Pupillary correlates of lapses of sustained attention

Attention, musicality, and familiarity shape cortical speech tracking at the musical cocktail party

The "cocktail party problem" challenges our ability to understand speech in noisy environments and often includes background music. Here, we explored the role of background music in speech-in-noise listening. Participants listened to an audiobook in familiar and unfamiliar music while tracking keywords in either speech or song lyrics. We used EEG to measure neural tracking of the audiobook. When speech was masked by music, the modeled temporal response function (TRF) peak latency at 50 ms (P1TRF) was prolonged compared to unmasked. Additionally, P1TRF amplitude was larger in unfamiliar background music, suggesting improved speech tracking. We observed prolonged latencies at 100 ms (N1TRF) when speech was not the attended stimulus, though only in less musical listeners. Our results suggest early neural representations of speech are stronger with both attention and concurrent unfamiliar music, indicating familiar music is more distracting. One's ability to perceptually filter "musical noise" at the cocktail party also depends on objective musical listening abilities.

Product, not process: Metacognitive monitoring of visual performance during sustained attention

The performance of the human visual system exhibits moment-to-moment fluctuations influenced by multiple neurocognitive factors. To deal with this instability of the visual system, introspective awareness of current visual performance (metacognitive monitoring) may be crucial. In this study, we investigate whether and how people can monitor their own visual performance during sustained attention by adopting confidence judgments as indicators of metacognitive monitoring - assuming that if participants can monitor visual performance, confidence judgments will accurately track performance fluctuations. In two experiments (N = 40), we found that participants were able to monitor fluctuations in visual performance during sustained attention. Importantly, metacognitive monitoring largely relied on the quality of target perception, a product of visual processing ("I lack confidence in my performance because I only caught a glimpse of the target"), rather than the states of the visual system during visual processing ("I lack confidence because I was not focusing on the task").

Retrospective attention: Examining temporally specific retrospective reports of mind wandering and engagement during online video lectures

Attention typically fluctuates on a moment-to-moment basis and often declines over time-on-task during online video lectures. We explored people's retrospective reports of specific moments of their prior states of mind wandering and engagement. Undergraduate participants reported in-the-moment levels of either mind wandering (n = 79) or engagement (n = 77) while watching two 15 min video lectures. Then, they were shown short clips from the videos as cues to retrospectively report their levels of mind wandering or engagement from their initial viewing of those specific sections. Finally, participants completed a short content quiz. We found that (a) typical time-on-task effects generally occurred for both in-the-moment and retrospective reports of mind wandering and engagement; (b) there was high temporal concordance between individuals' retrospective and in-the-moment ratings of both mind wandering and engagement; and (c) performance on the content quiz was correlated with both in-the-moment and retrospective reports of mind wandering and engagement. These findings suggest that individuals can retrospectively report their prior states of both mind wandering and engagement with temporal accuracy. These reports could be based on specific recollections of prior attentional states or inferences made from the video clips used to cue recall.

The Role of the LC-NE System in Attention: From Cells, to Systems, to Sensory-Motor Control

Attention control is a fundamental cognitive function that enables individuals to sustain focus, shift attention flexibly, and filter distractions in a goal-directed manner. The locus coeruleus-norepinephrine (LC-NE) system plays a pivotal role in this process by dynamically regulating arousal, prioritizing salient stimuli, and optimizing cognitive performance. This review synthesizes evidence from molecular, cellular, systems, cognitive neuroscience, and behavioral studies to elucidate the LC-NE system's role in attention control. We first examine the neurophysiological mechanisms of the LC, highlighting its distinct firing patterns-tonic and phasic activity-and their impact on attention. Next, we integrate findings from animal models, human neuroimaging, electrophysiology, and computational modeling, demonstrating how LC-NE activity influences sensory processing, cognitive flexibility, and executive function. We interpret these findings through the lens of three major theoretical frameworks: Adaptive Gain Theory (AGT), which describes how LC activity optimizes task engagement, the Network Reset Hypothesis (NRH), which describes how optimizes network connectivity, and the Glutamate Amplifies NE Effects (GANE) model, which explains how NE enhances neural selectivity and suppresses irrelevant signals. Collectively, the evidence underscores the LC-NE system's role in modulating the signal-to-noise ratio in cortical and subcortical circuits, thereby shaping attention and behavior. We conclude by discussing implications for individual differences, age-related cognitive decline, and emphasizing the need for interdisciplinary research that integrates emerging technologies to further unravel the complexities of LC function.

Characterizing the effects of emotional distraction on sustained attention and subsequent memory: A novel emotional gradual onset continuous performance task

This study examines the impact of emotional distraction on sustained attention using a novel gradual onset continuous performance task (gradCPT). Sustained attention is a foundational cognitive process, vulnerable to both internal (endogenous) and external (exogenous) disruptions. Reliable, validated paradigms to assess internal sources of variation in sustained attention have been used to characterize basic aspects of attention as well as individual differences and neurobiological mechanisms. However, sustained attention can also be disrupted by external distraction, especially highly salient distractors, due to their affective and/or arousing nature. Markedly less work has been conducted to develop reliable and validated paradigms to study these effects on sustained attention. This study introduces a novel task, the emogradCPT, to characterize the impact of emotional distractors (background images) on the ability to sustain attention during an emotionally neutral task (digit discrimination task). Across two experiments and three rounds of data collection, we demonstrate that emotionally negative distractors robustly and reliably disrupt ongoing ability to sustain attention, reflected in reduced accuracy, and slower RTs, relative to neutral, positive, and no distractor conditions. Further, we validated the task by correlating objective and subjective measures of distraction, as well as demonstrating the impact of these distractors on downstream memory encoding and affect. Making these data and tools publicly available, we encourage the use of this paradigm to inform future basic, clinical, and neuroimaging studies of affective interactions with ongoing goal-directed attentional processes.

Load-Dependent Relationship Between Lateral Prefrontal Cortex Activity and Pupil Diameter in the Context of Driving

Assessing arousal and cognitive load in the context of driving is important because inappropriate arousal and cognitive load increase the risk of accidents. Previous studies using n-back tasks showed that both lateral prefrontal activity and pupil diameter are good indicators of cognitive load. However, the relationship between lateral prefrontal activity and pupil diameter was load-dependent, and a significant positive correlation was observed in the low-load 0-back condition but not in the high-load 3-back condition. In this study, we utilized Near-Infrared Spectroscopy (NIRS) and eye tracking to investigate the load-dependent relationship between lateral prefrontal cortex activity and pupil diameter in the context of driving. Participants drove on a mountain pass using a commercially available driving game, with and without engagement in a secondary conversation task. The NIRS and eye tracker experiments were conducted separately. The results showed that the pupil diameter and Oxy-Hb concentrations in the dorsolateral prefrontal cortex increased significantly in the driving condition that included the conversation task compared to the normal driving condition. Furthermore, we found a significant positive correlation under the high-load conversational driving condition, in which individuals with larger pupil diameters showed greater left dorsolateral prefrontal cortex activity, but not so under low-load normal driving condition. Our findings provide further evidence of a load-dependent relationship between lateral prefrontal cortex activity and pupil diameter and reveal that the relationship was not simply dependent on the degree of cognitive load but also on the nature of the task, possibly due to the differential engagement of executive function and arousal.

Where is my mind? A neurocognitive investigation of mind blanking

During wakefulness, our thoughts transition between different contents. However, there are moments that are seemingly devoid of reportable content, referred to as mind blanking (MB). It remains unclear what these blanks represent, highlighting the definitional and phenomenological ambiguities surrounding MB. We map out MB in terms of its reportable expressions, neurophysiology, and relationship to adjacent phenomenology, including meditative practices and sleep. We propose a mechanistic account linking MB to changes at the physiological, neural, and cognitive levels. We suggest that ongoing experiences are characterized by degrees of richness, and that contentless events represent distinct mental states with their own diversity. We encourage future research to acknowledge MB as a reportable mental category, leading to a comprehensive understanding of ongoing experience.

