Temporal generalization gradients following an interdimensional discrimination protocol

Generalization of response patterns in a multiple peak procedure

Stimulus generalization is typically assessed by analyzing overall response rates. Studies of generalization of response-rate patterns across time are less common, despite the ubiquitous nature of time and the strong temporal control over behavior in the natural world. Thus, we investigated generalization of response-rate patterns across time using a multiple peak procedure in pigeons. The frequency (fast or slow) at which the color of a keylight changed signaled a fixed-interval (FI) 5-s or 20-s schedule, counterbalanced across subjects. In peak trials, the frequency of keylight-color changes was varied. For the fast and slow training stimuli, response rates in peak trials were controlled by the arranged FI schedule value; they increased as the arranged reinforcer time approached, and decreased thereafter. Response-rate patterns to all test stimuli were similar to response-rate patterns to the slow training stimulus for all subjects. Thus, overall, strong generalization from the slow training stimulus to all test stimuli was evident, whereas there was little to no generalization from the fast training stimulus. These findings extend past research examining generalization of temporally controlled response-rate patterns, and provide a useful starting point for future investigations of generalization of fixed-interval responding. A thorough understanding of generalization processes requires analysis of dependent variables other than overall response rates, especially when responding is likely to be temporally controlled.