Written By Jayden Checkinson & Victoria Velez
Introduction
The Broca’s Area is located in the upper left portion of the frontal lobe of the brain, specifically the left hemisphere. It is a key component for speech production, and articulation within daily speech and writing. The Broca's Area was discovered by Paul Broca in the 19th century when examining the brain of two speech-impaired patients; he noticed that there was damage alongside a specific portion of the frontal lobe. Yet, by numerous observations, he was able to produce deductions that this portion of the brain was vital for everyday speech production. Damage to this area can lead to various disabilities concerning speech and physical movement.
Function
The role of the Broca’s area is to assist in speech comprehension and speech production. This is due to the Broca’s Area interacting with the temporal cortex and the motor cortex. Both, in which cooperate concerning sensory information and movements of the mouth. Also, part of the main function of this area is to process speech. Without this, indulgence in processing different languages and speech would be nearly impossible.
Potential Causes
Cerebral Dominance Theory
The Cerebral Dominance Theory proposes stuttering as the consequence of a failure to establish dominance of the left hemisphere over the right. An observation was studied for the difference in cerebral dominance over people who did stutter (PWS) and who did not stutter (PWnS) regarding ear preference and handedness. It showed that only 45% of right-handed PWS exhibited a right-ear preference in dichotic listening exercises. This implication that PWS displays less left hemispheric speech dominance than PWnS. (Willemse, 2006). The natural dominance of the right hemispere over the left hemispheric of the brain can cause less control over motor functions and slow down neuroplasticity within that portion of the brain.
Cortical Areas
There is also a significant difference in brain function when stutterers and non-stutterers read. Magneto electroencephalogram investigations showed that, when PWnS read aloud, activation of the cortical areas involved occurs in the order of occipital areas to Broca's area to premotor and motor cortices. However, PWS displays a different pattern. A stutterer’s brain function goes from occipital region to premotor and motor regions to Broca's area. (Willemse, 2006).
Developmental and Childhood anomalies
Stuttering can also be coordinated with developmental issues throughout childhood as well. It has been reported that this speech occurrence can happen due to a dwindling amount of grey matter within the left inferior gyrus and a disorganized white matter in the rolandic operculum as compared to children who don't showcase stuttering issues.
Treatments
Many treatments consisting with stuttering and speech impediment can vary depending on the severity of either the damage to the area and the severity of the stuttering. Speech and language therapy is one of the most effective ways to resolve this issue. For this, the therapist will work with the patient to analyze and correct any abnormalities in vocabulary and grammar. They use repetition and certain mouthing techniques to fix the patient's stuttering issue. Also, therapeutic laryngeal injections of botulinum toxin or “Botox” are injected to the Broca's area to improve the nature of speech within the patient.
References
Willemse, Naudine, et al. "Neurological aspects of stuttering: summary overview of scientific findings." Health SA Gesondheid: Journal of Interdisciplinary Health Sciences, vol. 11, no. 1, Mar. 2006, pp. 58+. Gale Academic OneFile, link.gale.com/apps/doc/A170730427/AONE?u=lincclin_pcc&sid=bookmark-AONE&xid=756a14e3. Accessed 27 Jan. 2024.
Kell, Christian A, et al. “How the Brain Repairs Stuttering.” Brain : A Journal of Neurology, vol. 132, no. Pt 10, 2009, pp. 2747–60, www.ncbi.nlm.nih.gov/pubmed/19710179, https://doi.org/10.1093/brain/awp185.
Kell, C. A., Neumann, K., von Kriegstein, K., Posenenske, C., von Gudenberg, A. W., Euler, H., & Giraud, A.-L. (2009, August 26). How the brain repairs stuttering. OUP Academic. https://academic.oup.com/brain/article/132/10/2747/330765
Schluter, N.D, et al. “Cerebral Dominance for Action in the Human Brain: The Selection of Actions.” Neuropsychologia, vol. 39, no. 2, Feb. 2001, pp. 105–113, https://doi.org/10.1016/s0028-3932(00)00105-6. Accessed 14 Dec. 2021.
Finger, S. “Paul Broca (1824-1880).” Journal of Neurology, vol. 251, no. 6, June 2004, https://doi.org/10.1007/s00415-004-0456-6.
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