ROC Asymmetry and the Target-Probe Invariance Assumption in Recognition Memory

When modeling recognition-memory judgments, it is typically assumed that requesting participants to judge whether a given test item is ‘old’ is mnemonically equivalent to asking whether that very same item is ‘new’—an assumption denoted as target-probe invariance. Contrary to this notion, results we recently obtained by means of a detection-plus-identification tasks (Meyer-Grant & Klauer, 2023, Memory & Cognition) seem to suggest that the mnemonic information available to a decision maker in fact changes depending on the status of the target being probed (i.e., that target-probe invariance is actually violated). For example, one of the key observations was an impairment of identification performance when new items instead of old items were defined as targets to be detected and identified. As a side-effect of this finding, an important earlier test of receiver operating characteristic (ROC) asymmetry may be questioned inasmuch as a violation of target-probe invariance provides an alternative interpretation of effects observed with this test. Interestingly, however, assuming a contamination of identification responses with occasional guessing in trials where no target is detected allows one to account for the observed difference in identification performance while retaining the target-probe invariance assumption. To enable a more conclusive resolution of this issue, we conducted further analyses of our previously published data and a new experiment that comprised no target-absent trials. Overall, the results indicate that identification responses in our original study may indeed have been contaminated by occasional guessing, thus rehabilitating the target-probe invariance assumption as well as the previous test of ROC asymmetry. This highlights the importance of carefully considering the experiment model in addition to the theoretical model when conducting critical tests that are motivated by mathematical models of cognitive processes.