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N Prins

Publications and source records attributed to N Prins.

4 recordsLinked to original sources
PubMed2001

Relative roles of 3-D and 2-D coordinate systems in solving the correspondence problem in apparent motion.

There has been a controversy in the apparent motion literature regarding the influence of 3-D distances between motion tokens on correspondence matching. The current series of experiments indicates that this discrepancy results because the effect of three-dimensional distance is too small to be detected unless the retinal coordinates of the motion tokens are carefully chosen so as to lead to ambiguous correspondence matches on identical trials. It is also shown that, even when the retinal coordinates of motion tokens are equated, such that the different solutions to the correspondence problem are generated with equal probability, the effect of 3-D distances obtained is relatively small when compared to the effect of the retinal coordinates of motion tokens.

Depth Perception↗
PubMed2001

Adaptation reveals a neural code for the visual location of orientation change.

We apply an adaptation technique to explore the neural code for the visual location of textures defined by modulation of orientation over space. In showing that adaptation to textures modulated around one orientation shifts the perceived location of textures modulated around a different orientation, we demonstrate the existence of a neural code for the location of orientation change that generalises across orientation content. Using competitive adaptation, we characterise the neural processes underlying this code as single-opponent for orientation, that is with concentric excitatory/inhibitory receptive areas tuned to a single orientation.

Adaptation, Physiological↗
PubMed2000

Alignment of orientation-modulated textures.

We conducted a Vernier acuity experiment using orientation-modulated (OM) textures in which the overall shape (skewness) of the modulations was manipulated independently of their orientation content. Misalignments between OMs were consistent with the application of global positional tags, but not on the basis of a single cue (e.g. centroid, peak, or zero-crossing). Instead, modelling of our results in terms of orientation-opponent spatial filters not only led to an excellent fit, but also to estimates of the size and shape of these filters that correspond closely to those made by other researchers using a different task and different stimulus parameters and configurations.

Cues↗