|
The groundbreaking stuttering research emerging from those with expertise in the neurosciences—many of whom are not speech-language pathologists—demonstrates the value of background in the neurosciences.
Early neurological explorations of stuttering date back to the era of Lee Edward Travis, but one of the first cadre of researchers to employ technologies such as positron emission tomography (PET) to observe the stuttering brain at work were Fox, Ingham, and colleagues (e.g., Fox et al. 1996). They found that regions of the brain associated with speech planning and auditory self- monitoring may function differently in those who stutter as compared to fluent controls. In contrast to functional studies, Foundas and colleagues (e.g., Foundas et al., 2004) have employed volumetric MRI in a series of experiments testing the hypothesis that those who stutter have anomalous anatomy in cortical speech-language areas. Recent findings from this group indicate at least two subgroups of persons who stutter, suggesting that brain anatomy may influence treatment success and that the degree of auditory processing deficits in this population varies widely.
Neuroimaging has also been used to examine linguistic differences related to stuttering (e.g., Weber-Fox, Spencer, Spruill, & Smith, 2004), as well as changes in neural activation patterns following traditional stuttering treatment (e.g., De Nil, Kroll, Lafaille, & Houle, 2003).
Other Methodologies
Although imaging research has been the predominant neuroscience-based approach in the field of stuttering, other methodologies have also proven fruitful. For instance, Drayna and colleagues have investigated stuttering etiology through genome-wide linkage surveys in attempts to isolate the mutational origins of the disorder (e.g., Shugart et al., 2004), while ongoing research is investigating the value of pharmacologic approaches to treating the disorder (Indevus Pharmaceuticals, 2006).
Along with the obvious methodological influences, neuroscience theory has also influenced several theories about the mechanisms underlying stuttering. One such example is Per Alm (2005), who has forwarded a unified theory of stuttering etiology based on Gary Goldberg's dual premotor systems hypothesis and Alm's own biochemical and electromyographic research. Neuroscientists studying other populations have also influenced the interests of researchers within the realm of fluency disorders into issues related to sensitivity and temperament (e.g., Anderson, Pellowski, Conture, & Kelly, 2003).
|