Component analysis of verbal fluency performance in younger participants with moderate-to-severe traumatic brain injury

Abstract

Primary objective: To investigate phonemic and semantic verbal fluency performance in a group of young adult participants with and without traumatic brain injury.

Research design: Group comparison.

Methods and procedures: Twenty-five participants with moderate-to-severe TBI and 25 participants with no brain damage (NBD) were given phonemic and semantic verbal fluency tasks. Responses were analysed quantitatively and qualitatively.

Main outcomes and results: Young participants with moderate-to-severe TBI generated significantly fewer total correct words and sub-categories for both fluency conditions when compared to controls. The total number of correct words generated on the phonemic condition and for the semantic category of animals was positively correlated with the number of category switches produced during the task.

Conclusions: While young participants with moderate-to-severe TBI produced fewer total correct words on both verbal fluency conditions in comparison to controls, these differences were greater on the phonemic condition. Participants with moderate-to-severe TBI switched less frequently on both fluency tasks and produced smaller cluster sizes only on the phonemic task in comparison to controls. These results are in contrast with previous investigations that have observed greater age-related declines on semantic tasks when compared to phonemic tasks.

• Clustering
• phonemic verbal fluency
• semantic verbal fluency
• switching
• Traumatic brain injury