Variations of autonomic arousal mediate the reportability of mind blanking occurrences

Mind blanking (MB) is the inability to report mental events during unconstraint thinking. Previous work shows that MB is linked to decreased levels of cortical arousal, indicating dominance of cerebral mechanisms when reporting mental states. What remains inconclusive is whether MB can also ensue from autonomic arousal manipulations, pointing to the implication of peripheral physiology to mental events. Using experience sampling, neural, and physiological measurements in 26 participants, we first show that MB was reported more frequently in low arousal conditions, elicited by sleep deprivation. Also, there was partial evidence for a higher occurence of MB reports in high arousal conditions, elicited by intense physical exercise. Transition probabilities revealed that, after sleep deprivation, mind wandering was more likely to be followed by MB and less likely to be followed by more mind wandering reports. Using classification schemes, we found higher performance of a balanced random forest classifier trained on both neural and physiological markers in comparison to performance when solely neural or physiological were used. Collectively, we show that both cortical and autonomic arousal affect MB report occurrences. Our results establish that MB is supported by combined brain-body configurations, and, by linking mental and physiological states, they pave the way for novel embodied accounts of spontaneous thinking.'The stage 1 protocol for this Registered Report was accepted in principle on 02/01/23. The protocol, as accepted by the journal, can be found at: 10.17605/OSF.IO/SH2YE' Techniques: Life sciences techniques, Biophysical methods [Electrocardiography - EKG]; Life sciences techniques, Biophysical methods [Electroencephalography - EEG]; CTS received date: 27.11.2024.

Does deep processing protect against mind wandering and other lapses of attention during learning?

Three experiments examined if deep processing would aid in reducing off-task thoughts during learning. In each experiment, participants learned words or pairs of words under deep or shallow conditions. During learning, participants were periodically presented with thought-probes to examine if they were experiencing off-task thoughts (mind wandering, external distraction, mind blanking). Levels of processing was manipulated both within (Experiment 1) and between subjects (Experiments 2 and 3) using structural, rhyme, and semantic judgements and testing memory with cued-recall (Experiments 1 and 2) or recognition (Experiment 3). All three experiments demonstrated a levels of processing effect on memory with better performance in deep compared to shallow conditions. Importantly, in all three experiments rates of off-task thinking (and mind wandering more specifically) were the same across conditions and Bayes factors suggested moderate evidence in favour of the null hypothesis. The results suggest that deep processing does not necessarily protect against mind wandering and other lapses of attention.

Listening habits and subjective effects of background music in young adults with and without ADHD

Adults listen to an average of 20.7 hours of music per week, according to a study conducted across 26 countries. Numerous studies indicate that listening to music can have beneficial effects on cognitive performance and emotional well-being. Music listening habits may vary depending on individual needs and listening contexts. However, a limited number of studies have specifically examined the patterns of background music usage during various more or less cognitive activities, especially among individuals with attentional difficulties related to ADHD. This study primarily aimed to compare music listening habits during daily activities that are more and less cognitive (e.g., studying, problem-solving versus cleaning, engaging in sports) between neurotypical young adults and those screened for ADHD (respondents who were identified as likely having ADHD based on the number of self-reported symptoms). To achieve this, 434 young adults aged 17 to 30 responded to an online survey. The results indicate that certain listening habits differ significantly between the neurotypical and ADHD-screened groups. The ADHD-screened group reports significantly more background music listening during less cognitive activities and while studying, compared to the neurotypical group. The results also reveal a difference in the proportion of individuals preferring stimulating music between the groups: ADHD-screened individuals report significantly more frequent listening to stimulating music, regardless of the activity type (more or less cognitive). Other aspects of music listening are common to both groups. Regardless of the group, more respondents reported preferring to listen to relaxing, instrumental, familiar and self-chosen music during more cognitive activities, whereas for less cognitive activities, more individuals mentioned preferring to listen to music that is stimulating, with lyrics, familiar and self-chosen. Overall, the results confirm that most young adults listen to music during their daily activities and perceive positive effects from this listening.

Readiness for Perception and Action: Towards a More Mechanistic Understanding of Phasic Alertness

Human survival requires prompt perception and action to address relevant events in the environment. For this, the brain has evolved a system that uses warning stimuli to elicit phasic alertness, a state readying the brain for upcoming perception and action. Although a wealth of empirical evidence revealed how phasic alertness improves a wide range of perceptual and cognitive processing, it is still unclear by what cognitive mechanisms this is achieved. Here, we identify key problems that have to be solved for this to be possible and delineate concrete ways to achieve this. Specifically, we discover I) how to establish phasic alertness as a cognitive state of readiness for perception and action, II) how it can affect cognition online or offline, III) how it could be triggered internally without a warning, and IV) to what degrees it relied on bottom-up processing, or top-down temporal or stimulus expectations and the current task. As a result, the discussion provides us with a research program yielding the theoretical and empirical basis for mechanistic and computational models of phasic alertness and its neurophysiological underpinnings.

Increased attention towards progress information near a goal state

A growing body of evidence across psychology suggests that (cognitive) effort exertion increases in proximity to a goal state. For instance, previous work has shown that participants respond more quickly, but not less accurately, when they near a goal-as indicated by a filling progress bar. Yet it remains unclear when over the course of a cognitively demanding task do people monitor progress information: Do they continuously monitor their goal progress over the course of a task, or attend more frequently to it as they near their goal? To answer this question, we used eye-tracking to examine trial-by-trial changes in progress monitoring as participants completed blocks of an attentionally demanding oddball task. Replicating past work, we found that participants increased cognitive effort exertion near a goal, as evinced by an increase in correct responses per second. More interestingly, we found that the rate at which participants attended to goal progress information-operationalized here as the frequency of gazes towards a progress bar-increased steeply near a goal state. In other words, participants extracted information from the progress bar at a higher rate when goals were proximal (versus distal). In exploratory analysis of tonic pupil diameter, we also found that tonic pupil size increased sharply as participants approached a goal state, mirroring the pattern of gaze. These results support the view that people attend to progress information more as they approach a goal.

Strength of Low-Frequency EEG Phase Entrainment to External Stimuli Is Associated with Fluctuations in the Brain's Internal State

The brain attends to environmental rhythms by aligning the phase of internal oscillations. However, the factors underlying fluctuations in the strength of this phase entrainment remain largely unknown. In the present study, we examined whether the strength of low-frequency electroencephalography (EEG) phase entrainment to rhythmic stimulus sequences varied with the pupil size and posterior alpha-band power, thought to reflect the arousal level and excitability of posterior cortical brain areas, respectively. We recorded the pupil size and scalp EEG while participants carried out an intermodal selective attention task, in which they were instructed to attend to a rhythmic sequence of visual or auditory stimuli and ignore the other perceptual modality. As expected, intertrial phase coherence (ITC), a measure of entrainment strength, was larger for the task-relevant than for the task-irrelevant modality. Across the experiment, the pupil size and posterior alpha power were strongly linked with each other. Interestingly, ITC tracked both variables: larger pupil size was associated with a selective increase in entrainment to the task-relevant stimulus sequence, whereas larger posterior alpha power was associated with a decrease in phase entrainment to both the task-relevant and task-irrelevant stimulus sequences. Exploratory analyses showed that a temporal relation between ITC and posterior alpha power emerged in the time periods around pupil maxima and pupil minima. These results indicate that endogenous sources contribute distinctly to the fluctuations of EEG phase entrainment.

