An interventional study of Sparrow Hawk (Active) and Sparrow Hawk (Sham) in Acute Stress Reaction and Cognitive Performance, sponsored by Spark Biomedical, Inc.. Completed at 1 site in United States. Open to participants aged 18 Years to 41 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-08-01.
Sponsored by Spark Biomedical, Inc. · Not applicable, Interventional, and Treatment
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.
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.
Exclusion Criteria:
Prophylactic Active participants will undergo 20 minutes of active tAN while remaining seated and idle. After stimulation, participants will proceed into the 20-minute stressor protocol.
Device: Sparrow Hawk (Active)
Prophylactic Sham participants will undergo 20 minutes of sham stimulation while remaining seated and idle. After stimulation, participants will proceed into the 20-minute stressor protocol.
Device: Sparrow Hawk (Sham)
Acute Active participants will begin the stressor protocol immediately after baseline assessments. After a 5-min period of the stressor protocol without any intervention, active tAN treatment will be delivered concurrently for the remainder of the stressor protocol for a total of 20 minutes of stimulation and approximately 25 minutes of the stressor protocol.
Device: Sparrow Hawk (Active)
Acute Sham participants will begin the stressor protocol immediately after baseline assessments. After a 5-min period of the stressor protocol without any intervention, sham stimulation will be delivered concurrently for the remainder of the stressor protocol for a total of 20 minutes of stimulation and approximately 25 minutes of the stressor protocol.
Device: Sparrow Hawk (Sham)
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.
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.
Match-to-Sample Task (MST)
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.
Time frame: From baseline to post-stressor (up to 3 hours)
Psychomotor Vigilance Task (PVT)
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.
Time frame: From baseline to post-stressor (up to 3 hours)
Perdue Pegboard Task (PPT)
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.
Time frame: From baseline to post-stressor (up to 3 hours)
Maastricht Acute Stress Test (MAST)
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.
Time frame: After baseline tasks, approximately 35 minutes
Mean change in performance on the MST in the active tAN groups (Groups 1 and 3) compared to sham groups (Groups 2 and 4).
Mean change in performance on the MST in combination with PVT and PPT
Time frame: From baseline to post-stressor (up to 3 hours)
Mean change in performance on the PVT in the active tAN groups (Groups 1 and 3) compared to sham groups (Groups 2 and 4).
Mean change in performance on the PVT in combination with MST and PPT
Time frame: From baseline to post-stressor (up to 3 hours)
Mean change in performance on the PPT in the active tAN groups (Groups 1 and 3) compared to sham groups (Groups 2 and 4).
Mean change in performance on the PPT in combination with MST and PVT
Time frame: From baseline to post-stressor (up to 3 hours)
Mean change in performance on the MTS in the prophylactic active tAN group (Group 1) compared to the acute active tAN group (Group 3).
Mean change in performance on the MST in combination with PVT and PPT
Time frame: From baseline to post-stressor (up to 3 hours)
Mean change in performance on the PVT in the prophylactic active tAN group (Group 1) compared to the acute active tAN group (Group 3).
Mean change in performance on the PVT in combination with MST and PPT
Time frame: From baseline to post-stressor (up to 3 hours)
Mean change in performance on the PPT in the prophylactic active tAN group (Group 1) compared to the acute active tAN group (Group 3).
Mean change in performance on the PPT in combination with MST and PVT
Time frame: From baseline to post-stressor (up to 3 hours)
Change in working memory as measured by performance on the MST
Time frame: From baseline to post-stressor (up to 3 hours)
Change in reaction time as measured by performance on the PVT
Time frame: From baseline to post-stressor (up to 3 hours)
Change in dexterity as measured by performance on the PPT
Time frame: From baseline to post-stressor (up to 3 hours)
Change in heart rate variability in milliseconds (ms) across groups
Biomarker data will be collected throughout the study using wearable sensors, including the off-the-shelf Empatica E4 smart watch and the Corti SweatSensor.
Time frame: From baseline, during the stressor, and post-stressor (up to 3 hours)
Change in heart rate in beats per minute (bpm) across groups
Biomarker data will be collected throughout the study using wearable sensors, including the off-the-shelf Empatica E4 smart watch and the Corti SweatSensor.
Time frame: From baseline, during the stressor, and post-stressor (up to 3 hours)
Change in electrodermal activity across groups
Biomarker data will be collected throughout the study using wearable sensors, including the off-the-shelf Empatica E4 smart watch and the Corti SweatSensor.
Time frame: From baseline, during the stressor, and post-stressor (up to 3 hours)
Change in cortisol levels across groups
Biomarker data will be collected throughout the study using wearable sensors, including the off-the-shelf Empatica E4 smart watch and the Corti SweatSensor.
Time frame: From baseline, during the stressor, and post-stressor (up to 3 hours)
Change in Interleukin-6 (IL-6) levels across groups
Biomarker data will be collected throughout the study using wearable sensors, including the off-the-shelf Empatica E4 smart watch and the Corti SweatSensor.
Time frame: From baseline, during the stressor, and post-stressor (up to 3 hours)
Change in melatonin levels across groups
Biomarker data will be collected throughout the study using wearable sensors, including the off-the-shelf Empatica E4 smart watch and the Corti SweatSensor.
Time frame: From baseline, during the stressor, and post-stressor (up to 3 hours)
Change in Tumor Necrosis Factor Alpha (TNF-α) levels across groups
Biomarker data will be collected throughout the study using wearable sensors, including the off-the-shelf Empatica E4 smart watch and the Corti SweatSensor.
Time frame: From baseline, during the stressor, and post-stressor (up to 3 hours)
Change in self-reported stress across groups using the Stress Monitoring and Response Tool (SMART)
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.
Time frame: Before baseline to after post-stressor tasks (up to 3 hours; assessment valid up to 24 hours after event))
Mean therapeutic stimulation intensity
amplitude in milliamperes (mA)
Time frame: From start to end of tAN (30 minutes)
This study is completed, as verified in Jul 2025. You cannot join it, but the record below documents what was studied.
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Stress Disorders, Traumatic, Acute→
Spark Biomedical, Inc.