Explaining the Validity of the ASVAB for Job-Relevant Multitasking Performance: The Role of Placekeeping Ability.

Scores on the Armed Services Vocational Aptitude Battery (ASVAB) predict military job (and training) performance better than any single variable so far identified. However, it remains unclear what factors explain this predictive relationship. Here, we investigated the contributions of (Gf) and two executive functions- and -to the relationship between the Armed Forces Qualification Test (AFQT) score from the ASVAB and job-relevant multitasking performance.

Task independence of placekeeping as a cognitive control construct: Evidence from individual differences and experimental effects.

Many cognitive tasks have what we refer to as a placekeeping requirement: steps or subtasks must be performed in a linear or other systematic fashion, without repetitions or omissions that would compromise performance. Here we asked whether the cognitive control mechanisms that meet this requirement are specific to individual tasks or general enough to be shared across tasks. Participants (N = 289) performed two tasks (Letterwheel and UNRAVEL) that share a sequential structure but are otherwise distinct.

Slow-wave sleep during a brief nap is related to reduced cognitive deficits during sleep deprivation.

Sleeping for a short period (i.e. napping) may help mitigate impairments in cognitive processing caused by sleep deprivation, but there is limited research on effects of brief naps in particular.

Caffeine selectively mitigates cognitive deficits caused by sleep deprivation.

Sleep deprivation impairs a wide range of cognitive processes, but the precise mechanism underlying these deficits is unclear. One prominent proposal is that sleep deprivation impairs vigilant attention, and that impairments in vigilant attention cause impairments in cognitive tasks that require attention. Here, we test this theory by studying the effects of caffeine on visual vigilant attention and on placekeeping, a cognitive control process that plays a role in procedural performance, problem solving, and other higher order tasks.

Incremental validity of placekeeping as a predictor of multitasking.

Multitasking is ubiquitous in everyday life, which means there is value in developing measures that predict successful multitasking performance. In a large sample (N = 404 contributing data), we examined the predictive and incremental validity of placekeeping, which is the ability to perform a sequence of operations in a certain order without omissions or repetitions. In the context of multitasking, placekeeping should play a role in the performance of procedural subtasks and the interleaving of subtasks that interrupt each other.

Effects of total sleep deprivation on procedural placekeeping: More than just lapses of attention.

Total sleep deprivation (TSD) impairs attention as well as higher-order cognitive processes. Because attention is a core component of many tasks, it may fully mediate the effect of sleep deprivation on higher-order processes. We examined this possibility using the Psychomotor Vigilance Task as a measure of attention and the UNRAVEL task as a measure of placekeeping, a higher-order process that involves memory operations and supports performance in a wide range of complex tasks.

Is working memory capacity a causal factor in fluid intelligence?

It is well established that measures of reasoning ability and of working memory capacity (WMC) correlate positively. However, the question of what explains this relationship remains open. The purpose of this study was to investigate the capacity hypothesis, which ascribes causality to WMC.

Effects of sleep deprivation on procedural errors.

In a large sample ( = 234), we tested effects of 24-hr of sleep deprivation on error rates in a procedural task that requires memory maintenance of task-relevant information. In the evening, participants completed the task under double-blind conditions and then either stayed awake in the lab overnight or slept at home. In the morning, participants completed the task again.

Response-cue interval effects in extended-runs task switching: memory, or monitoring?

This study investigated effects of manipulating the response-cue interval (RCI) in the extended-runs task-switching procedure. In this procedure, a task cue is presented at the start of a run of trials and then withdrawn, such that the task has to be stored in memory to guide performance until the next task cue is presented. The effects of the RCI manipulation were not as predicted by an existing model of memory processes in task switching (Altmann and Gray, Psychol Rev 115:602-639, 2008), suggesting that either the model is incorrect or the RCI manipulation did not have the intended effect.

No Evidence That Sleep Deprivation Effects and the Vigilance Decrement Are Functionally Equivalent: Comment on Veksler and Gunzelmann (2017).

Veksler and Gunzelmann (2017) make an extraordinary claim, which is that sleep deprivation effects and the vigilance decrement are functionally equivalent. Extraordinary claims require extraordinary evidence, which is missing from Veksler and Gunzelmann's study. Their behavioral data offer only weak theoretical constraint, and to the extent their modeling exercise supports any position, it is that these two performance impairments involve functionally distinct underlying mechanisms.

Practice increases procedural errors after task interruption.

Positive effects of practice are ubiquitous in human performance, but a finding from memory research suggests that negative effects are possible also. The finding is that memory for items on a list depends on the time interval between item presentations. This finding predicts a negative effect of practice on procedural performance under conditions of task interruption.

Effects of interruption length on procedural errors.

