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Temporal Integration Of Movement: Fhe Time-Course Of Motion Streaks Revealed By Masking, David Alais, Deborah M. Apthorp, Aana Karmann, John Cass
Temporal Integration Of Movement: Fhe Time-Course Of Motion Streaks Revealed By Masking, David Alais, Deborah M. Apthorp, Aana Karmann, John Cass
Faculty of Health and Behavioural Sciences - Papers (Archive)
Temporal integration in the visual system causes fast-moving objects to leave oriented 'motion streaks' in their wake, which could be used to facilitate motion direction perception. Temporal integration is thought to occur over 100 ms in early cortex, although this has never been tested for motion streaks. Here we compare the ability of fast-moving ('streaky') and slow-moving fields of dots to mask briefly flashed gratings either parallel or orthogonal to the motion trajectory. Gratings were presented at various asynchronies relative to motion onset (from to ms) to sample the time-course of the accumulating streaks. Predictions were that masking would be …
The Spatial Tuning Of "Motion Streak" Mechanisms Revealed By Masking And Adaptation, Deborah Apthorp, John Cass, David Alais
The Spatial Tuning Of "Motion Streak" Mechanisms Revealed By Masking And Adaptation, Deborah Apthorp, John Cass, David Alais
Faculty of Health and Behavioural Sciences - Papers (Archive)
We previously reported that fast-moving dot arrays cause orientation-tuned masking of static gratings (D. Apthorp, J. Cass, & D. Alais, 2010), which we attribute to “motion streaks.” Using similar “streaky” dot motion, we describe spatial frequency tuning of grating threshold elevations caused by masking (Experiment 1) and adaptation (Experiment 2) to motion. To compare the streaks with psychophysical tunings, we Fourier analyzed time-averaged translating dots, which were bandpass (peaking at È2.3 c/deg). Masking, however, was strongest at lower test frequencies (e1 c/deg) and largely isotropic over orientation, although a small orientation-tuned effect occurred at È1.2 c/deg. Results were broadly similar …