L9: Right Hemisphere Brain Injury Flashcards
it is now consensually accepted that the contribution of both hemispheres …
is required to reach a functional level of communication
RHBI can occur due to
stroke, trauma, tumour, degenerative disease, vasculopathy, infection
of the patients with RHBI, _____ are right-handed adults
50% to 90%
RHBI impairments are _____, due to…
diverse
size and site of lesion, type of stroke
RH contributes to …
behaviours and multiple cognitive systems and processes
RH role in language is less clear but a growing area of literature…. only _____% of patients w RHBI referred for SLP services, ____ not the focus
45
communication
what are the 4 theoretical accounts of RHBI? (aka hypotheses)
Bilateral Activation Integration and Selection (BIAS)
Suppression Deficit Hypothesis
Cognitive Resource hypothesis
social cognition deficits hypothesis
describe Bilateral Activation Integration and Selection (BIAS) in terms of LH and RH responsibilities
both hemispheres process semantic info
LH responsible for fine semantic coding (activates features related to dominant, literal or contextually relevant meaning)
RH responsible for ‘coarse’ semantic coding (activates distant and unusual semantic features - evident in inferencing and nonliteral language interpretations)
describe Bilateral Activation Integration and Selection (BIAS) in terms of what RHBI leads to
reduced activation and limited selection of distant conceptual/lexical relationships
poor comprehension of implied info (ex. indirect requests)
suppression deficit hypothesis: discourse comprehension depends on…
heightened activation of info associated w contextually appropriate interpretations
suppressed activation of less appropriate or irrelevant info
AKA activate things that are relevant and suppress things that are not relevant
suppression deficit hypothesis: RHBI results in…
a delay in suppressing contextually inappropriate interpretations, especially in narrative comp
activation of competing interpretations
BIAS and suppression deficit hypothesis are not mutually exclusive; both…
complimentary for normal comprehension of language but can be differential contributors to cognitive-communication deficits in RHBI
cognitive resource hypothesis: RH assists LH processing when…
observed in…
LH’s cognitive resource capacities are exceeded (ex. attentional resources)
aka as cog demands inc RH takes on more of a role
observed in… more complex language tasks such as narrative processing (vs simple lexical decision making like noun vs verb)
cognitive resource hypothesis: RHBI reduces…
cognitive support to LH
one’s ability to comprehend complex discourse and pragmatic elements (ex. inferencing, similes, metaphors, sarcasm etc)
social cognition deficits hypothesis: RH plays a role in…
theory of mind functions:
- understand and interpret ppl’s mental state and predict and explain their behaviours
- R-dorsomedial frontal and R-temporal region
aka politeness in conversations, using and comprehending interpersonal relationship markers
social cognition deficits hypothesis: RHBI leads to…
reduced ability to engage in competent social relations and understand social information; indifference
poor integration of others feelings and perspectives
poor social judgements; reduced and self-monitoring relative to interactions w others
RHBI: Anosognosia is..
blunted awareness and insight of illness
more common in R parietal injuries
wide range of severity
linked to poorer functional outcomes
RHBI: prosopagnosia is..
impaired recognition of faces of people (famous and/or personal)
RHBI: topographic impairments are…
difficulty orienting to extra-personal space
geographic disorientation - environment agnosia
able to recognize general surroundings but not know where they are
RHBI: reduplicative paramnesia is…
perceive/believe in existence of duplicate places, persons, body parts, or events
RHBI: visuospatial impairments are…
difficulty w objects, pictures, drawings that are distorted or incomplete or changed from pro-typical appearance
ex. upside down table (cant tell what it is or orient it back to normal)
minimal to no issues w naturalistically displayed visual representations
likely visual organization probs more than perceptual
can occur in LHBI or RHBI - RH more common (parietal/occipital)
RHBI: reduced sensitivity to and use of ____ expression,…..
