Discrepancy processes may be helpful in noticing prospective memory targets (McDaniel, Guynn, Einstein, & Breneiser, 2004). We manipulated the discrepancy of prospective memory targets from the processing coherence established by the ongoing task by preexposing nontarget items in the ongoing task either five times (high discrepancy) or two times (low discrepancy). Prospective memory performance was significantly better in the high-discrepancy group than in the low-discrepancy group. These results support a discrepancy view of prospective remembering.
Prospective memory is crucial to daily life. Remembering to purchase bread on the drive home from work is an example of a prospective memory task. A central feature of prospective memory is that retrieval of the intended action must occur without the explicit request to remember. In considering how event-based prospective memory retrieval occurs, some theorists have suggested that different processes may mediate prospective memory retrieval under different circumstances; however, there is a bias against capacity-demanding monitoring processes that are devoted toward monitoring for the appropriate moment in which to perform the intended action (Einstein et al., 2005). Instead, people may rely on spontaneous processes that do not require additional cognitive resources for prospective remembering (McDaniel & Einstein, 2000; McDaniel, Guynn, Einstein, & Breneiser, 2004).
One potential ongoing cognitive process that might be appropriated for prospective remembering is discrepancy detection and attribution (McDaniel et al., 2004). Whittlesea and Williams (2001a, 2001b) have argued that people constantly evaluate the quality and fluency of their processing. This chronic evaluation sometimes yields discrepancies, resulting in subsequent attributions. McDaniel et al. (2004) have suggested that discrepancy could be one basis for noticing the prospective memory target (an event signaling that the intended action can be executed). When a participant encounters the target, it may be processed in a fashion that is discrepant in comparison with the quality of processing established by other stimuli. The differential quality of processing for the target could occur partially because of the previous encoding of the target with the intended action. Discrepancy may alert the participant that an item is significant. This sense of significance could alert the rememberer that something needs to be done (McDaniel et al., 2004). In this case, prospective remembering would not require an additional strategic process of monitoring for the prospective memory target (cf. Smith, 2003; Smith & Bayen, 2004). If people are chronically evaluating the quality of their processing, prospective remembering can simply "piggyback" onto this continual process. For example, perhaps forming the intention to buy bread on the way home creates a discrepancy in processing the bakery in comparison with processing for other stores that one might pass by. This perception may alert a person to the significance of the bakery.
Guynn and McDaniel (2005) have reported results consistent with the discrepancy approach. Some participants had to complete word fragments and anagrams of two words that were later introduced as the prospective memory targets, and other participants received no preexposure to the targets. Preexposure of the prospective memory targets increased prospective memory performance in comparison with no preexposure. According to a discrepancy-plussearch formulation (McDaniel et al., 2004), preexposing prospective memory targets would augment the differences in the quality of processing for the targets in comparison with that for the nontarget items in the ongoing task. In the context of a prospective memory task, the discrepancy would produce an attribution of significance for the targets, prompting further consideration of them (i.e., search).
The benefit of target preexposure, however, might also be explained by increased activation, or by the familiarity-plus-search view (e. …