Laura Monetta

Vocal emotion processing in Parkinson's disease: Reduced sensitivity to negative emotions

To document the impact of Parkinsons disease (PD) on communication and to further clarify the role of the basal ganglia in the processing of emotional speech prosody, this investigation compared how PD patients identify basic emotions from prosody and judge specific affective properties of the same vocal stimuli, such as valence or intensity. Sixteen non-demented adults with PD and 17 healthy control (HC) participants listened to semantically-anomalous pseudo-utterances spoken in seven emotional intonations (anger, disgust, fear, sadness, happiness, pleasant surprise, neutral) and two distinct levels of perceived emotional intensity (high, low). On three separate occasions, participants classified the emotional meaning of the prosody for each utterance (identification task), rated how positive or negative the stimulus sounded (valence rating task), or rated how intense the emotion was expressed by the speaker (intensity rating task). Results indicated that the PD group was significantly impaired relative to the HC group for categorizing emotional prosody and showed a reduced sensitivity to valence, but not intensity, attributes of emotional expressions conveying anger, disgust, and fear. The findings are discussed in light of the possible role of the basal ganglia in the processing of discrete emotions, particularly those associated with negative vigilance, and of how PD may impact on the sequential processing of prosodic expressions.

Irony comprehension and theory of mind deficits in patients with Parkinson's disease

Many individuals with Parkinsons disease (PD) are known to have difficulties in understanding pragmatic aspects of language. In the present study, a group of eleven non-demented PD patients and eleven healthy control (HC) participants were tested on their ability to interpret communicative intentions underlying verbal irony and lies, as well as on their ability to infer first- and second-order mental states (i.e., theory of mind). Following Winner et al. (1998), participants answered different types of questions about the events which unfolded in stories which ended in either an ironic statement or a lie. Results showed that PD patients were significantly less accurate than HC participants in assigning second-order beliefs during the story comprehension task, suggesting that the ability to make a second-order mental state attribution declines in PD. The PD patients were also less able to distinguish whether the final statement of a story should be interpreted as a joke or a lie, suggesting a failure in pragmatic interpretation abilities. The implications of frontal lobe dysfunction in PD as a source of difficulties with working memory, mental state attributions, and pragmatic language deficits are discussed in the context of these findings.

Effects of working memory capacity on inference generation during story comprehension in adults with Parkinson's disease

Abstract A group of non-demented adults with Parkinsons disease (PD) were studied to investigate how PD affects pragmatic-language processing, and, specifically, to test the hypothesis that the ability to draw inferences from discourse in PD is critically tied to the underlying working memory (WM) capacity of individual patients [Monetta, L., & Pell, M. D. (2007). Effects of verbal working memory deficits on metaphor comprehension in patients with Parkinsons disease. Brain and Language , 101 , 80–89]. Thirteen PD patients and a matched group of 16 healthy control (HC) participants performed the Discourse Comprehension Test [Brookshire, R. H., & Nicholas, L. E. (1993). Discourse comprehension test . Tucson, AZ: Communication Skill Builders], a standardized test which evaluates the ability to generate inferences based on explicit or implied information relating to main ideas or details presented in short stories. Initial analyses revealed that the PD group as a whole was significantly less accurate than the HC group when comprehension questions pertained to implied as opposed to explicit information in the stories, consistent with previous findings [Murray, L. L., & Stout, J. C. (1999). Discourse comprehension in Huntingtons and Parkinsons diseases. American Journal of Speech – Language Pathology , 8 , 137–148]. However, subsequent analyses showed that only a subgroup of PD patients with WM deficits, and not PD patients with WM capacity within the control group range, were significantly impaired for drawing inferences (especially predictive inferences about implied details in the stories) when compared to the control group. These results build on a growing body of literature, which demonstrates that compromise of frontal–striatal systems and subsequent reductions in processing/WM capacity in PD are a major source of pragmatic-language deficits in many PD patients.

Age-related changes in the processing of the metaphorical alternative meanings of words

Abstract The goal of this study was to contribute to a better understanding of the relative impacts of age and the occurrence of a right-hemisphere lesion on the processing of the non-literal alternative meanings of words. Eighty healthy individuals participated in this study. Participants were divided into two groups: the older group included participants between 50 and 65 years old whereas the younger group included participants between 20 and 30 years old. Participants performed a semantic pairing task involving metaphorical and non-metaphorical alternative meanings of words and a countdown task. There were two different task presentation conditions: (1) non-interfering context task in which participants completed the main task (word-triad task) without any interference, and (2) interfering-context task in which the word-triad task and the countdown task were executed simultaneously. The main results indicated an age-related change in the processing of the non-literal alternative meanings of words. The most interesting result was that the resource-limiting condition had an impact only on the young adult group.