized 1:1:2:2 into one of four experimental groups:

Group 1: Active tAN for prophylactic treatment prior to acute stress exposure (N=10)

Group 2: Sham stimulation for prophylactic treatment prior to acute stress exposure (N=10)

Group 3: Active tAN for acute treatment during acute stress exposure (N=20)

Group 4: Sham stimulation for acute treatment during acute stress exposure (N=20)

Participants will complete a baseline performance of three tasks. tAN treatment will then be administered prior to or during an acute stress test. Participants will complete the same three tasks preformed at baseline. In addition to the tAN therapy earpiece, subjects will have biosensors attached to them to collect biomarker information.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Adults 18 to 41 years old
  • Participant has the cognitive and physical abilities to carry out the study tasks
  • Proficient in the English language
  • Ability to understand the explanations and instructions given by the study personnel

Exclusion criteria

  • Participant presents current evidence of an uncontrolled and/or clinically significant medical condition or psychiatric condition
  • Participant has used any psychological stress-management intervention within the last 4 weeks
  • Participant is participating in another interventional trial within 90 days prior to or throughout duration of trial
  • Participant has a prior diagnosis of post-traumatic stress disorder, acute stress disorder, or generalized anxiety disorder
  • Participant is currently using anti-anxiety medications such as Xanax or beta blockers
  • Participant has a diagnosis of attention deficit hyperactivity disorder (ADHD) and/or is currently taking medications for the treatment of ADHD.
  • History of substance abuse or drug dependence including nicotine and alcohol in the past 3 months
  • Participant has abnormal ear anatomy, ear infection present, or earpiercing that could interfere with stimulation
  • Participant has a history of epileptic seizures
  • Participant has a history of neurologic diseases or traumatic brain injury
  • Participant wears or utilized other devices that cannot be removed during the study (e.g., pacemakers, cochlear prostheses, neurostimulators)
  • Females who are pregnant or lactating
  • Participant has any other significant disease or disorder which, in the opinion of the Investigator, may either put the participants are risk because of participation in the trial, or may influence the result of the trial, or the participant's ability to participate in the trial

Treatment and study plan

Sparrow Hawk (Active)

Device

Wearable, battery-operated, device designed to transcutaneously stimulate nerves on and/or around the auricle. The device will be used to deliver tAN sessions of active (prophylactic or acute) therapy according to the participant's randomization group.

Sparrow Hawk (Sham)

Device

Wearable, battery-operated, device designed to transcutaneously stimulate nerves on and/or around the auricle. The device will be used to deliver tAN sessions of sham (prophylactic or acute) therapy according to the participant's randomization group.

Primary outcomes

  1. Match-to-Sample Task (MST)

    Time frame: From baseline to post-stressor (up to 3 hours)

    Mean change in performance on the MST (in combination with the Psychomotor Vigilance Task (PVT) and Perdue Pegboard Task (PPT)) in the active tAN acute treatment group (Group 3) compared to sham acute treatment group (Group 4). The MST assesses short-term spatial memory (working memory) and pattern recognition skills. An 8 × 8 matrix of a red and green checkerboard pattern will be presented for 10 seconds, then removed, and then followed by a variable delay of 8 or 16 seconds. Two matrices will then be presented: the original matrix and a matrix with the color of 2 squares reversed. The subjects will attempt to select the original matrix. The task consists of 30 trials, ≈15 for each delay. A response (left or right arrow key) is required within 10 s, or a time-out error will be recorded. Correct matches were recorded, as was reaction time. This test takes less than 5 minutes to complete.

  2. Psychomotor Vigilance Task (PVT)

    Time frame: From baseline to post-stressor (up to 3 hours)

    Mean change in performance on the PVT (in combination with the MST and PPT) in the active tAN acute treatment group (Group 3) compared to sham acute treatment group (Group 4). The PVT is a test of visual reaction time. A series of stimuli are presented at random intervals on a screen, and the subject responds as rapidly as possible when a stimulus appears. Response time, false alarms, and the number of lapses (long duration responses) will be recorded. Performance lapses refer to the instances when a subject failed to respond in <500 ms. This test will be administered on a computer monitor or tablet.

  3. Perdue Pegboard Task (PPT)

    Time frame: From baseline to post-stressor (up to 3 hours)

    Mean change in performance on the PTT (in combination with the PVT and MST) in the active tAN acute treatment group (Group 3) compared to sham acute treatment group (Group 4). The PPT is a psychomotor test of manual dexterity and bimanual coordination. A pegboard consisting of two parallel sets of twenty-five holes arranged vertically is presented to the participant, and they are asked to remove pegs from concave cups at the top of the board and place them in the holes sequentially as rapidly as possible. The number of pegs placed successfully in thirty seconds is scored. Each participant is tested three times using both hands.

  4. Maastricht Acute Stress Test (MAST)

    Time frame: After baseline tasks, approximately 35 minutes

    The MAST is a safe, non-invasive, and expedited method to create a stress response in human subjects under laboratory conditions. The test combines two well-validated laboratory stress paradigms, the Trier Social Stress Test (TSST) and the Cold Pressor Test (CPT) into a single protocol. The MAST is effective in increasing salivary cortisol, increasing blood pressure, salivary alpha-amylase, and eliciting subjective stress reactions. Participants will be videotaped and monitored to analyze their facial expressions. They will undergo multiple hand immersion trials (HIT) in which they have to immerse their hand in ice-cold (2 °C) water. They will engage in mental arithmetic trials (MAT), counting backwards starting at 2043 in steps of 17 as fast and accurate as possible. For each mistake made, the experimenter will provide negative feedback and instruct them to start over at 2043.

