Week 1: chapter 1, 3 and McNeil & Pratt (2001)
Different definitions of aphasia throughout history; reflecting theoretical constructs; always
developing definition
Aphasia = acquired language impairment resulting from focal brain lesion in the absence of
other cognitive, motor, or sensory impairments (neurological); breakdown in specific
language domains resulting from a focal lesion (neurolinguistic); selective breakdown if
language processing itself, of underlying cognitive skills, or necessary cognitive resources
resulting from focal lesion (cognitive); communication impairment masking inherent
competence (functional)
→ can be present in every aspect of language (components, modalities, and input/output)
Researchers agree on:
● aphasia being mostly a language-level problem
● it includes receptive and expressive components
● has a multimodal nature
● is caused by a central nervous system dysfunction
Aphasia → acquired focal lesions in the language-dominant hemisphere
Focus on acquired neurological impairments → focus on the consequences of these
impairments (WHO)
For this text aphasia = acquired selective impairment of language modalities and functions
resulting from a focal brain lesion in the language-dominant hemisphere that affects the
person’s communicative and social functioning, and quality of life and the quality of life of
his/her relatives and caregivers.
Dysarthria = speaking disability
Dysphagia = swallowing disability
Long-term outcomes of people with aphasia → social isolation, depression, poor quality of
life (e.g. Cruice et al., 2006); people continue needing therapy
Treatment focuses on the individual person! Need for public awareness!
Underserved = communities where health and social services workforce is insufficient,
people experience barriers
Framework WHO (redefining functioning and
disability) for aphasiacs:
1) body structure and functioning →
impairments of the brain + its function
2) activity and participation → tasks/actions
involving the four language modalities + daily
functional communication tasks
,Environment (ICF) = relationships with others, policies and regulations, use of assistive
tech, physical environmental factors, and attitudes of individuals/society towards that person
with aphasia
Aphasia therapy = supportive process designed to help people with aphasia modify current
communicative behaviours to maximise communication proficiency
● Group therapy = didactic, social and emotional support; usually multipurpose
groups; positive efficacy (Wetz et al., 1981); essential component
○ Not as effective for functional discourse + all individuals
○ Effective for specific language processes (e.g. word finding); improved scores
on formal assessment
○ Positive changes in social networks
→ aphasia book clubs and choirs show positive outcomes, especially for functional
measures
● Pharmacotherapy = manipulation of neurotransmitter levels with the intent of
stimulating widespread cerebral activity; no specific impact on language, influence
cognitive substrates of language processing;
○ Galling et al. (2014) → non-fluent aphasia patient, bromocriptine + language
therapy → improvement language production, not comprehension → effective
for Broca’s and transcortical motor aphasia; only a combination helps
○ Zhang et al. (2018) → only donepezil (acetylcholine agonist) and memantine
(glutamate antagonist)
→ medication can enhance speech-language therapy to some extent; effects not per se on
language, but on underlying cognitive support functions
(agonist = creates response; antagonist = blocks response)
Technology in aphasia therapy → can be used, depending on people’s willingness and
abilities to use technology
● Additional practice = more therapy is better than less; therapy period becomes
more cost effective (possibility of at-home practice); extension of therapy contents →
should reflect rehabilitation process + closely followed by clinician
○ Independent skill practice
○ Overall effectiveness of application → Lavoie et al. (2017)
○ Contents need to remain individualised + tailored to the patient’s needs
● Communication compensation = external aid to communicate more effectively;
focus on functional measures and social participation implemented later in
rehabilitation, but this is challenged
○ Augmentative and alternative communication (AAC), should be adaptable and
can be temporary (Dietz et al., 2020)
○ Taylor et al. (2019) → age not necessarily a barrier for use; period of intense
practice is most crucial
○ Hoover & Carney (2014) → using apps improved functional language
measures + quality-of-life scales
,Telepractice = video contact between patient and clinician; used to fill service gaps in
different settings;
● Synchronous = interactive audio and video connection in real-time; similar to
traditional encounter; can connect client & clinician or an entire group with a clinician
● Asynchronous = store-and-forward; pre-recorded material for a practitioner to
review, e.g. language sampling
● Hybrid = a combination of synchronous, asynchronous, and in-person services
Effectiveness supported for patients with aphasia - Hall et al. (2013) → telepractice is
equivalent to face-to-face practices for both assessment and therapy
Weidner & Lowman (2020) → positive effect for diagnostic accuracy for telepractice; practice
through telepractice helps maintain naming skills
Cortical aphasia = symptoms related to a lesion of a specific area in the cerebral cortex,
e.g. Broca’s or Wernicke’s; subtypes that have hallmark features
Vs.
