In aphasia,a person may be unable to comprehend or unable to formulate language because of damage to specific brain regions. The major causes are stroke and head trauma;prevalence is hard to determine but aphasia due to stroke is estimated to be 0.1–0.4% in the Global North. Aphasia can also be the result of brain tumors,epilepsy,autoimmune neurological diseases,brain infections,or neurodegenerative diseases.
Wernicke's aphasia,also known as receptive aphasia,sensory aphasia,fluent aphasia,or posterior aphasia,is a type of aphasia in which individuals have difficulty understanding written and spoken language. Patients with Wernicke's aphasia demonstrate fluent speech,which is characterized by typical speech rate,intact syntactic abilities and effortless speech output. Writing often reflects speech in that it tends to lack content or meaning. In most cases,motor deficits do not occur in individuals with Wernicke's aphasia. Therefore,they may produce a large amount of speech without much meaning. Individuals with Wernicke's aphasia often suffer of anosognosia –they are unaware of their errors in speech and do not realize their speech may lack meaning. They typically remain unaware of even their most profound language deficits.
A communication disorder is any disorder that affects an individual's ability to comprehend,detect,or apply language and speech to engage in dialogue effectively with others. This also encompasses deficiencies in verbal and non-verbal communication styles. The delays and disorders can range from simple sound substitution to the inability to understand or use one's native language. This article covers subjects such as diagnosis,the DSM-IV,the DSM-V,and examples like sensory impairments,aphasia,learning disabilities,and speech disorders.
The National Institute on Deafness and Other Communication Disorders (NIDCD),a member of the U.S. National Institutes of Health,is mandated to conduct and support biomedical and behavioral research and research training in the normal and disordered processes of hearing,balance,smell,taste,voice,speech,and language. The institute also conducts and supports research and research training related to disease prevention and health promotion;addresses special biomedical and behavioral problems associated with people who have communication impairments or disorders;and supports efforts to create devices which substitute for lost and impaired sensory and communication function.
Transcortical motor aphasia (TMoA),also known as commissural dysphasia or white matter dysphasia,results from damage in the anterior superior frontal lobe of the language-dominant hemisphere. This damage is typically due to cerebrovascular accident (CVA). TMoA is generally characterized by reduced speech output,which is a result of dysfunction of the affected region of the brain. The left hemisphere is usually responsible for performing language functions,although left-handed individuals have been shown to perform language functions using either their left or right hemisphere depending on the individual. The anterior frontal lobes of the language-dominant hemisphere are essential for initiating and maintaining speech. Because of this,individuals with TMoA often present with difficulty in speech maintenance and initiation.
Language disorders or language impairments are disorders that involve the processing of linguistic information. Problems that may be experienced can involve grammar,semantics (meaning),or other aspects of language. These problems may be receptive,expressive,or a combination of both. Examples include specific language impairment,better defined as developmental language disorder,or DLD,and aphasia,among others. Language disorders can affect both spoken and written language,and can also affect sign language;typically,all forms of language will be impaired.
The American Speech–Language–Hearing Association (ASHA) is a professional association for speech–language pathologists,audiologists,and speech,language,and hearing scientists in the United States and internationally. The association reported over 234,000 members and affiliates in its 2023 report.
Speech–language pathology (a.k.a. speech and language pathology or logopedics) is a healthcare and academic discipline concerning the evaluation,treatment,and prevention of communication disorders,including expressive and mixed receptive-expressive language disorders,voice disorders,speech sound disorders,speech disfluency,pragmatic language impairments,and social communication difficulties,as well as swallowing disorders across the lifespan. It is an allied health profession regulated by professional bodies including the American Speech-Language-Hearing Association (ASHA) and Speech Pathology Australia. The field of speech-language pathology is practiced by a clinician known as a speech-language pathologist (SLP) or a speech and language therapist (SLT). SLPs also play an important role in the screening,diagnosis,and treatment of autism spectrum disorder (ASD),often in collaboration with pediatricians and psychologists.
