The neural substrates for atypical planning and execution of word production in stuttering

Abstract

a b s t r a c t a r t i c l e i n f oUsing an fMRI-based classification approach and the structural equation modeling (SEM) method, this study examined the neural bases of atypical planning and execution processes involved in stuttering. Twelve stuttering speakers and 12 controls were asked to name pictures under different conditions (single-syllable, multi-syllable, or repeated-syllable) in the scanner. The contrasts between conditions provided information about planning and execution processes. The classification analysis showed that, as compared to nonstuttering controls, stuttering speakers' atypical planning of speech was evident in their neural activities in the bilateral inferior frontal gyrus (IFG) and right putamen and their atypical execution of speech was evident in their activations in the right cerebellum and insula, left premotor area (PMA), and angular gyrus (AG). SEM results further revealed two parallel neural circuits-the basal ganglia-IFG/PMA circuit and the cerebellum-PMA circuit-that were involved in atypical planning and execution processes of stuttering, respectively. The AG appeared to be involved in the interface of atypical planning and execution in stuttering. These results are discussed in terms of their implications to the theories about stuttering and to clinical applications.

Lateralization of Brain Activation in Fluent and Non-Fluent Preschool Children: A Magnetoencephalographic Study of Picture-Naming

“…Furthermore, this overactivation was evident even when speech tasks were not required. Taken together, these observations support the idea that overactivation in the right hemisphere seen with functional neuroimaging in PWS reflects a compensatory mechanism rather than being a manifestation of abnormal cerebral dominance for speech control (e.g., Braun et al, 1997; Preibisch et al, 2003; Chang et al, 2008; Lu et al, 2010). …”

Neural anomaly and reorganization in speakers who stutter

“…Furthermore, the change of RSFC was significantly correlated with the change of stuttering severity when the change of duration of stuttering events and physical concomitants were regressed out. 20 Overactivations along the midline of the cerebellum in PDS patients have been reported previously, 2,6,11,38 and were taken to suggest a compensatory mechanism because of a lifetime of stuttering. This assumption is consistent with the evidence that the bilateral cerebellum closely cooperates with the left PO in the sequencing of subsyllabic aspects of the sound structure of verbal utterances.…”

Perception drives production across sensory modalities: A network for sensorimotor integration of visual speech

“…These include the left caudate nucleus, cingulate cortex, IFG, and insula. The caudate is part of the basal ganglia, a group of subcortical regions theorized to be crucial for sequencing and timing in speech production (Bohland et al, 2010; Fridriksson et al, 2005; Guenther, 2006; Lu et al, 2010a; Lu et al, 2010b; Pickett et al, 1998; Stahl et al, 2011), while the left IFG and cingulate cortex are crucial for conflict monitoring and resolving among competing alternatives (Botvinick et al, 2004; Carter et al, 1998; January et al, 2009; Kerns et al, 2004; Novick et al, 2005; Novick et al, 2010). In addition, recent data implicate the insula in time processing, focal attention, and cognitive control (Chang et al, 2012; Kosillo and Smith, 2010; Menon and Uddin, 2010; Nelson et al, 2010).…”