Impaired Comprehension of Speed Verbs in Parkinson's Disease

Neuropsychologia, 2008

Recent studies have demonstrated that processing of action words recruits cortical motor regions that are also involved in the planning and execution of the actions words refer to. The functional role of these regions in word understanding remains, however, to be clarified. The present study investigates this issue by examining the impact of Parkinson's disease (PD) on lexical decision performance for action words, relative to concrete nouns, in a masked priming paradigm. Priming effects for the two word categories were measured in non-demented PD patients off and on dopaminergic treatment, and in healthy participants. Our results revealed that although overall performances did not differ between verbs and nouns, priming effects showed a clear dissociation between word categories. While priming for concrete nouns was not affected by Levodopa intake, it dissociated as a function of treatment for action verbs. No priming was actually obtained for action verbs in PD patients off dopaminergic treatment. Following Levodopa intake, this deficit recovered, however, because priming effects for verbs became comparable to those for concrete nouns and similar to performance of healthy participants. Overall, this study thus brings compelling evidence that processing lexico-semantic information about action words depends on the integrity of the motor system.

Dementia e Neuropsychologia

The objective of the current review was to verify whether studies investigating lexical-semantic difficulties in patients with Parkinson’s disease (PD) support the Embodied Cognition model. Under this framework, it is predicted that patients with PD will have more difficulties in the semantic processing of action concepts (action verbs) than of motionless objects. We also verified how and whether these studies are following current debates of Neuroscience, particularly the debate between the Lexical and the Embodied Cognition models. Recent neuroimaging studies on the neural basis of the semantics of verbs were presented, as well as others that focused on the neural processing of verbs in PD. We concluded that few studies suitably verified the Embodied Cognition theory in the context of PD, especially using neuroimaging techniques. These limitations show there is much to investigate on the semantic difficulties with action verbs in these patients, where it is particularly important ...

2013

Cortex, 2015

Several studies have recently shown that basal ganglia deterioration leads to distinctive impairments in the domains of syntax, action verbs, and action semantics. In particular, such disruptions have been repeatedly observed in Parkinson's disease (PD) patients. However, it remains unclear whether these deficits are language-specific and whether they are equally dissociable from other reported disturbances-viz., processing of object semantics. To address these issues, we administered linguistic, semantic, and executive function tasks to two groups of non-demented PD patients, with and without mild cognitive impairment (PD-MCI and PD-nMCI, respectively). We compared these two groups with each other and with matched samples of healthy controls. Our results showed that PD patients exhibited linguistic and semantic deficits even in the absence of MCI. However, not all domains were equally related to EFs and MCI across samples. Whereas EFs predicted disturbances of syntax and object semantics in both PD-nMCI and PD-MCI, they had no impact on action-verb and action-semantic impairments in either group. Critically, patients showed disruptions of action-verb production and action semantics in the absence of MCI and without any executive influence, suggesting a sui generis deficit present since early stages of the disease. These findings indicate that varied language domains are differentially related to the basal ganglia, contradicting popular approaches to neurolinguistics.

2021

Language impairment in Parkinson’s disease (PD) may be attributable to motor and action/event knowledge deficits. We predicted that cognitively intact PD participants would be impaired in anticipating objects in sentences from event-based thematic fit information. Twenty-four PD and 24 healthy age-matched participants completed comprehensive neuropsychological assessments. We recorded participants’ eye movements as they heard predictive (The fisherman rocks the boat) and non-predictive baseline sentences (Look at the bathtub). Predictive sentences contained target, agent-related, verb-related, and unrelated images. Baseline sentences used phonologically and semantically unrelated distractors. We tested effects of group (PD/control) on gaze using growth curve models. There were no significant differences between PD and control participants in either sentence type, suggesting that PD participants successfully and rapidly use combinatory thematic fit information to predict upcoming lan...

Journal of Clinical and Experimental Neuropsychology, 2007

Turkish Journal Of Neurology

Parkinson's disease (PD), which is one of the most common neurodegenerative disorders, is a disorder that affects quality of life due to non-motor symptoms in addition to motor symptoms. The non-motor symptoms of this disease vary greatly and affect patients starting from early stages. These symptoms also include language deficits. Besides motor language disorders such as hypophonia and dysarthria, which are common in PD, deficits in morphosyntax, semantics, and understanding metaphors have been reported. Various studies have also shown deficits in action language in PD, in which the ability of action is affected. Although language deficits are thought to be caused by cognitive deficits in this disease, there are studies showing language deficits being independent of cognitive deficits. These language deficits in PD, caused by basal ganglia dysfunctions, may provide valuable information in determining brain areas related to language. In this review, we aimed to assess action language deficits in PD and to evaluate the location of action language in the brain in light of this disorder.

International Journal of Psychophysiology, 2016

Action verbs are critically embodied in motor brain networks. In Parkinson's disease (PD), damage to the latter compromises access to such words. However, patients are not fully incapable of processing them, as their performance is far from floor level. Here we tested the hypothesis that action-verb processing in PD may rely on alternative disembodied semantic circuits. Seventeen PD patients and 15 healthy controls listened to action verbs and nouns during functional MRI scanning. Using cluster-mass analysis with a permutation test, we assessed task-related functional connectivity considering seeds differentially engaged by action and non-action words (namely, putamen and M1 versus posterior superior temporal lobe, respectively). The putamen seed showed reduced connectivity within the basal ganglia in patients for both lexical categories. However, only action verbs recruited different cortical networks in each group. Specifically, the M1 seed exhibited more anterior connectivity for controls and more posterior connectivity for patients, with no differences in the temporal seed. Moreover, the patients' level of basal ganglia atrophy positively correlated with their reliance on M1-posterior connectivity during action-verb processing. PD patients seem to have processed action verbs via non-motor cortical networks subserving

