Generalization gradients following differential intradimensional autoshaping.

Three pigeons were trained on a differential, intradimensional autoshaped discrimination. A 45 degrees line tilt was always paired with food whereas a 15 degrees line tilt was never paired with food. All subjects learned the discrimination within 17 sessions. The pigeons were then given generalization tests in extinction over seven line tilts (0 degrees, 15 degrees, 30 degrees, 45 degrees, 60 degrees, 75 degrees and 90 degrees). The subjects yielded generalization gradients with maxima at 45 degrees and minima at 15 degrees. An area shift, but no peak shift, was found for each subject.