How pervasive is mind wandering, really?

Recent claims that people spend 30-50% of their waking lives mind wandering (Killingsworth & Gilbert, 2010; Kane et al., 2007) have become widely accepted and frequently cited. While acknowledging attention to be inconstant and wavering, and mind wandering to be ubiquitous, we argue and present evidence that such simple quantitative estimates are misleading and potentially meaningless without serious qualification. Mind-wandering estimates requiring dichotomous judgments of inner experience rely on questionable assumptions about how such judgments are made, and the resulting data do not permit straightforward interpretation. We present evidence that estimates of daily-life mind wandering vary dramatically depending on the response options provided. Offering participants a range of options in estimating task engagement yielded variable mind-wandering estimates, from approximately 60% to 10%, depending on assumptions made about how observers make introspective judgments about their mind-wandering experiences and how they understand what it means to be on- or off-task.

The origins of the vaccine cold chain and a glimpse of the future.

International efforts to eradicate smallpox in the 1960s and 1970s provided the foundation for efforts to expand immunization programmes, including work to develop immunization supply chains. The need to create a reliable system to keep vaccines cold during the lengthy journey from the manufacturer to the point of use, even in remote areas, was a crucial concern during the early days of the Expanded Programme on Immunization. The vaccine cold chain was deliberately separated from other medical distribution systems to assure timely access to and control of vaccines and injection materials. The story of the early development of the vaccine cold chain shows how a number of challenges were overcome with technological and human resource solutions. For example, the lack of methods to monitor exposure of vaccines to heat during transport and storage led to many innovations, including temperature-sensitive vaccine vial monitors and better methods to record and communicate temperatures in vaccine stores. The need for appropriate equipment to store and transport vaccines in tropical developing countries led to innovations in refrigeration equipment as well as the introduction and widespread adoption of novel high performance vaccine cold-boxes and carriers. New technologies also helped to make injection safer. Underlying this work on technologies and equipment was a major effort to develop the human resources required to manage and implement the immunization supply chain. This included creating foundational policies and a management infrastructure; providing training for managers, health workers, technicians, and others. The vaccine cold chain has contributed to one of the world's public health success stories and provides three priority lessons for future: the vaccine supply chain needs to be integrated with other public health supplies, re-designed for efficiency and effectiveness and work is needed in the longer term to eliminate the need for refrigeration in the supply chain.

"You're on ten, where can you go from there?" Tufnel problems in repeated experiential judgments.

We describe a set of Tufnel problems that arise when repeated use of a fixed-point scale precipitates failures to assess a full range of subjective experiences. As empirical evidence, participants in Study 1 periodically reported their depth of mind wandering on either 5- or 7-point Likert scales during a sustained attention task. The proportion of participants providing maximum scale ratings increased quickly over time-on-task and did so more quickly for the 5-point than for the 7-point group. Participants in Study 2 completed the same task using a 10-point scale before indicating whether and where they could have used a scale extended to "11" during the task. Slightly more than 20% of participants reported needing a scale extension. This Need for 11 was associated with differences in both reports of mind wandering depth and task performance. We conclude that Tufnel problems warrant methodological consideration and reflect interesting constraints on human judgment.

Is the cognitive reflection test a measure of both reflection and intuition?

The Cognitive Reflection Test (CRT) is one of the most widely used tools to assess individual differences in intuitive-analytic cognitive styles. The CRT is of broad interest because each of its items reliably cues a highly available and superficially appropriate but incorrect response, conventionally deemed the "intuitive" response. To do well on the CRT, participants must reflect on and question the intuitive responses. The CRT score typically employed is the sum of correct responses, assumed to indicate greater "reflectiveness" (i.e., CRT-Reflective scoring). Some recent researchers have, however, inverted the rationale of the CRT by summing the number of intuitive incorrect responses, creating a putative measure of intuitiveness (i.e., CRT-Intuitive). We address the feasibility and validity of this strategy by considering the problem of the structural dependency of these measures derived from the CRT and by assessing their respective associations with self-report measures of intuitive-analytic cognitive styles: the Faith in Intuition and Need for Cognition scales. Our results indicated that, to the extent that the dependency problem can be addressed, the CRT-Reflective but not the CRT-Intuitive measure predicts intuitive-analytic cognitive styles. These results provide evidence that the CRT is a valid measure of reflective but not of intuitive thinking.

