Detection of auditory signals presented at random times

One hundred msec tones of 1000 Hz at four intensities were presented according to two Poisson schedules in a background of wide band noise and as increments to a 1000 Hz tone. Each 15 minute test session was run under fixed conditions and one of three instructions to detect the signals; the two Ss were free to respond at any time. The data analyzed were several inter-response and signal-response distributions, and they were compared with a theory due to Luce. Discrepancies between the theory and data indicate needed modifications of both the theory and the procedure.     

Stimulus correlates of visual pattern discrimination by monkeys: Multidimensional analyses

Fourteen monkeys were presented with a series of simultaneous discrimination problems, each problem consisting of two visual metric patterns, and Ss’ performance was analyzed with respect to several physical dimensions of the patterns. Proficiency of discriminative performance was found to be directly and almost exclusively related to the extent to which the two patterns, when translated, had unique parts.