facial expression, gestures, and body language
JUST non verbal comm (aprosodia is separate)
RHBI: describe attention impairments
common to LHBI and RHBI, more salient in RHBI and TBI
attentional resources can be reduced or ineffectively allocated
typically 5 categories of attention organized hierarchically
For attention, default mode network is associated with what parts of the brain? what is it responsible for
prefrontal cortex, posterior cingulate gyri, and intraparietal sulci
responsible for “stream of consciousness” thinking
ex. what did I eat for breakfast, what am i doing after class
For attention, dorsal activation network is associated with what parts of the brain? what is it responsible for
frontal eye field and dorsal parietal lobes
top down attentional processes - ex. sustained
- voluntary intentional processes (ex. attending to class is top down)
For attention, ventral attentional network is associated with what parts of the brain? what is it responsible for
large network involving regions of frontal, temporal and parietal lobes, R>L
bottom up attentional processes (ex. attending to a sudden clap or loud sound, involuntary)
~25% of RH strokes have _____ neglect
unilateral/hemispatial/left/contralateral
RHBI: Unilateral neglect is …
most often R-parietal
failure to attend to stimuli and objects on side of the body opposite of brain injury primarily in vision but occurs in hearing and tactile domains
“the pt is looking to their stroke”
cannot be explained by sensory or motor impairments
may occur in the presence (or absence) of visual field cuts and anosognosia
associated w poor functional outcomes
in RHBI, executive function problems include…
probs w initiation, response inhibition, task persistance, organization, generative thinking, and self regulation, integration, reasoning and prob solving
More specifically (maybe focus on these ones):
- poor divergent thinking
- probs perceiving relevant properties of a task
- poor info integration and inferencing
RHBI: memory deficits include…
deficits in recall and recognition in nonverbal episodic memory (linked w attention and perceptual encoding probs)
deficits also present in verbal episodic memory (poor performances in story mem recall, word list and paired associate learning)
what are the 5 communication impairments in RHBI
receptive and expression aprosodias
spontaneous language: discourse
impaired comprehension
impaired pragmatics
reading and writing
aprosodia =
difficulty understanding or expressing the emotional aspects of speech
RHBI: describe receptive and expression aprosidias
can co-occur or occur in isolation
diminished ability to ‘read’ others
slower - equal temporal spacing bw sounds, syllables, words
reduced emphasis/stress patterns; flat intonation
reduced pitch variability
may compensate w propositional forms
contributions of affect and dysarthria possible
RHBI: there is _____ variability in discourse production
lots of
RHBI: discourse considerations; naming errors occur especially for
polysemous words (ex. ‘get’ = procure, become, or understand)… aka more than one meaning words
NOT THE SAME as anomia in those w LHBI
RHBI: discourse considerations; confabulatory errors are
made up events and actions
RHBI discourse: can sometimes be inappropriate or
terse/rude/crude
those with RHBI often have difficulty generating the _____structures more so than the _____structures
macrostructures = overall meaning, initial setting, gist, topic, theme
microstructures = words, propositions, clauses, or turns in convo
linked to selective attention probs or other cog impairments
RHBI 3 other discourse issues…
rambling and confused
repetitive
tangential and regressive
fails to establish relationships among events, places, ppl
RHBI: describe the impaired comprehension (compare w LHBI)
most ppl w LHBI do better on discourse comp vs single word comp
most ppl w RHBI show opp pattern (better single word comp) except for polysemous words (ex. appointment)
probs understanding ambiguous or conflicting elements w multiple possible interpretations (ex. sarcasm, irony, figurative expressions)
process narratives and conversations in ‘piecemeal’ not making connections among/bw characters, events, general topics, sub topics
RHBI: In terms of impaired comprehension, these patients can…
understand discourse when info is coherent and consistent
generate predictive inferences that are supported by discourse context
RHBI: Describe impaired pragmatics
not all w RHBI will exhibit pragmatic deficits
reduced eye contact; flat facial affect and intonation
interject irrelevant/inappropriate/tangential comments
probs using and understanding figurative/non literal forms (ex. metaphors)
interpret figurative language literally
difficulty extracting morals/themes from stories and making inferences
probs understanding humour based on multiple word meanings
usually unconcerned about the intent or consequences of their message
RHBI: Describe the reading and writing
not well researched beyond visuospatial deficits
language and pragmatic findings consistent w the oral and auditory modes
probs w visual scanning and tracking vertically and horizontally
neglect alexias
neglect agraphia
neglect alexias are
initial letter substitutions or deletions; performance declines when letters/graphemes are further apart
vertical presentation helps reduce neglect
neglect agraphia is
over written and misaligned letters or words; spatial relationships dysfunctional
overcrowding to R side of page or monitor
Wide L-sided margins on page or screen
