|
KMID : 1036820180230030647
|
|
Communication Sciences & Disorders
2018 Volume.23 No. 3 p.647 ~ p.659
|
|
|
Characteristics and Underlying Mechanisms of Semantic Clustering in Parkinson’s Disease
|
|
Lee Sun-Mi
Yoon Ji-Hye
Lee Soo-Jung
|
|
|
Abstract
|
|
|
Objectives: Patients with Parkinson’s disease (PD) tend to show impairment in switching, but not clustering, during semantic fluency tasks. When time limits are imposed for completing a fluency task, clustering and switching can be negatively correlated. To better understand the characteristics of clustering, verbal fluency needs to be assessed both with and without time limits. The purpose of this study was to investigate the effect of time limits on clustering performance, and to study characteristics of semantic impairment related to clustering in PD.
Methods: We studied 27 PD patients and 32 normal controls (NC). We conducted a semantic fluency task and measured the total number of words, average size of clusters, number of clusters, and number of switches generated in a 1-minute time limit, also making the same measurements without a time limit. Finally, we conducted a semantic knowledge task utilizing spontaneous production, specific guiding questions, and forced-choice questions.
Results: First, when there was no time limit the average size of clusters was significantly smaller in PD than in NC. Second, on the semantic knowledge task, the PD patients scored significantly lower than NC on the specific guiding questions and in total. Lastly, we found significant correlations between the average size of clusters and the scores on the semantic knowledge task in PD.
Conclusion: On semantic fluency tasks, time limits for completing a task may affect clustering in PD. Also, impaired clustering in PD may be attributed to impaired retrieval of semantic knowledge rather than a deficit in semantic knowledge itself.
|
|
|
KEYWORD
|
|
|
Parkinson’s disease, Semantic fluency task, Clustering, Switching, Semantic know
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
|
|