Eye pupils mirror information divergence in approximate inference

Pupil dilation is considered to track the arousal state linked to a wide range of cognitive processes. A recent article suggested the potential to unify findings in pupillometry studies based on an information theory framework and Bayesian methods. However, Bayesian methods become computationally intractable in many realistic situations. Thus, the present study examined whether pupil responses reflect the amount of information quantified in approximate inference, a practical method in a complex environment. We measured the pupil diameters of 27 healthy adults instructed to predict each subsequent number to be presented in a series, and to update their predictions at several discrete change points when an outcome generation criterion changed. Individual differences in task performance and pupil response were modeled by a variational Bayes method, which quantified prediction uncertainty and change point probability as Kullback-Leibler divergence (DKL) and Shannon's surprise (SS). This model-based approach revealed that covariance between trial-wise pupil dilation and trial-wise DKL varies depending on prediction accuracy. Further, SS was sensitive to several discrete change points. These findings suggest that the pupil-linked arousal system reflects information divergence during approximate inference in a dynamic environment.

Mobilizing effort to reduce lapses of sustained attention: examining the effects of content-free cues, feedback, and points

Three experiments with the psychomotor vigilance task examined whether presenting content-free cues, feedback, and points would reduce lapses of sustained attention. In all three experiments, behavioral lapses of attention (particularly slow reaction times) were reduced with the motivation manipulations compared with control conditions, but self-reports of off-task thinking (e.g., mind-wandering) were unaffected. Pupillary responses (preparatory and phasic) also tended to be larger with the different manipulations compared to control conditions. Collectively, the results are consistent with attentional effort models, suggesting that sustained attention was improved and lapses of attention reduced owing to participants in the motivation conditions mobilizing more attentional effort than participants in the control conditions. These results are consistent with recent research, which suggests that the locus coeruleus norepinephrine system is associated with the mobilization of effort.

Individual differences in attention control: A meta-analysis and re-analysis of latent variable studies

A meta-analysis and re-analysis of prior latent variable studies was conducted in order to assess whether there is evidence for individual differences in broad attention control abilities. Data from 90 independent samples and over 23,000 participants suggested that most (84.4%) prior studies find evidence for a coherent attention control factor with average factor loadings of .51. This latent attention control factor was related to other cognitive ability factors including working memory, shifting, fluid intelligence, long-term memory, reading comprehension, and processing speed, as well as to self-reports of task-unrelated thoughts and task specific motivation. Further re-analyses and meta-analyses suggest that the results remained largely unchanged when considering various possible measurement issues. Examining the factor structure of attention control suggested evidence for sub-components of attention control (restraining, constraining and sustaining attention) which could be accounted for a by a higher-order factor. Additional re-analyses suggested that attention control represents a broad ability within models of cognitive abilities. Overall, these results provide evidence for attention control abilities as an important individual differences construct.

Pupil Trend Reflects Suboptimal Alertness Maintenance over 10 s in Vigilance and Working Memory Performance: An Exploratory Study

Maintaining concentration on demanding cognitive tasks, such as vigilance (VG) and working memory (WM) tasks, is crucial for successful task completion. Previous research suggests that internal concentration maintenance fluctuates, potentially declining to suboptimal states, which can influence trial-by-trial performance in these tasks. However, the timescale of such alertness maintenance, as indicated by slow changes in pupil diameter, has not been thoroughly investigated. This study explored whether "pupil trends"-which selectively signal suboptimal tonic alertness maintenance at various timescales-negatively correlate with trial-by-trial performance in VG and WM tasks. Using the psychomotor vigilance task (VG) and the visual-spatial two-back task (WM), we found that human pupil trends lasting over 10 s were significantly higher in trials with longer reaction times, indicating poorer performance, compared with shorter reaction time trials, which indicated better performance. The attention network test further validated that these slow trends reflect suboptimal states related to (tonic) alertness maintenance rather than suboptimal performance specific to VG and WM tasks, which is more associated with (phasic) responses to instantaneous interference. These findings highlight the potential role of detecting and compensating for nonoptimal states in VG and WM performance, significantly beyond the 10 s timescale. Additionally, the findings suggest the possibility of estimating human concentration during various visual tasks, even when rapid pupil changes occur due to luminance fluctuations.

Individual differences in baseline eye movement indices: Examining the relationships between baseline pupil size, inhibitory control, and fixation stability

The relationship among baseline pupil size, fixation stability, and inhibitory control were examined in this study. Participants performed a baseline eye measure in which they were instructed to stare at a fixation dot on screen for 2 min. Following the baseline eye measure, participants completed an antisaccade task to measure inhibitory control ability. We found a correlation between baseline pupil size variability and inhibitory control, as well as between fixation stability and inhibitory control. We showed that participants with better inhibitory control exhibited larger variability in pupil size, and those with better fixation stability showed superior inhibitory control ability. Overall, our results indicate that there are significant correlations between inhibitory control and baseline pupil size, as well as between inhibitory control and fixation stability.

The influence of transcranial direct current stimulation to the trigeminal nerve on attention and arousal

One mechanism by which transcranial direct current stimulation (tDCS) has been proposed to improve attention is by transcutaneous stimulation of cranial nerves, thereby activating the locus coeruleus (LC). Specifically, placement of the electrodes over the frontal bone and mastoid is thought to facilitate current flow across the face as a path of least resistance. The face is innervated by the trigeminal nerve, and the trigeminal nerve is interconnected with the LC. In this study, we tested whether stimulating the trigeminal nerve impacts indices of LC activity and performance on a sustained attention task. We replicated previous research that shows deterioration in task performance, increases in the rate of task-unrelated thoughts, and reduced pupil responses due to time on task irrespective of tDCS condition (sham, anodal, and cathodal stimulation). Importantly, tDCS did not influence pupil dynamics (pretrial or stimulus-evoked), self-reported attention state, nor task performance in active versus sham stimulation conditions. The findings reported here are consistent with theories about arousal centered on a hypothesized link between LC activity indexed by pupil size, task performance, and self-reported attention state but fail to support hypotheses that tDCS over the trigeminal nerve influences indices of LC function.

Pupillary responses to directional uncertainty while intercepting a moving target

Pupillary responses serve as sensitive indicators of cognitive processes, attentional shifts and decision-making dynamics. Our study investigates how directional uncertainty and target speed (V T) influence pupillary responses in a foveal tracking task involving the interception of a moving dot. Directional uncertainty, reflecting the unpredictability of the target's direction changes, was manipulated by altering the angular range (AR) from which random directions for the moving dot were extracted. Higher AR values were associated with reduced pupillary diameters, indicating that heightened uncertainty led to smaller pupil sizes. Additionally, an inverse U-shaped relationship between V T and pupillary responses suggested maximal diameters at intermediate speeds. Analysis of saccade-triggered responses showed a negative correlation between pupil diameter and directional uncertainty. Dynamic linear modelling revealed the influence of past successful collisions and other behavioural parameters on pupillary responses, emphasizing the intricate interaction between task variables and cognitive processing. Our results highlight the dynamic interplay between the directional uncertainty of a single moving target, V T and pupillary responses, with implications for understanding attentional mechanisms, decision-making processes and potential applications in emerging technologies.

