Preprint / Version 1

Exploring Speech Disfluencies: An Investigation into Atypical and Typical Patterns, Genetic and Neurobiological Factors, and Psychological Responses


  • Sathvega Somasundaram student



Speech disfluencies, Stuttering, Genetic factors, Neurobiological mechanisms in speech, fluency, neurolinguistics, Psychological responses, speech processes


With stuttering’s vast spectrum of different factors and forms, this review paper focuses on the impact of genetic, neurobiological, and psychological factors on this phenomenon, with varying brain activity among stutterers. With respect to the types of disfluencies, their frequencies, and patterns, this paper examines their developmental, neurogenic, and psychogenic aspects. The causes of stuttering, encompassing genetic factors and neurobiological effects, are explored with an emphasis on the role of non-coding regions in DNA. The implications of neuroimaging technologies display altered patterns within the neural circuitry associated with speech production and motor control, and highlight the impact of emotional stress on brain regions. Exploring family heredity with a specific focus on twins investigates the role of specific genes that influence speech development and contribute to stuttering. Presenting a review of the current literature on neuroimaging, genomic, and brain studies, this paper aims to contribute to a broader spectrum of other speech disorders, overall raising awareness of stuttering among both professionals and the public. This paper aims to deliver a deeper understanding of a topic that is not as researched as others and sheds light on the various components that affect stuttering in many ways.




Admin. “Causes of Stuttering.” National Stuttering Association, 12 Jan. 2024,,of%20a%20person%20who%20stutters.

Benchek, Penelope, et al. “Association between Genes Regulating Neural Pathways for Quantitative Traits of Speech and Language Disorders.” Npj Genomic Medicine, vol. 6, no. 1, 27 July 2021, doi:10.1038/s41525-021-00225-5.

Blood GW;Blood IM;Frederick SB;Wertz HA;Simpson KC; “Cortisol Responses in Adults Who Stutter: Coping Preferences and Apprehension about Communication.” Perceptual and Motor Skills, U.S. National Library of Medicine,,largest%20elevations%20in%20cortisol%20levels.

“Brain activation abnormalities during speech and non-speech in stuttering speakers.” NCBI, 11 February 2009,

Bremner, J Douglas. “Traumatic Stress: Effects on the Brain.” Dialogues in Clinical Neuroscience, U.S. National Library of Medicine, 2006,

Büchel, Christian, and Martin Sommer. “What Causes Stuttering?” PLoS Biology, vol. 2, no. 2, 17 Feb. 2004, doi:10.1371/journal.pbio.0020046.

Craig-McQuaide, Anna, et al. “A Review of Brain Circuitries Involved in Stuttering.” Frontiers in Human Neuroscience, vol. 8, 17 Nov. 2014, doi:10.3389/fnhum.2014.00884.

Desai, Jay, et al. “Reduced Perfusion in Broca’s Area in Developmental Stuttering.” Human Brain Mapping, U.S. National Library of Medicine, Apr. 2017,

“The Dopamine System and Automatization of Movement Sequences: A Review With Relevance for Speech and Stuttering.” NCBI, 2 December 2021,

Gregg, Brent Andrew, and Ehud Yairi. “Disfluency Patterns and Phonological Skills near Stuttering Onset.” Journal of Communication Disorders, U.S. National Library of Medicine, 2012,

“Home.” Cincinnati Childrens,,a%20different%20type%20of%20disfluency.

Jani, Leanne, et al. “Procedures Used for Assessment of Stuttering Frequency and Stuttering Duration.” Clinical Linguistics & Phonetics, vol. 27, no. 12, 12 July 2013, pp. 853–861, doi:10.3109/02699206.2013.809791.

Junuzovic-Zunic, Lejla, et al. “Neurogenic Stuttering: Etiology, Symptomatology, and Treatment.” Medical Archives (Sarajevo, Bosnia and Herzegovina), U.S. National Library of Medicine, Dec. 2021,,39%2C%2040%2C%2041).

Kraft, Shelly Jo, and Ehud Yairi. “Genetic Bases of Stuttering: The State of the Art, 2011.” Folia Phoniatrica et Logopaedica : Official Organ of the International Association of Logopedics and Phoniatrics (IALP), U.S. National Library of Medicine, 2012,

“Prefrontal cortex executive processes affected by stress in health and disease.” NCBI, 6 July 2017,

Redford, Melissa A. “A Comparative Analysis of Pausing in Child and Adult Storytelling.” Applied Psycholinguistics, U.S. National Library of Medicine, July 2013,

Simpson, KC. “Cortisol responses in adults who stutter: coping preferences and apprehension about communication.” PubMed,

“Stuttering.” National Institute of Deafness and Other Communication Disorders, U.S. Department of Health and Human Services, 6 Mar. 2017,

“The Role of Basal Ganglia and Its Neuronal Connections in the Development of Stuttering: A Review Article.” NCBI, 31 August 2022,