Understanding the role of mind wandering in stress-related working memory impairments

Mind wandering has been identified as a possible cause for stress-related working memory (WM) task impairments following laboratory stressors. The current study attempted to induce mind wandering regarding negative, positive, or neutral events using an expressive writing task and examined the impact on WM task performance. We examined the role of mind wandering in understanding the impact of life stress on WM. Additionally, we explored the role of thought suppression on the relationship between mind wandering and WM. One hundred and fifty participants completed WM measures before (Time 1) and after (Time 2) the writing manipulation. The writing manipulation did not alter mind wandering or WM task performance. Time 1 WM predicted mind wandering during the Time 2 WM task, which subsequently predicted poorer Time 2 WM task performance. The impact of daily life stress on WM was mediated by mind wandering. Trait levels of thought suppression moderated the impact of mind wandering on WM. Specifically, higher levels of suppression resulted in stronger negative impact of mind wandering on WM task performance. Findings are discussed in terms of the impact of mind wandering on WM task performance.     

Differential recruitment of executive resources during mind wandering

Recent research has shown that mind wandering recruits executive resources away from the external task towards inner thoughts. No studies however have determined whether executive functions are drawn away in a unitary manner during mind wandering episodes, or whether there is variation in specific functions impacted. Accordingly, we examined whether mind wandering differentially modulates three core executive functions—response inhibition, updating of working memory, and mental set shifting. In three experiments, participants performed one of these three executive function tasks and reported their attentional state as either on-task or mind wandering at random intervals. We found that mind wandering led to poorer performance in the response inhibition and working memory tasks, but not the set-shifting task. These findings suggest that mind wandering does not recruit executive functions in a monolithic manner. Rather, it appears to selectively engage certain executive functions, which may reflect the adaptive maintenance of ongoing task performance.     

Absorbed in thought: the effect of mind wandering on the processing of relevant and irrelevant events

This study used event-related potentials to explore whether mind wandering (task-unrelated thought, or TUT) emerges through general problems in distraction, deficits of task-relevant processing (the executive-function view), or a general reduction in attention to external events regardless of their relevance (the decoupling hypothesis). Twenty-five participants performed a visual oddball task, in which they were required to differentiate between a rare target stimulus (to measure task-relevant processes), a rare novel stimulus (to measure distractor processing), and a frequent nontarget stimulus. TUT was measured immediately following task performance using a validated retrospective measure. High levels of TUT were associated with a reduction in cortical processing of task-relevant events and distractor stimuli. These data contradict the suggestion that mind wandering is associated with distraction problems or specific deficits in task-relevant processes. Instead, the data are consistent with the decoupling hypothesis: that TUT dampens the processing of sensory information irrespective of that information's task relevance.     

When is your head at? An exploration of the factors associated with the temporal focus of the wandering mind

Two experiments employed experience sampling to examine the factors associated with a prospective and retrospective focus during mind wandering. Experiment One explored the contribution of working memory and indicated that participants generally prospect when the task does not require continuous monitoring. Experiment Two demonstrated that in the context of reading, interest in what was read suppressed both past and future-related task-unrelated-thought. Moreover, in disinterested individuals the temporal focus during mind wandering depended on the amount of experience with the topic matter—less experienced individuals tended to prospect, while more experienced individuals tended to retrospect. Together these results suggest that during mind wandering participants’ are inclined to prospect as long as the task does not require their undivided attention and raise the intriguing possibility that autobiographical associations with the current task environment have the potential to cue the disinterested mind.     

Aging ebbs the flow of thought: Adult age differences in mind wandering,executive control,and self-evaluation

Two experiments examined the relations among adult aging, mind wandering, and executive-task performance, following from surprising laboratory findings that older adults report fewer task-unrelated thoughts (TUTs) than do younger adults (e.g., Giambra, 1989, Jackson and Balota, 2012). Because older adults may experience more ability- and performance-related worry during cognitive tasks in the laboratory, and because these evaluative thoughts (known as task-related interference, “TRI”) might be sometimes misclassified by subjects as task-related, we asked subjects to distinguish task-related thoughts from TRI and TUTs when probed during ongoing tasks. In Experiment 1, younger and older adults completed either a go/no-go or a vigilance version of a sustained attention to response task (SART). Older adults reported more TRI and fewer TUTs than did younger adults while also performing more accurately. In Experiment 2, subjects completed either a 1- or a 2-back version of the n-back task. Older adults again reported more TRI and fewer TUTs than younger adults in both versions, while performing better than younger adults in the 1-back and worse in the 2-back. Across experiments, older adults' reduced TUT rates were independent of performance relative to younger adults. And, although older adults consistently reported more TRI and less mind wandering than did younger adults, overall they reported more on-task thoughts. TRI cannot, therefore, account completely for prior reports of decreasing TUTs with aging. We discuss the implications of these results for various theoretical approaches to mind-wandering.     

