Cyclic variations in sustained human performance

Biological rhythms play a prominent role in the modulation of human physiology and behavior. [Smith, K., Valentino, D., & Arruda, J. (2003). Rhythmic oscillations in the performance of a sustained attention task. Journal of Clinical and Experimental Neuropsychology, 25, 561-570] suggested that sustained human performance may systematically fluctuate in a cyclic manner with periods of 1.5 min and 5.2 min. The current series of investigations sought to manipulate those periodicities by altering task difficulty, administering caffeine, and testing on a more ecologically valid task. Strong evidence of a 1.5 min periodicity was found across studies. Most participants did not demonstrate the 5.2 min periodicity. Moreover, the 1.5 min periodicity was resistant to task manipulations and appeared in similar levels across conditions in all three experiments. These rhythms may be indicative of an endogenous system that modulates sustained attention in humans. Evidence supporting this idea and implications of the research are discussed.     

Attention lapses and behavioural microsleeps during tracking,psychomotor vigilance,and dual tasks

This study examined the incidence of attention lapses and microsleeps under contrasting levels of task complexity during three tasks: PVT, 2-D tracking and a dual task combining the two. More attention lapses per participant (median 15 vs. 3; range 1–74 vs. 0–76, p = 0.001), with the greatest increase with time spent-on-task (p = 0.002), were evident on the more cognitively-demanding dual task than on the PVT. Conversely, fewer microsleeps (median 0 vs. 0; range 0–1 vs. 0–18, p = 0.022) occurred during the more complex task compared to the tracking task. An increase in microsleep rate with time spent-on-task (p = 0.035) was evident during the tracking task but not the dual task. These results indicate that the higher cognitive load, associated with an increase in task complexity, increased the likelihood of attention lapses, while a reduction in task complexity increased the likelihood of microsleeps.     

Identity formation in juvenile delinquents and clinically referred youth

IntroductionLittle is known about how juvenile delinquents and clinically referred youth handle the key developmental task of identity formation.ObjectiveThe aim of this study was to compare identity formation in juvenile delinquent and clinically referred boys to identity formation in boys drawn from the general population.MethodMean scores on identity dimensions and membership to identity statuses in ideological (i.e., education) and interpersonal (i.e., relationship with the best friend) domains were compared across groups of juvenile delinquent boys (n = 30), clinically referred boys (n = 21), and boys drawn from the general adolescent population (n = 30).ResultsJuvenile delinquents, but not clinically referred youth, displayed a weaker identity in both the ideological and interpersonal domain than adolescents from the general population.DiscussionIdentity formation among juvenile delinquents deserves more attention from both researchers and clinicians.     

Functional cortical connectivity analysis of mental fatigue unmasks hemispheric asymmetry and changes in small-world networks

Changes in functional connectivity across mental states can provide richer information about human cognition than simpler univariate approaches. Here, we applied a graph theoretical approach to analyze such changes in the lower alpha (8–10 Hz) band of EEG data from 26 subjects undergoing a mentally-demanding test of sustained attention: the Psychomotor Vigilance Test. Behavior and connectivity maps were compared between the first and last 5 min of the task. Reaction times were significantly slower in the final minutes of the task, showing a clear time-on-task effect. A significant increase was observed in weighted characteristic path length, a measure of the efficiency of information transfer within the cortical network. This increase was correlated with reaction time change. Functional connectivity patterns were also estimated on the cortical surface via source localization of cortical activities in 26 predefined regions of interest. Increased characteristic path length was revealed, providing further support for the presence of a reshaped global topology in cortical connectivity networks under fatigue state. Additional analysis showed an asymmetrical pattern of connectivity (right > left) in fronto-parietal regions associated with sustained attention, supporting the right-lateralization of this function. Interestingly, in the fatigue state, significance decreases were observed in left, but not right fronto-parietal connectivity. Our results indicate that functional network organization can change over relatively short time scales with mental fatigue, and that decreased connectivity has a meaningful relationship with individual difference in behavior and performance.     