Motivation, intentionality, and mind wandering: Implications for assessments of task-unrelated thought.

Researchers of mind wandering frequently assume that (a) participants are motivated to do well on the tasks they are given, and (b) task-unrelated thoughts (TUTs) that occur during task performance reflect unintentional, unwanted thoughts that occur despite participants' best intentions to maintain task-focus. Given the relatively boring and tedious nature of most mind-wandering tasks, however, there is the possibility that some participants have little motivation to do well on such tasks, and that this lack of motivation might in turn result in increases specifically in intentional TUTs. In the present study, we explored these possibilities, finding that individuals reporting lower motivation to perform well on a sustained-attention task reported more intentional relative to unintentional TUTs compared with individuals reporting higher motivation. Interestingly, our results indicate that the extent to which participants engage in intentional versus unintentional TUTs does not differentially relate to performance: both types of off-task thought were found to be equally associated with performance decrements. Participants with low levels of task-motivation also engaged in more overall TUTs, however, and this increase in TUTs was associated with greater performance decrements. We discuss these findings in the context of the literature on mind wandering, highlighting the importance of assessing the intentionality of TUTs and motivation to perform well on tasks assessing mind wandering.

Can research participants comment authoritatively on the validity of their self-reports of mind wandering and task engagement?

The study of mind wandering rests upon the assumption that people are able to consistently and accurately introspect and report on these sorts of mental experiences. Although there is some initial evidence that people can indeed accurately report on the subjective experience of mind wandering, to date, no work has directly examined people's degree of confidence in their self-reports of mind wandering and the effects that confidence has on the accuracy of such reports. In the present study, participants completed a sustained-attention task during which they intermittently provided assessments of task engagement (i.e., whether they were focused on the task or mind wandering), as well as reports of confidence in the accuracy of their assessments. This study yielded 3 key findings: We found substantial between- and within-subject variability in both (a) reported mind wandering and (b) confidence in mind-wandering reports, and, most critically, (c) we found that the relation of reported mind wandering and task performance varied as a function of confidence. We discuss the implications of these findings in the context of the literature on mind wandering.

On the relation of mind wandering and ADHD symptomatology.

Mind wandering seems to be a prototypical feature of attention-deficit/hyperactivity disorder (ADHD). However, an important emerging distinction of mind-wandering types hinges on whether a given episode of mind wandering reflects a failure of executive control (spontaneous mind wandering) or the engagement of controlled processes for internal processing (deliberate mind wandering). Here we distinguish between spontaneous and deliberate mind wandering and test the hypothesis that symptoms of ADHD are associated with the former but not the latter. We assessed ADHD symptomatology and everyday levels of deliberate and spontaneous mind wandering in two large non-clinical samples (Ns = 1,354). In addition, to provide converging evidence, we examined rates of deliberate and spontaneous mind wandering in a clinically diagnosed ADHD sample. Results provide clear evidence that spontaneous, but not deliberate, mind wandering is a central feature of ADHD symptomatology at both the clinical and non-clinical level. We discuss the implications of these results for understanding both ADHD and mind wandering.

Restless mind, restless body.

