The Dynamic Multiprocess Framework: evidence from prospective memory with contextual variability

Abstract

The ability to remember to execute delayed intentions is referred to as prospective memory. Previous theoretical and empirical work has focused on isolating whether a particular prospective memory task is supported either by effortful monitoring processes or by cue-driven spontaneous processes. In the present work, we advance the Dynamic Multiprocess Framework, which contends that both monitoring and spontaneous retrieval may be utilized dynamically to support prospective remembering. To capture the dynamic interplay between monitoring and spontaneous retrieval, we had participants perform many ongoing tasks and told them that their prospective memory cue may occur in any context. Following either a 20-min or a 12-h retention interval, the prospective memory cues were presented infrequently across three separate ongoing tasks. The monitoring patterns (measured as ongoing task cost relative to a between-subjects control condition) were consistent and robust across the three contexts. There was no evidence for monitoring prior to the initial prospective memory cue; however, individuals who successfully spontaneously retrieved the prospective memory intention, thereby realizing that prospective memory cues could be expected within that context, subsequently monitored. These data support the Dynamic Multiprocess Framework, which contends that individuals will engage monitoring when prospective memory cues are expected, disengage monitoring when cues are not expected, and that when monitoring is disengaged, a probabilistic spontaneous retrieval mechanism can support prospective remembering.

Keywords: Cognitive control; Intentions; Monitoring; Prospective memory; Spontaneous retrieval.

Copyright © 2013 Elsevier Inc. All rights reserved.

Figures

Figure 1. The Dynamic Multiprocess Framework

Retrieval processes are shown to interact dynamically to support the prospective memory intentions of remembering to ship a package after work (Examples 1–2) and deliver a message to a colleague (Example 3). At the bottom of each example, monitoring is indicated by a bolded solid line, the absence of monitoring is indicated by a dashed line, and spontaneous retrievals are indicated by yellow spikes. In Example 1, there is a long retention interval that contains no incidental reminders or opportunities to ship the package, but during the drive home a mailbox spontaneously triggers memory of the intention to ship the package. The individual subsequently monitors for the post office, but then disengages the monitoring because there is not a post office nearby. Later encountering the post office spontaneously triggers retrieval of the intention to ship the package, and the individual completes that intention. In Example 2, intermittent reminders (e.g., cues related to the intention such as packing tape and shipping boxes) spontaneously trigger retrieval of the intention to ship the package but monitoring is not engaged because these retrievals occur while the individual is at work and does not have an opportunity to perform the intention (though it remains plausible that repeated retrievals may increases cue—intention associations and augment the probability of a later spontaneous retrieval; e.g., Ozgis, Rendell, & Henry, 2009; Svarras & NiedŸwieńska, 2011). When leaving work, the individual spontaneously retrieves the intention to ship the package and subsequently monitors, but no post office is encountered and therefore monitoring is disengaged. Later on the drive home, a mailbox spontaneously triggers retrieval of the intention and the individual monitors until a post office is shortly thereafter approached, and the package is shipped. Example 3 incorporates the idea of contextual variability (as present in the current study). An individual forms the intention to deliver a message to a colleague when seeing him that day. The individual does not monitor during periods of the day in which the colleague is not expected or present (coffee shop, auto repair shop), but spontaneously retrieves the intention when walking past the colleague’s cubicle. The individual then searches for the colleague in the workplace but does not see him and ceases to monitor. Later during the day, the individual goes to the gym and serendipitously encounters the colleague, which spontaneously triggers memory of the message.

Figure 2. Experimental Procedure

Participants first completed baseline tasks, then post-encoding tasks, and then the experimental tasks. Highlighted borders indicate that the prospective memory target cues were presented. An example of a task block that is divided into tertiles (red lines) is provided under the Experimental Tasks subheader. Participants in the two-session condition left the laboratory for approximately 12 hours after completing the syllable learning phase. The procedure was identical in the control condition except that the prospective memory intention was never encoded. This figure was modified from Scullin and McDaniel (2010).

Figure 3. Single Session Conditions: Cost Across Segments of the Ongoing Tasks

Mean response times in milliseconds (adjusted for corresponding baseline) in the single session condition. Results are presented across experimental ongoing task blocks in participants who made a prospective memory response on the first target cue (for the specified ongoing task; PM-Hit Subgroup) relative to those who did not (PM-Miss Subgroup) and control group participants. Response times are separated between the first 50 trials of the block, the 50 trials preceding the first target cue, and the 50 trials that followed the first target cue and preceded the second target cue. Error bars represent standard errors and asterisks indicate the significance of the group main effect for the given tertile (* indicates that p < .05, ** indicates that p < .01, *** indicates that p < .001, and all other unmarked contrasts were nonsignificant). Similar, but less pronounced patterns are observed after excluding the three trials following prospective memory responses (Section 5.4).

Figure 4. Two Session Condition: Cost Across Segments of the Ongoing Tasks

Mean response times in milliseconds (adjusted for corresponding baseline) in the two-session condition. Results are presented across experimental ongoing task blocks in participants who made a prospective memory response on the first target cue (for the specified ongoing task; PM-Hit Subgroup) relative to those who did not (PM-Miss Subgroup) and control group participants. Response times are separated between the first 50 trials of the block, the 50 trials preceding the first target cue, and the 50 trials that followed the first target cue and preceded the second target cue. Error bars represent standard errors and asterisks indicate the significance of the group main effect for the given tertile (* indicates that p < .05, ** indicates that p < .01, *** indicates that p < .001, and all other unmarked contrasts were nonsignificant). Similar, but less pronounced patterns are observed after excluding the three trials following prospective memory responses (Section 5.4).