ABSTRACT
The transformations of perspective can be regarded as an unwanted source of target variability from the point of view of an image-processing device required to detect a particular object from a succession of objects. One might conjecture that the pigeons' progress through the graded problem sequence was nonetheless more rapid and more extended than it might have been given a sequence of purely abstract patterns of comparable complexity. Pigeons share the indifference to an order-reversing transformation with humans, who are likewise unable to distinguish normal and reflected alphabet letters except by an elaborate mental calculation. An experiment was devised to trace the pigeon's response to small magnitude X-rotations, Y-rotations, Z-rotations, expansions, contractions, and shifts; the projections were polar. Stimuli were quadrilaterals rather than alphabet letters, and two prototypes were employed, a chevron-like figure and a trapezoid-like figure, area matched with a 58 inch square.