Subcortical aphasia = affected regions beneath the cortex can result in aphasia, e.g.
thalamus regulating speech, language and memory processing; ‘borderline fluent’ aphasias
● Thalamic = characterised by variable phrase length and auditory comprehension +
preservations but with good repetition skills
● Capsular = in anterior-superior white matter → good auditory comprehension +
repetition skills with impairment in naming and reduced articulatory precision;
posterior white matter → poor auditory comprehension + repetition, with adequate
articulatory precision but a variety of paraphasic errors; global/both → damage to
both anterior-superior + posterior white matter, severely limited verbal output +
auditory comprehension deficits, varying based on degree of extension into temporal
lobe
Language processed in left hemisphere → typically, lesion here leads to aphasia;
left-handed people have language partly lateralized to the right hemisphere →
right-hemisphere lesion can lead to aphasia for those individuals
Crossed aphasia = right-hemisphere stroke causing aphasia in right-hand dominant
individuals; present other impairments consistent with right-hemisphere damage, like
decreased attention to the left (left neglect) + visuospatial deficits
Ambiguity in defining fluent & nonfluent aphasia → neuroanatomical approach may group
individuals together who don’t necessarily have symptoms in common
Cognitive neuropsychological approach → examines language performance in individual
people with aphasia across all processing levels and modalities; emphasis on importance of
error pattern examination; explaining language impairment in aphasia through models of
healthy language processing
Focus on the individual level → treatment approaches applied broadly to a group
demonstrating similar patterns of spared/impaired processes
, Psycholinguistic approach → similar to cognitive neuropsychological approach; focus on
individuals; no limit to the number of language impairments someone with aphasia can
demonstrate; identifying impairments through psycholinguistic factors (e.g. phonology),
processes activating information at different language levels, and different modalities;
allowing isolation of impairment to target directly
Data-driven approach → use of statistical methods to identify relationships between
measures of cognitive performance and the brain; key language processes consistently
associated with damage in certain brain areas;
● Phonological production deficits associated with damage to dorsal stream → inferior
parietal and frontal regions
● Phonological comprehension deficits associated with damage to ventral stream →
posterior to anterior superior temporal lobe
● Semantic impairments after damage to anterior temporal lobe
● Syntax not domain specific?
Dual-stream model → visual and auditory processing
Network involving bilateral frontal, temporal, and parietal regions for healthy language
processing.
➔ Dorsal stream activation for phonological processing
➔ Ventral stream activation for semantic processing
➔ Syntax relying on both phonology and semantics
Aphasia fucks everything up
Schwartz et al. (2012) → phonological errors correlate with lesion in dorsal tract regions
(supports NT studies)
Ivanova et al. (2016) → better microstructural integrity in part of the ventral stream white
matter tract is associated with better word-level comprehension for individuals with aphasia
Interactions left-hemisphere regions during naming + semantic processing tasks differ
between NT and aphasia → associated with language performance in post-stroke aphasia
Hypothesis: intact domain-general regions carry out functions that can no longer be
performed by damaged domain-specific language regions
Thompson et al. (2010) → 1) individuals with aphasia rely on neurotypical language
networks if possible and 2) processing syntactic information relies on an underlying network
integrating semantics + syntax
Domain-general processes (e.g. memory) can underlie various linguistic processes in
individuals with aphasia