Sustaining Aviator Performance During Extended Operational Flight

NCT04697901 | Completed

• 1 other identifier: USAARL 2019-014; IRB M-10804
• Study Type: interventional
• Target: 26
• Locations: 1 country
• Sites: 1

Brief Summary

Future aviation operations are anticipated to change as advances in technology enable automation of more tasks. Development of new platforms under the Future Vertical Lift program are also anticipated to change the nature of missions as they are being designed to cover further distances. Longer duration flights coupled with greater automated features are expected to shift the role of the aviator, resulting in an increased need for attention maintenance, which creates potential problems related to performance. To offset the likelihood of performance decrements related to the need to sustain attention, we propose examining the use of transcranial electrical current stimulation. In the present study, we will evaluate whether delivery of stimulation prior to or during the task enables sustainment of attention and thereby reduces performance decrements as measured through primary flight tasks and a secondary attentional task. Further, we will evaluate whether stimulation enhances the ability to respond to an unexpected emergency toward the end of the flight.

Conditions

Transcranial Direct Current Stimulation

Outcome Measures

Primary Outcomes (6)

• Rapid Visual Information Processing Task

  Cognitive function - sustained attention The RVIP is a well-validated measure of sustained attention (Bakan, 1959). In each trial, subjects are presented with a sequence of digits and must detect "target" sequences within those presented. The target sequence is an even-odd-even string of numbers. When participants detect this string, they press the spacebar as quickly as possible. Difficulty is manipulated by changing the speed at which the numbers are presented (1 vs. 2 seconds).

  7 min

• Continuous Performance Task

  Cognitive function - sustained attention The continuous performance task (Conners \& Sitarenios, 2011) is a well validated measure of sustained attention and response inhibition. In this task, subjects are presented with a series of letters and are instructed to respond when they see any letter except for the letter X. Subjects are presented with 360 trials with varied intervals of 1, 2, and 4 seconds. Total time to complete this task is 14 minutes.

  14 min

• Flight performance - primary task

  Simulated flight 90 min simulated flight scenario in a UH60 simulator.

  90 min

• Flight performance - secondary task

  Simulated flight with visual secondary task A visual task presented during the flight requiring monitoring.

  90 min

• Response to emergency

  Simulated emergency that requires response during flight.

  1 - 5 min

• Physiological response

  EEG recording before and after stimulation.

  90 min

Secondary Outcomes (6)

• Flight experience

  10 min

• Behavioral Scales Behavioral Inhibition / Avoidance Scale

  10 min

• Samn-Perelli Fatigue Scale

  1 min

• Short Stress State Questionnaire

  2 min

• 40 Mini-Marker Personality Scale

  10 min

Other Outcomes (12)

• Adult ADHD Self Report Scale Symptom Checklist

  2 min

• Sleep Timing Questionnaire

  3 min

• Beck Depression Inventory

  2 min

Study Arms (2)

Active Stimulation

EXPERIMENTAL

Active tDCS stimulation will be applied.

Device: Active Transcranial Direct Current Stimulation (tDCS)

Sham Stimulation

SHAM COMPARATOR

Sham tDCS stimulation will be applied.

Device: Sham Transcranial Direct Current Stimulation (tDCS)

Interventions

Active Transcranial Direct Current Stimulation (tDCS) DEVICE

Active simulation will be applied to the right PPC. To target this region for stimulation, the anode electrode will be placed on the subject using the 10-20 EEG system as reference location (Thair et al., 2017). Stimulation intensity for all conditions will be set to 2 mA, which was chosen based on previous studies that have compared 1 mA to 2 mA and found the higher intensity produced reliable changes to performance (e.g., Moos et al., 2012). Total time of active stimulation will be the same for each group (20 minutes). Delivery times of the stimulation will vary based on Group assignment: Group A: During pre-flight brief/checklist, for 20 minutes. Group B: First delivered at 30 minutes into flight for 10 minutes, second delivered at 60 minutes into flight for 10 minutes.

Active Stimulation

Sham Transcranial Direct Current Stimulation (tDCS) DEVICE

Sham simulation will be applied to the right PPC. To target this region for stimulation, the anode electrode will be placed on the subject using the 10-20 EEG system as reference location (Thair et al., 2017). Stimulation intensity for all conditions will be set to 2 mA, which was chosen based on previous studies that have compared 1 mA to 2 mA and found the higher intensity produced reliable changes to performance (e.g., Moos et al., 2012). Total time of active stimulation will be the same for each group (20 minutes). Sham stimulation will consist of active stimulation for 120s, including the ramping up to 2 mA and down to no stimulation. Delivery times of the stimulation will vary based on Group assignment: Group A: During pre-flight brief/checklist, for 20 minutes. Group B: First delivered at 30 minutes into flight for 10 minutes, second delivered at 60 minutes into flight for 10 minutes.

Sham Stimulation

Eligibility Criteria

• Age: 18 Years - 40 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Must be a male 18 (Active Duty) or 19 (National Guard, Reservist) to 40 years old.
• Must be a rated rotary-wing aviator with at least 200 hours of total flight experience, and have flown (aircraft or simulator) within the past 6 months, assessed by self-report.
• Must have a current DD-2292 (up-slip indicating clear for flight duties). Subjects will self-report this on the medical history questionnaire (Appendix A).
• Must have obtained at minimum 6 hours of sleep prior to data collection, as assessed by actigraphy data and self-report.
• Must have refrained from consumption of caffeine and medications that cause drowsiness, 16 hours, nicotine, 2 hours, and alcohol, 24 hours, prior to the study, assessed by self-report.

You may not qualify if:

• Not having a current DD-2992.
• Currently taking medications which induce drowsiness, such as over-the-counter antihistamines. Any self-medication will be assessed through self-report
• No current medical conditions or medications affecting cognitive function or attention.
• Any history of any attention deficit condition requiring medication.
• Any history of psychological/psychiatric disorder.
• Any history of seizures, migraines, or neurological disorders.
• History of a head injury involving loss of consciousness.
• Any metal implanted within the head (e.g., shrapnel, surgical clips) or any implanted devices (e.g., cardiac pacemaker, brain stimulator, hydrocephalic shunt).
• Skin condition on the scalp, such as psoriasis or eczema, or wounds on the head.
• Currently receiving hormonal therapy treatments.
• Potential for caffeine withdrawal symptoms that will impede cognitive testing.

Sponsors & Collaborators

• United States Army Aeromedical Research Laboratory: lead

Study Sites (1)

U.S. Army Aeromedical Research Laboratory

Fort Rucker, Alabama, 36362, United States

Location

Study Officials

• Katie Feltman, PhD

  US Army Aeromedical Research Laboratory

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: FED
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: June 8, 2020
• First Posted: January 6, 2021
• Study Start: November 9, 2020
• Primary Completion: September 30, 2021
• Study Completion: September 30, 2021
• Last Updated: January 25, 2022

Record last verified: 2022-01

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)