Figure 5. Universality across participants.

(a),(c),(e) Empirical probability density functions P(y) of the instantaneous amplitude of wavelet transformed coefficients at scale a = 18 for electrode O2 for a group of non-artists during resting condition, visual perception, and mental imagery, respectively. (b),(d), (f) Same pdfs as earlier but after suitable rescaling: P(y) by P _max, and y by 1/P _max to preserve the normalization to unit area. The values in inset indicate the degree of data collapsing as measured by the summed KL divergence measure (see the Materials and Methods for details). (g)–(l) The same as in (a)–(f) but for the group of professional artists. Stronger data collapsing were found during mental imagery.