Sustained attention failures are primarily due to sustained cognitive load not task monotony

We conducted two studies using a modified sustained attention to response task (SART) to investigate the developmental process of SART performance and the role of cognitive load on performance when the speed-accuracy trade-off is controlled experimentally. In study 1, 23 participants completed the modified SART (target stimuli location was not predictable) and a subjective thought content questionnaire 4 times over the span of 4 weeks. As predicted, the influence of speed-accuracy trade-off was significantly mitigated on the modified SART by having target stimuli occur in unpredictable locations. In study 2, 21 of the 23 participants completed an abridged version of the modified SART with a verbal free-recall memory task. Participants performed significantly worse when completing the verbal memory task and SART concurrently. Overall, the results support a resource theory perspective with concern to errors being a result of limited mental resources and not simply mindlessness per se.     

Conscious thought and the sustained attention to response task

We investigated the properties of the sustained attention to response task (SART). In the SART, participants respond to frequent (high probability of occurrence) neutral signals and are required to withhold response to rare (low probability of occurrence) critical signals. We examined whether SART performance shows characteristics of speed–accuracy tradeoffs and in addition, we examined whether SART performance is influenced by prior exposure to emotional picture stimuli. Thirty-six participants in this study performed SARTs after being exposed to neutral and negative picture stimuli. Performance in the SART changed rapidly over time and there was a high correlation between participants errors of commission rate and their reaction time to the neutral targets (r = −.61). Regardless of exposure self-reported thoughts significantly correlated with both errors of commission and reaction times. Overall, the results support the view that the SART is a better measure of impulsive responding than sustained attention.     

The relationship of age and extraversion to arousal and performance on a sustained attention task: A cross-sectional investigation using the Mackworth clock-test

H. J. Eysenck has postulated—and received some empirical support for—an inverse relationship between extraversion and arousal level. Age and extraversion have been found to be negatively correlated. These two outcomes led to the conclusion that arousal level must be increasing with age. This conclusion, however, runs counter to evidence which indicates a lowered arousal with old age. In an attempt to resolve this apparent conundrum a sample of 134 men from 32 to 91 years of age participated in the Mackworth Clock-Test of vigilance during which their arousal level was measured by electrodermal activity. One measure of arousal was unrelated to extraversion both within and across young, middle, and old age groups. For the second measure of arousal as age increased a decrease in arousal level was observed and the relationship of extraversion and arousal was found to be a function of age: inverse for young, none for middle-aged, direct for old. In addition no relation was found between vigilance performance and extraversion.     

Subjective experience and the attentional lapse: task engagement and disengagement during sustained attention

Three experiments investigated the relationship between subjective experience and attentional lapses during sustained attention. These experiments employed two measures of subjective experience (thought probes and questionnaires) to examine how differences in awareness correspond to variations in both task performance (reaction time and errors) and psycho-physiological measures (heart rate and galvanic skin response). This series of experiments examine these phenomena during the Sustained Attention to Response Task (SART, Robertson, Manly, Adrade, Baddeley, & Yiend, 1997). The results suggest we can dissociate between two components of subjective experience during sustained attention: (A) task unrelated thought which corresponds to an absent minded disengagement from the task and (B) a pre-occupation with one's task performance that seems to be best conceptualised as a strategic attempt to deploy attentional resources in response to a perception of environmental demands which exceed ones ability to perform the task. The implications of these findings for our understanding of how awareness is maintained on task relevant material during periods of sustained attention are discussed.     

Sensory modality, temperament, and the development of sustained attention: a vigilance study in children and adults

Applying optimal stimulation theory, the present study explored the development of sustained attention as a dynamic process. It examined the interaction of modality and temperament over time in children and adults. Second-grade children and college-aged adults performed auditory and visual vigilance tasks. Using the Carey temperament questionnaires (S. C. McDevitt & W. B. Carey, 1995), the authors classified participants according to temperament composites of reactivity and task orientation. In a preliminary study, tasks were equated across age and modality using d' matching procedures. In the main experiment, 48 children and 48 adults performed these calibrated tasks. The auditory task proved more difficult for both children and adults. Intermodal relations changed with age: Performance across modality was significantly correlated for children but not for adults. Although temperament did not significantly predict performance in adults, it did for children. The temperament effects observed in children--specifically in those with the composite of reactivity--occurred in connection with the auditory task and in a manner consistent with theoretical predictions derived from optimal stimulation theory.     

