Prior task experience and comparable stimulus exposure nullify focal and nonfocal prospective memory retrieval differences

ABSTRACT

We explored the nature of focal versus nonfocal event-based prospective memory retrieval. In the context of a lexical decision task, people received an intention to respond to a single word (focal) in one condition and to a category label (nonfocal) for the other condition. Participants experienced both conditions, and their order was manipulated. The focal instruction condition was a single word presented multiple times. In Experiment 1, the stimuli in the nonfocal condition were different exemplars from a category, each presented once. In the nonfocal condition retrieval was poorer and reaction times were slower during the ongoing task as compared to the focal condition, replicating prior findings. In Experiment 2, the stimulus in the nonfocal condition was a single category exemplar repeated multiple times. When this single-exemplar nonfocal condition followed in time the single-item focal condition, focal versus nonfocal performance was virtually indistinguishable. These results demonstrate that people can modify their stimulus processing and expectations in event-based prospective memory tasks based on experience with the nature of prospective cues and with the ongoing task.

KEYWORDS:

• Attention allocation
• Metacognition
• Prospective memory
• Task interference

Acknowledgements

We wish to thank Benjamin Perrodin, Alexi Petrou, Karyn Warner, and Jessica West for their dedicated help in collecting the data. Portions of these data were presented at the Fourth Annual Conference on Prospective Memory (ICPM 4) in Naples, Italy, May 2014.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1 We do not present data on the performance predictions in the main body of the paper because they are not relevant to changes in attention allocation policy over experience with the tasks. However, it is worth noting that predictions for the percentage of PM cues that would be detected averaged 71% in Experiment 1 and 68% in Experiment 2, and that these values were not affected statistically by the nonfocal versus focal instruction condition in either experiment. These data indicate that participants did not appreciate the potential differences in PM retrieval difficulty across these conditions from the instructions alone.

2 An anonymous reviewer argued that this should perhaps be treated as a one-tailed planned comparison because the focality effect is ubiquitous in the literature. Under this assumption, this particular hypothesis test would be declared significant (p = .03). Of course, the important outcome is that the focality effect size was greatly reduced under these circumstances as compared to either the focality effect from Experiment 1 or the focal-second condition of Experiment 2.

3 When PM accuracy was conditional on only the last 5 of the 6 cue presentations, there was no difference between nonfocal (M = 89%) and focal performance (M = 91%), F(1, 94) = 0.24,  = .003. When the nonfocal condition was first, nonfocal performance (M = 81%) was significantly lower than in the focal condition (M = 90%), F(1, 94) = 6.92,  = .07, but this difference was considerably weaker than the focality effect size for Experiment 1 ( = .46).