Tracking the train of thought from the laboratory into everyday life: An experience-sampling study of mind wandering across controlled and ecological contexts

In an experience-sampling study that bridged laboratory, ecological, and individual-differences approaches to mind-wandering research, 72 subjects completed an executive-control task with periodic thought probes (reported by McVay & Kane, 2009) and then carried PDAs for a week that signaled them eight times daily to report immediately whether their thoughts were off task. Subjects who reported more mind wandering during the laboratory task endorsed more mind-wandering experiences during everyday life (and were more likely to report worries as off-task thought content). We also conceptually replicated laboratory findings that mind wandering predicts task performance: Subjects rated their daily-life performance to be impaired when they reported off-task thoughts, with greatest impairment when subjects’ mind wandering lacked metaconsciousness. The propensity to mind wander appears to be a stable cognitive characteristic and seems to predict performance difficulties in daily life, just as it does in the laboratory     

Mindfulness and mind wandering: The protective effects of brief meditation in anxious individuals

Mind wandering can be costly, especially when we are engaged in attentionally demanding tasks. Preliminary studies suggest that mindfulness can be a promising antidote for mind wandering, albeit the evidence is mixed. To better understand the exact impact of mindfulness on mind wandering, we had a sample of highly anxious undergraduate students complete a sustained-attention task during which off-task thoughts including mind wandering were assessed. Participants were randomly assigned to a meditation or control condition, after which the sustained-attention task was repeated. In general, our results indicate that mindfulness training may only have protective effects on mind wandering for anxious individuals. Meditation prevented the increase of mind wandering over time and ameliorated performance disruption during off-task episodes. In addition, we found that the meditation intervention appeared to promote a switch of attentional focus from the internal to present-moment external world, suggesting important implications for treating worrying in anxious populations.     

Better control with less effort: The advantage of using focused-breathing strategy over focused-distraction strategy on thought suppression

It has been suggested that unwanted thoughts usually intrude during mind wandering due to a shortage of mental resources. However, strategies for suppressing such thoughts have never been examined from a mind wandering perspective. Here, we compare the effectiveness of two types of attention distraction strategies that either redirect users’ attention to their own breathing (focused-breathing strategy, FBS) or to a mental image (focused-distraction strategy, FDS) as related to working memory capacities. Eighty-two undergraduates were randomly assigned into a FBS or FDS group. They completed a concentration task and a thought suppression task, in which mind wandering and thought intrusions were each measured. Our results support the hypothesis that mind wandering is positively correlated to thought intrusions and shows that FBS is more effective than FDS in reducing mind wandering and thought intrusions. Moreover, in contrast to FDS, the effect of FBS is independent of users’ mental resources.     

Multiple routes to mind wandering: Predicting mind wandering with resource theories

Three experiments examine individual (attentional capacity) and task-related characteristics leading to mind wandering, and the effect of mind wandering on task performance. Drawing on resource theories, we tested interactive nonlinear effects of these predictors, manipulating task demand using math tests of varying difficulty (Exp 1: N = 143, three levels between-subjects; Exp 2: N = 59, three levels within-subjects; Exp 3: N = 133, four levels within-subjects). Results confirmed that mind wandering was most frequent during extreme task demand levels, although the effect varied somewhat between experiments. Additionally, results from Experiment 3 and an integrated analysis demonstrated that people with relatively higher attentional capacity were less likely to mind wander as task demand increased. Moreover, mind wandering was more detrimental to performance as task demand increased across all experiments. Our findings build on past research by demonstrating the importance of accounting for interactions and nonlinear effects of task demand and attentional capacity in mind wandering research.     

The more your mind wanders,the smaller your attentional blink: An individual differences study

The present studies investigate the hypothesis that individuals who frequently report experiencing episodes of mind wandering do so because they under-invest attentional/executive resources in the external environment. Here we examined whether self-reported instances of mind wandering predict the magnitude of the “attentional blink” (AB) in a rapid serial visual presentation (RSVP) task, since a prominent view is that the AB derives from an over-investment of attention in the information stream. Study 1 demonstrates that subjective reports of mind wandering in a sustained attention task have a negative predictive relation with respect to the magnitude of the AB measured in a subsequent RSVP task. In addition, using the Spontaneous and Deliberate Mind Wandering Questionnaire in Study 2, we were again able to show that trait-level mind wandering in everyday life negatively predicts AB magnitude. We suggest that mind wandering may be the behavioural outcome of an adaptive cognitive style intended to maximize the efficient processing of dynamic and temporally unpredictable events.     

