Orientation discrimination in WS 2

Orientation discrimination in WS 15

al., 1988b) suggest that the predominant cause of poor visuo-spatial construction
abilities in WS in tasks such as the Block Design task is reduced accuracy at the
global level, i.e. in placing the local elements together coherently. Facilitation at the
global level provided by the frame in the Squares construction task, could explain
why the level of performance on the two version of the Squares task did not differ
significantly in WS.

Experiment 2

The findings from Experiment 1 suggest that individuals with WS are poor at
orientation discrimination overall, and show a reduced effect of obliqueness on RT.
These results imply that any tasks that present stimuli at differing orientations may
have a detrimental impact on performance in WS. One such task is mental rotation
(Farran et al., 2001); poor performance on this task in WS could reflect difficulty in
orientation processing rather than, or in addition to, difficulties in mental image
transformation as was first supposed (Farran et al., 2001). A problem with orientation
coding could also contribute to the previously observed difference between mental
and manual rotation tasks. Poor orientation discrimination is more likely to affect
mental than manual rotation ability. This is due to the opportunity to make visual
matches in a manual rotation task, which lessens the general load on orientation
coding.

In order to test whether individuals with WS have a problem in mental
transformation that is not contaminated by poor orientation coding, Experiment 2
examined size transformation abilities. Individuals were shown two different sized
objects simultaneously and asked whether they are the same or different, regardless of
any difference in size. Unlike mental rotation, this task does not involve orientation
perception. Importantly, the task demands of size transformation are very similar to

<<   12   13   14   15   16   17   18   >>

More intriguing information