1. RESULTS AND DISCUSSION
Metaphor comprehension abilities in Parkinson’s disease patients .
Laura Monetta & Marc D. Pell
School of Communication Sciences and Disorders, McGill University, Montréal, Canada
INTRODUCTION
METHODOLOGY
RESULTS AND DISCUSSION
Participants
17 native English-speaker who were diagnosed with idiopathic Parkinson’s disease (PD) and 17 HC
Task
A metaphor-understanding task and a series of neuropsychological measures.
The metaphorical understanding task was a metaphorical list-priming sentence
task. Participants had to read a series of sentences, which appeared one at a
time on a computer screen, and to decide whether each sentence made sense
or not. The stimuli used were identical to those used by Gernsbacher (2001).
Parkinson disease (PD) is a chronic progressive nervous disease linked to decreased dopamine production in the basal ganglia, particularly in the substantia nigra.
PD patients have been used extensively as a model to study different cognitive functions of the basal ganglia.
Examples of this basal ganglia participation in language has been found in studies on prosody (Pell & Leonard, 2003), syntactic language processing (Kotz, et al., 2003) and also in sentences comprehension processing (Grossman et al., 2003) in PD patients.
Lately, new sets of studies have demonstrated that pragmatic communication abilities also seem to be impaired in PD’s patients (Natsopoulos et al., 1997; McNamara & Durso 2003; Berg et al 2003).
Their results suggest that some PD’s patients present deficits in high -level language difficulties, particularly in making inferences, recreating sentences and comprehending ambiguities and metaphors.
The PD participants were generally less efficient in understanding metaphors, making more errors and responding more slowly in all conditions.
When two groups of PD patients with different levels of working memory were isolated, results showed that PD-U patients performed similarly to the HC whereas the PD-I patients were slower and made notably more errors.
This pragmatic deficits seems to be in part related to the dopamine loss in the basal ganglia, but it also reflects a more general reduction in cognitive functions, such as working memory.
Objective
To achieve a rigorous evaluation of one of these pragmatic language abilities, such as metaphor comprehension in a well-defined PD sample, establishing a relationship between this ability to cognitive alterations, such as reduced working memory.
To extend the knowledge about the role of the basal ganglia on pragmatic language allowing commentaries on the basal ganglia’s role in the processing of metaphors.
Prediction
This pragmatic deficits is in part related to the dopamine loss in the basal ganglia, but also reflects a more general reduction in cognitive functions, such as working memory. Thus, only PD patients presenting reduced working memory abilities will show deficits on metaphor understanding.
Two subgroups of PD individuals were selected according to either their good or
poor performance on the verbal working memory span (Tompkins, et al., 1994).
REFERENCES
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Grossman M, Cooke A, DeVita C, Lee C, Alsop D, Detre J, Gee J, Chen W, Stern MB, Hurtig HI (2003). Grammatical and resource components of sentence processing in Parkinson's disease: an fMRI study. Neurology 60(5):
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