Performance of Bimanual Finger Coordination Tasks in Speakers Who Stutter

Abstract

Stuttering is a neurodevelopmental speech disorder characterized by the symptoms of speech repetition, prolongation, and blocking. Stuttering-related dysfluency can be transiently alleviated by providing an external timing signal such as a metronome or the voice of another person. Therefore, the existence of a core motor timing deficit in stuttering has been speculated. If this is the case, then motoric behaviors other than speech should be disrupted in stuttering. This study examined motoric performance on four complex bimanual tasks in 37 adults who stutter and 31 fluent controls. Two tasks utilized bimanual rotation to examine motor dexterity, and two tasks used the bimanual mirror and parallel tapping movements to examine timing control ability. Video-based analyses were conducted to determine performance accuracy and speed. The results showed that individuals who stutter performed worse than fluent speakers on tapping tasks but not on bimanual rotation tasks. These results suggest stuttering is associated with timing control for general motor behavior.

Neural oscillatory activity and connectivity in children who stutter during a non-speech motor task

“…Besides stuttering events, people who stutter exhibit more variable speech movements compared to people who do not stutter even when their speech is perceptually fluent (e.g., Wiltshire et al, 2021; MacPherson & Smith., 2013; Smith et al, 2012). In non-speech motor tasks, people who stutter often perform slightly worse than people who do not stutter, particularly in demanding tasks that involve complex sequences of movements or fine timing control (e.g., Smith-Bandstra et al 2006ab; Falk et al, 2014; Bauerly and De Nil, 2011; Toyomura et al, 2021), while results have been mixed for simple motor tasks, such as hand claps (Piispala et al, 2016; Hilger et al, 2016; Toyomura et al, 2021). These reported differences in speech and non-speech motor behavior could be related to subtle structural and functional differences in the sensorimotor system, including reduced size, activation and connectivity between the left prefrontal, premotor, motor and auditory cortices, as well as within the cortico-basal ganglia and cortico-cerebellar loops, and greater size, activation and connectivity in the right prefrontal and auditory cortices (Belyk et al, 2015; Brown et al, 2005; Chow and Chang 2017; Chang et al, 2019).…”