4B: Language Disorders Flashcards
Dorsal stream in language
dorsal regions of the brain involved in speech production
Ventral stream in language
ventral regions of the brain involved in speech comprehension
The Hickok-Poeppel language model
a model of brain areas involved in language comprehension and speech production; describes dorsal pathway for production and ventral pathway for comprehension
Aphasia
from Greek for ‘lack of speech” that is not a result of deficits in sensory, intellectual, or psychiatric functioning, nor muscle weakness; deficit arises from damage language- specific cortical regions; several types of aphasia exist
Broca’s aphasia
aphasia characterized by slow, effortful speech output lacking function words, problems with grammar and articulation, in which patients rely on high- frequency content words. Patients have deficits in repetition, naming, and fluency, but can comprehend normally.
Wernicke’s aphasia
aphasia characterized by fluent, meaningless speech with many semantic errors and little understanding. Patients have deficits in repetition, naming, comprehension, and have paraphasic fluency. In severe causes, patients appear to have no concept of what language is for.
Paraphasia
a notable feature of aphasia in which one loses the ability of speaking correctly, substitutes one word for another, and changes words and sentences in an inappropriate way. The patient’s speech is fluent but is error-prone, e.g. ‘treen’ instead of ‘train’.
Word salad
apparently fluent speech, but meaningless; seen in Wernicke’s aphasia
Anosognosia
a deficit of self-awareness; a condition in which a person who suffers a certain disability seems unaware of the existence of his or her disability.
Paraphasia
a condition in which one loses the ability to speak correctly, substituting one word for another, and changing words and sentences in an inappropriate way
Arcuate fasciculus
the neutral white matter pathway connecting Broca’s area and Wernicke’s areas
Conduction aphasia
aphasia due to damage to the arcuate fasciculus resulting in poor repetition and naming, but normal comprehension and fluency
Transcortical sensory aphasia
aphasia that is similar to Wernicke’s aphasia, except that patients are able to repeat language they have just heard (but still do not comprehend it)
Transcortical motor aphasia
aphasia associated with right hemiparesis (paralysis or inability to move) that is similar to Broca’s aphasia, except patients are able to repeat
Global aphasia
aphasia, associated with right hemiparesis, characterized by severe communication difficulties in both speech and comprehension; Patients may have no concept of language as communication.
Transcortical mixed aphasia
similar to global aphasia, but patients are still able to repeat
Anomic aphasia
aphasia in which word-finding is severely impaired, usually from damage to parietal and/or temporal lobes, and patients resort to circumlocution
Averbia
specific aphasia in which patient loses ability to use verbs
Color anomia
specific aphasia in which patient loses ability to use color words
Circumlocution
the use of other words to describe a specific word or idea which cannot be remembered (means ‘talking around’ something)
Pure word deafness
the selective inability to comprehend
the spoken word, in the absence of aphasia or defective basic hearing. Perception of
environmental sounds and other complex, non-speech sounds is generally normal. Pure
word deafness is usually caused by bilateral damage to temporal lobes (often including
white matter connecting temporal and frontal lobes). Patients can still read and write.
Amusia
the selective inability to recognize musical tones or to reproduce them (agnosia
for music). It involves loss of the ability to recognize musical notes, rhythms, and
intervals and the inability to experience music as musical. Patients often describe music
as being indistinguishable from the sound of pots and pans banging together. Amusia can
be congenital (present at birth) or be acquired sometime later in life (as from brain
damage)
Speech entrainment therapy
patients practice mimicking audio-visual speech stimuli; this therapy can enable them to produce fluent speech in real time.
Subsystems of speech
Respiration, phonation, resonance, articulation