Page 17 - JSOM Summer 2025

Performance-based Differences in Prefrontal Cortex Activation

Assessing Dynamic Marksmanship Performance
Using Functional Near-Infrared Spectroscopy

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Owen F. Salmon, MS *; Thomas X. Statz ; Cierra B. Ugale, MS ; Matthew D. Segovia, MS ;
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Joshua R. Thompson, BS ; Hunter D. Dobbs, BS ; Rachel M. Rauth, BS ; Cory M. Smith, PhD 8

ABSTRACT
Introduction: Marksmanship is a fundamental skill for all essential for proficient performance in dynamic marksmanship
servicemembers. However, the underlying neurophysiolog- scenarios.
ical differences in performance among marksmen remain
unclear. Incorporating neurophysiological tracking such as The combined physical and psychological stress associated
functional near-infrared spectroscopy (fNIRS) may identify with real-world operations has been shown to result in per-
performance-based differences in prefrontal cortex (PFC) ac- ceptual distortions, tunnel vision, reduced fine motor skills,
tivation during dynamic marksmanship scenarios. This study and loss of situational awareness. We hypothesize that the
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examined cognitive load within the PFC during a simulated impaired marksmanship performance may be caused by exces-
dynamic marksmanship scenario in non-proficient and profi- sive strain on cognitive resources, leading to heightened PFC
cient marksmen. Methods: Twenty-four participants (12 men, activation as the servicemember is overwhelmed by competing
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12 women) wore an fNIRS device over their forehead during cognitive inputs, ultimately resulting in poor performance.
a simulated stationary pistol marksmanship task (to determine For example, Johnson and colleagues reported that 72% of the
proficiency status) and a dynamic shoot/no-shoot course of performance variability in proficient marksmen was accounted
fire (COF) (to assess cognitive load). Relative concentrations for by the activation over the frontal lobe, while only 37% of
of oxyhemoglobin (HbO ), deoxygenated hemoglobin (deoxy- performance variability was accounted for in non-proficient
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genated Hb), and total hemoglobin (total Hb) were tracked to marksman during a lethal force judgment exercise. Thus,
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quantify PFC activation differences in twelve proficient (≥80% quantifying the degree of cognitive load during operational
hit percentage) and twelve non-proficient (<80% hit percent- tasks, such as marksmanship and lethal force decision-making,
age) marksmen. Results: No difference in completion time was remains critical, highlighting the need for knowledge prod-
observed between groups during the dynamic COF (p=.34). ucts that can rapidly improve the operational performance of
However, non-proficient marksmen showed 26.3% higher non-proficient servicemembers.
HbO (p=.02) and 42.1% higher total Hb (p<.01) in the PFC
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compared to proficient marksmen. Conclusion: Tracking PFC Despite its importance, proficiency in marksmanship during
hemodynamic activity identified proficiency-based differences qualification courses generally consists of static assessments,
in cognitive load during a dynamic COF. Applying fNIRS where individuals have the foreknowledge of the drills, tar-
during marksmanship-related tasks may be useful in develop- gets, and distances they will be firing upon before being
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ing stress resilience and mission readiness for servicemembers. evaluated. While this standardized approach is useful for
categorizing general proficiency levels in weapon handling, its
Keywords: marksmanship; functional near-infrared translation to real-world dynamic lethal force scenarios may
spectroscopy; cerebral hemodynamics; motor skills; be limited. 12–14 To better quantify mission readiness in terms
psychomotor performance; task performance and of marksmanship ability, it is essential to look beyond perfor-
analysis; military mance outcome metrics, such as hit percentage, and look into
the cognitive load associated with marksmanship tasks. 15–17

Functional near-infrared spectroscopy (fNIRS) is a portable,
Introduction
non-invasive neuroimaging technique that quantifies relative
Marksmanship is a critical sensorimotor skill required for all changes in oxygenated hemoglobin (HbO ) and deoxygenated
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active duty servicemembers regardless of their military occupa- hemoglobin (Hb) to infer neural activation in brain regions
tional specialty. Under dynamic marksmanship environments, associated with cognitive and motor tasks. 18–20 Recently, fNIRS
optimizing marksmanship performance requires complex cog- has been applied to the prefrontal cortex (PFC) to identify dif-
nitive processes that are heavily influenced by the prefrontal ferences in hemodynamic activity during cognitive and dex-
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cortex (PFC). The PFC plays a crucial role in executive func- terity tasks based on proficiency levels. 21–24 It is effective for
tion, adaptive behavior, and higher-order cognitive processes tracking PFC activity, such as executive function, inhibitory
*Correspondence to owen_salmon1@baylor.edu
1 Owen F. Salmon, Thomas X. Statz, Cierra B. Ugale, Matthew D. Segovia, Joshua R. Thompson, Hunter D. Dobbs, Rachel M. Rauth, and
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8 Dr. Cory M. Smith are affiliated with Robbins College of Health and Human Sciences, Human & Environmental Physiology Laboratory, De-
partment of Health, Human Performance and Recreation, Baylor University, Waco, TX.
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