“…Short latencies were ensured by withholding reinforcement for reaction times in excess of 1 sec. The characteristics of the latency-intensity functions closely resemble those obtained for man by Chocholle (1940) and more recently McGill (1963) and Greenbaum (1963), and for monkeys by Romba, Gates, and Martin (1963) and Stebbins and Miller (1964). In addition, the shape of the functions and the changes in variability with stimulus intensity are very similar to those obtained by neurophysiological recording of the latency of discharge of the first spike from single units in the auditory system of cats (Hind, Goldberg, Greenwood, and Rose, 1963), and the latency of intracellularly recorded excitatory post-synaptic potentials from the somatosensory system of cats by Towe and Morse (1962).…”