Differential Change in Oculomotor Performance among Female Collegiate Soccer Players versus Non-Contact Athletes from Pre- to Post-Season

Abstract

Sensitive and reliable tools are needed to evaluate potential behavioral and cognitive changes following head impact exposure in contact and collision sport participation. We evaluated change in oculomotor testing performance among female, varsity, collegiate athletes following variable exposure to head impacts across a season. Female, collegiate, contact sport (soccer, CONT) and non-contact sport (NON-CONT) athletes were assessed pre-season and post-season. Soccer athletes were grouped according to total season game headers into low dose (≤40 headers; CONT-Low Dose) or high dose (>40 headers; CONT-High Dose) groups. Performance on pro-saccade (reflexive visual response), anti-saccade (executive inhibition), and memory-guided saccade (MGS, spatial working memory) computer-based laboratory tasks were assessed. Primary saccade measures included latency/reaction time, inhibition error rate (anti-saccade only), and spatial accuracy (MGS only). NON-CONT (n = 20), CONT-Low Dose (n = 17), and CONT-High Dose (n = 7) groups significantly differed on pre-season versus post-season latency on tasks with executive functioning demands (anti-saccade and MGS, p ≤ 0.001). Specifically, NON-CONT and CONT-Low Dose demonstrated shorter (i.e., faster) anti-saccade (1.84% and 2.68%, respectively) and MGS (5.74% and 2.76%, respectively) latencies from pre-season to post-season, whereas CONT-High Dose showed 1.40% average longer anti-saccade, and 0.74% shorter MGS, latencies. NON-CONT and CONT-Low Dose demonstrated reduced (i.e., improved) inhibition error rate on the anti-saccade task at post-season versus pre-season, whereas CONT-High Dose demonstrated relative stability (p = 0.021). The results of this study suggest differential exposure to subconcussive head impacts in collegiate female athletes is associated with differential change in reaction time and inhibitory control performances on executive saccadic oculomotor testing.

Keywords: oculomotor; repetitive head impacts; saccade testing; soccer subconcussion.

FIG. 1.

Pro-saccade latency by visit, group, and condition. Error bars represent standard error of the mean. Compared to pre-season performance, CONT-High Dose trended toward longer latency at post-season particularly on gap and overlap conditions, to a greater degree than CONT-Low Dose and NON-CONT (visit-by-group-by-condition interaction effect, p = 0.082).

FIG. 2.

Anti-saccade latency by visit, group, and condition. Error bars represent standard error of the mean. Compared with pre-season performance, NON-CONT demonstrated shorter post-season latency to a greater degree than CONT-Low Dose, whereas CONT-High Dose demonstrated longer post-season versus pre-season latency on no gap and overlap conditions (visit-by-group-by-condition effect, p = 0.001).

FIG. 3.

Anti-saccade error rate by visit, group, and condition. Error bars represent standard deviation. Compared with pre-season performance, NON-CONT and CONT-Low Dose demonstrated greater reduction in anti-saccade error rate at post-season compared with CONT-High Dose (p = 0.021).

FIG. 4.

Memory-guided saccade latency by visit, group, and condition (delay period interval). Error bars represent standard error of the mean. NON-CONT demonstrated 5.74% shorter, CONT-Low Dose 2.76% shorter, and CONT-High Dose 0.79% shorter average post-season versus pre-season latency, with greater effects observed on the 1-sec and 2-sec delay conditions (visit-by-group-by-condition and visit-by group effects, p < 0.001).