Task unrelated thought: the role of distributed processing

Task unrelated thought (TUT) refers to thought directed away from the current situation; for example, a day dream. Encapsulated models of cognition propose that qualitative changes in consciousness, i.e., the production of TUT, can be explained in terms of changes in the quantity of resources deployed for task completion. In contrast, distributed models of cognition emphasize the importance of holistic processes in the generation and maintenance of task focus and are consistent with the effects of higher order variables such as schemata. Three experiments were conducted on healthy participants using a categorical stimulus organization to contrast distributed and encapsulated views of cognition. Experiments 1 and 2 showed that despite the increased difficulty of the alphabetical verbal fluency task fewer TUTs were produced during category fluency condition. Experiment 3 replicated the categorical suppression of TUT while encoding and recalling information in a memory task. The results of these three experiments support the predictions derived from models of cognition emphasizing the importance of stimulus organization in the generation and maintenance of task focus and have potential importance for the scientific evaluation of cognition.     

Validating a visual version of the metronome response task

The metronome response task (MRT)—a sustained-attention task that requires participants to produce a response in synchrony with an audible metronome—was recently developed to index response variability in the context of studies on mind wandering. In the present studies, we report on the development and validation of a visual version of the MRT (the visual metronome response task; vMRT), which uses the rhythmic presentation of visual, rather than auditory, stimuli. Participants completed the vMRT (Studies 1 and 2) and the original (auditory-based) MRT (Study 2) while also responding to intermittent thought probes asking them to report the depth of their mind wandering. The results showed that (1) individual differences in response variability during the vMRT are highly reliable; (2) prior to thought probes, response variability increases with increasing depth of mind wandering; (3) response variability is highly consistent between the vMRT and the original MRT; and (4) both response variability and depth of mind wandering increase with increasing time on task. Our results indicate that the original MRT findings are consistent across the visual and auditory modalities, and that the response variability measured in both tasks indexes a non-modality-specific tendency toward behavioral variability. The vMRT will be useful in the place of the MRT in experimental contexts in which researchers’ designs require a visual-based primary task.     

视觉空间工作记忆组间差异的神经机制

为考察视觉空间工作记忆（working memory, WM）维持和操作的组间差异及其神经机制,本研究记录了高、低WM组完成延迟再认（维持）任务和心理旋转（操作）任务时的行为和事件相关电位数据。结果发现,在操作任务中,高WM组比低WM组的反应时显著更短;高WM组的中前额叶慢波显著更正、双侧后顶区慢波显著更负,并且两者的波幅显著负相关。在维持任务中,两组被试的反应时无显著差异;高WM组的中前额叶慢波显著更正。结果表明,高WM组的执行注意能力可能更强,能通过有效调节和分配加工资源来表征视觉信息。     

Mind wandering in schizophrenia: A thought-sampling study

Mind wandering has consistently been associated with impairments in cognition, emotion and daily performance. However, few experimental studies on mind wandering have been conducted in individuals with schizophrenia. The present study aimed to examine mind wandering in schizophrenia patients with a thought-sampling experiment embedded in a rapid go/no-go task and the relationship between the frequency of mind wandering and psychotic symptoms. Fifty-eight schizophrenia patients and 56 matched healthy controls were recruited and engaged in a task that assessed mind wandering. The results showed that schizophrenia patients (1.4%) reported less frequent mind wandering than healthy controls (5.8%). Moreover, there was no significant correlation between the frequency of mind wandering and psychotic symptoms in schizophrenia patients. Further studies in different stages of schizophrenia and in patients with more severe psychotic symptoms are needed to demonstrate a more comprehensive picture of mind wandering in schizophrenia.     

On the link between mind wandering and task performance over time

Here we test the hypothesis that fluctuations in subjective reports of mind wandering over time-on-task are associated with fluctuations in performance over time-on-task. In Study 1, we employed a singleton search task and found that performance did not differ prior to on- and off-task reports, nor did individual differences in mind wandering predict differences in performance (so-called standard analytic methods). Importantly however, we find that fluctuations in mind wandering over time are strongly associated with fluctuations in behavior. In Study 2, we provide a replication of the relation between mind wandering and performance over time found in Study 1, using a Flanker interference task. These data indicate (1) a tight coupling between mind wandering and performance over time and (2) that a temporal-analytic approach can reveal effects of mind wandering on performance in tasks where standard analyses fail to do so. The theoretical and methodological implications of these findings are discussed.     