The effects of emotional arousal on pupil size depend on luminance

Pupillometry is widely used to measure arousal states. The primary functional role of the pupil, however, is to respond to the luminance of visual inputs. We previously demonstrated that cognitive effort-related arousal interacted multiplicatively with luminance, with the strongest pupillary effects of arousal occurring at low-to-mid luminances (< 37 cd/m2), implying a narrow range of conditions ideal for assessing cognitive arousal-driven pupillary differences. Does this generalize to other forms of arousal? To answer this, we assessed luminance-driven pupillary response functions while manipulating emotional arousal, using well-established visual and auditory stimulus sets. At the group level, emotional arousal interacted with the pupillary light response differently from cognitive arousal: the effects occurred primarily at much lower luminances (< 20 cd/m2). Analyses at the individual-participant level revealed qualitatively distinct patterns of modulation, with a sizable number of individuals displaying no arousal response to the visual or auditory stimuli, regardless of luminance. Together, our results suggest that effects of arousal on pupil size are not monolithic: different forms of arousal exert different patterns of effects. More practically, our findings suggest that lower luminances create better conditions for measuring pupil-linked arousal, and when selecting ambient luminance levels, consideration of the arousal manipulation and individual differences is critical.

Conscious but not thinking-Mind-blanks during visuomotor tracking: An fMRI study of endogenous attention lapses

Attention lapses (ALs) are complete lapses of responsiveness in which performance is briefly but completely disrupted and during which, as opposed to microsleeps, the eyes remain open. Although the phenomenon of ALs has been investigated by behavioural and physiological means, the underlying cause of an AL has largely remained elusive. This study aimed to investigate the underlying physiological substrates of behaviourally identified endogenous ALs during a continuous visuomotor task, primarily to answer the question: Were the ALs during this task due to extreme mind-wandering or mind-blanks? The data from two studies were combined, resulting in data from 40 healthy non-sleep-deprived subjects (20M/20F; mean age 27.1 years, 20-45). Only 17 of the 40 subjects were used in the analysis due to a need for a minimum of two ALs per subject. Subjects performed a random 2-D continuous visuomotor tracking task for 50 and 20 min in Studies 1 and 2, respectively. Tracking performance, eye-video, and functional magnetic resonance imaging (fMRI) were recorded simultaneously. A human expert visually inspected the tracking performance and eye-video recordings to identify and categorise lapses of responsiveness as microsleeps or ALs. Changes in neural activity during 85 ALs (17 subjects) relative to responsive tracking were estimated by whole-brain voxel-wise fMRI and by haemodynamic response (HR) analysis in regions of interest (ROIs) from seven key networks to reveal the neural signature of ALs. Changes in functional connectivity (FC) within and between the key ROIs were also estimated. Networks explored were the default mode network, dorsal attention network, frontoparietal network, sensorimotor network, salience network, visual network, and working memory network. Voxel-wise analysis revealed a significant increase in blood-oxygen-level-dependent activity in the overlapping dorsal anterior cingulate cortex and supplementary motor area region but no significant decreases in activity; the increased activity is considered to represent a recovery-of-responsiveness process following an AL. This increased activity was also seen in the HR of the corresponding ROI. Importantly, HR analysis revealed no trend of increased activity in the posterior cingulate of the default mode network, which has been repeatedly demonstrated to be a strong biomarker of mind-wandering. FC analysis showed decoupling of external attention, which supports the involuntary nature of ALs, in addition to the neural recovery processes. Other findings were a decrease in HR in the frontoparietal network before the onset of ALs, and a decrease in FC between default mode network and working memory network. These findings converge to our conclusion that the ALs observed during our task were involuntary mind-blanks. This is further supported behaviourally by the short duration of the ALs (mean 1.7 s), which is considered too brief to be instances of extreme mind-wandering. This is the first study to demonstrate that at least the majority of complete losses of responsiveness on a continuous visuomotor task are, if not due to microsleeps, due to involuntary mind-blanks.

Protocol and preregistration for the CODEC project: measuring, modelling and mechanistically understanding the nature of cognitive variability in early childhood

BACKGROUND

Children's cognitive performance fluctuates across multiple timescales. However, fluctuations have often been neglected in favour of research into average cognitive performance, limiting the unique insights into cognitive abilities and development that cognitive variability may afford. Preliminary evidence suggests that greater variability is associated with increased symptoms of neurodevelopmental disorders, and differences in behavioural and neural functioning. The relative dearth of empirical work on variability, historically limited due to a lack of suitable data and quantitative methodology, has left crucial questions unanswered, which the CODEC (COgnitive Dynamics in Early Childhood) study aims to address.

METHOD

The CODEC cohort is an accelerated 3-year longitudinal study which encompasses 600 7-to-10-year-old children. Each year includes a 'burst' week (3 times per day, 5 days per week) of cognitive measurements on five cognitive domains (reasoning, working memory, processing speed, vocabulary, exploration), conducted both in classrooms and at home through experience sampling assessments. We also measure academic outcomes and external factors hypothesised to predict cognitive variability, including sleep, mood, motivation and background noise. A subset of 200 children (CODEC-MRI) are invited for two deep phenotyping sessions (in year 1 and year 3 of the study), including structural and functional magnetic resonance imaging, eye-tracking, parental measurements and questionnaire-based demographic and psychosocial measures. We will quantify developmental differences and changes in variability using Dynamic Structural Equation Modelling, allowing us to simultaneously capture variability and the multilevel structure of trials nested in sessions, days, children and classrooms.

DISCUSSION

CODEC's unique design allows us to measure variability across a range of different cognitive domains, ages, and temporal resolutions. The deep-phenotyping arm allows us to test hypotheses concerning variability, including the role of mind wandering, strategy exploration, mood, sleep, and brain structure. Due to CODEC's longitudinal nature, we are able to quantify which measures of variability at baseline predict long-term outcomes. In summary, the CODEC study is a unique longitudinal study combining experience sampling, an accelerated longitudinal 'burst' design, deep phenotyping, and cutting-edge statistical methodologies to better understand the nature, causes, and consequences of cognitive variability in children.

TRIAL REGISTRATION

ClinicalTrials.gov - NCT06330090.

Distinct dynamic connectivity profiles promote enhanced conscious perception of auditory stimuli

The neuroscience of consciousness aims to identify neural markers that distinguish brain dynamics in healthy individuals from those in unconscious conditions. Recent research has revealed that specific brain connectivity patterns correlate with conscious states and diminish with loss of consciousness. However, the contribution of these patterns to shaping conscious processing remains unclear. Our study investigates the functional significance of these neural dynamics by examining their impact on participants' ability to process external information during wakefulness. Using fMRI recordings during an auditory detection task and rest, we show that ongoing dynamics are underpinned by brain patterns consistent with those identified in previous research. Detection of auditory stimuli at threshold is specifically improved when the connectivity pattern at stimulus presentation corresponds to patterns characteristic of conscious states. Conversely, the occurrence of these conscious state-associated patterns increases after detection, indicating a mutual influence between ongoing brain dynamics and conscious perception. Our findings suggest that certain brain configurations are more favorable to the conscious processing of external stimuli. Targeting these favorable patterns in patients with consciousness disorders may help identify windows of greater receptivity to the external world, guiding personalized treatments.

Effects of goal-setting on sustained attention and attention lapses

In three experiments, we examined the effects of goal-setting on sustained attention and attention lapses. We measured both behavioral task performance and subjective attentional states during a four -choice reaction time task (Experiments 1 and 2 administered online; Experiment 3 conducted in-person). Experiment 1 compared a vague goal versus a specific goal. The specific goal reduced lapses in the form of long response times (RTs) but did not impact task-unrelated thoughts. Experiment 2 expanded on E1 by making the specific goal progressively harder. Behavioral lapses (i.e., long RTs) were reduced in the harder-over-time goal condition compared to the control condition. Additionally, while RTs increased with time-on-task in the control condition, RTs in the harder-over-time goal condition remained stable with time-on-task. Experiment 3 aimed to replicate the results of E2 in-person and adjusted the difficulty of the harder-over-time goals to be slightly harder. The results largely replicated E2. Overall, setting specific and difficult task goals led to a reduction in lapses of attention and increased sustained attention performance.

