Consequently, at long intervals the recollection deficit associated with dysphoric mood can be expected to be reflected in know judgements.
The formula used to calculate recollection estimates from remember and know judgements is reported in Yonelinas et al. (1998).
More remember judgements were reported for pictures than for words, whereas an equal or larger number of know judgements were reported for words relative to pictures.
The recognition deficit in this sample of subclinically depressed participants was captured by a reduction in the number of the know judgements.
With this significant delay between study and test, a recollection deficit can also be expected to be evident as a reduction in the number of know judgements.
In Experiment 1, where the recognition test took place two weeks after encoding, subclinically depressed participants reported fewer know judgements which were likely to be at least partly due to a remember-to-know shift.
With the familiarity estimates, but not with the know judgements, we found that for all participants negative pictures (whether of high or low impact) were judged to be more familiar than the neutral ones.
We derived recollection and familiarity estimates (Table 3) from the remember and know judgements within a Dual-Process Signal-Detection Model (Yonelinas, Kroll, Dobbins, Lazzara, & Knight, 1998) based on the assumption of independence.
More specifically, with the remember/know procedure, it was found that recognition responses assigned with remember judgements were reliably fewer in depressed (Drakeford et al., 2010) and subclinically depressed participants (Ramponi et al., 2004) than in controls, whereas the number of recognition responses assigned with know judgements did not differ reliably.
In the current study recognition memory was not tested immediately as in the previous studies, but two weeks later to avoid ceiling effects, and what would have been fewer remember judgements at short delays become fewer know judgements at longer delays due to episodic details having been lost.
Criterion differences, and by implication their metacognitive origins, have very notable effects on remember and know judgements (Donaldson, 1996; Gardiner, Ramponi, & Richardson-Klavehn, 2002; Parks & Yonelinas, 2007; Postma, 1999; Wixted, 2007) that could substantially alter the view presented thus far on the effect of mood on memory; hence, these warrant systematic future investigation.