We investigated effects of task interruption on procedural performance, focusing on the effect of interruption length on the rates of different categories of error at the point of task resumption. Interruption length affected errors involving loss of place in the procedure (sequence errors) but not errors involving incorrect execution of a correct step (nonsequence errors), implicating memory for past performance, rather than generalized attentional resources, as the disrupted cognitive process. Within the category of sequence errors, interruption length produced a complex pattern of effects, with repetitions of the preinterruption step showing different effects than errors at other offsets from the correct step.

The role of placekeeping ability in fluid intelligence.

The question of what underlies individual differences in general intelligence has never been satisfactorily answered. The purpose of this research was to investigate the role of an executive function that we term placekeeping ability-the ability to perform the steps of a complex task in a prescribed order without skipping or repeating steps. Participants completed a newly developed test of placekeeping ability, called the UNRAVEL task.

Momentary interruptions can derail the train of thought.

We investigated the effect of short interruptions on performance of a task that required participants to maintain their place in a sequence of steps each with their own performance requirements. Interruptions averaging 4.4 s long tripled the rate of sequence errors on post-interruption trials relative to baseline trials.

When the rules are reversed: action-monitoring consequences of reversing stimulus-response mappings.

How does switching tasks affect our ability to monitor and adapt our behavior? Largely independent lines of research have examined how individuals monitor their actions and adjust to errors, on the one hand, and how they are able to switch between two or more tasks, on the other. Few studies, however, have explored how these two aspects of cognitive-behavioral flexibility interact. That is, how individuals monitor their actions when task rules are switched remains unknown.

Testing probability matching and episodic retrieval accounts of response repetition effects in task switching.

This study takes inventory of available evidence on response repetition (RR) effects in task switching, in particular the evidence for RR cost when the task switches. The review reveals that relatively few task-switching studies in which RR effects were addressed have shown statistical support for RR cost, and that almost all are affected by 1 of 2 potential artifacts, either a response bias caused by disallowing stimulus repetitions or the effect of including stimulus repetitions in data analysis. New results with these factors controlled support an episodic retrieval model in which features of the retrieved trace, including the stimulus but also the task, task cue, and response, facilitate or interfere with performance depending on whether they match or mismatch the current processing context.

How planful is routine behavior? A selective-attention model of performance in the Tower of Hanoi.

Routine human behavior has often been attributed to plans-mental representations of sequences goals and actions-but can also be attributed to more opportunistic interactions of mind and a structured environment. This study asks whether performance on a task traditionally analyzed in terms of plans can be better understood from a "situated" (or "embodied") perspective. A saccade-contingent display-updating paradigm is used to change the environment by adding, deleting, and moving task-relevant objects without participants' direct awareness.

An integrated model of cognitive control in task switching.

A model of cognitive control in task switching is developed in which controlled performance depends on the system maintaining access to a code in episodic memory representing the most recently cued task. The main constraint on access to the current task code is proactive interference from old task codes. This interference and the mechanisms that contend with it reproduce a wide range of behavioral phenomena when simulated, including well-known task-switching effects, such as latency and error switch costs, and effects on which other theories are silent, such as with-run slowing and within-run error increase.

Timecourse of recovery from task interruption: data and a model.

Interruption of a complex cognitive task can entail, for the "interruptee", a sense of having to recover afterward. We examined this recovery process by measuring the timecourse of responses following an interruption, sampling over 13,000 interruptions to obtain stable data. Response times dropped in a smooth curvilinear pattern for the first 10 responses (15 sec or so) of postinterruption performance.

Cue-independent task-specific representations in task switching: evidence from backward inhibition.

The compound-cue model of cognitive control in task switching explains switch cost in terms of a switch of task cues rather than of a switch of tasks. The present study asked whether the model generalizes to Lag 2 repetition cost (also known as backward inhibition), a related effect in which the switch from B to A in ABA task sequences is costlier than is the same switch in CBA task sequences. The model suggests that Lag 2 repetition cost should be absent from A'BA task sequences, in which A' and A are different cues for the same task.

Task switching is not cue switching.

With the aim of reducing cognitive control in task switching to simpler processes, researchers have proposed in a series of recent studies that there is little more to switching tasks than switching cues. The present study addresses three questions concerning this reduction hypothesis. First, does switching cues account for all relevant variance associated with switching tasks? Second, how well does this hypothesis generalize beyond the experimental procedure from which it was developed? Third, how well does this new procedure preserve relevant measures such as task-switch cost? The answers (no; not very; not very) suggest that task switching does not reduce to cue switching.

Comparing switch costs: alternating runs and explicit cuing.

The task-switching literature routinely conflates different operational definitions of switch cost, its predominant behavioral measure. This article is an attempt to draw attention to differences between the two most common definitions, alternating-runs switch cost (ARS) and explicit-cuing switch cost (ECS). ARS appears to include both the costs of switching tasks and the switch-independent costs specific to the first trial of a run, with the implication that it should generally be larger than ECS, but worse is that the alternating-runs procedure does not allow these costs to be separated.