Clustering and switching strategies in lexical evocation of adults post-stroke on the right and left hemispheres

Abstract

We compared the total number of words generated, the raw number of clusters and switches and mean cluster size in verbal fluency with semantic and phonemic criteria, and the performance between these tasks in each group. We analyzed the correlations between these variables and sociodemographic data. The sample consisted of 43 adults after stroke (11 with right cerebral hemisphere lesion-RHL; 32 with left cerebral hemisphere lesion-LHL) and 40 neurologically healthy adults. The main results indicated better performance on the total number of words and the raw number of clusters and switches in both verbal fluency tasks of healthy adults compared to LHL, but similar performance to RHL. In the task with phonemic criteria, the RHL group had a higher total number of words, number of clusters and switches than LHE. The groups presented a better performance in semantic verbal fluency than phonemic verbal fluency. Qualitative analysis identified cognitive processes underlying the total number of words evoked in verbal fluency after unilateral stroke.