Visual masking by light offset

Two experiments are reported which investigated whether or not the offset of light can serve as a backward masking stimulus (MS). In both studies, human Os made identification responses to graphemes (TS) presented tachistoscopically on a lighted field. Simultaneously with or at short intervals after TS offset, the lighted background field was shut off. The termination of the background field served as the MS. The results indicated a reliable masking effect due to light