Music in the eye of the beholder: a pupillometric study on preferred background music, attentional state, and arousal

Although background music listening during attention-demanding tasks is common, there is little research on how it affects fluctuations in attentional state and how these fluctuations are linked to physiological arousal. The present study built on Kiss and Linnell (2021) - showing a decrease in mind-wandering and increase in task-focus states with background music - to explore the link between attentional state and arousal with and without background music. 39 students between the ages of 19-32 completed a variation of the Psychomotor Vigilance Task in silence and with their self-selected background music (music they would normally listen to during attention-demanding tasks). Objective arousal measures (pretrial pupil diameter and task-evoked pupillary responses) and subjective attentional state measures (mind-wandering, task-focus, and external-distraction states) were collected throughout the task. Results showed a link between attentional state and arousal and indicated that background music increased arousal. Importantly, arousal mediated the effect of music to decrease mind-wandering and increase task-focus attentional states, suggesting that the arousal increase induced by music was behind the changes in attentional states. These findings show, for the first time in the context of background music listening, that there is a link between arousal and attentional state.

The role of mood and arousal in the effect of background music on attentional state and performance during a sustained attention task

Across two online experiments, this study explored the effect of preferred background music on attentional state and performance, as well as on mood and arousal, during a vigilance task. It extended recent laboratory findings-showing an increase in task-focus and decrease in mind-wandering states with music-to environments with more distractions around participants. Participants-people who normally listen to background music during attention-demanding tasks-completed the vigilance task in their homes both with and without their chosen music and reported their attentional state, subjective arousal, and mood valence throughout the task. Experiment 1 compared music to relative silence and Experiment 2 compared music against the backdrop of continuous noise to continuous noise alone. In both experiments, music decreased mind-wandering and increased task-focus. Unlike in previous laboratory studies, in both experiments music also led to faster reaction times while increasing low-arousal external-distraction states. Importantly, mood and arousal increased with music and were shown to mediate its effects on reaction time and for the first time attentional state, both separately and together. Serial mediation effects were mostly confined to models where mood was entered first and arousal second and were consistent with the mood-arousal account of the impact of background music listening.

Changes in pupil size track self-control failure

People are more likely to perform poorly on a self-control task following a previous task requiring self-control (ego-depletion), but the mechanism for this effect remains unclear. We used pupillometry to test the role of attentional effort in ego-depletion. We hypothesized that an elevated pupil diameter (PD)-a common physiological measure of effort-during an initial task requiring self-control should be negatively associated with performance on a subsequent control task. To test this hypothesis, participants were first assigned to either a high- or low-demand attention task (manipulation; a standard ego-depletion paradigm), after which all participants completed the same Stroop task. We then separately extracted both sustained (low-frequency) and phasic (high-frequency) changes in PD from both tasks to evaluate possible associations with lapses of cognitive control on the Stroop task. We first show that in the initial task, sustained PD was larger among participants who were assigned to the demanding attention condition. Furthermore, ego-depletion effects were serially mediated by PD: an elevated PD response emerged rapidly among the experimental group during the manipulation, persisted as an elevated baseline response during the Stroop task, and predicted worse accuracy on incongruent trials, revealing a potential indirect pathway to ego-depletion via sustained attention. Secondary analyses revealed another, independent and direct pathway via high levels of transient attentional control: participants who exhibited large phasic responses during the manipulation tended to perform worse on the subsequent Stroop task. We conclude by exploring the neuroscientific implications of these results within the context of current theories of self-control.

A dual process model of spontaneous conscious thought

In the present article, I review theory and evidence on the psychological mechanisms of mind wandering, paying special attention to its relation with executive control. I then suggest applying a dual-process framework (i.e., automatic vs. controlled processing) to mind wandering and goal-directed thought. I present theoretical arguments and empirical evidence in favor of the view that mind wandering is based on automatic processing, also considering its relation to the concept of working memory. After that, I outline three scenarios for an interplay between mind wandering and goal-directed thought during task performance (parallel automatic processing, off-task thought substituting on-task thought, and non-disruptive mind wandering during controlled processing) and address the ways in which the mind-wandering and focused-attention spells can terminate. Throughout the article, I formulate empirical predictions. In conclusion, I discuss how automatic and controlled processing may be balanced in human conscious cognition.

A Nomothetic Span Approach to the Construct Validation of Sustained Attention Consistency: Re-Analyzing Two Latent-Variable Studies of Performance Variability and Mind-Wandering Self-Reports

The ability to sustain attention consistency is frequently assessed using either objective behavioral measures, such as reaction time (RT) variability, or subjective self-report measures, such as rates of task-unrelated thought (TUT). The current studies examined whether the individual-difference covariation in these measures provides a more construct valid assessment of attention consistency than does either alone. We argue that performance and self-report measures mutually validate each other; each measurement approach has its own sources of error, so their shared variance should best reflect the attention consistency construct. We reanalyzed two latent-variable studies where RT variability and TUTs were measured in multiple tasks (Kane et al. in J Exp Psychol Gen 145:1017-1048, 2016; Unsworth et al. in J Exp Psychol Gen 150:1303-1331, 2021), along with several nomological network constructs to test the convergent and discriminant validity of a general attention consistency factor. Confirmatory factor analyses assessing bifactor (preregistered) and hierarchical (non-preregistered) models suggested that attention consistency can be modeled as the shared variance among objective and subjective measures. This attention consistency factor was related to working memory capacity, attention (interference) control, processing speed, state motivation and alertness, and self-reported cognitive failures and positive schizotypy. Although bifactor models of general attention consistency provide the most compelling construct validity evidence for a specific ability to sustain attention, multiverse analyses of outlier decisions suggested they are less robust than hierarchical models. The results provide evidence for the general ability to sustain attention consistency and suggestions for improving its measurement.

Nonlinear changes in pupillary attentional orienting responses across the lifespan

The cognitive aging process is not necessarily linear. Central task-evoked pupillary responses, representing a brainstem-pupil relationship, may vary across the lifespan. Thus we examined, in 75 adults ranging in age from 19 to 86, whether task-evoked pupillary responses to an attention task may serve in as an index of cognitive aging. This is because the locus coeruleus (LC), located in the brainstem, is not only among the earliest sites of degeneration in pathological aging, but also supports both attentional and pupillary behaviors. We assessed brief, task-evoked phasic attentional orienting to behaviorally relevant and irrelevant auditory tones, stimuli known specifically to recruit the LC in the brainstem and evoke pupillary responses. Due to potential nonlinear changes across the lifespan, we used a novel data-driven analysis on 6 dynamic pupillary behaviors on 10% of the data to reveal cut off points that best characterized the three age bands: young (19-41 years old), middle aged (42-68 years old), and older adults (69 + years old). Follow-up analyses on independent data, the remaining 90%, revealed age-related changes such as monotonic decreases in tonic pupillary diameter and dynamic range, along with curvilinear phasic pupillary responses to the behaviorally relevant target events, increasing in the middle-aged group and then decreasing in the older group. Additionally, the older group showed decreased differentiation of pupillary responses between target and distractor events. This pattern is consistent with potential compensatory LC activity in midlife that is diminished in old age, resulting in decreased adaptive gain. Beyond regulating responses to light, pupillary dynamics reveal a nonlinear capacity for neurally mediated gain across the lifespan, thus providing evidence in support of the LC adaptive gain hypothesis.

