Broca's areaBroca's area, or the Broca area (ˈbroʊkə, also UKˈbrɒkə, USˈbroʊkɑː), is a region in the frontal lobe of the dominant hemisphere, usually the left, of the brain with functions linked to speech production. Language processing has been linked to Broca's area since Pierre Paul Broca reported impairments in two patients. They had lost the ability to speak after injury to the posterior inferior frontal gyrus (pars triangularis) (BA45) of the brain.
Speech and language impairmentSpeech and language impairment are basic categories that might be drawn in issues of communication involve hearing, speech, language, and fluency. A speech impairment is characterized by difficulty in articulation of words. Examples include stuttering or problems producing particular sounds. Articulation refers to the sounds, syllables, and phonology produced by the individual. Voice, however, may refer to the characteristics of the sounds produced—specifically, the pitch, quality, and intensity of the sound.
DyslexiaDyslexia, previously known as word blindness, is a learning disability that affects either reading or writing. Different people are affected to different degrees. Problems may include difficulties in spelling words, reading quickly, writing words, "sounding out" words in the head, pronouncing words when reading aloud and understanding what one reads. Often these difficulties are first noticed at school. The difficulties are involuntary, and people with this disorder have a normal desire to learn.
Auditory processing disorderAuditory processing disorder (APD), rarely known as King-Kopetzky syndrome or auditory disability with normal hearing (ADN), is a neurodevelopmental disorder affecting the way the brain processes sounds. Individuals with APD usually have normal structure and function of the outer, middle, and inner ear (peripheral hearing). However, they cannot process the information they hear in the same way as others do, which leads to difficulties in recognizing and interpreting sounds, especially the sounds composing speech.
AphasiaIn 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, brain damage and brain infections, or neurodegenerative diseases (such as dementias). To be diagnosed with aphasia, a person's language must be significantly impaired in one (or more) of the four aspects of communication.