Examining the role of emotional valence of mind wandering: All mind wandering is not equal

To evaluate the role of emotional valence on the impact of mind wandering on working memory (WM) and sustained attention, we reanalyzed data from three independently conducted studies that examined the impact of stress on WM (Banks & Boals, 2016; Banks, Welhaf, & Srour, 2015) and sustained attention (Banks, Tartar, & Welhaf, 2014). Across all studies, participants reported the content of their thoughts at random intervals during the WM or sustained attention task. Thought probes in all studies included a core set of response options for task-unrelated thoughts (TUTs) that were negatively, positively, or neutrally emotionally valenced. In line with theories of emotional valenced stimuli on capture of attention, results suggest negatively valenced TUTs, but not positively valenced TUTs, were related to poorer WM and sustained attention in two studies. Neutral TUTs were related to poorer WM but not sustained attention performance. Implications for models of mind wandering are discussed.     

Tracking arousal state and mind wandering with pupillometry

In four experiments, the association between arousal state and different mind-wandering states was examined. Participants performed a sustained attention task while pupil responses were continuously recorded. Periodically during the task, participants were presented with thought probes to determine if they were on task or mind wandering. Across the four experiments, the results suggested that in situations that promoted on-task behaviors and focused external attention, mind wandering was associated with lowered arousal, as seen by smaller tonic pupil diameters and smaller phasic pupillary responses. However, in situations that promoted a more internal focus of attention, there were no differences between on-task states and mind wandering in tonic pupil diameter (although differences emerged for phasic pupillary responses), suggesting similar arousal levels. Furthermore, across the four experiments, mind blanking and mind wandering dissociated in terms of whether the situation promoted focused external attention or focused internal attention. These results are broadly consistent with the notion that mind wandering is a heterogeneous construct, with different forms of mind wandering being associated with different arousal states, and suggest that a combination of behavioral and pupillary measures can be used to track these various states.     

Working memory maintenance contributes to long-term memory formation: Evidence from slow event-related brain potentials

Behavioral research has led to conflicting views regarding the relationship between working memory (WM) maintenance and long-term memory (LTM) formation. We used slow event-related brain potentials to investigate the degree to which neural activity during WM maintenance is associated with successful LTM formation. Participants performed a WM task with objects and letter strings, followed by a surprise LTM test. Slow potentials were found to be more negative over the parietal and occipital cortex for objects and over the left frontal cortex for letter strings during WM maintenance. Within each category, they were enhanced for items that were subsequently successfully remembered. These effects were topographically distinct, with maximum effects at those electrodes that showed the maximum negativity during WM maintenance in general. Together, these results are strongly consistent with the ideas that WM maintenance contributes to LTM formation and that this may occur through strengthening of stimulus-specific cortical memory traces.     

毅力与学业成绩的关系：有意走神和自发走神的不同中介作用

以3372名5年级小学生为研究对象,采用毅力量表、有意走神和自发走神量表以及学业成绩测验,考察毅力（兴趣一致性和坚持努力）对学业成绩的影响,并检验有意走神和自发走神的中介作用。结果发现：（1）兴趣一致性和坚持努力均显著正向预测学业成绩;（2）有意走神、自发走神在兴趣一致性和坚持努力与学业成绩之间均起显著的中介作用,但两者的中介作用模式存在差异。有意走神在兴趣一致性和坚持努力与学业成绩间的中介作用不同：兴趣一致性负向影响有意走神,有意走神正向影响学业成绩,坚持努力正向影响有意走神,有意走神正向影响学业成绩;而自发走神在兴趣一致性和坚持努力对学业成绩预测的中介作用相同,即兴趣一致性和坚持努力均负向影响自发走神,自发走神负向影响学业成绩。     

Mind wandering while reading easy and difficult texts

Mind wandering is a phenomenon in which attention drifts away from the primary task to task-unrelated thoughts. Previous studies have used self-report methods to measure the frequency of mind wandering and its effects on task performance. Many of these studies have investigated mind wandering in simple perceptual and memory tasks, such as recognition memory, sustained attention, and choice reaction time tasks. Manipulations of task difficulty have revealed that mind wandering occurs more frequently in easy than in difficult conditions, but that it has a greater negative impact on performance in the difficult conditions. The goal of this study was to examine the relation between mind wandering and task difficulty in a high-level cognitive task, namely reading comprehension of standardized texts. We hypothesized that reading comprehension may yield a different relation between mind wandering and task difficulty than has been observed previously. Participants read easy or difficult versions of eight passages and then answered comprehension questions after reading each of the passages. Mind wandering was reported using the probe-caught method from several previous studies. In contrast to the previous results, but consistent with our hypothesis, mind wandering occurred more frequently when participants read difficult rather than easy texts. However, mind wandering had a more negative influence on comprehension for the difficult texts, which is consistent with the previous data. The results are interpreted from the perspectives of the executive-resources and control-failure theories of mind wandering, as well as with regard to situation models of text comprehension.