Schema bias in source monitoring varies with encoding conditions: Support for a probability-matching account.

Abstract

Two experiments examined reliance on schematic knowledge in source monitoring. Based on a probability-matching account of source guessing, a schema bias will only emerge if participants do not have a representation of the source-item contingency in the study list, or if the perceived contingency is consistent with schematic expectations. Thus, the account predicts that encoding conditions that affect contingency detection also affect schema bias. In Experiment 1, the schema bias commonly found when schematic information about the sources is not provided before encoding was diminished by an intentional source-memory instruction. In Experiment 2, the depth of processing of schema-consistent and schema-inconsistent source-item pairings was manipulated. Participants consequently overestimated the occurrence of the pairing type they processed in a deep manner, and their source guessing reflected this biased contingency perception. Results support the probability-matching account of source guessing.

Hierarchical modeling of contingency-based source monitoring: A test of the probability-matching account

“…The provision of schematic information about the sources at encoding should have improved contingency detection (Kuhlmann et al, 2012); however, individual differences in contingency detection had consequences for the source-guessing bias. In our sample, several participants misperceived the source-item contingency as somewhat conforming with schematic knowledge, and hence the overall source-guessing bias was above .5.…”

“…We used the German version of Bayen et al's (2000) doctor-lawyer materials, as developed by Kuhlmann et al (2012), who normed the sentences with expectancy ratings from 60 native German speakers. The materials consisted of 96 statement pairs, of which 32 were expected for a doctor, 32 were expected for a lawyer, and 32 were filler statement pairs that were equally expected for both.…”

“…In both conditions, schematically expected statements were presented with equal probabilities by the expected and by the unexpected source. Previous studies with traditional MPT analyses on aggregated data had shown that the guessing bias is near the true contingency if the schematically relevant information is available during encoding (e.g., Kuhlmann et al, 2012). In this case, participants notice the contingencies during the encoding phase and later adjust their guessing accordingly.…”

“…We used Submodel 4 (see Bayen et al, 1996, for details), which assumes that the levels of item memory as well as source memory are equal for both sources, and which had fit the data from previous studies using the same standard source-monitoring paradigm we used in the present study (Bayen & Kuhlmann, 2011;Bayen et al, 2000;Kuhlmann, Vaterrodt, & Bayen, 2012). The model (see Fig.…”

“…In this case, participants notice the contingencies during the encoding phase and later adjust their guessing accordingly. If, however, participants have difficulties accessing the true contingency (because the schema information was not available during encoding), source guessing is biased toward the schematically expected source (Kuhlmann et al, 2012). Thus, we wanted to replicate previous findings, namely that the guessing parameter g would equal .5 (i.e., reflect the true source-item contingency) in the encoding condition, and be larger than .5 (i.e., biased toward the schematically expected source) in the retrieval condition.…”