When is context used to guide prospective memory monitoring?

Monitoring the environment for prospective memory (PM) targets can be attentionally demanding, such as searching for a pharmacy to pick up medication while driving in traffic. It is therefore optimal to increase monitoring in contexts when the probability of encountering a PM target is high (e.g., business plaza) and decrease monitoring in contexts when the probability is low (e.g., residential area), referred to as strategic monitoring. In some instances, though, identifying whether the context is appropriate for monitoring can be attentionally demanding. For example, when contextual information varies unpredictably, it may be easier to continuously monitor rather than dynamically increase and decrease monitoring on a moment-by-moment basis. The current study extends previous research by showing that participants strategically monitor when the ongoing task automatically orients attention to contextual information (i.e., focal context cues), regardless of the difficulty of checking for PM targets (Experiment 1). In contrast, when ongoing task processing does not orient attention to contextual information (i.e., nonfocal context cues), participants only strategically monitor when the demands of target checking are high (Experiment 2). These findings suggest that the decision to utilize context to adjust monitoring is driven by a cost-benefit analysis that weighs the perceived efforts of context identification relative to the expected benefit of not having to check for PM targets on half of the trials. When the perceived effort of identifying context on each trial is outweighed by the benefit of reducing target checking on a subset of trials, strategic monitoring occurs.