The relationship between visual attention and expertise in sports

ObjectivesGiven the prevalence of misperception and failed perception, particularly in attention-demanding team sports, surprisingly few studies have explored whether experts in team sports differ from other athletes and from non-athletes in their basic attention abilities.MethodIn this study, we examined group differences between experts in team handball (n = 40), athletes from non-team sports (n = 40), and novice athletes (n = 40) using a battery of three attention tasks: a functional field of view task, a multiple-object tracking task, and an inattentional blindness task.ResultsPerformance on the three attention tasks was largely independent, with no significant correlations among the tasks. Team sports experts showed no better performance on the basic attention tasks than did athletes from non-teams sports or novice athletes.ConclusionsThe finding that all basic attention tasks are largely independent provides preliminary support for the idea that attentional breadth, tracking performance, and inattentional blindness are distinct attentional processes. Our results demonstrate that sports expertise effects are unrelated to basic differences in attention—expertise does not appear to produce differences in basic attention and basic differences in attention do not appear to predict eventual expertise. Further experiments could focus on the ways in which more specific attentional strategies and processes contribute to sports performance.     

Walking impairs cognitive performance among people with multiple sclerosis but not controls

People with multiple sclerosis (MS) complain of problems completing two tasks simultaneously; sometimes called ‘dual-tasking’ (DT). Previous research in DT among people with MS has focused on how adding a cognitive task interferes with gait and few have measured how adding a motor task could interfere with cognition. We aimed to determine the extent to which walking affects a concurrent working memory task in people with MS compared to healthy controls. We recruited MS participants (n = 13) and controls (n = 10) matched by age (±3 years), education (±3 years) and gender. Participants first completed the cognitive task (subtracting 7’s from the previous number) and then again while walking on an instrumented walkway. Although there were no baseline differences in cognition or walking between MS participants and controls, MS participants demonstrated a 52% decrease in number of correct answers during DT (p < 0.001). Mental Tracking Rate (% correct answers/min) correlated strongly with MS-related disability measured using the Expanded Disability Status Scale (EDSS; r(11) = −0.68, p < 0.01). We propose that compromised mental tracking during walking could be related to limited neural resource capacity and could be a potentially useful outcome measure to detect ecologically valid dual tasking impairments.     

Comparison of fetal and maternal heart rate measures using electrocardiographic and cardiotocographic methods

PurposeTo determine the reliability at term of: (1) two methods of measuring fetal heart rate (HR), electrocardiographic (ECG, the ‘gold standard’) and cardiotocographic (CTG) and (2) two ECG methods of measuring maternal HR variability over relatively brief periods of time (s–min).MethodsDuring 20 min of rest (N = 39) and during 2 min of auditory stimulation (mother's recorded voice, n = 19), fetal HR data were collected using an ECG (Monica AN24) and a Hewlett-Packard Model 1351A CTG. Simultaneously, maternal HR data (n = 37) were collected using the same ECG device (Monica AN24) and a second stand-alone cardiac monitor (Spacelab 514T cardiac monitor with a QRS detector).ResultsDuring 20 min of maternal rest, correlations of individual fetal CTG with ECG measures of HR at each second were moderate to high (r = .57–.97) for 77% of fetuses. Correlations of HR averaged over fetuses and over each of the 20 min were high (r = .93–.97); fetal HR averaged over 20 min varied between devices from 0.0 to 0.8 bpm. During 2 min of maternal voice presentation, correlations of fetal HR over each second were moderate to high (r = .54–.99) for 95% of fetuses and high (all rs = .99) when averaged across fetuses in 30 s or 2 min epochs. Average fetal HR between devices over the 2 min voice varied from 0.0 to 0.6 bpm. Correlations and/or % agreement between the two ECG methods of measuring maternal HR were high. Average maternal HR over 10 min showed 81% of pairs with a difference of ≤1 bpm; correlations for HR variability measures varied from r = .89 to .97.ConclusionsGood reliability was demonstrated between individual spontaneous and auditory induced fetal CTG and ECG with high correlations when HR data were averaged over fetuses or in 30–120 s epochs. High reliability of maternal HR measures was obtained using two ECG devices.     

Attention and memory biases toward body-related images among restrained eaters

This study examined biases in attention and memory toward body-related images among restrained (n = 31) and unrestrained (n = 29) eaters. Attentional allocation to images of thin and overweight bodies during a visual search task was measured by tracking participants’ eyegaze. This task was followed by a recognition test assessing participants’ memory for those images. Restrained and unrestrained eaters allocated more attention to body-related images than to control images, but there was no difference in attentional allocation between the two groups. Restrained eaters showed better recognition of body-related images that they had previously seen during the visual search task. Finally, increased attention was associated with better recognition of body-related images for both restrained and unrestrained eaters, but restrained eaters had better overall recognition regardless of the level of attention. These findings suggest that restrained eaters may have more organized strategies for processing body-related information than do unrestrained eaters.     

