Figure 2
Results of Experiment 1. Accuracy (a) and reaction times (b) as a function of number of elements when elements were located on the vertices of simple shapes (red) or random (green). (c) Grand average ERPs collapsed across number of elements, for shape (red) and random (green) configurations. The ERPs are an average of the six channels (P7, P8, PO5, PO6, PO7, & PO8) used to quantify the N1 and N2 components and highlights the N2 effect between 250 and 400 ms after stimulus onset (yellow region and difference topography between all shape and random conditions). Blue regions represent TANOVA differences between shape and random configuration stimuli. (d) Grand average ERPs collapsed across spatial configuration for different number of elements. The ERPs are an average of the LMF analysis electrodes (FC1, FC3, C1, and C3) between 400 and 650 ms (yellow region and difference topography). The difference topography, for graphical purposes, is the difference between low (3, 4) minus high (5, 6) number of elements irrespective of spatial configuration. TANOVA differences (blue regions) are also for low versus high number of elements. (e) Microstate segmentation of grand averaged ERPs for all eight conditions. Horizontally oriented bars show stable microstates and the point in time when they change for each condition (R3—random configuration with 3 elements, through to S6—shape configuration with 6 elements). Each map is represented by a different colour. Further, Global Field Power (GFP) waveforms, a measure of differences in the scalp electric field strength, are displayed for a visual comparison to topographic microstates which are independent of field strength. (f) Topographic microstates derived from the segmentation procedure for three maps which best fit the individual subject data. Topographic maps show the head from above with nasion plotted upward.
