Page 82 - JSOM Spring 2026

and cognitive performance during an obstacle-clearance course FIGURE 1 Course map. Each of the “!” signs indicates where
with and without NVGs. We hypothesize that performance participants must step over a foam block. Each “X” indicates the
in marksmanship, cognitive assessments, and biomechanical point where the participant fired the simulated firearm at a target.
Calculators denote the cognitive assessment locations. Created in
function will decline during the NVG condition, which will BioRender. Smith, C. (2026) https://BioRender.com/d98jcfg
coincide with elevated rScO in the PFC, indicating greater
2
mental effort associated with NVG use.
[2.7M]
Methods [3.7M] [3.7M] [1.8M]

Participants [3.7M] [1.8M ]
A total of 12 civilian participants (4M, 8W) with a mean age [2.7M]
of 21 (SD .6) years participated in this study. Participants were [2.7M] Legend
required to be either United States citizens or legal permanent Start of course [3.7M]
Cognitive
residents between 18 and 35 years old. Recruitment occurred Assessment
on a college campus. Participants had varying levels of marks- [3.7M] Foam Block [2.7M]
manship experience. Individuals with significant uncorrected Marksmanship
Target
visual impairments or neuromuscular or musculoskeletal in-
[2.7M]
juries in the last six months were excluded. Informed consent [3.7M]
was obtained during a screening visit before being familiarized [1.8M]
with the fNIRS, pistol, and NVGs. NVGs were focused at 2.74 [1.8M] [3.7M] [3.7M]
meters away for target identification. The study was approved [2.7 M]
by the University’s Institutional Ethical Review Board and
aligned with the principles outlined within the Declaration of
Helsinki (approval no. 2123422).
magazine held 21 0.24 caliber BBs. All participants were in-
Experimental Procedures structed on how to use the simulated pistol during the screen-
Participants completed two separate testing sessions within ing visit. Participants engaged each of the six 23cm by 18cm
7 days. Each session lasted 20 minutes, with approximately 5 paper targets with two shots per target. Marksmanship 1 re-
minutes dedicated to completing the course and the remaining ferred to targets one, two, and three, and Marksmanship 2 re-
time spent on fitting, NVG focusing, and baseline measure- ferred to targets 4, 5, and 6. Targets were located 2.74m away
ments. Upon arrival, participants were fitted with the fNIRS from an X on the course, indicating the engagement location.
device and a tactical helmet. Participants followed a predeter- A maximum of 10 points per shot was possible, as depicted
mined course (Figure 1), completing it in light while wearing by Figure 2. There were 20 points possible per target, for a
a sham NVG and in darkness while wearing a real NVG. The maximum possible participant score of 120.
visit order was randomized to avoid ordering effects. FIGURE 2 Example of a paper target with a maximum score
of 10 points per shot. Created in BioRender. Smith, C. (2026)
Course https://BioRender.com/xxmeawe.
Participants navigated a taped path, stepping over 15.24cm
black foam blocks while a GoPro recorded their gait pattern
to calculate toe clearance, toe velocity, and ankle dorsiflexion.
Participants continued to the marked “X” spots to engage tar-
gets, repeating this sequence before performing the cognitive
assessment task. Course direction was randomized, and each
direction had identical distances, obstacles, and difficulty.

Cognitive Assessment 5 6 7 8 9
Cognitive assessment tasks were divided into Task 1 and Task 2,
as illustrated in Figure 1. Each cognitive assessment task station
presented five numbered cards spread across a 2.4 meter-long
table. Question specifics were adjusted per condition and task
number to prevent familiarity bias, but question difficulty re-
mained unchanged. During the control visit, participants (1)
identified all odd numbers, (2) added the three right-most num-
bers, (3) subtracted the second largest from the largest number,
(4) added all even numbers, and (5) listed numbers between 20
and 30. During the NVG condition, participants (1) identified
all even numbers, (2) added the three left-most numbers, (3) Night Vision Goggles
subtracted the smallest from the largest number, (4) added all The EOTECH Night Vision Binocular goggles (model BINO-
odd numbers, and (5) listed numbers between 10 and 20. Par- A-I-B-C, featuring ×1 magnification) (EOTECH, Plymouth,
ticipants received 1 point for each correct answer. MI) were affixed to an Advanced Combat Helmet (ACH) with
a Wilcox mount during the NVG visit. During the control
Marksmanship condition, participants wore the ACH with a weight-matched
A Sig Sauer Proforce M18 Airsoft Pistol (Sig Sauer, Newing- sham NVG. These goggles provided a 40º field of view and
ton, NH) with green gas blowback was used for this study. The employed 4G white phosphor image intensification tubes.

80 | JSOM Volume 26, Edition 1 / Spring 2026