Attention Mobilization as a Modulator of Listening Effort: Evidence From Pupillometry

Listening to speech in noise can require substantial mental effort, even among younger normal-hearing adults. The task-evoked pupil response (TEPR) has been shown to track the increased effort exerted to recognize words or sentences in increasing noise. However, few studies have examined the trajectory of listening effort across longer, more natural, stretches of speech, or the extent to which expectations about upcoming listening difficulty modulate the TEPR. Seventeen younger normal-hearing adults listened to 60-s-long audiobook passages, repeated three times in a row, at two different signal-to-noise ratios (SNRs) while pupil size was recorded. There was a significant interaction between SNR, repetition, and baseline pupil size on sustained listening effort. At lower baseline pupil sizes, potentially reflecting lower attention mobilization, TEPRs were more sustained in the harder SNR condition, particularly when attention mobilization remained low by the third presentation. At intermediate baseline pupil sizes, differences between conditions were largely absent, suggesting these listeners had optimally mobilized their attention for both SNRs. Lastly, at higher baseline pupil sizes, potentially reflecting overmobilization of attention, the effect of SNR was initially reversed for the second and third presentations: participants initially appeared to disengage in the harder SNR condition, resulting in reduced TEPRs that recovered in the second half of the story. Together, these findings suggest that the unfolding of listening effort over time depends critically on the extent to which individuals have successfully mobilized their attention in anticipation of difficult listening conditions.

Self-regulating arousal via pupil-based biofeedback

The brain's arousal state is controlled by several neuromodulatory nuclei known to substantially influence cognition and mental well-being. Here we investigate whether human participants can gain volitional control of their arousal state using a pupil-based biofeedback approach. Our approach inverts a mechanism suggested by previous literature that links activity of the locus coeruleus, one of the key regulators of central arousal and pupil dynamics. We show that pupil-based biofeedback enables participants to acquire volitional control of pupil size. Applying pupil self-regulation systematically modulates activity of the locus coeruleus and other brainstem structures involved in arousal control. Furthermore, it modulates cardiovascular measures such as heart rate, and behavioural and psychophysiological responses during an oddball task. We provide evidence that pupil-based biofeedback makes the brain's arousal system accessible to volitional control, a finding that has tremendous potential for translation to behavioural and clinical applications across various domains, including stress-related and anxiety disorders.

No relationships between frequencies of mind-wandering and perceptual rivalry

Our minds frequently wander from a task at hand. This mind-wandering reflects fluctuations in our cognitive states. The phenomenon of perceptual rivalry, in which one of the mutually exclusive percepts automatically switches to an ambiguous sensory input, is also known as fluctuations in our perceptual states. There may be possible relationships between the mind-wandering and perceptual rivalry, given that physiological responses such as fluctuations in pupil diameter, which is an index of attentional/arousal states, are related to the occurrence of both phenomena. Here, we investigate possible relationships between mind-wandering and perceptual rivalry by combining experimental and questionnaire methods in an online research protocol. In Study 1, we found no statistically significant relationships between subjective mind-wandering tendencies measured by questionnaires and frequencies of perceptual rivalry for Necker-cube or structure-from-motion stimuli. Study 2 replicated the results of Study 1 and further confirmed no statistically significant relationships between behavioral measurements of mind-wandering tendencies estimated by sustained attention to response task and frequencies of perceptual rivalry. These findings suggest that mind-wandering and perceptual rivalry would be based on different mechanisms, possibly higher-level cognitive and lower-level perceptual ones.

The effects of self-selected background music and task difficulty on task engagement and performance in a visual vigilance task

Listening to self-selected background music has been shown to be associated with increased task focus and decreased mind wandering during a sustained attention task (Kiss and Linnell, Psychological Research Psychologische Forschung 85:2313-2325, 2021). It is unclear, however, how this relation may depend on the potentially critical factor of task difficulty. To address this knowledge gap, we explored how listening to self-selected music, compared to silence, affects subjectively experienced task engagement (i.e., task focus, mind wandering, and external distraction/bodily sensation states) and task performance during either an easy or a hard vigilance task. We also examined how these effects vary with time-on-task. Our results replicated prior work demonstrating that background music enhanced task focus and decreased mind wandering, compared to silence. There was also lower reaction time variability in the background music condition relative to the silence condition. Notably, these findings held regardless of task difficulty. Interestingly, when examined over time-on-task, the presence of music led to smaller task focus declines and mind wandering increases, compared to silence. Thus, listening to self-selected music appears to confer a protective effect on task engagement, especially over time-on-task.

Attention, Musicality, and Familiarity Shape Cortical Speech Tracking at the Musical Cocktail Party

The "cocktail party problem" challenges our ability to understand speech in noisy environments, which often include background music. Here, we explored the role of background music in speech-in-noise listening. Participants listened to an audiobook in familiar and unfamiliar music while tracking keywords in either speech or song lyrics. We used EEG to measure neural tracking of the audiobook. When speech was masked by music, the modeled peak latency at 50 ms (P1TRF) was prolonged compared to unmasked. Additionally, P1TRF amplitude was larger in unfamiliar background music, suggesting improved speech tracking. We observed prolonged latencies at 100 ms (N1TRF) when speech was not the attended stimulus, though only in less musical listeners. Our results suggest early neural representations of speech are enhanced with both attention and concurrent unfamiliar music, indicating familiar music is more distracting. One's ability to perceptually filter "musical noise" at the cocktail party depends on objective musical abilities.

When the mind's eye prevails: The Internal Dominance over External Attention (IDEA) hypothesis

Throughout the 20th century, the psychological literature has considered attention as being primarily directed at the outside world. More recent theories conceive attention as also operating on internal information, and mounting evidence suggests a single, shared attentional focus between external and internal information. Such sharing implies a cognitive architecture where attention needs to be continuously shifted between prioritizing either external or internal information, but the fundamental principles underlying this attentional balancing act are currently unknown. Here, we propose and evaluate one such principle in the shape of the Internal Dominance over External Attention (IDEA) hypothesis: Contrary to the traditional view of attention as being primarily externally oriented, IDEA asserts that attention is inherently biased toward internal information. We provide a theoretical account for why such an internal attention bias may have evolved and examine findings from a wide range of literatures speaking to the balancing of external versus internal attention, including research on working memory, attention switching, visual search, mind wandering, sustained attention, and meditation. We argue that major findings in these disparate research lines can be coherently understood under IDEA. Finally, we consider tentative neurocognitive mechanisms contributing to IDEA and examine the practical implications of more deliberate control over this bias in the context of psychopathology. It is hoped that this novel hypothesis motivates cross-talk between the reviewed research lines and future empirical studies directly examining the mechanisms that steer attention either inward or outward on a moment-by-moment basis.

Memory Consolidation during Ultra-short Offline States

Traditionally, neuroscience and psychology have studied the human brain during periods of "online" attention to the environment, while participants actively engage in processing sensory stimuli. However, emerging evidence shows that the waking brain also intermittently enters an "offline" state, during which sensory processing is inhibited and our attention shifts inward. In fact, humans may spend up to half of their waking hours offline [Wamsley, E. J., & Summer, T. Spontaneous entry into an "offline" state during wakefulness: A mechanism of memory consolidation? Journal of Cognitive Neuroscience, 32, 1714-1734, 2020; Killingsworth, M. A., & Gilbert, D. T. A wandering mind is an unhappy mind. Science, 330, 932, 2010]. The function of alternating between online and offline forms of wakefulness remains unknown. We hypothesized that rapidly switching between online and offline states enables the brain to alternate between the competing demands of encoding new information and consolidating already-encoded information. A total of 46 participants (34 female) trained on a memory task just before a 30-min retention interval, during which they completed a simple attention task while undergoing simultaneous high-density EEG and pupillometry recording. We used a data-driven method to parse this retention interval into a sequence of discrete online and offline states, with a 5-sec temporal resolution. We found evidence for three distinct states, one of which was an offline state with features well-suited to support memory consolidation, including increased EEG slow oscillation power, reduced attention to the external environment, and increased pupil diameter (a proxy for increased norepinephrine). Participants who spent more time in this offline state following encoding showed improved memory at delayed test. These observations are consistent with the hypothesis that even brief, seconds-long entry into an offline state may support the early stages of memory consolidation.

