Figure 2.

Response waveforms from channel O_z for three horizontal lattice types: top; rectangular, middle; hexagonal, and bottom’ random. Each waveform represents the response to each cycle of organized/random alternation, averaged over the 10 seconds of each trial, averaged over trials for each observer, and averaged over observers. The dark bars at the top of each plot axis indicate epochs of significant difference by permutation testing across observers (p<0.05, corrected for multiple comparisons) between the test (black traces) and control conditions (gray traces). For all lattices, the responses to the organized/random transitions differ from those generated by random/random transitions. Responses to vertical lattices (not shown) were similar, but somewhat weaker.