Effects of participation in a simulated live-fire maneuver on cognitive performance of firefighters: An examination of individual differences

Firefighting involves numerous physical, mental, and environmental stressors that could potentially impact cognition and, ultimately, safety. PURPOSE: Examine the effects of participation in a live-fire maneuver on executive control of new-recruit firefighters immediately following supervised fireground operations and determine which select physiological variables [heart rate (HR)], psychological states (e.g., state anxiety), or perceptual responses (e.g., thermal sensation) relate to cognitive performance. Individual differences (e.g., aerobic fitness, personality) related to differing levels of cognitive performance in firefighters were also identified. METHODS: New-recruit, male firefighters (N = 85; 25.76 ± 4.06 yrs) participated in a live-fire night-burn drill as part of a 6-wk academy training program. This involved emergency response, fire attack, and sear-and-rescue (54:44 ± 4:56 mins). Computerized tests of cognitive inhibition (modified flanker task), attention (0-back task), and working memory (n-back task: 1-back, 2-back) were completed pre and post firefighting. Throughout the evening, HR was continuously recorded and affective and perceptual states of each firefighter (thermal sensation, RPE, respiratory distress, feelings, felt arousal, fatigue, anxiety) were recorded pre and post (Post-0, End) firefighting. On separate days, participants completed questionnaires assessing personality and other individual characteristics, and aerobic fitness was estimated from a 1.5-mile run time. RESULTS: RT was significantly shorter Post Drill than Pre Drill for both Congruent (Mdiff = -33.61±4.15 ms, p <.001, 95% CI: -41.92,-25.31) and Incongruent (Mdiff = -43.39±4.06 ms, p <.001, 95% CI: -51.51,-35.27) trials of the modified flanker task. Shorter RT was also demonstrated Post compared to Pre Drill for target (Mdiff = -84.43±22.68 ms, p < .001, 95% CI:-129.83,-39.03) and non-target (Mdiff = -145.61±23.49 ms, p < .001, 95% CI:-192.63,-98.60) trials on the 2-back task. On the other hand, RT on the 1-back task (to both non-targets and targets) did not significantly change pre to post drill (ps >.05) and 0-back RT to non-target trials became longer (Mdiff = 20.46±8.11 ms, p = .014, 95% CI: 4.22,36.70). Flanker accuracy significantly decreased for both congruent (Mdiff = -1.12±0.35%, p =.002, 95% CI: -1.82,-0.42) and incongruent (Mdiff = -3.00±0.80%, p <.001, 95% CI: -4.60,-1.40) trials from pre to post drill, with selectively greater decrement to incongruent trial accuracy accompanied by a diminished interference effect for RT (Mdiff = 9.77±2.23 ms, p <.001, 95% CI: 5.31,14.24) and an increase in interference accuracy (Mdiff = 1.88±0.67%, p = .007, 95% CI: 0.54,3.23). 0-back accuracy on target trials (Mdiff = -2.05±0.90%, p = .027, 95% CI:-3.85,-0.24) and d' (Mdiff = -0.11±0.04, p = .020, 95% CI:-0.19,-0.02) were significantly lower Post Drill than Pre Drill, with no significant change in accuracy on non-target trials. For the 1-back task, target trial accuracy (Mdiff = -5.00±1.38%, p = .001, 95% CI:-7.77,-2.23) and d’ (Mdiff = -0.33±0.10, p = .001, 95% CI:-0.52,-0.14) were significantly lower Post Drill than Pre Drill, with no significant change in non-target trial accuracy (p < .05). However, the nominal decrease in 2-back accuracy on target trials only approached significance, with no significant change in non-target trial accuracy or d'. A preliminary examination of individual-level factors, including physiological and perceptual responses to firefighting and personality, indicated potential ability to predict cognitive performance, but require future investigation. HR and dispositional resilience revealed the most steadfast relationships to performance. CONCLUSIONS: Current findings suggest a selective effect of firefighting performance on executive control processes, such that aspects of cognition requiring more control (such as incongruent trials on the flanker task and target trials on the n-back task) are more detrimentally affected by firefighting than less challenging counterparts (i.e., congruent trials and non-target trials). This provokes future investigation of the timing of cognitive changes, the extent to which scores on computerized assessments might reflect real-life firefighting performance, the possible manipulation of predictive factors to enhance performance through training, and the ability to recognize the need for rehabilitation and recovery in terms of cognitive function beyond physical needs.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Kinesiology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2016

Author dc:creator

• Greenlee, Tina A.

Contributors dc:contributor

• Petruzzello, Steven J.
• Hillman, Charles H.
• Horn, Gavin P.
• von Thaden, Terry

• firefighting
• stress
• individual differences
• cognitive performance
• working memory
• cognitive inhibition

Statement dc:rights

• Copyright 2016 Tina Greenlee

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/93045

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/93045