Identification of Language-Induced Mental Load from Eye Behaviors in Virtual Reality

Experiences of virtual reality (VR) can easily break if the method of evaluating subjective user states is intrusive. Behavioral measures are increasingly used to avoid this problem. One such measure is eye tracking, which recently became more standard in VR and is often used for content-dependent analyses. This research is an endeavor to utilize content-independent eye metrics, such as pupil size and blinks, for identifying mental load in VR users. We generated mental load independently from visuals through auditory stimuli. We also defined and measured a new eye metric, focus offset, which seeks to measure the phenomenon of "staring into the distance" without focusing on a specific surface. In the experiment, VR-experienced participants listened to two native and two foreign language stimuli inside a virtual phone booth. The results show that with increasing mental load, relative pupil size on average increased 0.512 SDs (0.118 mm), with 57% reduced variance. To a lesser extent, mental load led to fewer fixations, less voluntary gazing at distracting content, and a larger focus offset as if looking through surfaces (about 0.343 SDs, 5.10 cm). These results are in agreement with previous studies. Overall, we encourage further research on content-independent eye metrics, and we hope that hardware and algorithms will be developed in the future to further increase tracking stability.

Effects of internally directed cognition on smooth pursuit eye movements: A systematic examination of perceptual decoupling

Eye behavior differs between internally and externally directed cognition and thus is indicative of an internal versus external attention focus. Recent work implicated perceptual decoupling (i.e., eye behavior becoming less determined by the sensory environment) as one of the key mechanisms involved in these attention-related eye movement differences. However, it is not yet understood how perceptual decoupling depends on the characteristics of the internal task. Therefore, we systematically examined effects of varying internal task demands on smooth pursuit eye movements. Specifically, we evaluated effects of the internal workload (control vs. low vs. high) and of internal task (arithmetic vs. visuospatial). The results of multilevel modelling showed that effects of perceptual decoupling were stronger for higher workload, and more pronounced for the visuospatial modality. Effects also followed a characteristic time-course relative to internal operations. The findings provide further support of the perceptual decoupling mechanism by showing that it is sensitive to the degree of interference between external and internal information.

Testing locus coeruleus-norepinephrine accounts of working memory, attention control, and fluid intelligence

The current set of studies examined the relationship among working memory capacity, attention control, fluid intelligence, and pupillary correlates of tonic arousal regulation and phasic responsiveness in a combined sample of more than 1,000 participants in two different age ranges (young adults and adolescents). Each study was designed to test predictions made by two recent theories regarding the role of the locus coeruleus-norepinephrine (LC-NE) system in determining individual differences in cognitive ability. The first theory, proposed by Unsworth and Robison (2017a), posits two important individual differences: the moment-to-moment regulation of tonic arousal, and the phasic responsiveness of the system to goal-relevant stimuli. The second theory, proposed by Tsukahara and Engle (2021a), argues that people with higher cognitive abilities have greater functional connectivity between the LC-NE system and cortical networks at rest. These two theories are not mutually exclusive, but they make different predictions. Overall, we found no evidence consistent with a resting-state theory. However, phasic responsiveness was consistently correlated with working memory capacity, attention control, and fluid intelligence, supporting a prediction made by Unsworth and Robison (2017a). Tonic arousal regulation was not correlated with working memory or fluid intelligence and was inconsistently correlated with attention control, which offers only partial support for Unsworth and Robison's (2017a) second prediction.

A pupillometric investigation of state regulation in adults scoring high versus low on ADHD symptomatology

According to the state regulation deficit (SRD) account, ADHD is associated with difficulties regulating tonic arousal levels, which may be due to inefficient effort allocation. We aimed to test the SRD account by using a target detection task with three different event rates (ER; 700 ms, 1800 ms, 6000 ms), in order to manipulate the tonic arousal state and its effects on performance and pupil indices in adults with high (n = 40) versus low (n = 36) ADHD symptom levels. In an additional condition, a fast ER (700 ms) was accompanied by auditory white noise (WN), to further increase tonic arousal level. The ER manipulation had a clear effect on RT and variability of RT. These effects were more pronounced for the high-ADHD group, especially for variability of RT with decreasing ER, suggestive of deficient upregulation of a tonic arousal state in that group, in line with their self-reported SRDs in daily life. Adding WN to the fast condition led to more errors, however similarly for both groups. Contrary to our predictions, the ER manipulation had no effect on tonic pupil size (as a measure of tonic arousal). Phasic pupil amplitude (as a measure of cognitive effort) linearly increased with decreasing ER, suggesting more effort allocation during slower ERs. WN decreased phasic pupil amplitude, but had no impact on tonic pupil size. Importantly, however, no ADHD-related differences were present for the pupil indices. In conclusion, adults with elevated levels of ADHD symptoms reported more SRDs in daily life and showed a performance pattern that suggests difficulties in upregulating but not downregulating the tonic arousal state. Surprisingly, these findings were not accompanied by group differences in pupillometric indices. This casts some doubts on the relationship between these measures of autonomic nervous system activity and state regulation, in particular in the context of ADHD symptomatology.

The influence of imagery vividness and internally-directed attention on the neural mechanisms underlying the encoding of visual mental images into episodic memory

Attention can be directed externally toward sensory information or internally toward self-generated information. Using electroencephalography (EEG), we investigated the attentional processes underlying the formation and encoding of self-generated mental images into episodic memory. Participants viewed flickering words referring to common objects and were tasked with forming visual mental images of the objects and rating their vividness. Subsequent memory for the presented object words was assessed using an old-new recognition task. Internally-directed attention during image generation was indexed as a reduction in steady-state visual evoked potentials (SSVEPs), oscillatory EEG responses at the frequency of a flickering stimulus. The results yielded 3 main findings. First, SSVEP power driven by the flickering word stimuli decreased as subjects directed attention internally to form the corresponding mental image. Second, SSVEP power returned to pre-imagery baseline more slowly for low- than high-vividness later remembered items, suggesting that longer internally-directed attention is required to generate subsequently remembered low-vividness images. Finally, the event-related-potential difference due to memory was more sustained for subsequently remembered low- versus high-vividness items, suggesting that additional conceptual processing may have been needed to remember the low-vividness visual images. Taken together, the results clarify the neural mechanisms supporting the encoding of self-generated information.

Attentional fluctuations and the temporal organization of memory

Event boundaries and temporal context shape the organization of episodic memories. We hypothesized that attentional fluctuations during encoding serve as "events" that affect temporal context representations and recall organization. Individuals encoded trial-unique objects during a modified sustained attention task. Memory was tested with free recall. Response time variability during the encoding tasks was used to characterize "in the zone" and "out of the zone" attentional states. We predicted that: 1) "in the zone", vs. "out of the zone", attentional states should be more conducive to maintaining temporal context representations that can cue temporally organized recall; and 2) temporally distant "in the zone" states may enable more recall "leaps" across intervening items. We replicated several important findings in the sustained attention and memory fields, including more online errors during "out of the zone" vs. "in the zone" attentional states and recall that was temporally structured. Yet, across four studies, we found no evidence for either of our main hypotheses. Recall was robustly temporally organized, and there was no difference in recall organization for items encoded "in the zone" vs. "out of the zone". We conclude that temporal context serves as a strong scaffold for episodic memory, one that can support organized recall even for items encoded during relatively poor attentional states. We also highlight the numerous challenges in striking a balance between sustained attention tasks (long blocks of a repetitive task) and memory recall tasks (short lists of unique items) and describe strategies for researchers interested in uniting these two fields.

