Stuttering and brain maturity

Document Type : Original Articles


1 Assistant Professor of Neuroscience, School of Education & Psychology, University of Tabriz, Tabriz, Iran

2 PhD Student in Cognitive Neuroscience, School of Education and Psychology, University of Tabriz, Tabriz, Iran

3 PhD Student in Cognitive Neuroscience, School of Education & Psychology, University of Tabriz, Tabriz, Iran



Introduction: Several studies have shown various deficits in linguistic, auditory, and speech-motor processing of people who stutter. The Diversity of pathological findings makes it hard to suggest a comprehensive hypothesis to explain the nature of stuttering. However it seems possible to integrate heterogeneous findings in terms of maturity hypothesis which has been recently proposed on the basis of an electro-encephalographic study. Materials and Methods: This narrative review article was an attempt to integrate diverse findings on stuttering into the frame of brain maturity hypothesis. Literature review was performed using “neurophysiology of stuttering” and “brain maturity hypothesis” as keywords in PubMed, Science Direct, Proquest databases, and Google Scholar search engines and also among library sources from 1990 to 2012. Results: Thirty-two papers and 4 books were selected according to subject relevance and their respective citation numbers. Records on neurogenic or psychogenic stuttering were excluded so that only those papers on developmental stuttering with a citation number of at least 10 (for papers published from 1990 to 1999) or 2 (for those published from 2010 to 2012) were selected. Three papers were obtained in abstract form. Results the present article focused on the pattern of spontaneous recovery as an evidence for maturity hypothesis. To be more specific, spontaneous recovery was considered as an index of slow neural maturity, which in return, results in linguistic, auditory and motor ability deficits in stuttering. Conclusion: Diversity of deficits in stuttering may imply slow neural maturity of linguistic-motor system. It seems that, this slowness causes disturbances in the laterality of linguistic-motor processes in people who stutter. More research about hypothesis is possible via using techniques which can facilitate neural maturity generally or specificly. Keywords: Neurophysiology of stuttering, Stuttering recovery, Brain maturity