Thought probes during prospective memory encoding: Evidence for perfunctory processes

Concurrent prospective memory task increases mind wandering during online reading for difficult but not easy texts

Many prior theories have tried to explain the relationship between attentional processes and mind wandering. The resource-demand matching view argues that a mismatch between task demands and resources led to more mind wandering. This study aims to test this view against competing models by inducing mind wandering through increasing the level of demands via adding a prospective memory task to cognitively demanding tasks like reading. We hypothesized that participants with a second task still in mind (unfinished group) engage more in task-unrelated thoughts (TUTs) and show less text comprehension compared to participants who think a second task is finished (finished group). Seventy-two participants had to study 24 items of a to-do list for a recall test. After a first cued recall of ten items, participants were either told that a second task was finished or that the recall was interrupted and continued later. All participants then started reading an easy or difficult version of the same unfamiliar hypertext, while being thought probed. Text comprehension measures followed. As expected, participants in the unfinished group showed significantly more TUTs than participants in the finished group when reading difficult texts, but, contrary to our assumptions, did not show better text comprehension measures when reading difficult text. Nevertheless, participants compensate for the influence of the second task by reading longer, which in turn has a positive effect on their reading knowledge. These findings support the resource-demand-matching model and thus strengthen assumptions about the processing of attention during reading.

External Time Monitoring in Time-Based Prospective Memory: An Integrative Framework

We propose a new integrative framework of external time monitoring in prospective memory (PM) tasks and its relation with performance. Starting from existing empirical regularities and our theoretical analysis, the framework predicts that external monitoring in PM tasks comprises a first stage of loose monitoring to keep track of the passage of time, and a subsequent stage of finer-grained monitoring, based on interval reduction, to meet the PM deadline. Following our framework, we predicted and observed in three different datasets (N = 375): (1) a marked increase in external monitoring frequency in the final part of the period of the PM task, well captured by a proportional rate exponential growth function; (2) a positive association between individual compliance with this monitoring pattern and PM performance; (3) a positive relation between monitoring frequency in the time window immediately preceding the PM deadline and PM performance at the individual level; and (4) good individual compliance with an interval reduction pattern in external monitoring, especially in the time window closer to the PM deadline. These results support the proposed integrative framework, which has the potential to foster future research on external monitoring in PM and in other fields of cognitive science.

Prior experience with target encounter affects attention allocation and prospective memory performance

We examined how prior experience encountering targets affected attention allocation and event-based prospective memory. Participants performed four color match task blocks with a difficult, but specified prospective memory task (Experiment 1) or an easier, but unspecified prospective memory task (Experiment 2). Participants were instructed to search for targets on each block. Participants in the prior experience condition saw targets on each block, participants in the no prior experience condition only saw targets on the fourth block, and, in Experiment 2, participants in the mixed prior experience condition encountered some of the targets on the first three blocks, and saw all the targets on the fourth block. In Experiment 1, participants in the no prior experience condition were less accurate at recognizing targets and quicker to respond on ongoing task trials than participants in the prior experience condition. In Experiment 2, we replicated the effect of prior experience on target accuracy, but there was no effect on ongoing trial response time. The mixed experience condition did not vary from the other conditions on either dependent variable, but their target accuracy varied in accordance with their experience. These findings demonstrate that prospective memory performance is influenced by experience with related tasks, thus extending our understanding of the dynamic nature of search efforts across related prospective memory tasks. This research has implications for understanding prospective memory in applied settings where targets do not reliably occur such as baggage screenings and missing person searches.

Effect of Encoding on Prospective Memory

Event-based prospective memory (ProM) refers to remembering to execute planned actions in response to a target ProM cues. Encoding modality influences ProM performance; visual encoding has been studied more than auditory encoding. Further, it has not yet been examined whether different encoding may influence ProM performance in different encoding modalities. This study examines the effects of encoding modality (visual vs. auditory), cue-encoding specificity (specific cue vs. non-specific cue), and encoding modes (standard vs. implementation intention) on event-based ProM tasks. In Experiment 1, cue specificity and encoding modality were manipulated as a within-groups encoding of visual cues is more commonly and between-groups variable. Results revealed the facilitative effect of cue specificity on ProM performance. Also, with respect to encoding modality, participants showed better performance when receiving auditory instructions compared with the visual encoding condition. In Experiment 2, as in Experiment 1, cue specificity and encoding modality were manipulated. Encoding mode was added as a new between-group variable. Result revealed that there was a significant interaction between encoding modality and encoding modes. Visual implementation intention encoding was a more effective method for improving ProM performance compared with visual standard encoding. Furthermore, there was a significant interaction between cue-encoding specificity and encoding modes. Implementation intention encoding enhances ProM performance in non-specific cue-encoding conditions. Overall, the present study found that (1) auditory encoding modality showed superior ProM performance compared with visual encoding, although implementation intention had facilitative on ProM performance regardless of the encoding modalities, and (2) there was better ProM performance under specific encoding compared with non-specific encoding, and implementation intention had a facilitative effect on ProM performance in the non-specific condition.

