The effects of background factors on working memory and processing speed in auditory processing intervention

Traumatic brain injury (TBI) commonly produces persistent deficits in working memory and processing speed. This study examined whether background factors and time post-injury predict response to a 14-week auditory-based computerized cognitive remediation (CCR) program in 48 adults with chronic mild-to-severe TBI. Cognitive changes were assessed on measures of working memory and attention, processing speed, executive functions, and self-reported perceived cognitive difficulties. Multiple regression models tested age, education, premorbid intelligence, months since injury, and their interactions with group as predictors of change scores. Less time since injury significantly predicted greater gains in auditory processing speed. Higher premorbid intelligence predicted greater improvement on visual processing speed, while the inverse association on verbal attention and working memory was best interpreted as a ceiling effect. Age and education were non-significant predictors. These findings underscore the critical roles of time post-injury and cognitive reserve proxies in determining responsiveness to auditory CCR in chronic mild-to-severe TBI, supporting earlier intervention within the chronic phase and the need for personalized rehabilitation strategies tailored to premorbid cognitive capacity.Trial registration: ClinicalTrials.gov identifier: NCT02507271.