Right Hemisphere Disorder Flashcards
(32 cards)
RIGHT HEMISPHERE DISORDERS
FOR OVER 100 YEARS THE LEFT HEMISPHERE DOMINATED COGNITIVE RESEARCH
AND THE RIGHT HEMISPHERE WAS REFERRED TO AS “THE SILENT OR MINOR HEMISPHERE”
1865-HUGHLINGS JACKSON
ROLE OF PERCEPTION
1940’S
ROLE IN VISUAL PERCEPTION
Late 1940’s
COMMISSUROTOMY Spilt of the corpus callous 1960’S-VOGEL AND BOGEN COMMISSUROTOMY OPPORTUNITY TO INVESTIGATE THE 2 HEMISPHERES (LATERALITY RESEARCH) SPLIT-BRAIN RESEARCH
1970’S
DICHOTIC LISTENING TASKS
HEMIFIELD TACHISTOSCOPES RIGHT HEMISPHERE DISORDERS
Prominent role in visual perception
Small role in decoding certain linguistic forms
Split-Brain Research
Roger Sperry
Patients with split-brains displayed a clear ability to function without the benefit of communication between the hemispheres
the right brain had some language capabilities
Eran Zaidel-
each disconnected cerebral hemisphere “constituted a complete cognitive system with its own sensations, perceptions, memory, even language, personality and consciousness”
the two hemispheres process information simultaneously and independently
There are discrepancies between profiles of hemispheric specialization seen in the normal brain and in a hemisphere damaged patient
THIS LEAD TO INCREASED INTEREST IN DAMAGE TO THE RIGHT HEMISPHERE
Visual memory Visual imagery Visual perception Spatial orientation Awareness of illness
Communication
More than speech and language
Focus began to shift from semantics and syntax to pragmatics and discourse
Patients with RHD served as controls in language studies
CLINICAL RESEARCH AND OBERVATION IN RHD SUBJECTS FROM THE 1970’S AND 1980’S
HOWARD GARDNER AND HIS COLLEGUES
Comprehension of humor
The role of the right hemisphere in understanding complex linguistic stimuli
Elliot Ross and colleagues began studying emotion and the right hemisphere-
Aprosodia
“NEW WAVE OF RESEARCH” FOCUSED ON THE UNDERLYING MECHANISMS
Brownell Tompkins Meyers Bisiach Ross Heilman Moya & Bennowitz
Justice William O. Douglass December 31, 1974
Continued coming to work after he had been let go but had perfect verbal language… studies based on him
Deficits
NEGLECT
Patients with neglect don’t respond to information presented to the side opposite of their lesion. Grooming Attending to limbs Appropriate use of margins Localizing sound Awareness Naming their limbs Poor awareness of their deficits Denial of deficits Neglect may be as prominent to right hemisphere lesions as naming disorders are in left hemisphere lesions.
Theories of Neglect
Representational Theory-disordered mental representation of space
Bisiach-city plaza in Milan
they loose their definitions of things to only the right side
that is why they only draw half the shape
Attentional Theory-abnormal distribution of attention
Heilman-The RH and the LH direct attention to the contralateral space but the RH can distribute attention across hemispace.
PROSODIC DEFICITS
The melodic contour and rhythm of speech
Facilitates decoding of meaning across words and sentences
Facilitates knowledge of the emotional content
3 parameters
Pitch
Stress
Duration
Prosodic Comprehension Deficits
Studies have shown that damage to the right hemisphere can interfere with understanding of prosody
Associate with both right anterior and posterior lesions but majority of posterior lesions
Prosodic Production
Studies have shown that damage to the right hemisphere may result in difficulty conveying emotion through prosody
Ross, 1981
Cortical lesions
Prosodic deficits are mapped in a similar way to aphasic deficits
Motor or Broca’s aprosodia
Transcortical aprosodia
can repeat posits but cant understand or produce
Cortical lesions and basal ganglia lesions
Aprosodias
Motor aprosodia. Sensory aprosodia. Global aprosodia. Conduction aprosodia. Transcortical motor aprosodia. Transcortical sensory aprosodia. Mixed aprosodia.
Affective Deficits
Right hemisphere plays a role in the perception and production of emotional behavior
Seem Indifference
Right hemisphere is more adept at processing negative emotion
Difficulty processing facial expression, body language and gesture
Difficulty producing a wide range of facial expressions, body language and gesture
Delusions and Confusional states
Agitation Misidentification syndromes- disconnection between identity and familiarity (limbic) Reduplicative paramnesia-place you believe you are in another place Capgras syndrome-people you think people closer to you are imposters Somatoparaphrenia-limbs this is not my hand Prosopagnosia-familiar faces
LINGUISTIC DEFICITS
Non aphasic language difficulties described as
“looseness of verbalization”
“missing the point”
concrete interpretations
Interpretating figurative language
Idioms-”hit the ceiling”
Metaphors- “the job is a prison”
