Abstract
BACKGROUND: Concussion has been a major public health concern due to the substantial cognitive sequelae it results. Although the dysfunctions of the frontal lobe and corpus callosum owing to concussions have been documented, the existing concussion screening tools merely examine cognitive functions in isolation of motor functions and failed to detect the chronic cognitive-motor impairments following concussions. Yet, there has been no concussion screening test aimed specifically to assess the coupled cognitive-motor functions. OBJECTIVE: This study aimed to provide preliminary evidence for using computerized eye-hand coordination tasks to detect chronic cognitive-motor deficits associated with concussion history. METHODS: The computerized eye-hand coordination tasks were used to assess the coupled cognitive-motor functions of the participants with and with no history of concussion. In experiment 1, a total of 12 participants (6 young adults with a history of concussion and 6 healthy controls) completed longitudinal assessments of coordination profiles across a year. Experiment 2 examined a total of 20 participants (10 participants with a history of concussion and 10 healthy controls) using an iterated single-session protocol. Just noticeable difference (JND) and proportion of time-on-task (PTT) were used to assess cognitive-motor performance. Mixed-design ANOVAs were used to examine group differences, and the effect sizes were assessed using Cohen d test. RESULTS: In experiment 1, participants with a history of concussion exhibited more inconsistent ability to visually discriminate the in-phase coordination pattern (coefficient of variation of JND: participants with a history of concussion = mean 0.27, SD 0.04, and healthy controls = mean 0.17, SD 0.07; t10=2.93; P=.02). Similarly, their performance on unimanual and bimanual in-phase and anti-phase coordination patterns was significantly poorer (at in-phase: PTTConcussed=mean 0.63, SD 0.10, and PTTHealthy=mean 0.73, SD 0.08 [F1,10=8.49; P=.02]; at anti-phase: PTTConcussed=mean 0.46, SD 0.14, and PTTHealthy=mean 0.60, SD 0.10 [F1,10=10.67; P=.008]). In experiment, 2 where only the unimanual coordination tasks were implemented for screening, participants with a history of concussion showed impaired performance in both in-phase and anti-phase tasks (at in-phase: PTTConcussed=mean 0.62, SD 0.13, and PTTHealthy=mean 0.74, SD 0.07 [F1,54=4.20; P=.045]; at anti-phase: PTTConcussed=mean 0.37, SD 0.15, and PTTHealthy=mean 0.56, SD 0.14 [F1,54=10.26; P=.002]), and they also failed to show the differentiated performance between anti-phase and 90° coordination patterns (PTTAnti-phase=mean 0.37, SD 0.15, and PTT90° coordination=mean 0.37, SD 0.13). CONCLUSIONS: Due to their ability to detect both impaired and undifferentiated performance in producing intrinsic and novel coordination patterns, the unimanual coordination tasks appear to be a sensitive screening tool for chronic cognitive-motor deficits associated with history of concussion.