The development of hand preference in children: The effect of task demands and links with manual dexterity

Lateralisation of hand preference and manual dexterity are known to develop over childhood, while in adulthood strength of hand preference has been shown to interact with extrinsic task demands. Some evidence exists to suggest that strength of hand preference and motor skill may be related. In the current study a handedness inventory, midline crossing (QHP) and peg-moving tasks were used to investigate: (1) the development of hand preference between 4 and 11 years; (2) whether extrinsic task demands affect strength of hand preference, and (3) whether strength of hand preference was associated with manual dexterity. Younger children (4–5 years) showed weak hand preference in comparison to older children (8–11 years), and extrinsic task demands influenced willingness to cross the body’s midline with the preferred hand. Age and peg-moving speed were associated with midline crossing in certain task conditions. Overall, results suggest a coupling between manual dexterity and brain maturation in typical development.     

Prospective memory in children: the effects of age and task interruption

Prospective memory (PM), remembering to carry out a task in the future, is highly relevant to children's everyday functioning, yet relatively little is known about it. For these reasons the effects of age and task interruption on PM were studied in 3 experiments. Children aged 4, 5, and 7 years were asked to name pictures in stacks of cards (the ongoing task) and to remember to do something when they saw a target picture (the PM task). Significant age differences were identified, but age explained only a small amount of variance. As predicted, children in the no-interruption condition performed significantly better than those who had to interrupt the ongoing activity in order to carry out the PM task. An additional finding was that no relation was detected between performance on prospective and retrospective memory tasks. Taken together, these findings provide support for current models of PM and identify ways to assist children's PM.     

The effect of feedback on timing in children and adults: the temporal generalization task.

Children aged 5 and 8 years and adults were tested on a temporal generalization task with a standard duration of 600 ms in a condition with or without corrective feedback. In all conditions, the participants produced orderly temporal generalization gradients, although these were flatter in the younger children, especially in the no-feedback condition. Nevertheless, the results show that the feedback increased the steepness of the generalization gradient in all age groups and in a greater extent in the younger children. Our clock-based model suggested that feedback reduces the variability of the memory representation of the standard duration but also the probability of random responses in the 5-year-olds.     

Selective and sustained attention in children with spina bifida myelomeningocele

This study examined memory functioning in children and adolescents with 22q11.2 Deletion Syndrome (DS; velocardiofacial syndrome). An overall verbal better than nonverbal memory pattern was evident on the Test of Memory and Learning (TOMAL), with children with 22q11.2 DS performing significantly below their siblings and children with low average IQ but similar to children with autism on facial memory. Children with 22q11 DS also performed significantly below their siblings on tests of verbal working memory. Children with autism performed significantly poorer than the siblings of children with 22q11.2 DS only on their recall of stories. Delayed recall was significantly poorer in children with 22q11.2 DS and children with autism, compared to sibling controls. Although there were no significant group differences on tests of multiple trial verbal or visual learning, a relative weakness was noted with multiple trial visual learning in children with 22q11.2 DS and their siblings, suggesting that an alternative or interactive factor other than the deletion may account for the relatively better verbal compared to nonverbal memory abilities. Deficits in facial memory in children with both 22q11.2 DS and autism suggest disruptions in ventral temporal pathways such as between fusiform gyrus and parahippocampal/hippocampal regions whereas deficits in verbal working memory in children with 22q11.2 DS implicates dorsolateral prefrontal regions, both intimating aberrant white matter pathways.     

Effects of test order and modality on sustained attention in children with epilepsy.

Neurological conditions affect sustained attention, but the effects of modality and interactions with test order have not been examined. In a 2 x 2 (Order x Modality) design using 54 children with chronic epilepsy, performance was compared on an auditory measure (modified Seashore Rhythm Test) versus a visual measure of attention (modified Conners' Continuous Performance Test). Auditory scores were worse than visual, F(1, 52) = 98.93, p<.001, but there was no order effect or interaction (p>.05). Implications for assessment and intervention are discussed.     

Evidence of difficulties in sustained attention in children with ADDH

It has been suggested that children with ADDH have specific difficulties in sustained attention. Despite some early studies supporting this position, many recent reports using continuous peformance tests (CPTs) have failed to confirm this hypothesis. Possible reasons for this discrepancy are outlined and an attempt to corroborate and extend an earlier study (Sykes, Douglas, & Morgenstern, 1973) was undertaken. CPT results in normal children indicated that changes in performance over time, although not affected by gender, were influenced by age. Data from ADDH subjects indicated that they performed significantly more poorly with time on task than did controls. These results suggest that the ability to sustain attention increases with age and does not vary by gender. Furthermore, difficultues in the ability to sustain attention can be demonstrated in children with ADDH. Finally, it is suggested that within-age-level comparisons between groups of ADDH and controls would be more clinically sensitive than across-age-group comparisons.This research was supported in part by a Sara Spencer Research Fellowship granted to the first author. Portions of this research were presented at the 17th annual meeting of the International Neuropsychological Society, Vancouver.     

