List Length in Verbal and Nonverbal Memory Performance in Mild Traumatic Brain Injury

Memory abilities are often affected following mild traumatic brain injury (mTBI), yet findings across studies remain mixed. This study examined short-term memory (STM) and working memory (WM) performance in individuals with mTBI and matched neurotypical controls using finer grained analyses to explore variability in performance.

Thirty-six individuals with mTBI and 36 matched neurotypical controls completed verbal and nonverbal STM and WM tasks, with performance across list lengths assessed using analysis of variance. To examine individual variability across the full sample, hierarchical cluster analysis was conducted to identify distinct performance-based profiles and evaluate how mTBI and control participants were distributed across clusters.

As expected, memory performance declined with increased list length across both groups and all tasks. While no significant group differences were found for STM tasks, analyses revealed lower performance among participants with mTBI on more complex WM tasks, particularly in nonverbal modalities. The hierarchical cluster analysis revealed clusters that differed in WM performance but not diagnostic group composition, indicating that variability in memory performance occurred along a continuum across participants rather than strictly by diagnosis.

These findings highlight the heterogeneity of memory outcomes following mTBI and underscore the importance of tailored cognitive assessments that consider task complexity and memory load.

https://doi.org/10.23641/asha.32209599.