Jan Rummel

Behavioral and emotional consequences of brief delays in human-computer interaction

It was thought that computer-performance-related problems in human-computer interaction (HCI) would become negligible with the constant increase in computing power. However, despite major advances in computer technology, contemporary HCI is still characterized by brief delays in computer responsiveness caused, for example, by background processes or network delays. Research on long system-response times (SRTs) indicates that delays may have negative behavioral and emotional consequences. However, there are fundamental differences between previously researched long SRTs and delays as they occur in contemporary HCI, such as different timings and occurrence probabilities. Therefore the previous research is not necessarily applicable to modern HCIs. We developed a paradigm aimed at mimicking important aspects of contemporary HCI to empirically test the effects of sporadic brief delays with an average duration of 1.6s. Results showed performance decrements in the response directly following a delay in terms of increased reaction times and error rates. Furthermore, blocks in which delays occurred were less liked than blocks without delays, suggesting that delays may affect the emotional state. The data provide evidence that delays cause a significant deterioration of performance, and indicates that delays in contemporary HCI may negatively affect work productivity, work satisfaction, and health-and-safety. Suggestions for HCI design and the relationship to user interruption are discussed.

Controlling the stream of thought: Working memory capacity predicts adjustment of mind-wandering to situational demands

Although engaging in task-unrelated thoughts can be enjoyable and functional under certain circumstances, allowing one’s mind to wander off-task will come at a cost to performance in many situations. Given that task-unrelated thoughts need to be blocked out when the current task requires full attention, it has been argued that cognitive control is necessary to prevent mind-wandering from becoming maladaptive. Extending this idea, we exposed participants to tasks of different demands and assessed mind-wandering via thought probes. Employing a latent-change model, we found mind-wandering to be adjusted to current task demands. As hypothesized, the degree of adjustment was predicted by working memory capacity, indicating that participants with higher working memory capacity were more flexible in their coordination of on- and off-task thoughts. Notably, the better the adjustment, the smaller performance decrements due to increased task demands were. On the basis of these findings, we argue that cognitive control does not simply allow blocking out task-unrelated thoughts but, rather, allows one to flexibly adjust mind-wandering to situational demands.

A diffusion model analysis of task interference effects in prospective memory

Holding an intention often interferes with other ongoing activities, indicating that resource-demanding processes are involved in maintaining the intention and noticing the appropriate event to fulfill it. Little is known, however, about the nature of the processes underlying this task interference effect. The goal of the present research was to decompose the processes contributing to the task interference effect by applying the diffusion model (Ratcliff, Psychological Review 85:59–108, 1978) to an event-based prospective memory task. In the first experiment, we validated the interpretation of the response criterion parameter (a) of the diffusion model as reflecting strategies to cope with the anticipated demands of a prospective memory task in the context of the ongoing task. The second experiment served to investigate which underlying processes contribute to the task interference often found with prospective memory tasks. Diffusion model analyses revealed that the task interference effect was due to (1) less efficient processing in the more demanding than in the less demanding prospective memory task and (2) a more conservative response criterion. We suggest that the anticipated demands and the additional processing demands of the prospective memory task jointly contribute to the task interference effect.

Implementation intention encoding in a prospective memory task enhances spontaneous retrieval of intentions

Although forming implementation intentions (Gollwitzer, 1999) has been demonstrated to generally improve prospective memory, the underlying cognitive mechanisms are not completely understood. It has been proposed that implementation-intention encoding encourages spontaneous retrieval (McDaniel & Scullin, 2010). Alternatively one could assume the positive effect of implementation-intention encoding is caused by increased or more efficient monitoring for target cues. To test these alternative explanations and to further investigate the cognitive mechanisms underlying implementation-intention benefits, in two experiments participants formed the intention to respond to specific target cues in a lexical decision task with a special key, but then had to suspend this intention during an intervening word-categorisation task. Response times on trials directly following the occurrence of target cues in the intervening task were significantly slower with implementation-intention encoding than with standard encoding, indicating that spontaneous retrieval was increased (Experiment 1). However, when activation of the target cues was controlled for, similar slowing was found with both standard and implementation-intention encoding (Experiment 2). The results imply that implementation-intention encoding as well as increased target–cue activation foster spontaneous retrieval processes.

The role of metacognition in prospective memory: Anticipated task demands influence attention allocation strategies

The present study investigates how individuals distribute their attentional resources between a prospective memory task and an ongoing task. Therefore, metacognitive expectations about the attentional demands of the prospective-memory task were manipulated while the factual demands were held constant. In Experiments 1a and 1b, we found attentional costs from a prospective-memory task with low factual demands to be significantly reduced when information about the low to-be-expected demands were provided, while prospective-memory performance remained largely unaffected. In Experiment 2, attentional monitoring in a more demanding prospective-memory task also varied with information about the to-be-expected demands (high vs. low) and again there were no equivalent changes in prospective-memory performance. These findings suggest that attention-allocation strategies of prospective memory rely on metacognitive expectations about prospective-memory task demands. Furthermore, the results suggest that attentional monitoring is only functional for prospective memory to the extent to which anticipated task demands reflect objective task demands.

