New insights in implicit sequence learning of adults with traumatic brain injury: As measured by an ocular serial reaction time (O-SRT) task.

Objective: We investigated the effect of traumatic brain injury (TBI) on implicit sequence learning (ISL) and its relation with demographic, clinical, and working memory (WM) capacity using an eye-tracked variant of the standard serial reaction time (RT; SRT) task. Besides RT, this ocular SRT (O-SRT) task enables generation of correct anticipations (CA) and stucks, reflecting other critical aspects of ISL. Method: ISL was tested in 26 individuals with TBI and 28 healthy controls using the O-SRT task. Mixed analyses of variance were conducted to analyze RT and CA in three phases: learning, interference, and recovery from interference. The average number of stucks was compared with an independent-samples t test. Finally, Pearson correlation analyses of ISL with demographic, clinical, and WM capacity measures were performed. Results: Based on RT, ISL was impaired in the TBI group. However, CA demonstrated improved learning, but with deficits in the interference and recovery from interference phases. Stucks were more frequent in the TBI group, which affected RT and CA measures. Neither demographic nor clinical factors were associated with ISL. Verbal, but not spatial, WM capacity was impaired in the TBI group, and spatial WM capacity positively correlated with ISL in controls only. Conclusion: We suggest that the high TBI group stuck rate can be attributed to lack of initiative and/or conservative response bias associated with TBI, and view it as a main cause leading to deficits in ISL. Unlike controls, the TBI group could not muster their relatively preserved spatial WM capacity to support their ISL performance. (PsycInfo Database Record (c) 2021 APA, all rights reserved).