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Orientation Tuning Of Contrast Masking Caused By Motion Streaks, Deborah Apthorp, John Cass, David Alais

Faculty of Health and Behavioural Sciences - Papers (Archive)

We investigated whether the oriented trails of blur left by fast-moving dots (i.e., “motion streaks”) effectively mask grating targets. Using a classic overlay masking paradigm, we varied mask contrast and target orientation to reveal underlying tuning. Fast-moving Gaussian blob arrays elevated thresholds for detection of static gratings, both monoptically and dichoptically. Monoptic masking at high mask (i.e., streak) contrasts is tuned for orientation and exhibits a similar bandwidth to masking functions obtained with grating stimuli (È30 degrees). Dichoptic masking fails to show reliable orientation-tuned masking, but dichoptic masks at very low contrast produce a narrowly tuned facilitation (È17 degrees). For …