工作记忆负荷对无意注意的影响

通过探讨工作记忆负荷对无意注意的影响,考察工作记忆的认知控制功能对选择性注意的作用机制。为了避免工作记忆和选择注意的目标或者干扰子之间的知觉注意资源的竞争,采用言语工作记忆任务和视觉空间位置辨别任务,同时视觉干扰刺激采用被试无法识别的韩语。结果发现,在高负荷条件下,干扰效应显著;而在低和中负荷条件下,没有观察到干扰效应。说明在高负荷条件下,被试没有额外的资源来抑制干扰加工,从而出现了显著的干扰效应。由此,本研究支持负荷理论的观点：工作记忆在选择性注意中执行认知控制功能。     

Age-related changes in visual and auditory sustained attention in preschool-aged children

Objective: The development of sustained attention in the preschool years is not yet fully understood. Delineating age-related changes of attentional proficiencies and deficiencies is important for understanding atypical developmental trajectories, specifically in neurodevelopmental disorders that are characterized by attentional difficulties. The objective of the current study was to develop preschool-appropriate measures for assessing sustained attention and to chart developmental changes in attention in early childhood. Method: Using adapted computerized paradigms, the present study investigated age-related changes in visual and auditory sustained attention in seventy typically developing children aged 3 to 6 years. Results: The results indicated that similar age-related gains in performance emerged across both visual and auditory attention tasks. Conclusion: The findings suggest that the adapted measures developed in this study are sensitive enough to capture developmental variations in attention performance.     

Encoding during the attentional lapse: accuracy of encoding during the semantic sustained attention to response task

An experiment investigated the relationship between the ability to encode verbal stimuli during an attentional lapse. The task employed a variation on the sustained attention to response task (SART, Robertson, Manly, Andrade, Baddeley, & Yiend, 1997) which involved the detection of an infrequent target against a background of words. As a manipulation, participants were either instructed to encode the stimuli or were merely exposed to the stimuli. Retrieval was measured using process dissociation. Irrespective of the instructions given to the participants during the task, participants were more likely to retrieve information on the basis of recollection after an error was made than before, whilst the likelihood of retrieving information on the basis of familiarity remained invariant over the same period. The implications of this result for methods of investigating subjective experience are discussed.     

Effects of increasing cognitive load on sustained attention tasks in schizophrenic disorders and schizotypy

In this study we analyze the attentional performance using different cognitive load attentional tasks: low-load cognition (0-CPT) and high-load cognition (DS-CPT). Participants were a group of schizophrenic patients and two groups of normal population psychometrically classified as low schizotypy and high schizotypy according to the SPQ. Our results show that schizophrenic patients were more sensitive to increments on cognitive load, being their attentional performace worse than the rest of the groups. The lack of significant findings in vigilance on the schizotypal traits group is discussed in terms of conceptual and methodological issues about the utility of psychometric strategies to identify vulnerable populations within the spectrum of the schizophrenic disorders.     

A continuous performance task in preschool children: Relations between attention and performance

The continuous performance task is currently used to detect attention disorders in school-age children. However, its use with younger children is problematical, because indices measuring attention indirectly (omissions, commissions, reaction time) may be distorted by difficulties in following instructions: the ability to maintain and manipulate instructions in working memory, and to inhibit inappropriate actions increases with age. In the present research, we adapted such a task for children between 2 years 6months and 5 years 6 months, and recorded visual activity in order to measure directly visual attention and to relate it to performance. Even very young children spend most of the time looking at the screen, but they display poor performances and are unable to re-engage in the task after a gap (2 consecutive omissions). At a medium level (age 3 years 6 months to 4 years) endogenous control of attention increases, children come back to the task, off-task looks shorten and reach the short values observed in older children. After 4 years 6 months no more gaps are observed, the consistency of reaction times shows that a controlled strategy, including shifts from and to the screen, is now adopted. The discussion suggests that only at this upper level do indirect performance indices evaluate attention.     

The interacting effect of load and space on visual selective attention

In the study of visual attention, two major determinants of our ability to ignore distracting information have been isolated, namely, (1) the spatial separation from the focus of attention and (2) perceptual load. This study manipulated both factors using a dual-task adaptation of the flanker paradigm (Eriksen & Hoffman, 1973). It showed that (1) although attention followed a gradient profile under low perceptual load it followed a Mexican-hat profile under high perceptual load, consistent with the idea that increasing load focuses spatial attention; and (2) increasing perceptual load did not improve overall selectivity: Though selectivity improved at near separations, it was impaired at far ones. Load and spatial separation exert interacting effects.