STEREOTYPY OF SPATIAL MOVEMENTS DURING NONCONTINGENT AND CONTINGENT REINFORCEMENT

The degree of stereotypy in the movement patterns of 3 pigeons during noncontingent and contingent periodic food reinforcement was quantifie d by analyzing the distribution of turning angles, and by using inform ation and Fourier analyses. The results indicated that (1) movement pa tterns were less stereotyped during noncontingent than during continge nt reinforcement, (2) a reversal to noncontingent reinforcement result ed in a degree of stereotypy comparable to that during the first phase of noncontingent reinforcement, (3) movement patterns were maximally stereotyped immediately after food withdrawal and generally became les s stereotyped as reinforcement approached, regardless of whether reinf orcement was noncontingent or contingent, and (4) higher frequency mov ements generally accounted for more variance in the movements during c ontingent than during noncontingent reinforcement. Greater stereotypy in the movements during contingent reinforcement was Likely due to a g reater probability that similar movements were reinforced during conti ngent reinforcement. Momentary changes in the stereotypy of the moveme nts within the interfood interval might reflect changes in the level o f arousal.