Linguistic Complexity, Speech Production, and Comprehension in Parkinson’s Disease: Behavioral and Physiological Indices

Abstract

Purpose To investigate the effects of increased syntactic complexity and utterance length demands on speech production and comprehension in individuals with Parkinson’s disease (PD) using behavioral and physiological measures. Method Speech response latency, interarticulatory coordinative consistency, accuracy of speech production, and response latency and accuracy on a receptive language task were analyzed in 16 individuals with PD and 16 matched control participants. Results Individuals with PD had higher oral motor coordination variability, took a longer time to initiate speech, and made more errors on the speaking task compared with the control group. They also received lower scores on the 2 complex conditions of the receptive language task. Increased length and syntactic complexity negatively affected performance in both groups of speakers. Conclusions These findings provide a novel window into the speech deficits associated with PD by examining performance on longer, sentence-level utterances in contrast to earlier investigations of single-word or nonword productions. Speech motor control processes and language comprehension were adversely affected in the majority of our participants with mild to moderate PD compared to the control group. Finally, increased syntactic complexity and sentence length affected both the healthy aging and PD groups’ speech production performance at the behavioral and kinematic levels.

Clear Speech Variants: An Acoustic Study in Parkinson's Disease

“…Contrary to previous studies (Canter, 1963;Fox & Ramig, 1997;Goberman et al, 2002;Skodda et al, 2011a;Tjaden et al, 2013;Walsh & Smith, 2011; but see Canter, 1963;Sadagopan & Huber, 2007;Tjaden & Wilding, 2004), mean SPL and mean F0 did not differ across groups in the current study. However, speakers with PD did produce less variation in sentence-level SPL compared with controls, as indexed by SPL standard deviation.…”

“…At the suprasegmental level, speakers with PD tend to pause more often (Torp & Hammen, 2000; but see Goberman & Elmer, 2005), utilize an increased fundamental frequency (F0; Canter, 1963;Goberman, Coelho, & Robb, 2002), and exhibit decreased variability in F0 (Canter, 1963(Canter, , 1965Flint, Black, Campbell-Taylor, Gailey, & Levinton, 1992;Skodda, Visser, & Schlegel, 2011a). Some studies have also reported reduced sound pressure levels (SPLs; Fox & Ramig, 1997;Skodda, Visser, & Schlegel, 2011b;Tjaden et al, 2013;Walsh & Smith, 2011). However, other studies have reported no differences in mean SPL for speakers with PD relative to healthy controls (Canter, 1963;Sadagopan & Huber, 2007;Tjaden & Wilding, 2004).…”

“…More recent acoustic studies have helped characterize the nature of the speech impairment in PD. For example, relative to healthy controls, speakers with PD produce more centralized vowel space areas (VSAs; Liu, Tsao, & Kuhl, 2005;Tjaden, Lam, & Wilding, 2013;Turner, Tjaden, & Weismer, 1995;Weismer, Jeng, Laures, Kent, & Kent, 2001), less spectrally distinct consonants (Tjaden & Wilding, 2004), weakened or less precise stop closures (Ackermann & Ziegler, 1991), and shallower second formant (F2) slopes, indicating slowed changes in vocal tract adjustments (Kent & Adams, 1989;Kim, Kent, & Weismer, 2011;Walsh & Smith, 2011). At the suprasegmental level, speakers with PD tend to pause more often (Torp & Hammen, 2000; but see Goberman & Elmer, 2005), utilize an increased fundamental frequency (F0; Canter, 1963;Goberman, Coelho, & Robb, 2002), and exhibit decreased variability in F0 (Canter, 1963(Canter, , 1965Flint, Black, Campbell-Taylor, Gailey, & Levinton, 1992;Skodda, Visser, & Schlegel, 2011a).…”

Dopamine regulation of human speech and bird song: A critical review

“…Along with the main PD symptoms, such as bradykinesia, muscular rigidity, tremor and disturbances of gait and posture, nearly 90% of PD patients experience severe changes of their voice quality, characterized by monotone and hypotonic speech with limited pitch range, reduced loudness, decreased accuracy of articulation, and a raspy voice (Aronson, 1980). With the advancement of disease, more than half of non-demented patients develop additional cognitive deficits affecting speech and language, such as difficulties with phonological processing, syntactic complexity, and language comprehension (Walsh and Smith, 2011). In addition, patients with advanced Parkinson's disease occasionally develop compulsive involuntary singing and humming while receiving high-dose dopamine replacement therapy (Friedman, 1993; Bonvin et al, 2007; Kataoka and Ueno, 2010).…”

Speaking rate effects on articulatory pattern consistency in talkers with mild ALS

“…This measure has been commonly used to determine if disruptions in the speech motor system affect speech motor control (Dromey, 2000; Kleinow, Smith, & Ramig, 2001; McHenry, 2003; Walsh & Smith, 2011). Although its impact on speech output is poorly understood, increased articulatory pattern variability may result in less predictable speech acoustic patterns and, therefore, may contribute to decrements in speech intelligibility in talkers with dysarthria (Mefferd & Green, 2010).…”