In the present work, we investigate the hypothesis that failures of task-related executive control that occur during episodes of mind wandering are associated with an increase in extraneous movements (fidgeting). In 2 studies, we assessed mind wandering using thought probes while participants performed the metronome response task (MRT), which required them to synchronize button presses with tones. Participants performed this task while sitting on a Wii Balance Board providing us with an index of fidgeting. Results of Study 1 demonstrate that relative to on-task periods, mind wandering is indeed accompanied by increases in fidgeting, as well as increased response variability in the MRT. In Study 2, we observed that only deep mind wandering was associated with increases in fidgeting, whereas task-related response variability increased even during mild mind wandering. We interpret these findings in the context of current theories of mind wandering and suggest that (a) mind wandering is associated with costs not only to primary-task performance but also to secondary-task goals (e.g., controlling extraneous movements) and (b) these costs may depend on the degree to which task-related executive control processes are disengaged during mind wandering (i.e., depth of mind wandering).

Media multitasking and failures of attention in everyday life.

Using a series of online self-report measures, we examine media multitasking, a particularly pervasive form of multitasking, and its relations to three aspects of everyday attention: (1) failures of attention and cognitive errors (2) mind wandering, and (3) attentional control with an emphasis on attentional switching and distractibility. We observed a positive correlation between levels of media multitasking and self-reports of attentional failures, as well as with reports of both spontaneous and deliberate mind wandering. No correlation was observed between media multitasking and self-reported memory failures, lending credence to the hypothesis that media multitasking may be specifically related to problems of inattention, rather than cognitive errors in general. Furthermore, media multitasking was not related with self-reports of difficulties in attention switching or distractibility. We offer a plausible causal structural model assessing both direct and indirect effects among media multitasking, attentional failures, mind wandering, and cognitive errors, with the heuristic goal of constraining and motivating theories of the effects of media multitasking on inattention.

Cognitive style and religiosity: the role of conflict detection.

Recent research has indicated a negative relation between the propensity for analytic reasoning and religious beliefs and practices. Here, we propose conflict detection as a mechanism underlying this relation, on the basis of the hypothesis that more-analytic people are less religious, in part, because they are more sensitive to conflicts between immaterial religious beliefs and beliefs about the material world. To examine cognitive conflict sensitivity, we presented problems containing stereotypes that conflicted with base-rate probabilities in a task with no religious content. In three studies, we found evidence that religiosity is negatively related to conflict detection during reasoning. Independent measures of analytic cognitive style also positively predicted conflict detection. The present findings provide evidence for a mechanism potentially contributing to the negative association between analytic thinking and religiosity, and more generally, they illustrate the insights to be gained from integrating individual-difference factors and contextual factors to investigate analytic reasoning.

Performance reactivity in a continuous-performance task: implications for understanding post-error behavior.

Although there has been considerable interest in the effects of errors on subsequent performance, relatively few studies have considered the effects of non-error events that contain some performance-relevant information, such as correct performance on critical trials. In the present article, we propose and assess a hypothesis of performance reactivity. In support of this hypothesis, we provide evidence of performance decrements following both incorrect and correct responses but not following performance-irrelevant events. More specifically, in a continuous response task (Sustained Attention to Response Task), we (1) replicate previous findings that errors of commission on rare NOGO trials produce decrements in subsequent performance, and (2) observe that correct withholds to NOGO trials produce decrements in subsequent accuracy relative to task-irrelevant tones. These results corroborate a hypothesis that some error-related effects on subsequent performance are not unique, but are instead a particularly salient version of a more general performance-reactivity effect.

Enhancing SART Validity by Statistically Controlling Speed-Accuracy Trade-Offs.

Numerous studies focused on elucidating the correlates, causes, and consequences of inattention/attention-lapses employ the Sustained Attention to Response Task (SART), a GO-NOGO task with infrequent withholds. Although the SART has become popular among inattention researchers, recent work has demonstrated its susceptibility to speed-accuracy trade-offs (SATOs), rendering its assessment of inattention problematic. Here, we propose and illustrate methods to statistically control for the occurrence of SATOs during SART performance. The statistical solutions presented here can be used to correct standard SART-error scores, including those of already-published data, thereby allowing researchers to re-examine existing data, and to more sensitively evaluate the validity of earlier conclusions.

Age differences in attention lapses mask age differences in memory failures: a methodological note on suppression.