Decreased attention to object size information in scale errors performers

Young children sometimes make serious attempts to perform impossible actions on miniature objects as if they were full-size objects. The existing explanations of these curious action errors assume (but never explicitly tested) children's decreased attention to object size information. This study investigated the attention to object size information in scale errors performers. Two groups of children aged 18–25 months (N = 52) and 48–60 months (N = 23) were tested in two consecutive tasks: an action task that replicated the original scale errors elicitation situation, and a looking task that involved watching on a computer screen actions performed with adequate to inadequate size object. Our key finding – that children performing scale errors in the action task subsequently pay less attention to size changes than non-scale errors performers in the looking task – suggests that the origins of scale errors in childhood operate already at the perceptual level, and not at the action level.     

Promoting an equitable and supportive school climate in high schools: The role of school organizational health and staff burnout

In response to persistent racial disparities in academic and behavioral outcomes between Black and White students, equitable school climate has drawn attention as a potential target for school reform. This study examined differences in Black and White students' experiences of school climate and explored whether indicators of school organizational health and staff burnout moderated differences in students' school experiences by race. Utilizing hierarchical linear modeling with a sample of 18,397 Black students (n = 6228) and White students (n = 12,169) and 2391 school staff in 53 schools, we found a consistent pattern of racial inequalities, such that Black students reported less positive experiences than White students across three indicators of school climate (caring γ = − 0.08, p < .001; equity γ = − 0.05, p = .007; and engagement γ = − 0.05, p < .001). In addition, we found significant, positive associations between aggregated staff-report of school organizational health and student-reported school climate (e.g., staff affiliation and student-perceived equity, γ = 0.07, p < .001). Surprisingly, a number of school organizational health indicators were more strongly associated with positive perceptions of school climate among White students than Black students, translating into greater racial disparities in perceived school climate at schools with greater organizational health (e.g., supportive leadership by race on student-perceived engagement, γ = − 0.03, p = .042). We also found negative associations between staff-reported burnout and students' experience of equity, such that the racial gap was smaller in schools with high ratings of burnout (γ = 0.04, p = .002). These findings have implications for educators and education researchers interested in promoting school social contexts that equitably support student engagement and success.     

Electrocortical Evidence of Enhanced Performance Monitoring in Social Anxiety

Self-focused attention is thought to be a key feature of social anxiety disorder. Yet few studies have used event-related potentials (ERPs) to examine whether socially anxious individuals display greater monitoring of their performance and attention to their errors. Similarly, only a few studies have used ERPs to examine how social anxiety is related to processing of performance feedback. Individuals with high (n = 26) and low (n = 28) levels of social anxiety completed a trial-and-error learning task. Self-focus was manipulated using false heart-rate feedback during a random subset of trials. Performance feedback was given using emotional and neutral faces in a positive context (correct = happy face; incorrect = neutral face) and negative context (correct = neutral face; incorrect = disgust face) in order to investigate biased interpretation and attention to feedback. Socially anxious subjects displayed enhanced amplitude of the ERN and CRN, suggesting greater response monitoring, and enhanced Pe amplitude, suggesting greater processing of errors relative to the low social anxiety group. No group differences were observed with respect to feedback processing. Before learning stimulus–response mappings in the negative context, the FRN was larger for self-focus compared to standard trials and marginally larger for socially anxious subjects compared to controls. These findings support cognitive models and suggest avenues for future research.     

Variability of kinematic graphomotor fluency in adults with ADHD

Although graphomotor differences and variability of performance have been observed in children with attention deficit hyperactivity disorder (ADHD), no study has investigated whether this variability manifests in the kinematic graphomotor domain in adults with ADHD. Fourteen ADHD and 20 control participants wrote a novel grapheme and common word on a digitizing tablet 30 times each, with ADHD participants counterbalanced on and off stimulant medication. Variability of graphomotor fluency was significantly greater in ADHD versus control participants only in the novel writing task, both on, F(1, 31) = 5.988, p = .020, and off stimulant medication, F(1, 32) = 8.789, p = .006. Results suggest that motor control differences in ADHD are not limited to childhood and extend into adulthood. Given sufficient additional research, variability of kinematic graphomotor fluency may increase the sensitivity/specificity of differential diagnoses and/or represent a biomarker for ADHD.     

