Verbal fluency in individuals with mild traumatic brain injury

Tests of verbal fluency that require either retrieval by semantic category or retrieval by initial letter were presented to 19 participants with mild traumatic brain injury (MTBI) and 24 control (NC) participants. Performance on these tasks was analyzed for total number of words produced, the presence of semantic clusters in the order of words produced, the presence of phonemic clusters in the order of word, produced, and number of errors (i.e., perseverations, words out of category). Individuals with MTBI produced fewer words and made more errors than NCs, but their production contained an equal proportion of semantic and phonemic clusters. These data are discussed in relation to a previous study in patients with Parkinson's disease (PD). FD participants did not make more errors than age-matched NCs despite reduced production. Implications for memory and executive function deficits following MTBI are discussed.