Although objective measures of memory performance typically indicate memory declines with age, self-reported memory failures often show no relation to age. In contrast, self-reported attention failures are reliably negatively correlated with age. This contrast suggests the possibility that age-related awareness and reporting of memory failures might be masked by a concurrent decrease in attention failures, which would reduce encoding failures with age and hence reduce perceived memory failures. Self-reported problems of attention and memory were evaluated in two samples with the ages spanning eight decades. Initial analysis indicated that attention failures significantly decreased with age, whereas memory problems did not to differ across age. The association of self-reported memory failures became significantly positive, however, when residualized on attention lapses. In contrast, the correlation between attention lapses and age was modestly affected when memory failures were controlled. These results highlight the close relation of attention lapses and memory problems and, beyond the implications of individual differences in attention for memory research, suggest the advisability of assessing attention failures for a full evaluation of memory problems.

Belief bias during reasoning among religious believers and skeptics.

We provide evidence that religious skeptics, as compared to believers, are both more reflective and effective in logical reasoning tasks. While recent studies have reported a negative association between an analytic cognitive style and religiosity, they focused exclusively on accuracy, making it difficult to specify potential underlying cognitive mechanisms. The present study extends the previous research by assessing both performance and response times on quintessential logical reasoning problems (syllogisms). Those reporting more religious skepticism made fewer reasoning errors than did believers. This finding remained significant after controlling for general cognitive ability, time spent on the problems, and various demographic variables. Crucial for the purpose of exploring underlying mechanisms, response times indicated that skeptics also spent more time reasoning than did believers. This novel finding suggests a possible role of response slowing during analytic problem solving as a component of cognitive style that promotes overriding intuitive first impressions. Implications for using additional processing measures, such as response time, to investigate individual differences in cognitive style are discussed.

A methodological note on evaluating performance in a sustained-attention-to-response task.

We evaluated the influence of speed-accuracy trade-offs on performance in the sustained attention to response task (SART), a task often used to evaluate the effectiveness of techniques designed to improve sustained attention. In the present study, we experimentally manipulated response delay in a variation of the SART and found that commission errors, which are commonly used as an index of lapses in sustained attention, were a systematic function of manipulated differences in response delay. Delaying responses to roughly 800 ms after stimulus onset reduced commission errors substantially. We suggest the possibility that any technique that affects response speed will indirectly alter error rates independently of improvements in sustained attention. Investigators therefore need to carefully explore, report, and correct for changes in response speed that accompany improvements in performance or, alternatively, to employ tasks that control for response speed.

Wandering minds and wavering rhythms: linking mind wandering and behavioral variability.

Mind wandering is a pervasive feature of human cognition often associated with the withdrawal of task-related executive control processes. Here, we explore the possibility that, in tasks requiring executive control to sustain consistent responding, moments of mind wandering could be associated with moments of increased behavioral variability. To test this possibility, we developed and administered a novel task (the metronome response task) in which participants were instructed to respond synchronously (via button presses) with the continuous rhythmic presentation of tones. We provide evidence (replicated across 2 independent samples) that response variability during the 5 trials preceding probe-caught reports of mind wandering (tuned-out and zoned-out mind wandering) is significantly greater than during the 5 trials preceding reports of on-task performance. These results suggest that, at least in some tasks, behavioral variability is an online marker of mind wandering.

Intended actions and unexpected outcomes: automatic and controlled processing in a rapid motor task.

