Chapter 16 - Lateralization, Language, and the Split Brain Flashcards
Cerebral commissures
Tracts that connect the left and right cerebral hemispheres
Lateralization of function
The unequal representation of various psychological functions in the two hemispheres of the brain
Split-brain patients
Commissurotomized patients
Commissurotomy
Surgical severing of the cerebral commissures
Aphasia
A brain damage–produced deficit in the ability to produce or comprehend language
Frontal operculum
The area of prefrontal cortex that in the left hemisphere is the location of Broca’s area
Planum temporale
An area of temporal lobe cortex that lies in the posterior region of the lateral fissure and, in the left hemisphere, roughly corresponds to Wernicke’s area
Heschl’s gyrus
The temporal lobe gyrus that is the location of primary auditory cortex
Motor theory of speech perception
The theory that the perception of speech involves activation of the same areas of the brain that are involved in the production of speech
Wernicke’s area
The area of the left temporal cortex hypothesized by Wernicke to be the center of language comprehension
Broca’s area
The area of the inferior prefrontal cortex of the left hemisphere hypothesized by Broca to be the center of speech production
Apraxia
A disorder in which patients have great difficulty performing movements when asked to do so out of context but can readily perform them spontaneously in natural situations
Dominant hemisphere
A term used in the past to refer to the left hemisphere, based on the incorrect assumption that the left hemisphere is dominant in all complex behavioral and cognitive
activities
Minor hemisphere
A term used in the past to refer to the right hemisphere, based on the incorrect assumption that the left hemisphere is dominant
Sodium amytal test
A test involving the anesthetization of first one cerebral hemisphere and then the other to determine which hemisphere plays the dominant role in language
Dichotic listening test
A test of language lateralization in which two different sequences of three spoken digits are presented simultaneously, one to each ear, and the subject is asked to report all of the digits heard
Dextrals
Right-handers
Sinestrals
Left-handers
Expressive
Pertaining to the generation of language; that is, pertaining to writing or talking
Broca’s aphasia
A hypothetical disorder of speech production with no associated deficits in language comprehension
Receptive
Pertaining to the comprehension of language and speech
Wernicke’s aphasia
A hypothetical disorder of language comprehension with no associated deficits in speech production
Arcuate fasciculus
The major neural pathway between Broca’s area and Wernicke’s area
Conduction aphasia
A hypothetical aphasia that is thought to result from damage to the arcuate fasciculus—the pathway between Broca’s and Wernicke’s areas
Angular gyrus
The gyrus of the posterior cortex at the boundary between the temporal and parietal lobes. According to the Wernicke-Geschwind model the left hemisphere angular gyrus plays a role in reading.
Alexia
A specific inability to read; one that does not result from general visual, motor, or intellectual deficits.
Agraphia
A specific inability to write; one that does not result from general visual, motor, or intellectual deficits
Wernicke-Geschwind model
An influential model of cortical language localization in the left hemisphere
Global aphasia
Severe disruption of all language-related abilities
Phoneme
The smallest unit of sound that distinguishes among various words in a language
Corpus callosum
The largest cerebral commissure
Scotoma
An area of blindness produced by damage to, or disruption of, an area of the visual system
Cross-cuing
Communication between hemispheres that have been separated by commissurotomy via an external route
Helping-hand phenomenon
The redirection of one hand of a splitbrain patient by the other hand
Visual completion
The completion or filling in of a scotoma by the brain
Chimeric figures test
A test of visual completion in split-brain subjects that uses pictures composed of the left and right halves of two different faces
Phonological analysis
Analysis of the sound of language
Grammatical analysis
Analysis of the structure of language
Semantic analysis
Analysis of the meaning of language
Dyslexia
A reading disorder that does not result from general visual, motor, or intellectual deficits
Developmental dyslexias
Dyslexias that become apparent when a child is learning to read
Acquired dyslexias
Dyslexias caused by brain damage in people previously capable of reading
Lexical procedure
A procedure for reading aloud that is based on specific stored information acquired about written words
Phonetic procedure
A procedure for reading aloud that involves the recognition of letters and the application of a language’s rules of pronunciation
Surface dyslexia
A reading disorder in which the lexical procedure is disrupted while the phonetic procedure is not
Deep dyslexia
A reading disorder in which the phonetic procedure is disrupted while the lexical procedure is not
Hemispherectomy
The removal of one cerebral hemisphere
