LAUSR

A 56-year-old patient with drug-resistant epilepsy was evaluated by intracranial electroencephalogram (EEG) monitoring for seizure localization. During electrical cortical 50-Hz stimulation (ECS) functional mapping, the patient experienced a profound illusion of time perception. The illusion resulted from the direct electrical stimulation of the right mid-dorsal insular-claustrum at 4 mA during functional mapping (Fig A). The patient described the experience “like an eternity” and “hours long” during stimulation. Longer trains 5 versus 3 seconds correlated with a more extended interpretation of that interval. He passed standard language tasks and could move during the stimulation. He further denied pain and attributed his discomfort to the distraction resulting from the insight into the time perception illusion. The patient recalled specific phrases provided during stimulation and denied correlation with seizure symptomatology. He later divulged that the symptoms overlapped with those experienced while “tripping” as a teenager with lysergic acid diethylamide (LSD) and mushrooms. The stimulation of the right pars opercularis reproduced the symptomatology to a lesser degree at higher current stimulation 9 to 11 mA (Fig B). None of 3 sham stimulations at each site nor the other 64 stimulation mapping sessions at other sites reproduced the symptoms. Granger causality connectivity analysis of highfrequency (>80 Hz) resting state awake electrocorticography at the primary site in the right claustrum (shown in Fig A) identified bidirectional connections with an extensive cortico-cortical network; a stronger outflow (Fig D) than inflow (Fig C) component was noted. The areas included the right prefrontal cortex with greater involvement of the superior and middle than inferior frontal gyri, the supplementary motor area (SMA; by depth electrode) and mesial temporal depth electrode, intra-parietal cortex, and junctional temporo-occipital regions. Less prominent connections were seen over the temporal region at large and the peri-Rolandic regions. Resting-state functional-magnetic resonance imaging (MRI) connectivity of a seed area in the right claustrum (shown in Fig A) by arithmetic correlation of a BOLD signal at 0.2 threshold, revealed co-activation in the bilateral homologous mid-claustrum-insular, putamen, and SMA regions (Fig E) and contralateral cerebellum. Afterward, the patient underwent a resection of the right face motor area, where the seizures originated and sparing the regions producing the illusion. He remained free of motor seizures at 27-month follow-up. Reports of humans experiencing time dilation during ECS are rare. It is most consistent with a right “non-dominant” hemispheric lateralization that is not mapped as frequently as the dominant hemisphere. These findings are consistent with previous reports on right hemispheric preferences in time perception. The connectivity with the superior frontal gyrus highlights the complexity of the executive relationship in humans. The relationship with the mesial frontal and supplementary motor areas substantiates the role of time processing in motor decision making and vice versa. Interaction of the intra-parietal area