Increased motor preparation activity during fluent single word production in DS: A correlate for stuttering frequency and severity. (August 2015)

• Record Type: Journal Article
• Authors: Vanhoutte, Sarah; Santens, Patrick; Cosyns, Marjan; van Mierlo, Pieter; Batens, Katja; Corthals, Paul; De Letter, Miet; Van Borsel, John
• Is Part Of: Neuropsychologia. Volume 75(2015)
• Page Start: 1
• Page End: 10
• Publication Date: 2015-08
• Subjects: Contingent negative variation -- Stuttering severity -- Stuttering frequency -- Compensation -- Motor preparation -- Basal ganglia -- Dopamine; Neuropsychology -- Periodicals; Neurology -- Periodicals; Psychophysiology -- Periodicals; Neuropsychologie -- Périodiques; Neuropsychology; Periodicals; Electronic journals; 616.8
• DOI: 10.1016/j.neuropsychologia.2015.05.013
• Languages: English
• ISSNs: 0028-3932

Abstract

Abstract: Abnormal speech motor preparation is suggested to be a neural characteristic of stuttering. One of the neurophysiological substrates of motor preparation is the contingent negative variation (CNV). The CNV is an event-related, slow negative potential that occurs between two defined stimuli. Unfortunately, CNV tasks are rarely studied in developmental stuttering (DS). Therefore, the present study aimed to evaluate motor preparation in DS by use of a CNV task. Twenty five adults who stutter (AWS) and 35 fluent speakers (FS) were included. They performed a picture naming task while an electro-encephalogram was recorded. The slope of the CNV was evaluated at frontal, central and parietal electrode sites. In addition, a correlation analysis was performed with stuttering severity and frequency measures. There was a marked increase in CNV slope in AWS as compared to FS. This increase was observed over the entire scalp with respect to stimulus onset, and only over the right hemisphere with respect to lip movement onset. Moreover, strong positive correlations were found between CNV slope and stuttering frequency and severity. As the CNV is known to reflect the activity in the basal ganglia-thalamo-cortical-network, the present findings confirm an increased activation of this loop during speech motor preparation in stuttering. The more a person stutters, the more neurons of this cortical–subcortical network seem to be activated. Because this increased CNV slope was observed during fluent single word production, it is discussed whether or not this observation refers to a successful compensation strategy. Highlights: Speech motor preparation is evaluated through a CNV task in developmental stuttering. CNV slope is significantly increased in stuttering compared to fluent speakers. CNV slope correlates positively with stuttering severity and frequency. The cortical-basal ganglia loop is overactive during speech motor preparation. It is discussed whether this result refers to a successful compensation strategy.