Individual Strategies of Response Organization in Multitasking Are Stable Even at Risk of High Between-Task Interference

Recently, reliable interindividual differences were found for the way how individuals process multiple tasks (at a cognitive level) and how they organize their responses (at a response level). Previous studies have shown mixed results with respect to the flexibility of these preferences. On the one hand, individuals tend to adjust their preferred task processing mode to varying degrees of risk of crosstalk between tasks. On the other, response strategies were observed to be highly stable under varying between-resource competition. In the present study, we investigated whether the stability of response strategies also persists with increased risk of crosstalk or whether individuals adjust their choice of response strategy, similar to what has been found at the level of task processing modes. Besides, related differences in multitasking efficiency were assessed. For this purpose, 53 participants performed the Free Concurrent Dual-Tasking (FCDT) paradigm, which allows them to control their task scheduling and response organization. The participants completed the FCDT paradigm under two conditions including task pairs characterized by either low or high levels of risk of crosstalk. The free choice of task scheduling resulted in the previously found distinct response patterns, best described as blocking, switching or response grouping. Remarkably, we did not find any notable adjustments of strategies of response organization to the extent of crosstalk. However, we observed suspected performance decrements of a switching strategy in the condition of high risk of crosstalk. The results suggest that individual strategies of response organization are stable habits. Further, they illustrate disadvantages of switching vs. blocking strategies of response organization in case of high task similarity

Individual preferences for task coordination strategies in multitasking: exploring the link between preferred modes of processing and strategies of response organization

Recent investigation of individual differences in multitasking revealed evidence for individual preferences for modes of task processing (serial vs. overlapping) in a task switching with preview (TSWP) paradigm and different strategies of response organization (blocking, switching, and response grouping) in a free concurrent dual-tasking (FCDT) paradigm. However, this research on individual differences at the levels of cognitive task processing and behavioral response organization has been pursued separately, thus far, by testing independent samples of participants. In the current study, we investigated whether these two levels of task coordination were linked intra-individually. As individuals preferring an overlapping task processing mode can generate time gains particularly at task switches, we predicted that they prefer a switching strategy of response organization. In contrast, individuals preferring a serial processing mode are expected to prefer a blocking strategy to reduce dual-task demands. These predictions were confirmed in an experiment based on n = 70 participants. Indeed, most serial processors preferred a blocking strategy, whereas overlapping processors predominantly preferred to switch between the tasks. This finding suggests a strong correspondence between individual preferences emerging in both aspects of task coordination, which might reflect a common basic difference in the preferred style of cognitive control (flexible vs. persistent). Moreover, in case the preferred modes of task processing and strategies of response organization did not correspond to each other, the overall multitasking efficiency was comparably low. Thus, the distinction between the preferences for both aspects of multitasking seems to be an important aspect of understanding multitasking performance and should be considered in future studies.TU Berlin, Open-Access-Mittel – 202

Flexibilität und Effizienz individueller Präferenzen für Strategien der Aufgabenkoordination in Multitasking

