Case Study - MS Flashcards
What disorder did they have, which one is the most important in terms of this module ?
Visual object agnosia *
Achromatopsia
Left homonymous hemianopia
Prosopagnosia *
Which researcher studied the patient ?
Cavina-pratesi (2010)
Where were the patients lesions ?
Extensive damage to the ventromedial occipito-temporal cortices
Left hemisphere - temporal pole, parahippocampal gyrus, fourth temporal gyri, the CoS and the medial occipital-temporal junction
Right hemisphere - similar to the left with the addition of the 2nd and 3rd temporal gyri and the striate cortex
What function was impaired?
Can’t see colour
Can’t do texture discriminations
Also can’t see out of their right visual field, but aren’t aware that they can’t
Where are the lesions that are responsible for the lack of texture discrimination?
The lesions stretch over the medial and therefore alone the collateral sulcus
What function is spared in MS?
Not a form agnosic because he can readily discriminate between different shakes , therefore he’s an object agnosic
Can do shape discrimination because he has a preserved LH(LOC)
What tasks were used to test MS ?
Task included two conditions,
1) same shape different textures
2) different shape same textures
What were the results of the shape/texture task?
Shape discrimination showed activation in the lateral occipital cortex (LOC)
Texture discrimination showed activation in the V4 region involved in colour, collateral sulcus (CoS)
So are there specific areas for texture and shape?
Texture - collateral sulcus
Shape - lateral occipital cortex
How do you normally get activations from the LOC?
Show Images and then show scrambled images and you will see more activation for the non-scrambled image (Malach et al 1995)
Does MS show a double dissociation with any other case study?
Yes with DF
DF is a visual form agnosic that can see texture but not see shapes
How did patient MS come about their brain damage?
Contracted herpes encephalitis