Time Course of Attention in Socially Anxious Individuals: Investigating the Effects of Adult Attachment Style

Theoretical models of social anxiety propose that attention biases maintain symptoms of social anxiety. Research findings regarding the time course of attention and social anxiety disorder have been mixed. Adult attachment style may influence attention bias and social anxiety, thus contributing to the mixed findings. This study investigated the time course of attention toward both negative and positive stimuli for individuals diagnosed with social anxiety disorder (SAD) and assessed whether attachment style moderates this relationship.One hundred and thirty participants (age: M = 29.03) were assessed using a semistructured clinical interview. Those meeting eligibility criteria for the clinical sample met DSM-IV criteria for SAD (n = 90, age: M = 32.18), while those in the control sample did not meet criteria for any mental disorder (n = 23, age: M = 26.04, 11 females). All participants completed self-report measures examining depression, social anxiety, adult attachment style, and completed an eye-tracking task used to measure the time course of attention. Eye-tracking data were analysed using growth curve analysis.The results indicate that participants in the control group overall displayed greater vigilance towards emotional stimuli, were faster at initially fixating on the emotional stimulus, and had a greater percentage of fixations towards the emotional stimulus as the stimulus presentation time progressed compared to those in the clinical group. Thus, the clinical participants were more likely to avoid fixating on emotional stimuli in general (both negative and positive) compared to those in the control group.These results support the Clark and Wells (1995) proposal that socially anxious individuals avoid attending to emotional information. Attachment style did not moderate this association, however anxious attachment was related to greater vigilance toward emotional compared to neutral stimuli.     

Influence of practice schedules and attention on skill development and retention

Focus of attention during dual-tasks and practice schedules are important components of motor skill performance and learning; often studied in isolation. The current study required participants to complete a simple key-pressing task under a blocked or random practice schedule. To manipulate attention, participants reported their finger position (i.e., skill-focused attention) or the pitch of an auditory tone (i.e., extraneous attention) while performing two variations of a dual-task key-pressing task. Analyses were conducted at baseline, 10 min and 24 h after acquisition. The results revealed that participants in a blocked schedule, extraneous focus condition had significantly faster movement times during retention compared to a blocked schedule, skill focus condition. Furthermore, greatest improvements from baseline to immediate and delayed retention were evident for an extraneous attention compared to the skill-focused attention, regardless of practice schedule. A discussion of the unique benefits an extraneous focus of attention may have on the learning process during dual-task conditions is presented.     

Distributed attentional deficits in chronic methamphetamine abusers: Evidence from the Attentional Network Task (ANT)

ObjectiveThe goal of the present study was to examine distributed attentional functions in long-term but currently abstinent methamphetamine (MA) abusers using a task that measures attentional alertness, orienting, and conflict resolution.MethodsThirty currently abstinent MA abusers (1 month–5 years) and 22 healthy non-substance using adults were administered a multimodal version of the Attentional Network Task (ANT-I). In this task subjects identified the direction of a centrally presented arrow using a key press. Analyses examined the interaction between alerting tones, location cueing and congruency between the target arrows and flanking distractor stimuli.ResultsAll participants were faster when an auditory tone preceded the trial onset (p < 0.001), on trials in which a valid cue preceded the location of the target arrow (p < 0.001), and on congruent trials (i.e., when all display arrows faced in the same direction) (p < 0.001). Of primary interest was the finding that MA abusers were more influenced by the conflict between the peripheral arrows and the central target arrow (p = 0.009). There were also correlations between length of drug sobriety and executive function as well as between drug-induced psychiatric symptoms and alertness.ConclusionsThese results suggest that chronic MA abusers display cognitive deficits that may reflect a specific vulnerability to distraction on a task of executive function. These findings are consistent with other studies that have reported deficits in anterior attentional systems and top-down cognitive control.     

