THE ROLE OF VISUAL-FIELD POSITION IN PATTERN-DISCRIMINATION LEARNING

Invariance of object recognition to translation in the visual field is a fundamental property of human pattern vision. In three experiments we investigated this capability by training subjects to distinguish be tween random checkerboard stimuli. We show that the improvement of dis crimination performance does not transfer across the visual field if l earning is restricted to a particular location in the retinal image. A ccuracy after retinal translation shows no sign of decay over time and remains at the same level it had at the beginning of the training. It is suggested that in two-dimensional translation invariance-as in thr ee-dimensional rotation invariance-the human visual system is relying on memory-intensive rather than computation-intensive processes. Multi ple position- and stimulus-specific learning events may be required be fore recognition is independent of retinal location.