Human action involves a combination of controlled and automatic behavior. These processes may interact in tasks requiring rapid response selection or inhibition, where temporal constraints preclude timely intervention by conscious, controlled processes over automatized prepotent responses. Such contexts tend to produce frequent errors, but also rapidly executed correct responses, both of which may sometimes be perceived as surprising, unintended, or "automatic". In order to identify neural processes underlying these two aspects of cognitive control, we measured neuromagnetic brain activity in 12 right-handed subjects during manual responses to rapidly presented digits, with an infrequent target digit that required switching response hand (bimanual task) or response finger (unimanual task). Automaticity of responding was evidenced by response speeding (shorter response times) prior to both failed and fast correct switches. Consistent with this automaticity interpretation of fast correct switches, we observed bilateral motor preparation, as indexed by suppression of beta band (15-30 Hz) oscillations in motor cortex, prior to processing of the switch cue in the bimanual task. In contrast, right frontal theta activity (4-8 Hz) accompanying correct switch responses began after cue onset, suggesting that it reflected controlled inhibition of the default response. Further, this activity was reduced on fast correct switch trials suggesting a more automatic mode of inhibitory control. We also observed post-movement (event-related negativity) ERN-like responses and theta band increases in medial and anterior frontal regions that were significantly larger on error trials, and may reflect a combination of error and delayed inhibitory signals. We conclude that both automatic and controlled processes are engaged in parallel during rapid motor tasks, and that the relative strength and timing of these processes may underlie both optimal task performance and subjective experiences of automaticity or control.

Analytic cognitive style predicts religious and paranormal belief.

An analytic cognitive style denotes a propensity to set aside highly salient intuitions when engaging in problem solving. We assess the hypothesis that an analytic cognitive style is associated with a history of questioning, altering, and rejecting (i.e., unbelieving) supernatural claims, both religious and paranormal. In two studies, we examined associations of God beliefs, religious engagement (attendance at religious services, praying, etc.), conventional religious beliefs (heaven, miracles, etc.) and paranormal beliefs (extrasensory perception, levitation, etc.) with performance measures of cognitive ability and analytic cognitive style. An analytic cognitive style negatively predicted both religious and paranormal beliefs when controlling for cognitive ability as well as religious engagement, sex, age, political ideology, and education. Participants more willing to engage in analytic reasoning were less likely to endorse supernatural beliefs. Further, an association between analytic cognitive style and religious engagement was mediated by religious beliefs, suggesting that an analytic cognitive style negatively affects religious engagement via lower acceptance of conventional religious beliefs. Results for types of God belief indicate that the association between an analytic cognitive style and God beliefs is more nuanced than mere acceptance and rejection, but also includes adopting less conventional God beliefs, such as Pantheism or Deism. Our data are consistent with the idea that two people who share the same cognitive ability, education, political ideology, sex, age and level of religious engagement can acquire very different sets of beliefs about the world if they differ in their propensity to think analytically.

Consistency of sustained attention across modalities: comparing visual and auditory versions of the SART.

We develop and assess an auditory version of an increasingly widely used measure of sustained attention, the Sustained Attention to Response Task (SART). In two separate studies, the auditory SART generated slower response times and fewer errors than the visual SART. Proportion of errors, response times, and response time variability were, however, significantly and strongly correlated across the two modalities. The cross-modality correlations were generally equivalent to split-half correlations within modalities, indicating a strong agreement of the assessment of individual differences in sustained attention in the visual and auditory modalities. The foregoing results plus the finding that errors on the auditory SART were reduced suggests that the auditory SART may be a preferred alternative for use with populations with deficits in sustained attention.

Attention failures versus misplaced diligence: separating attention lapses from speed-accuracy trade-offs.

In two studies of a GO-NOGO task assessing sustained attention, we examined the effects of (1) altering speed-accuracy trade-offs through instructions (emphasizing both speed and accuracy or accuracy only) and (2) auditory alerts distributed throughout the task. Instructions emphasizing accuracy reduced errors and changed the distribution of GO trial RTs. Additionally, correlations between errors and increasing RTs produced a U-function; excessively fast and slow RTs accounted for much of the variance of errors. Contrary to previous reports, alerts increased errors and RT variability. The results suggest that (1) standard instructions for sustained attention tasks, emphasizing speed and accuracy equally, produce errors arising from attempts to conform to the misleading requirement for speed, which become conflated with attention-lapse produced errors and (2) auditory alerts have complex, and sometimes deleterious, effects on attention. We argue that instructions emphasizing accuracy provide a more precise assessment of attention lapses in sustained attention tasks.