Journal of the International Neuropsychological Society, 2016

Objectives: Cognitive-linguistic impairments in Parkinson’s disease (PD) have been well documented; however, few studies have explored the neurophysiological underpinnings of semantic deficits in PD. This study investigated semantic function in PD using event-related potentials. Methods: Eighteen people with PD and 18 healthy controls performed a semantic judgement task on written word pairs that were either congruent or incongruent. Results: The mean amplitude of the N400 for new incongruent word pairs was similar for both groups, however the onset latency was delayed in the PD group. Further analysis of the data revealed that both groups demonstrated attenuation of the N400 for repeated incongruent trials, as well as attenuation of the P600 component for repeated congruent trials. Conclusions: The presence of N400 congruity and N400 repetition effects in the PD group suggests that semantic processing is generally intact, but with a slower time course as evidenced by the delayed N4...

Journal of Clinical and Experimental Neuropsychology, 2010

Recognizing the specific speech act ) that a speaker performs with an utterance is a fundamental feature of pragmatic competence. However, little is known about neurocognitive mediation of speech act comprehension. The present research examined the extent to which people with Parkinson's disease (PD) comprehend specific speech acts. In the first experiment, participants read conversational utterances and then performed a lexical decision task (decide whether a target string of letters was a word). Consistent with past research, nonimpaired participants performed this task more quickly when the target string was the speech act associated with the preceding utterance. In contrast, people with PD did not demonstrate this effect, suggesting that speech act activation is slowed or is not an automatic component of comprehension for people with PD. In a second study, participants were given unlimited time to indicate their recognition of the speech act performed with an utterance. PD participants were significantly poorer at this task than were control participants. We conclude that a previously undocumented language disorder exists in PD and that this disorder involves a selective deficit in speech act comprehension. Frontostriatal systems (the systems impaired in PD) likely contribute to normal speech act comprehension.

The linguistic profile of Parkinson's disease (PD) is characterized by difficulties in processing units which denote bodily movements. However, the available evidence has low ecological validity, as it stems from atomistic tasks which are never encountered in real life. Here, we assessed whether such deficits also occur for meanings evoked by context-rich narratives, considering patients with and without mild cognitive impairment (PD-MCI and PD-nMCI, respectively) and matched controls for each group. Participants read two naturalistic stories (an action text and a neutral text) and responded to questions tapping the appraisal of verb-related and circumstantial information. In PD-MCI, impairments in the appraisal of action meanings emerged alongside difficulties in other

2015

Cognitive changes in Parkinson disease (PD) affect language processing, including sentence comprehension impairments, difficulties with processing verbs, and discourse impairments. In many theories of language comprehension, efficient language processing depends on successful implicit prediction of upcoming concepts and grammatical structures. Such prediction processes, in part, may be regulated by the neural dopaminergic system, which is markedly impaired in PD. In non-language tasks, persons with PD (PwPD) are impaired in prediction, sequencing, and probabilistic learning. However, the contributions of these dopaminergic-mediated prediction and probabilistic learning processes to language processing impairments in PD remain unexplored. We tested whether PwPD are impaired in implicit prediction during auditory language processing. The visual-world paradigm was used to investigate implicit predictive eye movements based on verb meaning. Participants listened to semantically predictive and non-predictive sentences while viewing picture stimuli. Both PwPD and controls showed prediction of upcoming nouns from verbs when hearing sentences like "She will drive the car." Furthermore, PwPD performed equivalently to controls. These results are surprising given the literature, suggesting either that PwPD have normal linguistic prediction, or that more challenging conditions for prediction are required to reveal PD impairments.

Cognitive Neuropsychology, 2013

Patients affected by Parkinson's disease (PD) can provide crucial information about the involvement of the motor system and prefrontal cortex in processing idioms including action verbs, since dopamine modulates the activity of these structures, and, consequently, different levels of this neurotransmitter can induce different cognitive impairments. In order to investigate the ability to process ambiguous idioms containing an action verb in patients, we asked 15 PD patients, in both OFF- and ON-phases, and 15 healthy matched participants to judge the plausibility of literal and idiomatic sentences, each presented at a self-paced rate. Patients in OFF-phase were faster in reading idiomatic than literal sentences, supporting the view that the motor system is not involved in online idiom processing. However, patients during OFF-phase were impaired in judging the plausibility of idiomatic ambiguous sentences, possibly due to the reduction of dopamine in prefrontal regions. The involvement of the motor system was evident in the ON-phase for literal sentences, suggesting that motor activation is strictly dependent on the context.

Movement Disorders, 2006

Dementia & Neuropsychologia

Motor-action verbs (MAVs) production and comprehension are compromised in patients with Parkinson's disease (PD). Objectives: The aim of this study was to characterize the sequential production of three subtypes of MAVs in PD patients: whole body (e.g., run), specific body part (e.g., kick), and instrumental (e.g., saw). This study also aimed to identify the production characteristics for each of the two main phases in fluency performance: selection (initial abundant item production) and retrieval (more paced and scarce production). Methods: This study involved a group of 20 nondemented, on-medication PD patients, with an average age of 66.59 years (standard deviation = 4.13), and a comparison group (CG) of 20 normal elderly individuals, matched by years of education and controlled for cognitive performance and depression. Both groups performed a classical verb fluency task. Sequential word-by-word analyses were conducted. Results: Significant differences were found at the initi...