A new adaptive temporal filter: Application to photosensitive seizure patients


Correspondence address: ToshimasaYamazakiPhD Fundamental Research Laboratories, NEC Corporation, 34 Miyukigaoka, Tsukuba, Ibaraki 305-8501, Japan. Email: yamazaki@FRL.cl.nec.co.jp


Abstract A new adaptive temporal filtering (ATF) technique was developed to prevent heath hazards due to flicker stimuli from televisions, videos or other displays. This ATF method could reduce frame-to-frame or field-to-field flicker stimuli at around 10–30 Hz which are particularly risky for photosensitive individuals. The present ATF efficacy with a computer simulation was studied in 11 photosensitive epilepsy patients. In order to control visual stimuli and induce photoparoxysmal response (PPR), we employed a problematic scene of the Pocket Monster incident containing 12 Hz red/blue flicker images lasting for 4 s. This image, shown with a 14-inch television set 2 m in front of subjects, promptly elicited generalized PPR in all cases, while the filtered image did not induce any PPR. These results suggest that the present ATF method may be useful as a preventive measure of photosensitive seizures triggered by stimulative images from televisions or other displays.