Control of Primal Sketch Processing
Roger J. Watt · Psychology Press eBooks · 2022
Texture was the original reason for incorporating spatial filters of various sizes into the Primal Sketch. The need to maintain some form of representation of the finest scales was the reason for combining the outputs from spatial filters of different sizes. Kahn and Foster performed an experiment that is particularly interesting in this respect. They briefly presented to subjects two patterns, right and left of fixation, each comprising seven randomly placed dots. A very general finding is that some patterns may be distinguished very rapidly, whereas others require detailed scrutiny. These may be discrete categories derived from the operations of different mechanisms or the creation of different representations. The representation of spatial position that is produced is hierarchical, with the position of an element referred upwards to the next larger-scale group and so on, to the largest scale. Control of the nature of the Primal Sketch representation by a time-extended process with simple feedback is an attractive suggestion.