Distinct monitoring strategies underlie costs and performance in prospective memory

Prospective memory (PM) describes the ability to remember to perform goal-relevant actions at an appropriate time in the future amid concurrent demands. A key contributor to PM performance is thought to be the effortful monitoring of the environment for PM-related cues, a process whose existence is typically inferred from a behavioral interference measure of reaction times. This measure, referred to as "PM costs," is an informative but indirect proxy for monitoring, and it may not be sufficient to understand PM behaviors in all situations. In this study, we asked participants to perform a visual search task with arrows that varied in difficulty while concurrently performing a delayed-recognition PM task with pictures of faces and scenes. To gain a precise measurement of monitoring behavior, we used eye-tracking to record fixations to all task-relevant stimuli and related these fixation measures to both PM costs and PM accuracy. We found that PM costs reflected dissociable monitoring strategies: higher costs were associated with early and frequent monitoring while lower costs were associated with delayed and infrequent monitoring. Moreover, the link between fixations and PM costs varied with cognitive load, and the inclusion of fixation data yielded better predictions of PM accuracy than using PM costs alone. This study demonstrates the benefit of eye-tracking to disentangle the nature of PM costs and more precisely describe strategies involved in prospective remembering.

Spatial ability contributes to memory for delayed intentions

Most everyday activities involve delayed intentions referring to different event structures and timelines. Yet, past research has mostly considered prospective memory (PM) as a dual-task phenomenon in which the primary task to fulfill PM intentions is realized within an ongoing secondary task. We hypothesized that these simplified simulations of PM may have obscured the role of spatial relational processing that is functional to represent and meet the increased temporal demands in more complex PM scenarios involving multiple timelines. To test this spatiotemporal hypothesis, participants monitored four digital clocks, with PM deadlines referring either to the same clock (single-context condition) or different clocks (multiple-context condition), along with separate tests of spatial ability (mental rotation task) and executive functioning (working memory updating). We found that performance in the mental rotation task incrementally explained PM performance in the multiple-context, but not in the single-context, condition, even after controlling for individual differences in working memory updating and ongoing task performance. These findings suggest that delayed intentions occurring in multiple ongoing task contexts reflect independent contributions of working memory updating and mental rotation and that spatial relational processing may specifically be involved in higher cognitive functions, such as complex PM in multiple contexts or multitasking.

How did I remember to do that? Self-reported strategy use for laboratory prospective memory tasks

The role of metacognition in prospective memory (PM) has received relatively little attention. This study combined data from several experiments to identify the strategy repertoire employed during a classic laboratory PM task and to determine whether self-reported strategy was related to performance. Participants (N = 668) completed either a focal or nonfocal PM task embedded in an ongoing lexical decision task. The results indicated that participants reported the same strategy repertoire regardless of PM task focality. Participants who reported using a strategy performed better than those who did not report using one, and this was especially true under nonfocal conditions. Self-reported strategy use was also associated with more cost to the ongoing task when the opportunity to complete the PM task was present. These findings add to what is known about the metacognitive components of PM and underscore the need for additional research in this area.

Characterising monitoring processes in event-based prospective memory: Evidence from pupillometry

In event-based prospective memory (PM) paradigms, participants are engaged in an ongoing task (e.g. lexical decision) while maintaining an intention to produce a special response if they encounter pre-defined targets (e.g. animal words). This leads to slowed response times even on nontarget trials, which might be caused by: (A) a periodic or intermittent process that occurs transiently to check whether the current stimulus is a target, and/or (B) a sustained monitoring process maintained throughout task performance rather than being time-locked to stimulus presentation. These processes are hard to distinguish, seeing as the key difference between them occurs in the gap between trials. Processes occurring in these gaps cannot be measured directly by behavioural methods. Here we measured pupil size as a continuous index of intention-related processing in an event-based prospective memory task. Participants performed a lexical decision task while remembering intentions based on either specific target words or categories (e.g. animal words). In two experiments, response times were slowed during PM conditions. Pupil size was significantly increased in the category but not the specific-word condition. This effect was sustained throughout task performance rather than occurring transiently when stimuli were presented. Therefore there was no evidence for a transient pupillometric response associated with nontarget checking, although there was a strong transient response when targets were presented in either PM condition. These results provide evidence for a sustained PM monitoring process that occurs even in the gaps between trials.