Differential effects of cue specificity and list length on the prospective and retrospective prospective-memory components

Abstract

Event-based prospective memory (PM) refers to the ability to remember to perform an intended action at an appropriate moment that is indicated by some cue. It has been shown that increasing the number of PM cues as well as decreasing the cues' specificity can impair PM performance. Although both manipulations result in similar detrimental effects to PM accuracy, they may affect different underlying cognitive processes. To test this hypothesis, we manipulated both the number of cues and cue specificity and found the expected detrimental effects on PM accuracy. Analyses with the multinomial model of PM, which considers false PM responses and accounts for guessing biases, imply that the cue-list-length manipulation affected cue singularisation as well as intention retrieval, whereas cue specificity selectively affected intention retrieval. These results are original evidence that the performance decrements from the two manipulations have different cognitive underpinnings.

Keywords:

• False prospective-memory responses
• Multinomial model of event-based prospective memory
• Number of cues
• Prospective memory
• Specificity of cues

Notes

¹ As we were interested in effects of cue-quality manipulations on the prospective and the retrospective PM components, we controlled for retrospective-memory failures regarding the intended action (cf. Einstein et al., 2005; Smith & Bayen, 2004).

² To be consistent with previous studies using the MPT model of PM (e.g., Smith & Bayen, 2004; Rummel et al., 2011), we applied this rather strict scoring criterion to the PM accuracy measure. However, for both accuracy and false-response rates, the same pattern of results was obtained using a more liberal scoring criterion (i.e., scoring PM responses on the four trials following a PM cue as accurate). The correlations between the liberal and the strict PM accuracy measures (r = .96, p < .001) and PM false-response measures (r = .78, p < .001) were very high.

³ This result remained stable even when including only those cues that were recognised in the post-experiment recognition test [short cue list (M = .62, SE = .05); long cue list (M = .34, SE = .05), t(99) = 5.09, p < .001, d = 0.10]. Thus, the present results are not due to mere differences in memory for the cues. We thank an anonymous reviewer for suggesting this analysis.

⁴ About 25% of the participants in the long list, but only about 10% in the short list and 5% in the non-specific-cues conditions committed at least one false PM response. In all conditions, false PM response rates were rather low (i.e., ≤ .003 for each participant).

⁵ Applying a more lenient criterion of counting late PM responses (i.e., PM responses occurring on the four trials following a PM cue) as correct in the MPT analyses yielded the same pattern of results. Therefore, it is unlikely that different tendencies to perform late PM responses can account for observed differences between the experimental conditions. We thank Michael Scullin and an anonymous reviewer for bringing this possibility to our attention.