Immediate short-lasting impact of cognitive stimuli on ripple rate across subjects. a Transient suppression of relative ripple rate within epileptic (upper
a) and non-epileptic (bottom
a) hippocampus. Red vertical line defines visual stimulation onset (trigger). Full lines represent median, dotted lines 25 and 75 percentile across all subjects and all recording contacts. The figure clearly demonstrates task-induced HFOs reduction in non-epileptic hippocampus in time period approximately 0.3–1 s after the stimulation (arrow). White and gray horizontal bars indicate an area that corresponds to the box plots in the right
Box plots computed in baseline period before stimuli (−0.6 to −0.1 s) and after cognitive stimulation (0.4–0.9 s). Black asterisk means significant difference in non-epileptic hippocampus (p < 0.02).