In human development,muteness or mutism is defined as an absence of speech,with or without an ability to hear the speech of others. Mutism is typically understood as a person's inability to speak,and commonly observed by their family members,caregivers,teachers,doctors or speech and language pathologists. It may not be a permanent condition,as muteness can be caused or manifest due to several different phenomena,such as physiological injury,illness,medical side effects,psychological trauma,developmental disorders,or neurological disorders. A specific physical disability or communication disorder can be more easily diagnosed. Loss of previously normal speech (aphasia) can be due to accidents,disease,or surgical complication;it is rarely for psychological reasons.
Apraxia of speech (AOS),also called verbal apraxia,is a speech sound disorder affecting an individual's ability to translate conscious speech plans into motor plans,which results in limited and difficult speech ability. By the definition of apraxia,AOS affects volitional movement pattern. However,AOS usually also affects automatic speech.
Speech and language impairment are basic categories that might be drawn in issues of communication involve hearing,speech,language,and fluency.
Ingo R. Titze is a voice scientist and executive director of the National Center for Voice and Speech and Adjunct Professor in the Department of Otolaryngology/Head and Neck Surgery at the University of Utah in Salt Lake City. He also teaches at the Summer Vocology Institute,also housed at the University of Utah. He is a Distinguished Professor at the Department of Communication Sciences and Disorders at the University of Iowa and has written several books relating to the human voice.
Sandra Bond Chapman is a cognitive neuroscientist,founder and chief director of the Center for Brain Health,Dee Wyly Distinguished Professor in Brain Health,and a professor in the School of Behavioral and Brain Sciences at The University of Texas at Dallas.
Sign language refers to any natural language which uses visual gestures produced by the hands and body language to express meaning. The brain's left side is the dominant side utilized for producing and understanding sign language,just as it is for speech. In 1861,Paul Broca studied patients with the ability to understand spoken languages but the inability to produce them. The damaged area was named Broca's area,and located in the left hemisphere’s inferior frontal gyrus. Soon after,in 1874,Carl Wernicke studied patients with the reverse deficits:patients could produce spoken language,but could not comprehend it. The damaged area was named Wernicke's area,and is located in the left hemisphere’s posterior superior temporal gyrus.
Mary Pannbacker was a speech-language pathologist and university professor. She held an endowed chair,the Albertson's Professor of Speech-Language Pathology,at LSU Health Sciences Center Shreveport. She was a Fellow of the American Speech-Language-Hearing Association.
Caroline Bowen is a speech pathologist who was born in New Zealand,and who has lived and worked in Australia most of her life. She specialises in children's speech sound disorders. Her clinical career as a speech-language pathologist spanned 42 years from 1970 to 2011.
Susan Ellis Weismer is a language and communication scientist known for her work on language development in children with specific language impairment and autism spectrum disorder (ASD). She is the Oros Family Chair and Professor of Communication Sciences and Disorders at the University of Wisconsin–Madison,where she is a Principal Investigator and Director of the Language Processes Lab. She has also served as the Associate Dean for Research,College of Letters and Sciences at the University of Wisconsin–Madison.
Debara Lyn Tucci is an American otolaryngologist,studying ear,nose,and throat conditions. She co-founded the Duke Hearing Center and currently serves as a professor of Surgery and Director of the Cochlear Implant Program at Duke University. In September 2019 she became Director of the National Institute on Deafness and Other Communication Disorders,one of the National Institutes of Health's 27 Institutes and Centers.
Nancy Helm-Estabrooks is an emeritus professor at Western Carolina University where she was the first Brewer Smith Distinguished Professor. She is known for her work on persons with aphasia and acquired cognitive-communication disorders.
Cynthia K. Thompson is a neurolinguist and cognitive neuroscientist most known for her research on the brain and language processing and the neurobiology of language recovery in people with aphasia. She served as a member of the faculty at Northwestern University (NU) for 30 years as a Distinguished Ralph and Jean Sundin Professor in the Department of Communication Sciences and Disorders. She also directed the Aphasia and Neurolinguistics Research Laboratory (ANRL) and the Center for the Neurobiology of Language Recovery (CNLR) and is a Distinguished Ralph and Jean Sundin Professor Emerita at NU.
