Spatial reliability at group level. = number of significant channels at S1; = number of significant channels at S2; = number of the same channels significant at both sessions; = an intersession measure of the size of the response (number of significant channels) at both sessions; = an intersession measure of the spatial overlap of significant channels at both sessions. Results are given for the response for all available channels in the sensor array [whole array ()], the HHb response in the sensor array [whole array (HHb)]; both the and HHb response for all available channels in the sensor array [whole array ( and HHb)], and the responses from channels within the ROI.