Fig. 4.

HHT time–frequency spectrum of CDT EEG data for set size 8. Analysis was carried out with data for all trials time-locked to the onset of the test array. For category 2 comparisons, on set size 8 of the task, the contrast between change and no change trials was performed for HMLA (A) and LMHA (B) groups and a contrast between the two groups were also performed on difference in power between change trials and no change trials (C). (The white circles indicate the regions of significance, P < 0.05 CBnPP).