Abstract
Purpose :
Traumatic brain injury(TBI) leads to cognitive, attentional and sensorimotor disturbances. Antisaccades and memory-guided saccades have been used to investigate inhibitory control and working memory respectively. However, no study has compared the extent of deficits across these tasks in TBI. In this study, we investigated the responses of delayed antisaccades and memory-guided pro- and antisaccades by systematically varying the delay in individuals with TBI and compared the performance across tasks.
Methods :
Twenty-six subjects((mean age=22.4yr±6.6),12 males) with TBI participated. Subjects fixated on a central target and made either1)an antisaccade in response to a peripheral visible target for a delayed antisaccade task, 2)a prosaccade towards or 3)an antisaccade away from the remembered target cued for a memory-guided task. Saccades were made after a variable delay of 0,0.125,0.250,0.500 and 1s indicated by a visual cue. Saccadic latency, disinhibition errors (premature incorrect/correct saccades made before the cue) and directional errors(incorrect saccades made after the cue) were determined.
Results :
A 5(delays)x3(tasks) repeated measures ANOVA with delays as within subject and tasks as between subject variables was conducted for latency, disinhibition and directional errors. There was a significant interaction effect between delays and tasks for latency (F(8,281)=2.341, p=0.02), directionally-correct (F(6,204)=3.78, p=0.001) and incorrect disinhibition errors (F(6,244)=7.12, p<0.0001) but not for directional errors (p=0.62). However, for directional errors, there was a significant main effect both for delay (F(3.820,259.8)=15.08, p<0.0001) and tasks (F(2,75)=7.01, p=0.002). The delayed antisaccade task demonstrated prolonged latency, increased directionally incorrect disinhibition and directional errors compared to memory-guided tasks while the memory-guided prosaccade task showed increased directionally correct disinhibition errors compared to antisaccade tasks.
Conclusions :
Participants with TBI took longer time to generate delayed antisaccades and could not inhibit prosaccade responses towards the target during and after delay. For the memory-guided prosaccade task, the TBI participants could not inhibit premature prosaccades with longer delays. These deficits in voluntary saccades suggest impaired cognitive functions specific to response inhibitory control and impulsivity in TBI.
This is a 2021 ARVO Annual Meeting abstract.