Secondary outcomes

  1. Mean change in performance on the MST in the active tAN groups (Groups 1 and 3) compared to sham groups (Groups 2 and 4).

    Time frame: From baseline to post-stressor (up to 3 hours)

    Mean change in performance on the MST in combination with PVT and PPT

  2. Mean change in performance on the PVT in the active tAN groups (Groups 1 and 3) compared to sham groups (Groups 2 and 4).

    Time frame: From baseline to post-stressor (up to 3 hours)

    Mean change in performance on the PVT in combination with MST and PPT

  3. Mean change in performance on the PPT in the active tAN groups (Groups 1 and 3) compared to sham groups (Groups 2 and 4).

    Time frame: From baseline to post-stressor (up to 3 hours)

    Mean change in performance on the PPT in combination with MST and PVT

  4. Mean change in performance on the MTS in the prophylactic active tAN group (Group 1) compared to the acute active tAN group (Group 3).

    Time frame: From baseline to post-stressor (up to 3 hours)

    Mean change in performance on the MST in combination with PVT and PPT

  5. Mean change in performance on the PVT in the prophylactic active tAN group (Group 1) compared to the acute active tAN group (Group 3).

    Time frame: From baseline to post-stressor (up to 3 hours)

    Mean change in performance on the PVT in combination with MST and PPT

  6. Mean change in performance on the PPT in the prophylactic active tAN group (Group 1) compared to the acute active tAN group (Group 3).

    Time frame: From baseline to post-stressor (up to 3 hours)

    Mean change in performance on the PPT in combination with MST and PVT

  7. Change in working memory as measured by performance on the MST

    Time frame: From baseline to post-stressor (up to 3 hours)

  8. Change in reaction time as measured by performance on the PVT

    Time frame: From baseline to post-stressor (up to 3 hours)

  9. Change in dexterity as measured by performance on the PPT

    Time frame: From baseline to post-stressor (up to 3 hours)

Other outcomes

  1. Change in heart rate variability in milliseconds (ms) across groups

    Time frame: From baseline, during the stressor, and post-stressor (up to 3 hours)

    Biomarker data will be collected throughout the study using wearable sensors, including the off-the-shelf Empatica E4 smart watch and the Corti SweatSensor.

  2. Change in heart rate in beats per minute (bpm) across groups

    Time frame: From baseline, during the stressor, and post-stressor (up to 3 hours)

    Biomarker data will be collected throughout the study using wearable sensors, including the off-the-shelf Empatica E4 smart watch and the Corti SweatSensor.

  3. Change in electrodermal activity across groups

    Time frame: From baseline, during the stressor, and post-stressor (up to 3 hours)

    Biomarker data will be collected throughout the study using wearable sensors, including the off-the-shelf Empatica E4 smart watch and the Corti SweatSensor.

  4. Change in cortisol levels across groups

    Time frame: From baseline, during the stressor, and post-stressor (up to 3 hours)

    Biomarker data will be collected throughout the study using wearable sensors, including the off-the-shelf Empatica E4 smart watch and the Corti SweatSensor.

  5. Change in Interleukin-6 (IL-6) levels across groups

    Time frame: From baseline, during the stressor, and post-stressor (up to 3 hours)

    Biomarker data will be collected throughout the study using wearable sensors, including the off-the-shelf Empatica E4 smart watch and the Corti SweatSensor.

  6. Change in melatonin levels across groups

    Time frame: From baseline, during the stressor, and post-stressor (up to 3 hours)

    Biomarker data will be collected throughout the study using wearable sensors, including the off-the-shelf Empatica E4 smart watch and the Corti SweatSensor.

  7. Change in Tumor Necrosis Factor Alpha (TNF-α) levels across groups

    Time frame: From baseline, during the stressor, and post-stressor (up to 3 hours)

    Biomarker data will be collected throughout the study using wearable sensors, including the off-the-shelf Empatica E4 smart watch and the Corti SweatSensor.

  8. Change in self-reported stress across groups using the Stress Monitoring and Response Tool (SMART)

    Time frame: Before baseline to after post-stressor tasks (up to 3 hours; assessment valid up to 24 hours after event))

    The SMART tool is a patient-reported assessment of acute stress. The questionnaire contains questions asking the participant to rate their severity of stress related symptoms on a scale of 0 ("none") to 10 ("severe"). Symptoms include feeling worthless, sad, distant, irritable, headaches, dizziness, fatigue, nausea, difficulty concentrating, pain, etc. This study will ask participants 23 questions on the SMART tool based on their recent experiences.

  9. Mean therapeutic stimulation intensity

    Time frame: From start to end of tAN (30 minutes)

    amplitude in milliamperes (mA)

Sponsors and collaborators

Lead sponsor

Spark Biomedical, Inc.

Industry

Collaborators

  • Battelle Memorial Institute
  • United States Department of Defense

Registry information

Acronym: ASR

Important dates

Study start
2024
Primary completion
2025
Study completion
2025
First posted
Apr 30, 2024
Registry last updated
Aug 1, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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