Which verbal fluency measure is most useful in demonstrating executive deficits after traumatic brain injury?

Abstract

This paper examines switching and clustering in phonemic and semantic fluency tasks in individuals with traumatic brain injury (TBI). Fluency tasks were administered to 30 Hebrew-speaking patients with TBI and 30 age-matched control participants. Significant group differences were found in total output, number of switches, and number of clusters on both tasks, but not in mean cluster size. Unlike prediction, z scores of the number of semantic switches and clusters were lower than the equivalent z scores on the phonemic test. Results highlight the executive component of semantic fluency and the importance of using this task when assessing cognitive functioning after TBI.

Keywords:

• Verbal fluency
• Traumatic brain injury
• Switching and clustering
• Executive functions
• Language testing
• Hebrew

Acknowledgments

This study was partially supported by a grant from the Rehabilitation Center for Veterans after traumatic brain injury (TBI) in Jaffa, Israel, given to the third author. We wish to thank Ayelet Avraham and Reut Lerer for their help in coding the data. There are no financial or other relationships that could be interpreted as a conflict of interests.