Aphasia III Flashcards
Resource Allocation Theory
Accounts for the relationship between attention, arousal and language processing units
Shared attention among cognitive demands; unequally distributed attention, inefficient allocation of attention, threshold of attention
Default Mode Network
Responsible for internally focussed attention
Supports internally directed cognitive processing
(wakeful rest, day dreaming)
Attention Allocation
Control structure that allocates attention
Amount allocated depends on task demands
Amount of attention needed = degree of effort/energy required
Factors affecting attention allocation
Novelty of task
Intent to attend to specific input (reading difficult text, scanning for name on list)
Arousal level - low (fatigue), high (time pressure)
Breakdown of Attention Allocation
Insufficient capacity
Misdirected resources
Slow mobilisation of resources
Dual tasks
Performance reduction on one/both tasks - only occur if they share the same resources
More overlap = more competition on cognitive load
Neurological Structures involved
Frontal lobe, thalamus, reticular activating formation
Widely distributed system = more vulnerable to brain damage
Aphasia - Resource Allocation Deficit
Strongest form - spared linguistic representations, impaired mechanisms that activate, select, inhibit language
Weaker form - some aspects vulnerable to attention deficits
Neural Multifunctionality
Constant and dynamic interaction between cognitive, affective, praxic function neural networks and those for lexical retrieval, sentence comprehension and discourse processing
Suggests clinicians should integrate language with cognitive and motor functions
Application to Levelt
Conceptualiser
- limited capacity to perform work
- inefficient allocation of attentional resources
Impaired self monitoring
Assessing Resource Allocation
Test language abilities in variety of conditions/contexts to consider impacts of attentional factors
Rate attention behaviours during task performance
Modularity
Decontextualised language tasks to isolate pure process
- phoneme discrimination
- picture naming
- word fluency
- sentence construction
Dynamic systems
Discourse analysis to capture relationship between cognitive processes
Sampling across speaking genres/contexts to capture impact of context on performance
Measure of speech timing, fluency and efficiency
Treating Resource Allocation
Target attention directly vs indirectly
- Attention Process Training: greater reading speed over time, increased ability to concentrate, better coping with distractions
Consider attention and resource allocation demands in treatment design
- early stages - quiet clinic room, move to noisy cafe
Neuroplasticity Principles (Kleim & Jones, 2008)
Best hope of remodelling damaged brain
reorganised damaged brain in absence of rehab
Damage changes the way the brain responds to learning
Principle 1 - Use it or lose it
Failure to drive specific brain functions = functional degradation
Principle 2 - Use it and improve it
Training that drives specific brain function = enhancement of that function
Principle 3 - Specificity
Nature of training experience dictates the nature of the plasticity
Principle 4 - Repetition matters
Induction of plasticity requires sufficient repetition
Principle 5 - intensity matters
Induction of plasticity requires sufficient training intensity
Principle 6 - Time matters
Different forms of plasticity occur at different times during training
Principle 7 - salience matters
Must be relevant; motivate and engage
Principle 8 - Age matters
more likely to occur in younger brains at a faster rate
Principle 9 - Transferencce
Some behaviour generalise; training in one skill = plasticity in related skill
Principle 10 - Interference
Plasticity in response to one training can interfere with acquisition of other behaviours