In our rapidly changing world, we are often juggling several task demands at once, and in doing so we constantly need to adapt to changing task requirements. To date, a plethora of studies addressed the question to which degree humans can perform two or more tasks in a concurrent or sequential manner. Notably, most of these studies disregarded that people might differ considerably in their individual means of dealing with multiple task requirements. This \textit{individual differences} perspective on multitasking ability has only recently received increased attention. First paradigms have been developed that allow participants to view and process task stimuli concurrently or even to develop their own response strategies. Together with new statistical analyses, this approach seems promising to capture individual preferences in multitasking. The three studies included in the present thesis were conducted to further advance the research on the existence of individually preferred cognitive styles and response strategies in concurrent multitasking, especially, their adaptive adjustment and implications for performance efficiency. The three studies enclosed in the work presented here replicate the finding of individual preferences for serial versus parallel task processing (study 1 and 2) and blocking versus interleaving response strategies (study 2 and 3) in multitasking. Further, study 2 indicates a systematic link between the cognitive styles and response strategies. That is, in most individuals, serial processing is associated with a blocking strategy, whereas overlapping processing is associated with interleaving strategies. Moreover, study 1 and study 3 addressed to which degree the task coordination strategies are adapted to varying task characteristics, with individual preferences turning out to be remarkably stable. Across both studies, only individuals who preferred overlapping processing showed indications of adaptive behavior (study 1), whereas all other tendencies at the level of task processing (study 1) or response organization (study 3) were largely unaffected. In addition, the studies contribute to our understanding of the multitasking efficiency achieved depending on the preferences. Study 2 showed that multitasking efficiency is higher when cognitive styles and response strategies correspond with each other as described above than when they do not. Study 1 and study 3 indicated that the multitasking efficiency does not only rely on task characteristics, but rather on the interplay of individually preferred task coordination strategies and task characteristics. Finally, the present thesis explored factors that might be relevant to the question of which cognitive style an individual engages in and which response strategy is chosen. The cognitive style of individuals was influenced by their working memory capacity, whereas the individually chosen response strategy was rather determined by the polychronicity of the individual (i.e., the general attitude of an individual towards multitasking). Overall, the present thesis supports the notion of existing individual preferences in multitasking, their intra-individual link, as well as emphasizes their stability and important influence on multitasking efficiency.In unserer sich schnell verändernden Umwelt müssen wir uns ständig an die sich ändernden Aufgabenanforderungen anpassen, und dabei häufig mehrere Aufgaben gleichzeitig bearbeiten. Mittlerweile hat sich eine Fülle von Studien mit der Frage befasst, inwieweit Menschen zwei oder mehr Aufgaben gleichzeitig oder nacheinander ausführen können. Allerdings wurde in den meisten dieser Studien außer Acht gelassen, dass sich Menschen in ihren individuellen Möglichkeiten zur Bewältigung mehrerer Aufgabenanforderungen erheblich unterscheiden können. Der Betrachtung individueller Unterschiede im Erleben und Verhalten während des Multitaskings wurde erst in jüngster Zeit verstärkte Aufmerksamkeit zuteil. Kürzlich wurden erste Paradigmen entwickelt, die es den Probanden erlauben, Aufgabenreize gleichzeitig zu betrachten und zu verarbeiten oder sogar eigene Handlungsstrategien zu entwickeln. Zusammen mit neuen statistischen Analysen scheint dieser Ansatz vielversprechend, um individuelle Präferenzen beim Multitasking zu identifizieren. Die drei in der vorliegenden Arbeit enthaltenen Studien wurden durchgeführt, um die Forschung über die Existenz individuell bevorzugter kognitiver Stile und Handlungsstrategien beim gleichzeitigen Multitasking weiter voranzutreiben, insbesondere aber ihre adaptive Anpassung und ihre Auswirkungen auf die Leistungseffizienz zu untersuchen. Die drei Studien, die in der hier vorgestellten Arbeit enthalten sind, replizieren den Befund individueller Präferenzen für serielle versus parallele Aufgabenverarbeitung (Studie 1 und 2) und Separierungs- versus Integrationsstrategien (Studie 2 und 3) im Multitasking. Überdies weist Studie 2 auf eine systematische Verbindung zwischen den kognitiven Stilen und Handlungsstrategien hin. Das heißt, dass bei den meisten Individuen die serielle Verarbeitung mit einer Separierungsstrategie assoziiert ist, während die überlappende Verarbeitung mit Integrationsstrategien assoziiert ist. Darüber hinaus wurde in Studie 1 und Studie 3 untersucht, inwieweit die Aufgabenkoordinationspräferenzen an unterschiedliche Aufgabenmerkmale angepasst werden, wobei sich die individuellen Präferenzen als bemerkenswert stabil erwiesen. In beiden Studien zeigten nur Personen, die eine überlappende Verarbeitung bevorzugten, Hinweise auf adaptives Verhalten (Studie 1), während alle anderen Tendenzen auf der Ebene der Aufgabenverarbeitung (Studie 1) oder der Antwortorganisation (Studie 3) weitgehend unbeeinflusst blieben. Darüber hinaus tragen die Studien zu unserem Verständnis der je nach Präferenzen erreichten Multitasking-Effizienz bei. Studie 2 zeigte, dass die Multitasking-Effizienz höher ist, wenn kognitive Stile und Handlungsstrategien wie oben beschrieben miteinander korrespondieren, als wenn sie nicht miteinander korrespondieren. Studie 1 und Studie 3 zeigten, dass die Multitasking-Effizienz nicht nur von den Aufgabenmerkmalen abhängt, sondern vielmehr vom Zusammenspiel der individuell bevorzugten Art der Aufgabenkoordination und Aufgabenmerkmale. Schließlich untersuchte die vorliegende Arbeit Faktoren, die für die Frage relevant sein könnten, welchen kognitiven Stil ein Individuum aufweist und welche Handlungsstrategie gewählt wird. Der kognitive Stil der Individuen stand im Zusammenhang mit ihrer jeweiligen Arbeitsgedächtniskapazität, während die individuell gewählte Handlungsstrategie eher mit der Polychronizität des Individuums (d.h. die allgemeine Einstellung eines Individuums zu Multitasking) zusammenhing. Insgesamt unterstützt die vorliegende Arbeit die Annahme bestehender individueller Präferenzen beim Multitasking, ihre intra-individuelle Verknüpfung sowie ihre Stabilität und die Relevanz ihres Einflusses auf die Effizienz des Multitaskings

