Associative Strength Theory of Recognition Memory for Pitch1

Recognition memory for pitch was studied by means of a delayed comparison task, with the standard (S) tone and the comparison (C) tone separated by a variable delay interval (O-180 set). Evidence is presented for the existence of an unsigned familiarity or similarity dimension, in addition to the signed pitch-difference dimension. Subjects relied on familiarity exclusively in the same-different judgment and used both dimensions in the higher-same-lower judgment. There appear to be two memory traces, short-term and intermediate-term, which are decaying exponentially to zero at very different rates. The decay of the short-term trace appears to be an essentially passive, temporal decay process, rather than an interference process, since the frequencysimilarity and intensity of the interference tone have no effect on the rate of decay. The decay of the memory trace appears to have the same form and rate regardless of the initial level of acquisition and regardless of the frequency difference between the S and C tones.