Affective state and event-based prospective memory

Event-based prospective memory tasks require the realisation of a delayed intention at the occurrence of a specific target event. The present research investigates how performance in this kind of prospective memory task is influenced by the current affective state. By manipulating participants’ mood during intention realisation we tested two competing models of mood effects on memory (i.e., a capacity consuming account and a processing style account). Furthermore, we manipulated the valence of the target event to investigate mood-congruency effects in prospective memory. No evidence was found for a mood-congruency effect, but the results showed that prospective memory performance increased with a sad mood. This effect is consistent with recent theories on mood-dependent processing-style regulation, postulating that a sad mood produces a more analytic and detailed processing style whereas a happy mood produces a more global and less detailed processing style.

Assessing the validity of multinomial models using extraneous variables: An application to prospective memory

The class of multinomial processing tree (MPT) models has been used extensively in cognitive psychology to model latent cognitive processes. Critical for the usefulness of a MPT model is its psychological validity. Generally, the validity of a MPT model is demonstrated by showing that its parameters are selectively and predictably affected by theoretically meaningful experimental manipulations. Another approach is to test the convergent validity of the model parameters and other extraneous measures intended to measure the same cognitive processes. Here, we advance the concept of construct validity (Cronbach & Meehl, 1955) as a criterion for model validity in MPT modelling and show how this approach can be fruitfully utilized using the example of a MPT model of event-based prospective memory. For that purpose, we investigated the convergent validity of the model parameters and established extraneous measures of prospective memory processes over a range of experimental settings, and we found a lack of convergent validity between the two indices. On a conceptual level, these results illustrate the importance of testing convergent validity. Additionally, they have implications for prospective memory research, because they demonstrate that the MPT model of event-based prospective memory is not able to differentiate between different processes contributing to prospective memory performance.

Working memory load eliminates the survival processing effect

In a series of experiments, Nairne, Thompson, and Pandeirada (2007) demonstrated that words judged for their relevance to a survival scenario are remembered better than words judged for a scenario not relevant on a survival dimension. They explained this survival-processing effect by arguing that nature “tuned” our memory systems to process and remember fitness-relevant information. Kroneisen and Erdfelder (2011) proposed that it may not be survival processing per se that facilitates recall but the richness and distinctiveness with which information is encoded. To further test this account, we investigated how the survival processing effect is affected by cognitive load. If the survival processing effect is due to automatic processes or, alternatively, if survival processing is routinely prioritized in dual-task contexts, we would expect this effect to persist under cognitive load conditions. If the effect relies on cognitively demanding processes like richness and distinctiveness of encoding, however, the survival processing benefit should be hampered by increased cognitive load during encoding. Results were in line with the latter prediction, that is, the survival processing effect vanished under dual-task conditions.

Context-specific prospective-memory processing: Evidence for flexible attention allocation adjustments after intention encoding

Prospective memory (PM) is remembering to fulfill intentions in the future. Interference of unfulfilled intentions with ongoing activities reflects the allocation of attention to the PM task. Prior research has shown that, when people know in which specific context PM cues will occur, attention allocation is adaptive, with slower responses in the PM-relevant context. We examined whether people flexibly adjust their attention allocation when the PM–context association is unknown at intention encoding and must be learned on-task. Different stimulus shapes represented contexts in an ongoing task, with PM cues only occurring in trials with one specific shape. Participants informed about the PM-relevant shape responded more slowly on trials with this shape. Participants instructed that only one, unspecified shape was PM-relevant learned the PM–context association and also allocated attention flexibly, depending on context relevance. However, participants with no context-related information at intention encoding failed to learn the PM–context association, resulting in inflexible attention allocation and poorer PM performance. The present study provides evidence that people can flexibly update their attention-allocation policy, and thereby optimize their PM performance after initial intention encoding, but self-guided learning of intention–context associations appears to be limited.

Performance predictions affect attentional processes of event-based prospective memory

To investigate whether making performance predictions affects prospective memory (PM) processing, we asked one group of participants to predict their performance in a PM task embedded in an ongoing task and compared their performance with a control group that made no predictions. A third group gave not only PM predictions but also ongoing-task predictions. Exclusive PM predictions resulted in slower ongoing-task responding both in a nonfocal (Experiment 1) and in a focal (Experiment 2) PM task. Only in the nonfocal task was the additional slowing accompanied by improved PM performance. Even in the nonfocal task, however, was the correlation between ongoing-task speed and PM performance reduced after predictions, suggesting that the slowing was not completely functional for PM. Prediction-induced changes could be avoided by asking participants to additionally predict their performance in the ongoing task. In sum, the present findings substantiate a role of metamemory for attention-allocation strategies of PM.