Adaptation of lower limb movement patterns when maintaining performance in the presence of muscle fatigue

Adaptations in lower limb movement patterns were examined when performance was maintained during a fatiguing repetitive loading task. Forty recreationally active male and female participants performed single-leg hopping to volitional exhaustion at 2.2 Hz to a submaximal height. Spatio-temporal characteristics, mechanical characteristics and variability of the knee-ankle and hip-knee joint couplings were determined at 20% increments during the duration of the hopping task. Variability of the knee-ankle and hip-knee couplings in the flexion/extension axis significantly increased during the loading and propulsion phases during the hopping task (p < 0.05). Performance (vertical stiffness, hopping frequency and height) did not change significantly during the task (p > 0.05), however foot contact time increased progressively during this task (p < 0.05) and maximum hop height significantly decreased after the task (p < 0.05). The observed increase in variability between adjoining lower limb segments demonstrated the ability of the neuromotor system to adapt and maintain performance even with the onset of fatigue. This finding highlights that during the performance of a rapid and repetitive loading activity, performance can be preserved when there is variability in the neuromotor system.     

Task-specificity of balance training

Despite much research on balance training, it is still unclear whether balance training leads to highly task-specific adaptations or rather non-specific adaptations. Hence, in this study we examined whether balance training increased performance only in the balance task that was trained or also in non-trained tasks. Forty healthy participants (28 m 12 f, 25 ± 4 years, 177 ± 10 cm, 73 ± 14 kg) were assigned to one of two training groups (TGs) or a control group. Both TGs completed six sessions over 2 weeks, only the training device differed. Before and after the training, performance in the trained task as well as in additional untrained tasks was recorded. ANOVAs showed that each TG outperformed the other groups only in the task they had trained (e.g., task trained by TG1: +225% in TG1, only +41% and +30% in TG2 and control, group * time interaction, p < 0.001; Untrained task 1: TG1 +48%, TG2 +48%, and control +30%, no significant interaction, p = 0.72). In summary, 2 weeks of balance training resulted in highly task-specific effects, no transfer even to very similar tasks was observed. Therefore, we recommend identifying and training exactly those tasks that need improvement, and test the efficacy of training programs using specific tests instead of general tests with limited functional relevance.     

Linking preschool language and sustained attention with adolescent achievement through classroom self-reliance

This study examined self-reliant classroom behaviors during middle childhood as a mechanism through which early language and sustained attention become associated with academic achievement in adolescence. Participants were enrolled in the NICHD Study of Early Child Care and Youth Development (N = 1364). Path analyses revealed that preschool language and sustained attention predicted self-reliant classroom behaviors during middle childhood and that self-reliant classroom behaviors predicted changes in math achievement in adolescence. Self-reliant classroom behaviors mediated the relations of preschool sustained attention and linguistic ability with adolescent math achievement, but not reading achievement. These findings extend research highlighting the importance of self-reliant classroom behaviors for children's academic outcomes.     

The effects of autonomous difficulty selection on engagement,motivation, and learning in a motion-controlled video game task

This experiment investigated the relationship between motivation, engagement, and learning in a video game task. Previous studies have shown increased autonomy during practice leads to superior retention of motor skills, but it is not clear why this benefit occurs. Some studies suggest this benefit arises from increased motivation during practice; others suggest the benefit arises from better information processing. Sixty novice participants were randomly assigned to a self-controlled group, who chose the progression of difficulty during practice, or to a yoked group, who experienced the same difficulty progression but did not have choice. At the end of practice, participants completed surveys measuring intrinsic motivation and engagement. One week later, participants returned for a series of retention tests at three different difficulty levels. RM-ANCOVA (controlling for pre-test) showed that the self-controlled group had improved retention compared to the yoked group, on average, β = 46.78, 95% CI = [2.68, 90.87], p = 0.04, but this difference was only statistically significant on the moderate difficulty post-test (p = 0.004). The self-controlled group also showed greater intrinsic motivation during practice, t(58) = 2.61, p = 0.01. However, there was no evidence that individual differences in engagement (p = 0.20) or motivation (p = 0.87) were associated with learning, which was the relationship this experiment was powered to detect. These data are inconsistent with strictly motivational accounts of how autonomy benefits learning, instead suggesting the benefits of autonomy may be mediated through other mechanisms. For instance, within the information processing framework, the learning benefits may emerge from learners appropriately adjusting difficulty to maintain an appropriate level of challenge (i.e., maintaining the relationship between task demands and cognitive resources).