Ecological momentary assessment of mind-wandering: meta-analysis and systematic review

Mind-wandering (MW) is a universal human phenomenon and revealing its nature contributes to understanding consciousness. The ecological momentary assessment (EMA), in which subjects report a momentary mental state, is a suitable method to investigate MW in a natural environment. Previous studies employed EMA to study MW and attempted to answer the most fundamental question: How often do we let our minds wander? However, reported MW occupancies vary widely among studies. Further, while some experimental settings may induce bias in MW reports, these designs have not been explored. Therefore, we searched PubMed and Web of Science for articles published until the end of 2020 and systematically reviewed 25 articles, and performed meta-analyses on 17 of them. Our meta-analysis found that people spend 34.504% of daily life in mind-wandering, and meta-regression revealed that using subject smartphones for EMA, frequent sampling, and long experimental duration significantly affect MW reports. This result indicates that EMA using subject smartphones may tend to collect sampling under habitual smartphone use. Furthermore, these results indicate the existence of reactivity, even in MW research. We provide fundamental knowledge of MW and discuss rough standards for EMA settings in future MW studies.

Physically active undergraduates perform better on executive-related oculomotor control: Evidence from the antisaccade task and pupillometry

Previous studies have shown that exercise can improve executive function in young and older adults. However, it remains controversial whether a sufficient amount of physical activity leads to higher-level executive function. To examine the effect of physical activity on executive function, we used eye-tracking technology and the antisaccade task in 41 young undergraduates with various levels of physical activity. Moreover, we also investigated their differences in cognitive ability by examining their pupil size during the antisaccade task. Eye-tracking results showed that physically active individuals showed shorter saccade latency and higher accuracy in the antisaccade task than their physically inactive counterparts. Furthermore, the former showed larger pupil size during the preparatory period of antisaccade. These findings suggest that individuals with higher-level physical activity have higher-level executive function. The larger pupil sizes of physically active individuals may imply that their locus coeruleus-norepinephrine system and executive-related prefrontal cortex are more active, which contributes to their higher-level cognitive ability.

Does framing an assignment as involving one or multiple components influence subjective experiences of attentional engagement?

Across two studies, we explored whether framing an assignment as involving either multitasking or single-tasking (Srna et al. Psychol Sci 29(12):1942-1955, 2018) leads to differences in both subjective ratings of attentional engagement (i.e., depth of concentration and attentional control) and performance during the assignment. In Experiment 1, we manipulated task framing in the context of an assignment in which participants (N_collected = 238) simultaneously completed a word-search and an anagram task (Srna et al. Psychol Sci 29(12):1942-1955, 2018). While we replicated prior findings that participants who receive multitasking instructions perform better than those who receive single-tasking instructions, we did not find any influence of task framing on participants' subjective evaluations of their attentional engagement. Exploratory analyses, however, revealed that regardless of group assignment, those who believed they were multitasking reported greater levels of attentional engagement than those who believed they were single-tasking. In Experiment 2 (N_collected = 238), task framing was varied in the context of the 2-back task (Kirchner J Exp Psychol 55(4): 352, 1958). Unexpectedly, we found that, relative to participants who received single-tasking instructions, those who received multitasking instructions reported exerting less attentional control over their thoughts and showed a greater number of incorrect responses to non-target trials on the 2-back. Taken together, the results do not support a straightforward conclusion regarding the influence of task framing on either subjective reports of attentional engagement or task performance. Nevertheless, they provide insight into our understanding of the role of task framing in contexts ranging from commonly performed real-world tasks to typical laboratory tasks.

Pavlovian-based neurofeedback enhances meta-awareness of mind-wandering

Absorption in mind-wandering (MW) may worsen our mood and can cause psychological disorders. Researchers indicate the possibility that meta-awareness of MW prevents these mal-effects and enhances favorable consequences of MW, such as boosting creativity; thus, meta-awareness has attracted psychological and clinical attention. However, few studies have investigated the nature of meta-awareness of MW, because there has been no method to isolate and operate this ability. Therefore, we propose a new approach to manipulate the ability of meta-awareness. We used Pavlovian conditioning, tying to it an occurrence of MW and a neutral tone sound inducing the meta-awareness of MW. To perform paired presentations of the unconditioned stimulus (neutral tone) and the conditioned stimulus (perception accompanying MW), we detected participants' natural occurrence of MW via electroencephalogram and a machine-learning estimation method. The double-blinded randomized controlled trial with 37 participants found that a single 20-min conditioning session significantly increased the meta-awareness of MW as assessed by behavioral and neuroscientific measures. The core protocol of the proposed method is real-time feedback on participants' neural information, and in that sense, we can refer to it as neurofeedback. However, there are some differences from typical neurofeedback protocols, and we discuss them in this paper. Our novel classical conditioning is expected to contribute to future research on the modulation effect of meta-awareness on MW.

Previous Mental Load and Incentives Influence Anticipatory Arousal as Indexed by the Baseline Pupil Diameter in a Speech-in-Noise Task

Listening effort and fatigue are common experiences when conversing in noisy environments. Much research has investigated listening effort in relation to listening demand using the speech-in-noise paradigm. Recent conceptualizations of listening effort postulate that mental fatigue should result in decreased arousal and a reluctance to invest further effort, particularly when the effort is not worthwhile. The aim of the study was to investigate the influence of fatigue on listening effort, in interaction with listening demands and motivation. To induce fatigue 30 adults with normal hearing completed a 40-minute long speech-in-noise task ("load sequence"). Pre- and post-load sequence listening effort was probed in easy and hard listening demands (individually adjusted signal-to-noise ratios); with high and low motivation (manipulated with monetary incentives). Subjective effort, estimated performance, and tendency to quit listening were collected using rating scales. Baseline pupil diameter and mean pupil dilation were recorded as indices of anticipatory arousal and objective effort. Self-reported effort and mean pupil dilation were overall larger during hard SNR as compared to easy SNR. Baseline pupil diameter declined from pre- to post-load sequence, suggesting an overall decrease in arousal. Monetary incentives had no influence on the baseline pupil diameter for the easy SNR condition, but for the hard SNR condition larger incentives led to larger baseline pupil diameter. These results suggest that anticipatory arousal may be influenced by fatigue and motivation effects. Models of listening effort should account for the independent influence of motivation and previous load on anticipatory arousal and effort in distinct parameters.

Inconclusive evidence that breathing shapes pupil dynamics in humans: a systematic review

More than 50 years ago, it was proposed that breathing shapes pupil dynamics. This widespread idea is also the general understanding currently. However, there has been no attempt at synthesizing the progress on this topic since. We therefore conducted a systematic review of the literature on how breathing affects pupil dynamics in humans. We assessed the effect of breathing phase, depth, rate, and route (nose/mouth). We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and conducted a systematic search of the scientific literature databases MEDLINE, Web of Science, and PsycInfo in November 2021. Thirty-one studies were included in the final analyses, and their quality was assessed with QualSyst. The study findings were summarized in a descriptive manner, and the strength of the evidence for each parameter was estimated following the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. The effect of breathing phase on pupil dynamics was rated as "low" (6 studies). The effect of breathing depth and breathing rate (6 and 20 studies respectively) were rated as "very low". Breathing route was not investigated by any of the included studies. Overall, we show that there is, at best, inconclusive evidence for an effect of breathing on pupil dynamics in humans. Finally, we suggest some possible confounders to be considered, and outstanding questions that need to be addressed, to answer this fundamental question. Trial registration: This systematic review has been registered in the international prospective register of systematic reviews (PROSPERO) under the registration number: CRD42022285044.