Language and Lateralization Flashcards
What kind of other potential damage will you see if Broca’s area is damaged?
Because Broca’s area is right next to the primary motor cortex, a person may be unable to form words. This is called nonfluent (or Broca’s) aphasia - difficulty producing speech but comprehension is still good.
Describe the effects of fluent aphasia (Wernicke’s aphasia)
Werenicke’s area is a region of the left posterior temporal cortex.
They have trouble understanding what they read or hear and have trouble repeating words or phrases. Speech appears unintelligible. It also may be accompanied by anomia, which is a difficulty in naming persons or objects.
Describe global aphasia
The total loss of the ability to understand or produce language. Results from widespread left-hemisphere lesions, affecting all speech zones. The prognosis for language recovery is poor and this aphasia is often accompanied by other neurological impairments.
Cerebral lateralization
The division of labor between the two cerebral hemispheres such that each hemisphere is specialized for particular types of processing
Split-brain individuals
An individual whose corpus callosum has been severed, halting communication between the right and left hemispheres
Hemispheric Information
Sensory info felt on one side fo the body is processed by the contralateral hemisphere
Words presented to either visual field showed language ability only in the left hemisphere
Right hemisphere is mainly for spatial processing, with limited linguistic ability
Stimulus presented in left visual field goes to the _______ hemisphere, stimulus presented in right visual field goes to the _______ hemisphere
Right
Left
Dichotic Presentation
The simultaneous delivery of different stimuli to both the right and the left ears at the same time
Tachistoscope Test
A test in which stimuli are very briefly presented to either the left or right visual half field
Planum Temporale
An auditory region of superior temporal cortex
Related to speech
Right Ear Advantage
Right-handers identify verbal stimuli delivered to R ear more easily
-language strongly lateralized to left
Music
Auditory areas of the right hemisphere play a major role in the perception of music
Prosody
The perception of emotional aspects of language
A RIGHT hemisphere specialization
Handedness
Left handedness is influenced by heredity and left handed people make up about 10% of the population
-The left hemisphere is specialized for language in most left handed people (like normal)
Right hemisphere dominance for language is rare, but when it does occur, it is likely to be a left-handed person
Wada Test
A test in which a short-lasting anesthetic is delivered into one carotid artery to determine which cerebral hemisphere principally mediates language
Right Hemisphere Spatial Functions
Normal people demonstrate a right hemisphere advantage for processing spatial stimuli
Lesions of areas in the RH can produce visuospatial impairments
Involved in recognizing one’s own face
Astereogenesis
Prosopagnosia
Prosopagnosia
The inability to recognize faces, including one’s own
Astereogenesis
The inability to recognize objects by touching or feeling them
Fusiform Gyrus
A region on the inferior surface of the cortex, at the junction of the temporal and occipital lobes, that has been associated with the recognition of faces
Both hemispheres have some capacity for recognizing faces, but Fusiform Gyrus plays the biggest role
Aphasia
An impairment in language understanding and/or production that is caused by a brain injury
Paraphasia
A symptom of aphasia that is distinguished by the substitution of a word by a sound, an incorrect word, an unintended word, or a neologism (a meaningless word).
Agraphia and Alexia
The inability to write and the inability to read, respectfully.
Apraxia
An impairment in the ability to carry out complex movements, even though there is no muscle paralysis
Connectionist Model of Aphasia (Wernicke-Geschwind Model)
A theory proposing that left-hemispheric language deficits result from disconnection between the brain regions in a language network, each which serves a particular linguistic function
Wernicke’s area decodes sounds and transmits information to Broca’s area via the arcuate fasciculus,
Broca’s area sends a speech plan adjacent motor cortex to produce speech.
Conduction aphasia
An impairment in the ability to repeat words and sentences.
Pathway of Speaking a Heard Word
Primary Auditory Cortex - Wernicke’s Areas - Arcuate Fasciculus - Broca’s Area - Motor Cortex
Pathway of Speaking a Written Word
Visual Cortex - Angular Gyrus - Wernicke’s Areas - Arcuate Fasciculus - Broca’s Area - Motor Cortex
Motor theory of language
The theory that speech is perceived using the same left-hemisphere mechanisms that are used to produce the complex movements that go into speech
William’s Syndrome
A disorder characterized by impairments of spatial cognition and IQ but superior linguistic abilities
Dyslexia
A reading disorder attributed to brain impairment
Deep Dyslexia
Acquired dyslexia in which the patient reads a word as another word that is semantically related
Surface Dyslexia
Acquired dyslexia in which the patient seems to attend only to the fine details of reading
