Temporal and spatial frequency tuning of the flicker motion aftereffect


Bex PJ, Verstraten FA, Mareschal I. Temporal and spatial frequency tuning of the flicker motion aftereffect. Vision Research [Internet]. 1996;36 :2721–7.


The motion aftereffect ({MAE)} was used to study the temporal and spatial frequency selectivity of the visual system at supra-threshold contrasts. Observers adapted to drifting sine-wave gratings of a range of spatial and temporal frequencies. The magnitude of the {MAE} induced by the adaptation was measured with counterphasing test gratings of a variety of spatial and temporal frequencies. Independently of the spatial or temporal frequency of the adapting grating, the largest {MAE} was found with slowly counterphasing test gratings (at approximately 0.125-0.25 Hz). The largest {MAEs} were also found when the test grating was of similar spatial frequency to that of the adapting grating, even at very low spatial frequencies (0.125 c/deg). These data suggest that {MAEs} are dominated by a single, low-pass temporal frequency mechanism and by a series of band-pass spatial frequency mechanisms. The band-pass spatial frequency tuning even at low spatial frequencies suggests that the "lowest adaptable channel" concept [Cameron et al. (1992). Vision Research, 32, 561-568] may be an artifact of disadvantaged low spatial frequencies using static test patterns.