Modularity and physical pathways Flashcards
What are modules?
Specialised to process information of a particular perceptual type (e.g. colour, movement etc)
How are modules defined?
What kind of sensation information they process - can be defined at different levels so can be more specialised modules within a larger module
Give an example of a physiologically defined visual processing modules
Middle temporal (MT) area - cells respond to visual movement and 90% of neurons only respond to movement in particular directions
What are modules described as in cognitive science?
Hypothetical (theoretically and functionally defined)
According to Fodor, what makes a module?
Domain specific, innately specified, informationally encapsulated, fast, hardwired, autonomous - don’t have to be all these things, they are functionally defined not physically
What is domain specificity?
Only responding to stimuli of a particular task. (Coltheart, ‘99) - makes a system modular
What is Information encapsulation?
Modules are fast as they only have access to required information and don’t have access to higher level processes. Can receive top-down input from outside the module
What is a retinotopic map?
Each location corresponds to a location on the retina, neighbouring locations correspond to neighbouring locations on the retina
What is cortical magnification factor?
Area of the cortex devoted to an area of visual field varies with eccentricity (more eccentric means more peripheral, fewer cells on retina and smaller area of the cortex)
What are sub-cortical pathways?
Sub-cortical projections go to areas such as the superior colliculus as the largest projection goes to the visual cortex via the lateral geniculate nucleus
Where is the brain damaged in patients with blind sight?
Visual cortex or pathways to the visual cortex
What is blindsight?
Patients have no visual experience in damaged parts of visual field, but they can respond accurately to visual stimuli presented at these locations
What is parallel processing?
Parallel pathways may process the same visual information, but serve different functions.
What is double dissociation?
Two functions involve different mechanisms which work independently of one another - test for dissociations between patients
What is the case of DF?
Good acuity and colour vision but couldn’t visually recognise pictures of objects or shapes due to damage in ventral pathway. The dorsal pathway is preserved so vision for action is preserved
