Lexical ambiguity resolution during sentence processing in Parkinson's disease: An event-related potential study

• Published in: PloS one 2017-05, Vol.12 (5), p.e0176281-e0176281
• Main Authors: Angwin, Anthony J, Dissanayaka, Nadeeka N W, McMahon, Katie L, Silburn, Peter A, Copland, David A
• Format: Article
• Language: English
• Subjects: Activation; Activation analysis; Adults; Aged; Aging; Ambiguity; Ambiguity resolution (mathematics); Anomalies; Attention; Auditory evoked potentials; Bacon; Biology and Life Sciences; Brain; Brain mapping; Brain research; Case-Control Studies; Caudate nucleus; Circuits; Clinical trials; Cognitive ability; Cortex (motor); Cortex (temporal); Cues; Decay; Dementia disorders; Dopamine; Electroencephalography; Event-related potentials; Evoked Potentials; Female; Functional magnetic resonance imaging; Heterogeneity; Humans; Impedance; Infections; Inhibition; Language; Lesions; Male; Medicine and Health Sciences; Middle Aged; Mismatch negativity; Movement disorders; Natural language processing; Neurodegenerative diseases; Neuroimaging; Neurology; Norms; Nuclei; Parkinson disease; Parkinson Disease - physiopathology; Parkinson's disease; People and Places; Priming; Psychology; Repetition; Representations; Research and Analysis Methods; Resonance; Semantics; Social Sciences; Studies; Temporal lobe; Visual cortex; Visual perception; Word processing
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0176281

Event-related potentials (ERPs) were recorded to investigate lexical ambiguity resolution during sentence processing in 16 people with Parkinson's disease (PD) and 16 healthy controls. Sentences were presented word-by-word on computer screen, and participants were required to decide if a subsequent target word was related to the meaning of the sentence. The task consisted of related, unrelated and ambiguous trials. For the ambiguous trials, the sentence ended with an ambiguous word and the target was related to one of the meanings of that word, but not the one captured by the sentence context (e.g., 'He dug with the spade', Target 'ACE'). Both groups demonstrated slower reaction times and lower accuracy for the ambiguous condition relative to the unrelated condition, however accuracy was impacted by the ambiguous condition to a larger extent in the PD group. These results suggested that PD patients experience increased difficulties with contextual ambiguity resolution. The ERP results did not reflect increased ambiguity resolution difficulties in PD, as a similar N400 effect was evident for the unrelated and ambiguous condition in both groups. However, the magnitude of the N400 for these conditions was correlated with a measure of inhibition in the PD group, but not the control group. The ERP results suggest that semantic processing may be more compromised in PD patients with increased response inhibition deficits.