Nature and measurement of attention control.

Individual differences in the ability to control attention are correlated with a wide range of important outcomes, from academic achievement and job performance to health behaviors and emotion regulation. Nevertheless, the theoretical nature of attention control as a cognitive construct has been the subject of heated debate, spurred on by psychometric issues that have stymied efforts to reliably measure differences in the ability to control attention. For theory to advance, our measures must improve. We introduce three efficient, reliable, and valid tests of attention control that each take less than 3 min to administer: Stroop Squared, Flanker Squared, and Simon Squared. Two studies (online and in-lab) comprising more than 600 participants demonstrate that the three "Squared" tasks have great internal consistency (avg. = .95) and test-retest reliability across sessions (avg. r = .67). Latent variable analyses revealed that the Squared tasks loaded highly on a common factor (avg. loading = .70), which was strongly correlated with an attention control factor based on established measures (avg. r = .81). Moreover, attention control correlated strongly with fluid intelligence, working memory capacity, and processing speed and helped explain their covariation. We found that the Squared attention control tasks accounted for 75% of the variance in multitasking ability at the latent level, and that fluid intelligence, attention control, and processing speed fully accounted for individual differences in multitasking ability. Our results suggest that Stroop Squared, Flanker Squared, and Simon Squared are reliable and valid measures of attention control. The tasks are freely available online: https://osf.io/7q598/. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Fluid intelligence and the locus coeruleus-norepinephrine system.

The last decade has seen significant progress identifying genetic and brain differences related to intelligence. However, there remain considerable gaps in our understanding of how cognitive mechanisms that underpin intelligence map onto various brain functions. In this article, we argue that the locus coeruleus-norepinephrine system is essential for understanding the biological basis of intelligence. We review evidence suggesting that the locus coeruleus-norepinephrine system plays a central role at all levels of brain function, from metabolic processes to the organization of large-scale brain networks. We connect this evidence with our executive attention view of working-memory capacity and fluid intelligence and present analyses on baseline pupil size, an indicator of locus coeruleus activity. Using a latent variable approach, our analyses showed that a common executive attention factor predicted baseline pupil size. Additionally, the executive attention function of disengagement--not maintenance--uniquely predicted baseline pupil size. These findings suggest that the ability to control attention may be important for understanding how cognitive mechanisms of fluid intelligence map onto the locus coeruleus-norepinephrine system. We discuss how further research is needed to better understand the relationships between fluid intelligence, the locus coeruleus-norepinephrine system, and functionally organized brain networks.

The visual arrays task: Visual storage capacity or attention control?

Extant literature suggests that performance on visual arrays tasks reflects limited-capacity storage of visual information. However, there is also evidence to suggest that visual arrays task performance reflects individual differences in controlled processing. The purpose of this study is to empirically evaluate the degree to which visual arrays tasks are more closely related to memory storage capacity or measures of attention control. To this end, we conducted new analyses on a series of large data sets that incorporate various versions of a visual arrays task. Based on these analyses, we suggest that the degree to which the visual arrays is related to memory storage ability or effortful attention control may be task-dependent. Specifically, when versions of the task require participants to ignore elements of the target display, individual differences in controlled attention reliably provide unique predictive value. Therefore, at least some versions of the visual arrays tasks can be used as valid indicators of individual differences in attention control. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Is baseline pupil size related to cognitive ability? Yes (under proper lighting conditions).

There has been some controversy as to whether baseline pupil size is related to individual differences in cognitive ability. Previously, we had shown that a larger baseline pupil size was associated with higher cognitive ability and that the correlation to fluid intelligence was larger than that to working memory capacity (Tsukahara, Harrison, & Engle, 2016). However, other researchers have not been able to replicate our findings - though they only measured working memory capacity and not fluid intelligence. Many of the studies showing no relationship had major methodological issues, namely small baseline pupil size values - down to the physiological minimum - that resulted in reduced variability on baseline pupil size. We conducted two large-scale studies to investigate how different lighting conditions affect baseline pupil size values and the correlation with cognitive abilities. We found that fluid intelligence, working memory capacity, and attention control did correlate with baseline pupil size except in the brightest lighting conditions. We showed that a reduced variability in baseline pupil size values is due to the monitor settings being too bright. Overall, our findings demonstrated that the baseline pupil size - working memory capacity relationship was not as strong or robust as that with fluid intelligence or attention control. Our findings have strong methodological implications for researchers investigating individual differences in task-free or task-evoked pupil size. We conclude that fluid intelligence does correlate with baseline pupil size and that this is related to the functional organization of the resting-state brain through the locus coeruleus-norepinephrine system.

A toolbox approach to improving the measurement of attention control.

Cognitive tasks that produce reliable and robust effects at the group level often fail to yield reliable and valid individual differences. An ongoing debate among attention researchers is whether conflict resolution mechanisms are task-specific or domain-general, and the lack of correlation between most attention measures seems to favor the view that attention control is not a unitary concept. We have argued that the use of difference scores, particularly in reaction time (RT), is the primary cause of null and conflicting results at the individual differences level, and that methodological issues with existing tasks preclude making strong theoretical conclusions. The present article is an empirical test of this view in which we used a toolbox approach to develop and validate new tasks hypothesized to reflect attention processes. Here, we administered existing, modified, and new attention tasks to over 400 participants (final N = 396). Compared with the traditional Stroop and flanker tasks, performance on the accuracy-based measures was more reliable, had stronger intercorrelations, formed a more coherent latent factor, and had stronger associations to measures of working memory capacity and fluid intelligence. Further, attention control fully accounted for the relationship between working memory capacity and fluid intelligence. These results show that accuracy-based measures can be better suited to individual differences investigations than traditional RT tasks, particularly when the goal is to maximize prediction. We conclude that attention control is a unitary concept. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Attention control: The missing link between sensory discrimination and intelligence.

Intelligence is correlated with the ability to make fine sensory discriminations. Although this relationship has been known since the beginning of intelligence testing, the mechanisms underlying this relationship are still unknown. In two large-scale structural equation-modelling studies, we investigated whether individual differences in attention control abilities can explain the relationship between sensory discrimination and intelligence. Across these two studies, we replicated the finding that attention control fully mediated the relationships of intelligence/working-memory capacity to sensory discrimination. Our findings show that attention control plays a prominent role in relating sensory discrimination to higher-order cognitive abilities.

The relationship between baseline pupil size and intelligence.

Pupil dilations of the eye are known to correspond to central cognitive processes. However, the relationship between pupil size and individual differences in cognitive ability is not as well studied. A peculiar finding that has cropped up in this research is that those high on cognitive ability have a larger pupil size, even during a passive baseline condition. Yet these findings were incidental and lacked a clear explanation. Therefore, in the present series of studies we systematically investigated whether pupil size during a passive baseline is associated with individual differences in working memory capacity and fluid intelligence. Across three studies we consistently found that baseline pupil size is, in fact, related to cognitive ability. We showed that this relationship could not be explained by differences in mental effort, and that the effect of working memory capacity and fluid intelligence on pupil size persisted even after 23 sessions and taking into account the effect of novelty or familiarity with the environment. We also accounted for potential confounding variables such as; age, ethnicity, and drug substances. Lastly, we found that it is fluid intelligence, more so than working memory capacity, which is related to baseline pupil size. In order to provide an explanation and suggestions for future research, we also consider our findings in the context of the underlying neural mechanisms involved.