Week 1 Flashcards
What is Cognitive Neuropsychology?
Examine variety problems associated with brain injury • Study patients understand mind understand patients rehabilitation • Explain symptoms brain injured patients relative to normal cognitive function – eg. perception, memory, language, movement
Optic Aphasia
inability to name
visually presented objects with intact
visual object recognition processes
(patient can mime the use of objects)
Utilization Behaviour
actions for use of objects intact but patient uses objects in an inappropriate context. – Occurs because of poor task based control and actions are triggered by strong “use” of environmental cues
What is Cognitive Neuropsychology? (how does it build on other realms of psych)
Cognitive Psychology: study mental processes
– eg. face and object recognit
ion, speech, write, planning
• Neuropsychology: study how particular brain
structures and processes mediate behaviour
• Cognitive Neuropsychology: combination of both
emphasis on understanding the mind
• Developmental Cognitive Neuropsychology: study
the development of normal cognitive function
• Cognitive Neuroscience: branch of neuroscience,
study of the neural systems (brain) that carry out
cognitive function
• Cognitive Neuropsychiatry
Aims of Cognitive Neuropsychology
Explain patterns of impaired and intact
cognitive function in brain injured patients
• Link these patterns of damage to components
of theory/models normal cognitive function
• Information from brain injured patients
(impaired and intact processes)
conclusions (theories and models) normal
cognitive function
How do we achieve these two aims?
Dissociations • Dissociations between tasks allow inferences to be made about the working of the intact mind Task 1 (word) Task 2 (face) • Patient A Good Poor • Tasks must tap separate Cognitive Processes • BUT what if 1 easier than 2? Double Dissociation • 2 patients with opposite performance patterns Task 1(word) Task 2 (face) • Patient A Good Poor • Patient B Poor Good
Associations
• Look for pattern of
impairments across tasks
• Association of symptoms
– patient KM impaired on three
tasks - face, word and object
recognition
– Then they must all use the same
processor?
Association deficits – all 3 tasks require
common cognitive processes
• No overlap between processes and discrete
sets of cognitive processes are mediated by
adjacent brain areas
• e.g., Gerstmann’s syndrome (damage to left
parietal cortex) – acalculia, finger agnosia,
right-left disorientation and dysgraphia
• Association is ok but Dissociation or Double
Dissociation is better
Dissociations
Dissociations between tasks allow inferences
to be made about the working of the intact
mind
Task 1 (word)
Task 2 (face)
• Patient A
Good
Poor
• Tasks must tap separate Cognitive Processes
• BUT what if 1 easier than 2?
Double Dissociation
Double Dissociation • 2 patients with opposite performance patterns Task 1(word) Task 2 (face) • Patient A Good Poor • Patient B Poor Good
Associations
Look for pattern of impairments across tasks • Association of symptoms – patient KM impaired on three tasks - face, word and object recognition – Then they must all use the same processor?
Association deficits – all 3 tasks require
common cognitive processes
• No overlap between processes and discrete
sets of cognitive processes are mediated by
adjacent brain areas
Gerstmann’s syndrome
An example of an association: (damage to the left parietal cortex) -acalculia -finger agnosia -right-left disorientation -dysgraphia
acalculia
Acalculia is an acquired impairment in which patients have difficulty performing simple mathematical tasks, such as adding, subtracting, multiplying and even simply stating which of two numbers is larger.
finger agnosia
s the loss in the ability “to distinguish, name, or recognize the fingers”, not only the patient’s own fingers, but also the fingers of others, and drawings and other representations of fingers.
right-left disorientation
Left-right disorientation describes confusion of the right and left limbs and suggests a lesion in the dominant parietal lobe. It can be tested by asking the patient to show you their right and then their left hand, and then asking them to touch their left ear with their right hand and vice-versa.
dysgraphia
Dysgraphia is a deficiency in the ability to write, primarily handwriting, but also coherence.[1] Dysgraphia is a transcription disability, meaning that it is a writing disorder associated with impaired handwriting, orthographic coding (orthography, the storing process of written words and processing the letters in those words), and finger sequencing (the movement of muscles required to write)
Studies of Groups
Traditional Neuropsych:
group patients based on common co-occurrence of symptoms (study “syndromes” eg gerstmanns)
aim of neuropsych is to determine location of brain regions
not concerned with specific cognitive processes
Studies of individuals
this is the approach taken by cognitive neuropsych
syndromes and categories are too coarse
options - subdivide syndromes based on assocation of disorders:
– e.g. acquired dyslexia
deep dyslexia, neglect
dyslexia, attentional dyslexia
Each patient single case requiring unique
explanation
– Case studies used in Co
gnitive Neuropsychology
• Neuropsychology: patient group vs.. normal
group
>
loss info
Cognitive Neuropsychology aims
To have generalisability
Theory/model cognitive function must account for all cases disorder • Theory/model must also explain normal cognitive function • Based on experimental data • 1) cognitive psychology • 2) cognitive neuropsychology patient data and • 3) computer modelling
Assumptions of Cognitive Neuropsychology
Neurological specificity (isomorphism) – some
correspondence between mind and brain
(monism)
• Universality assumption – all cognitive
architectures the same initially
• Transparency – analysis of pattern of intact and
impaired performance and pattern of errors by
patients
nature and function of impaired
processes and components (which component
or module was disrupted)
• Converging operations – data multiple sources
What is the Modularity Hypothesis (MH)?
mental life is made possible by activity of multiple cognitive processors or modules
-e.g. reading, face recognition, speech, -higher order eg. decision making etc
modules independent but inter-communicate
modules > diagrams of cognitive processes
fodor came up with the MH. in terms of our cognitive processes we have modules (eg - object recognition a distinct module to face recognition which is a distinct module from word recognition)
data from double dissocation cases shows that we don’t have 1 module that does all your cognitive processes
- each process/system impaired separately
- semi-independent
Problems with use of diagrams
• Diagrams limited e.g. single word vs. syntax
• Lack specification internal workings modules
• Basis patient data
post-hoc theories
(falsifiable)
• Diagrams superimposed on outline left
hemisphere
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Problems with use of diagrams
• Diagrams limited e.g. single word vs. syntax
• Lack specification internal workings modules
• Basis patient data
post-hoc theories
(falsifiable)
• Diagrams superimposed on outline left
hemisphere
Cognitive Neuropsychology today
diagrams used
• Careful study mind-brain
• Used to explain the overall workings of an
information processing system – pathways of
information flow and the specific components
of the system
Modularity of Mind -revisited
Information encapsulated: processing within
module isolated from rest of system
• Domain specific: 1 type of input e.g. visual,
spoken word
• Mandatory module operation: automatic e.g.
recognition familiar persons
• Innate
• Fast operation
• Neural specificity
• Higher level processes not modular
– e.g. reasoning, decision making
Functional modularity
mental processes are functionally independent but intercommunicate
eg. object reco vs face reco
Anatomical modularity
specific brain region
neurochemical modularity
specific neurotransmitter
Knowledge modules
independent knowledge modules, independent of other bodies of knowledge
Processing modules
independent processor of
information
