Cognitive Neuropsychology Methods. Aims and Objectives By the end of this lecture you will have learned: The key methodological approaches used in cognitive neuropsychology The importance of double dissociations in cognitive neuropsychology
By the end of this lecture you will have learned:
An association implies a link or connection between two phenomena.
Patient A: Performance on task X impaired, but performance on task Y intact
Patient B: Performance on task X intact, but performance on task Y impaired
Traditional neuropsychology often based on ‘syndromes’ - a collection of symptoms which often co-occur in individuals. Early syndromes were anatomically based (e.g. Broca’s Aphasia)
Gerstmann’s Syndrome: Acalculia, left-right disorientation, pure agraphia, finger agnosia
Can the study of GS provide information about the
functional architecture of cognitive processes?
This is one reason why some cognitive neuropsychologists favour single-case studies over group (syndrome) studies
“Research based on classical syndrome types should not be carried out if the goal of the research is to address issues concerning the structure of cognitive processes” Caramazza (1984)
No individual patient is impaired on both tasks
One response is to study Functional Syndromes - based on IP models of normal function
E.g. specify criteria on basis of cognitive model which will identify a group of patients who are homogenous with respect to the proposed cognitive impairment
E.g. deep dyslexia, surface dyslexia, phonological dyslexia
Objections to Caramazza’s position:
Other arguments against a single case only position:
…cognitive neuropsychology practice not only must steer clear of the Scylla of sole reliance on a standard reductionist approach that relies soley on group studies, but also would do better to avoid the Charybdis of ultra-cognitive neuropsychology” Shallice, 1988.
Utility of functional neuroimaging for cognitive neuropsychology: