Je ne comprend pas la différence entre l'expérience 1A et 1B : Evaluating Accounts of Improved Memory Accuracy Using Signal Detection Analysis Although the distinctiveness heuristic and impoverished relational encoding accounts are usually treated as competitors, they actually refer to different factors that can affect recognition decisions and as such they are not mutually exclusive. Recognition judgments are driven by two factors: the information that was encoded at study, and the standards participants use to evaluate that information at test. Therefore, generation (and perhaps other distinctiveness tasks) may produce a mirror effect by changing the amount of memory information available and/or the criteria people use to evaluate their memories. The present study used signal detection analyses (e.g., Snodgrass & Corwin, 1988; Wickens, 2002) to examine the origin(s) of generation’s beneficial effects. The impoverished relational encoding account makes predictions regarding the amount of memory information available for critical lures after distinctive encoding. A common index of memory information derived from signal detection theory is d (e.g., Snodgrass & Corwin, 1988; Wickens, 2002). Memory information for critical lures can be captured by calculating d with the proportion of yes responses to critical lures as the “hit rate” and the proportion of yes responses to critical lure controls (i.e., critical lures from lists that were not studied) as the false alarm rate. If generation reduces the amount of memory information available for critical lures relative to reading, as predicted by the impoverished relational encoding account, then d for these critical lures should be lower after generation. The distinctiveness heuristic account, by contrast, makes predictions about the strategic decision-making process participants use to evaluate the information they have encoded in memory. Using a distinctive heuristic involves setting a more stringent standard for classifying an item as studied. Therefore, use of an effective decision-making rule in the DRM paradigm can be modeled as a shift to a more conservative response bias (e.g., Schacter et al., 1999). We used a shift in response bias as an index of the stringency of participants’ decision making at test, acknowledging that the distinctiveness heuristic is but one theoretical claim as to the specific nature of the shift (see Gallo, Weiss, & Schacter, 2004). The measure of response bias we used, lambda (; Wickens, 2002; see also Banks, 1970, who refers to this measure as Cj ), captures response bias in relation to the mean of the lure distribution only (i.e., it is the standardized z-score of 1   the appropriate control lure mean). On the advice of a reviewer, we used this measure rather than another bias measure (e.g., C or BD; Snodgrass & Corwin, 1988) because the information in memory about the studied words and critical lures was expected to change across the read and generate conditions. The  scores calculated for noncritical lure control items should thus be unconfounded with changes in memory information. If generation causes participants to use a distinctiveness heuristic,  values should therefore increase relative to reading. Consistent with this claim, Schacter et al. (1999) found participants were more conservative after pictorial encoding than after reading (as measured by BD). In summary, we examined whether a “stock” generation task (solving visually presented anagrams) would produce a mirror effect in the DRM paradigm. We also sought to build upon previous DRM studies of generation by determining the origin(s) of generation-induced changes in correct and false recognition using signal detection analyses (Experiment 1A) appropriate for evaluating the distinctiveness heuristic and impoverished relational encoding accounts. To further evaluate these accounts, we included both meaning-instructions conditions (Experiment 1B) and a within-group design (Experiment 2). Finally, in Experiment 3 we tested whether the mirror effect is limited to generation tasks involving distinctive cues, or if it can also result from a purely mnemonic means of increasing item-specific processing (i.e., self-referential encoding).