Preliminary evidence of discourse improvement with dopaminergic medication

Abstract

Dopaminergic therapy can improve motor functioning in Parkinson's Disease (PD), but its effect on spoken discourse is poorly understood. This study addressed whether discourse produced during a one-minute monologue would be affected by medication withdrawal. We performed a detailed analysis of semistructured speech samples in 38 patients with PD, including measures of efficiency, syntactic complexity, cohesion (i.e., lexical and grammatical ties between sentences), and coherence (i.e., semantic relationship between the utterances and the topic, or between utterances). We found that patients produced more efficient and coherent monlogues when on versus off medication. As discourse relies heavily on cognitive processes such as working memory, these findings are consistent with research showing improved working memory and executive processes with dopaminegic medication.

The relationship between trained ratings and untrained listeners’ judgments of global coherence in extended monologues

“…Global coherence has been used as a measure to understand the differences between macroversus microlinguistic processing, as a means to explore potential cognitive and linguistic contributions to discourse, and as a way of tracking progress in treatment and recovery. The 4-point and 5-point GC scales have been used to analyze the spoken discourse patterns of a number of different clinical and non-brain-injured populations (e.g., Cahana-Amitay & Jenkins, 2018;Coelho & Flewellyn, 2003;Coelho et al, 2012;Gola et al, 2015;Hough & Barrow, 2003;Kurczek & Duff, 2011Laine et al, 1998;Lê et al, 2014;Rogalski et al, 2010;Rogalski & Edmonds, 2008;Sanchez & Spencer, 2013;Van Leer & Turkstra, 1999;Wright & Capilouto, 2012;Wright et al, 2013;Wright et al, 2014). The current study provides preliminary evidence of external validity for the 4-point GC scale.…”

Temporal Aspects of Global Coherence during Discourse Production in Early Stage Parkinson’s Disease

“…As a first step in further understanding the nature and impact of PD on expressive language, we examined the discourse of a convenience sample of individuals with PD in the early stages of the disease. A previous study of discourse among individuals with PD found that that discourse production was more efficient and coherent when on medication vs. off medication [25]. The study highlighted that the cognitive resources supporting expressive language could be impacted by the disease even in the earliest disease stage.…”

“…Additional insights may have been learned by also collecting data during the "on" medication state. Sanchez and Spencer (2013) found individuals with PD produced more efficient and coherent discourse when "on" medication versus "off" medication [25]. Third, although PD participants were all at H & Y stages 2 -3, the average disease duration for the sample was greater than 4 years.…”

“…In contrast, local coherence is a skill that reflects the conceptual linkage between adjacent sentences designed to maintain meaning in the discourse. Coherence has been evaluated in a range of individuals with neurological disorders including: traumatic brain injury [20]- [22], stroke [17] [19] [23], Alzheimers disease [19] [24], frontotemporal dementia [17], Parkinson's Disease [25] and adults absent of neurological conditions [24] [26] [27].…”