Lecture 12 Flashcards
What do cognitive psychologists study?
Behaviour of people with normally functioning mental systems to draw conclusions about the mind.
What do cognitive neuro psychologists study?
The behaviour of individuals whose mental processes are not functioning normally (e.g. after a stroke or head injury)
What are the aims of neuropsychology?
Use data from studies of people with cognitive
impairments after brain damage to test or extend
or develop theories about normal cognitive
processing.
Use models of normal cognitive functioning to
better understand and explain the patterns of
cognitive impairment seen in brain injured patients.
Use detailed theories and models of cognitive
processes to guide assessment and diagnosis, and
also the development of evaluation and treatment
programmes
What are the 6 key assumptions of cog neuropsych?
1- Brain injured patients can show dissociations of function. e.g. recognising words but not recognising faces
2- We can make inferences about functional architecture by looking at dissociations
3- Double dissociations provide the strongest evidence for independent processes
4-Associations are not particularly useful in cognitive neuropsychology
5- The primacy of case studies.
6- The modularity of the mind.
How can a dissociation occur?
- When a performance is normal on one task, but impaired on the other
- Or when performance on both tasks is impaired but they differ from each other significantly
What are double dissociations
Provide much stronger support for independence than single dissociations
-Difference in performance can’t be easily attributed to
task difficulty
What are the problems with associations?
Classical neuropsych- based on associations rather than dissociations
Co-occurrences of symptoms used to group patients into syndromes (e.g. aphasias)
However, symptoms often occur for anatomical
rather than functional reasons
Associations are fine for localisation (which was the traditional aim) but not useful for understanding the organisation of cognitive processes.
What is the logic of case studies?
Potentially valuable information can be lost in averaging across groups
Therefore, argue for intensive individual case studies, where each patient is a unique case requiring separate explanation
Each case is like a separate experiment- separate test of cognitive theory
What is modularity?
Cognitive functioning involves the orchestrated activity of multiple cognitive processors or modules.
What are the key properties of modules?
– Informationally encapsulated - does its work in ignorance
of, and isolated from, other things going on in the mind
– Domain specific - can only accept one type of input
– Mandatory - can’t be turned on or off
How do you use cog neuropsych to look at mental processes?
Visual perception
What is a case in Visual perception?
LM
- Stroke produced bi-lateral lesions of occipital cortex
- Could see and identify stationary objects
- but unable to perceive movement
- Saw the world as a series of snapshots
e. g. could not cross road because couldnt judge movements of cars
e. g. couldnt pour or coffee
What are the two types of perception in visual perception?
Form perception
Movement perception
What is the case of Uffz. S
Following head injury, unable to identify once familiar faces
Faces all looked the same
But visual perception of objects was normal
What are the two parts within form perception?
Faces and Objects
What is the case of JBR?
23 year old
• Herpes simplex encephalitis
• Difficulty naming pictures of only some types of
objects:
Living things: 6%
Inanimate objects: 90%
• Perception deficit specific to inanimate objects
What are the two parts within objects?
Animate and Inanimate
What is acquired dyslexia
Impaired reading occurring a consequence of brain injury in a previously literate person
What is developmental dyslexia?
– Unexpected difficulty in learning to read in the first place.
What are the routes to reading outloud?
The non-lexical route and the lexical route
What is the non-lexical route?
Used by skilled readers in pronouncing unfamiliar words or invented non-words
Does not involve recognising a latter string as a familiar word.
Apply knowledge of English spelling-sound correspondences to assemble a pronunciation
Left-to-right process
• Will mispronounce words that have irregular spellings
QUAY -> “kway”
COLONEL -> “kollonell”
What is phonological dyslexia?
Familiar words read better than unfamiliar words or nonwords.
Errors to nonwords tended to be visually similar real words (lexicalisations)
Could name letters (h=aitch) but not give their sounds (h=huh)
What is the lexical route?
A word is recognised as familiar • Its meaning is accessed • Its spoken word form is retrieved • "Reading via meaning" - only applicable to familiar words.
What is interpretation
kjnedfns
