2.9.4 Exploratory Statistical Cluster Plot (SCP) Analysis
To provide a more complete picture of the dataset, a secondary analysis
was conducted across all 64 channels at all timepoints in the epoch
(-350 ms before response-onset onset to 300 ms after the button press
response). The x-axis of the SCP represents time post-response onset in
milliseconds, and the y-axis represents individual electrodes spatially
clustered at the scalp regional level. ERP waveforms were compared
between ASD and TD groups using a running two-tailed independent samples
t-test with a significance threshold set to p < 0.05. Data
were additionally compared across four levels of RT stratification
(fastest 25% of trials, middle 25-50%, middle 50-75%, slowest 25%)
using 1-way ANOVAs with the significance threshold set to 0.05. To
examine age-related effects between ASD and TD participants, two-tailed
independent sample t-tests were performed for each timepoint separately
using the same significance threshold. We are aware that conclusions
based on SCPs could potentially result in a high rate of false-positive
errors due to the large volume of tests performed. To account for this
issue, we have implemented temporal corrections. Only timepoints for
which the 0.05 p-value criterion for at least 7 consecutive data points
(13.6 ms) were considered significant.
Results