The processing of verbal memories after traumatic brain injury

Abstract

Objective: Memory dysfunction is a persistent cognitive symptom following traumatic brain injury (TBI), negatively impacting capacity for independent living and productivity. Traditional scoring of neuropsychological memory tests does not allow for differentiation of specific impairments of encoding, consolidation and/or retrieval, or the potential impact of strategy deficits. Method: The current study examined performance of 142 moderate-to-severe TBI participants and 68 demographically matched healthy controls on the Rey Auditory Verbal Learning Test (RAVLT) using Item Specific Data Analysis (ISDA) and strategy use analyses. Results: Results revealed significantly greater impairments in encoding, consolidation, and retrieval in TBI participants, compared to controls. Encoding deficits significantly explained the most variance in the long-delayed recall of TBI participants, followed by consolidation, and then retrieval. Participants with TBI showed a reduced ability to spontaneously apply strategies during learning, evident in decreased subjective clusters and increased word omissions, compared to controls. No difference was found between groups in passive learning strategy application, shown through serial clustering. Spontaneous strategy measures both uniquely accounted for variance in the encoding ability of TBI participants. Conclusions: These findings highlight the potential value in using ISDA and strategy use measures to assess RAVLT results to better characterize individual memory profiles and inform rehabilitative interventions.