Visually-guided Reaching Under Varying Cognitive and Motor Demand in Young Adult Females with a History of Concussions

Every day, vision guides one’s actions to help one successfully navigate through a complex environment. When our visual and motor systems interact efficiently, we may not fully appreciate how flawless and beneficial this process can be to our daily functioning. Yet, one’s available neural resources needed to successfully perform visually-guided movements do have limits. When an individual suffers a brain injury, such as a concussion, the available resources may be compromised. Examining the extent of this decreased resource pool requires challenging the cognitive abilities enough to observe a behavioral deficit. The purpose of this study was to examine the long-term effects of a history of concussions in young adult females on visuomotor behavior during a visually-guided reaching task of various complexities. We hypothesized that by manipulating an increase of both cognitive and motor demand, visuomotor behavior would decrease more in individuals with a history of concussion than those without a history of concussion. Twenty females without a history of concussion (age: 21.2 ± 2.16 years) and twenty females with a history of concussion (age: 22.3 ± 2.43 years) quickly and accurately performed a delayed reach to a previously cued location. To control for confounding factors, information was collected regarding the participants’ head injury history, lifestyles, and level of sports participation. The visually guided reaching task was manipulated by varying the complexities of cognitive and motor demand to alter attentional load. As both cognitive and motor load increased, task performance decreased for both groups (p \u3c .05). However, contrary to our primary hypothesis, no differences in task performance were found between the two experimental groups (p \u3e .05). While confounding variables of age, sex, time since last concussion (i.e. acute vs. long-term), stimulant use, sleep patterns, and prescription medication for mood disorders were either controlled or considered during the analysis, participants in the two groups did differ on level of sports participation (p \u3c .05), when accounting for this difference, still no changes in performance were identified (p \u3c .05) on the dependent measures. The young adult females with a history of concussion demonstrated no deficits in visuomotor behavior on an attention-mediated reaching task as compared to control participants. Future studies should include an assessment of both motivation and competitiveness of the participants. Furthermore, longitudinal studies are needed to assess if the normal declines in visuomotor behavior due to healthy aging are accentuated by a history of concussion

Remote concussion history does not affect visually-guided reaching in young adult females

Aim: We examined the long-term effects of concussions in young adult females on visuomotor behavior during a visually-guided reaching task of various complexities. Materials & methods: 20 females with a history of longer than 6 months since a concussion and 20 healthy females quickly and accurately performed a delayed reach to a previously cued target. Results: As both cognitive and motor load increased, task performance decreased for both groups (p \u3c 0.05). However, contrary to our primary hypothesis, no differences in task performance were found between the two experimental groups (p \u3e 0.05). Conclusion: The young adult females with a remote history of concussion demonstrated no deficits in visuomotor behavior on an attention-mediated reaching task as compared with control participants. Lay abstract: Current literature is inconclusive regarding the long-term effects of concussion. Some have argued that the differing results are due to many uncontrolled factors in study design. In this study, 20 females with a history of concussion more than 6 months ago and 20 healthy females performed a reaching task under different levels of difficulty. As the reaching task got harder, both groups had greater difficulty doing the task quickly and accurately (p \u3c 0.05). Surprisingly, however, no differences in reaching performance existed between the two groups (p \u3e 0.05). Young adult females with a remote history of concussion demonstrated no greater problems with complicated reaching tasks when compared with control participants when experimental conditions are tightly controlled