Unwelding The Visuo-Spatial Sketchpad Flashcards
How good is the evidence that the VSSP can be fractionated into separate visual and spatial components? 1. PET & fMRI Scans 2. Tentative lesion Evidence 3. Alzheimers HOWEVER -> tests are not sufficient enough -> new test shows rigid double dissociation.
Patient Evidence - LH - Farah - Good Spatial
LH - Farah - Patient could perform well on tasks requiring spatial imagery (Corsi block) but had great difficulty retrieving shapes
Patient Evidence - ELD - Hanley - Good Visual
ELD - Hanley - good visual bad spatial - however not double dissociation with LH as she scored badly on tasks that required visual imput, Brooks matrix and she was bad at remembering faces
Alzheimer tentative double dissociation research - Above evidence does indicate visual and spatial distinction
Grossi -> one is good at visual but bad at spatial/ another is the converse -> does indicate that corsi block and Visual pattern task utilises different areas- however small sample size restricts from using this evidence.
DellaSala 1999 - introduction of the VPT a purer test of visual memory - double dissociation with Corsi block span which looks at spatial WM - Crucially used normal subjects.
In a double dissociation with Corsi block span The fact,however, that one can score well on one test, yet have great diculty with the other, and vice versa, strongly confirms the view that each test taps components that
the other does not. Specifically, in this case it would seem that there are indeed two short-term non-verbal memory systems: a visual system and a spatio-sequential system.
The interference tasks on DellaSala 1999 double dissociation.
- The visual interference task -requires the subject to view irrelevant pictures
during the retention interval. 2. The spatial interference task -> required the subject
to follow, by touch alone, an arrangement of small wooden pegs
PET and fMRI Evidence for dissociation of visual/spatial sections
PET - Smith 1995 - fMRI - Courtney - 1996
Animal lesion studies showing dissociation of visual/spatial sections
Meunier 1997
Logie 1995
- Visual Cache (form and colour) & inner scribe (spatial and rehearsal) - This initial DD found that 2 spatial tasks interfered with each other more than a spatial & visual task did with each other
Logie 1995
- Visual Cache (form and colour) & inner scribe (spatial and rehearsal) - This initial DD found that 2 spatial tasks interfered with each other more than a spatial & visual task did with each other
Logie 1995
- Visual Cache (form and colour) & inner scribe (spatial and rehearsal) - This initial DD found that 2 spatial tasks interfered with each other more than a spatial & visual task did with each other
