The ironic effect of guessing: increased false memory for mediated lists in younger and older adults

ABSTRACT

Younger and older adults studied lists of words directly (e.g., creek, water) or indirectly (e.g., beaver, faucet) related to a nonpresented critical lure (CL; e.g., river). Indirect (i.e., mediated) lists presented items that were only related to CLs through nonpresented mediators (i.e., directly related items). Following study, participants completed a condition-specific task, math, a recall test with or without a warning about the CL, or tried to guess the CL. On a final recognition test, warnings (vs. math and recall without warning) decreased false recognition for direct lists, and guessing increased mediated false recognition (an ironic effect of guessing) in both age groups. The observed age-invariance of the ironic effect of guessing suggests that processes involved in mediated false memory are preserved in aging and confirms the effect is largely due to activation in semantic networks during encoding and to the strengthening of these networks during the interpolated tasks.

KEYWORDS:

• False memory
• spreading activation
• aging
• ironic effect of guessing

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1. Although we have framed the discussion in the context of AMT (Roediger et al., 2001a), we note that an alternative theoretical account, namely FTT (e.g., Brainerd & Reyna, 2002) also predicts that deeper processing during encoding would increase the process of gist extraction, thereby resulting in increases in semantically driven responding.

2. Due to the small number of male participants (there were between 5 and 13 men in each cell of the design, compared to 19–26 women), we did not examine performance as a function of gender.

3. Participants in the guess condition were allowed to advance to the next list once they had made their guess if the full minute was not required.

4. As noted by an anonymous reviewer, a score on MMSE of 25 might reflect some cognitive impairment. Only one participant scored below 27; all analyses were also conducted after omitting this participant’s data. Because this did not change any of the outcomes, we report the results with the full data set for completeness’ sake.

5. A comparison between initial guessing and initial false recall indicated that overall guessing resulted in similar numbers of CLs being produced relative to recall (M = .19 and .16, respectively), both of which were higher than false recall following a warning (M = .10), F(2, 186) = 7.76, η_p2 = .08, as well as an interaction between condition and age, F(2, 186) = 3.39, p = .04, η_p2 = .04, with older adults having slightly higher false recall than correct guesses (M = .18 and .15, respectively), whereas younger adults made fewer critical intrusions than correct guesses (M = .22 and .15, respectively). For both age groups, warnings yielded the lowest rate of CL production.

6. Signal detection analyses (dʺ) were also conducted. dʺ values were calculated by treating control items (CLs and list items) as false alarms and studied items (or CLs related to studied items) as hits. For the sake of brevity, we do not report the results here; however, we note that the signal detection results mirrored the corrected recognition analyses reported here.