Orientation discrimination in WS 11
taken for all responses, but those for erroneous responses were not used. The number
of correct responses was also recorded and treated as a second dependent variable.
Figures 2a, 2b & 3 about here
Results
Group matching was analysed using a one-way ANOVA with RCPM score as
the dependent variable and group as the independent factor (2 levels: WS, TD). This
revealed that the groups were adequately matched: F(1, 43)=.12, p=.74. Data from the
Squares discrimination task were analysed in two ways in terms of both the number of
correct responses and response time (RT). Each analysis employed a 2 factor
ANOVA with obliqueness as the within participant factor (2 levels: oblique,
nonoblique), and group as the between participant factor (2 levels: WS, TD).
Preliminary analysis of the RT and correct response data was carried out using the
Kolmogorov-Smirnoff one-sample test. This indicated that the data set was
approximately normal and not in need of transformation prior to further analyses.
Correct responses
The number of correct responses across each condition are shown in Table 2
below. Analysis showed a significant main effect of group, F(1, 42)=4.79, p=.03,
partial η2 =.10, due to less accuracy in the WS group than the TD controls. There was
also a significant main effect of obliqueness, F(1, 42)=58.01, p<.001, partial η2 = .05,
which reflected reduced accuracy on the oblique trials. The interaction between
obliqueness and group was not significant, F(1, 42)=2.39, p=.13, partial η2 = .05.
Table 2 about here
Response Time
Response times for those trials in which the participant had given an incorrect
response were replaced by a response time of 4.10 seconds, as this was the mean