Flexibility of individual multitasking strategies in task-switching with preview: are preferences for serial versus overlapping task processing dependent on between-task conflict?

The prevalence and the efficiency of serial and parallel processing under multiple task demands are highly debated. In the present study, we investigated whether individual preferences for serial or overlapping (parallel) processing represent a permanent predisposition or depend on the risk of crosstalk between tasks. Two groups (n = 91) of participants were tested. One group performed a classical task switching paradigm, enforcing a strict serial processing of tasks. The second group of participants performed the same tasks in a task-switching-with-preview paradigm, recently introduced by Reissland and Manzey (2016), which in principle allows for overlapping processing of both tasks in order to compensate for switch costs. In one condition, the tasks included univalent task stimuli, whereas in the other bivalent stimuli were used, increasing risk of crosstalk and task confusion in case of overlapping processing. The general distinction of voluntarily occurring preferences for serial or overlapping processing when performing task switching with preview could be confirmed. Tracking possible processing mode adjustments between low- and high-crosstalk conditions showed that individuals identified as serial processors in the low-crosstalk condition persisted in their processing mode. In contrast, overlapping processors split up in a majority adjusting to a serial processing mode and a minority persisting in overlapping processing, when working with bivalent stimuli. Thus, the voluntarily occurring preferences for serial or overlapping processing seem to depend at least partially on the risk of crosstalk between tasks. Strikingly, in both crosstalk conditions the individual performance efficiency was the higher, the more they processed in parallel

Multitasking strategies make the difference: Separating processing-code resources boosts multitasking efficiency when individuals prefer to interleave tasks in free concurrent dual tasking

Previous research has shown that individuals differ with respect to their preferred strategies in self-organized multitasking: They either prefer to work on one task for long sequences before switching to another (blocking), prefer to switch repeatedly after short sequences (switching), or prefer to respond almost simultaneously after processing the stimuli of two concurrently visible tasks (response grouping). In two experiments, we tested to what extent the choice of strategy and related differences in multitasking efficiency were affected by the between-resource competition (Wickens, 2002) of two tasks to be performed concurrently in a self-organized manner. All participants performed a set of dual tasks that differed with respect to the kind of stimuli (verbal vs. spatial) and/or responses (manual vs. vocal). The choice of strategy was hardly affected as most individuals persisted in their response strategy independent of the degree of resource competition. However, the efficiency of individuals preferring a switching or response-grouping strategy increased especially when the reduction in resource competition was response related (manual vs. vocal), leading even to considerable dual-tasking benefits under these circumstances. In contrast, individuals who preferred to block their responses did not achieve any considerable benefits (or costs) with either of the different dual tasks

Data from: Estimating the reproducibility of psychological science

This record contains the underlying research data for the publication "Estimating the reproducibility of psychological science" and the full-text is available from: https://ink.library.smu.edu.sg/lkcsb_research/5257Reproducibility is a defining feature of science, but the extent to which it characterizes current research is unknown. We conducted replications of 100 experimental and correlational studies published in three psychology journals using high-powered designs and original materials when available. Replication effects were half the magnitude of original effects, representing a substantial decline. Ninety-seven percent of original studies had statistically significant results. Thirty-six percent of replications had statistically significant results; 47% of original effect sizes were in the 95% confidence interval of the replication effect size; 39% of effects were subjectively rated to have replicated the original result; and if no bias in original results is assumed, combining original and replication results left 68% with statistically significant effects. Correlational tests suggest that replication success was better predicted by the strength of original evidence than by characteristics of the original and replication teams