An item response theory approach to the measurement of working memory capacity.

Complex span tasks are perhaps the most widely used paradigm to measure working memory capacity (WMC). Researchers assume that all types of complex span tasks assess domain-general WM. However, most research supporting this claim comes from factor analysis approaches that do not examine task performance at the item level, thus not allowing comparison of the characteristics of verbal and spatial complex span tasks. Item response theory (IRT) can help determine the extent to which different complex span tasks assess domain-general WM. In the current study, spatial and verbal complex span tasks were examined using IRT. The results revealed differences between verbal and spatial tasks in terms of item difficulty and block difficulty, and showed that most subjects with below-average ability were able to answer most items correctly across all tasks. In line with previous research, the findings suggest that examining domain-general WM by using only one task might elicit skewed scores based on task domain. Further, visuospatial complex span tasks should be prioritized as a measure of WMC if resources are limited.

On the psychometric evaluation of cognitive control tasks: An Investigation with the Dual Mechanisms of Cognitive Control (DMCC) battery.

The domain of cognitive control has been a major focus of experimental, neuroscience, and individual differences research. Currently, however, no theory of cognitive control successfully unifies both experimental and individual differences findings. Some perspectives deny that there even exists a unified psychometric cognitive control construct to be measured at all. These shortcomings of the current literature may reflect the fact that current cognitive control paradigms are optimized for the detection of within-subject experimental effects rather than individual differences. In the current study, we examine the psychometric properties of the Dual Mechanisms of Cognitive Control (DMCC) task battery, which was designed in accordance with a theoretical framework that postulates common sources of within-subject and individual differences variation. We evaluated both internal consistency and test-retest reliability, and for the latter, utilized both classical test theory measures (i.e., split-half methods, intraclass correlation) and newer hierarchical Bayesian estimation of generative models. Although traditional psychometric measures suggested poor reliability, the hierarchical Bayesian models indicated a different pattern, with good to excellent test-retest reliability in almost all tasks and conditions examined. Moreover, within-task, between-condition correlations were generally increased when using the Bayesian model-derived estimates, and these higher correlations appeared to be directly linked to the higher reliability of the measures. In contrast, between-task correlations remained low regardless of theoretical manipulations or estimation approach. Together, these findings highlight the advantages of Bayesian estimation methods, while also pointing to the important role of reliability in the search for a unified theory of cognitive control.

The impact of auditory distraction on reading comprehension: An individual differences investigation.

Background noise disrupts auditory selective attention and impairs performance on cognitive tasks, but the degree to which it is disruptive depends on the task and the individual. According to the load theory of attention and cognitive control, selective attention is influenced by both the perceptual load and the cognitive load of the primary task. Recent studies suggest that hard-to-read font in a reading task may shield attention against background noise and auditory distraction. The current study examined the disruptive effect of background noise on reading comprehension as a function of perceptual load and cognitive load. Perceptual load was manipulated by introducing task disfluency (hard-to-read or easy-to-read font), and cognitive load was manipulated by varying the type of background noise and investigating individual differences in working memory capacity. The results suggest that high perceptual load and high working memory capacity both facilitate reading comprehension. However, contrary to previous research, neither perceptual load nor capacity moderates the disruptive effect of background noise. These results failed to support the generalizability and applicability of the shield effect of perceptual disfluency against auditory distraction during reading but supported the beneficial effect of perceptual disfluency on reading comprehension.

The evolution of fluid intelligence meets formative g.

The argument by Burkart et al. in the target article relates to fluid (not general) intelligence: a domain-general ability involved in complex, novel problem solving, and strongly related to working memory and executive functions. A formative framework, under which the general factor of intelligence is the common consequence, not the common cause of the covariance among tests is more in line with an evolutionary approach.

Phonological similarity in working memory span tasks.

In a series of four experiments, we explored what conditions are sufficient to produce a phonological similarity facilitation effect in working memory span tasks. By using the same set of memoranda, but differing the secondary-task requirements across experiments, we showed that a phonological similarity facilitation effect is dependent upon the semantic relationship between the memoranda and the secondary-task stimuli, and is robust to changes in the representation, ordering, and pool size of the secondary-task stimuli. These findings are consistent with interference accounts of memory (Brown, Neath, & Chater, Psychological Review, 114, 539-576, 2007; Oberauer, Lewandowsky, Farrell, Jarrold, & Greaves, Psychonomic Bulletin & Review, 19, 779-819, 2012), whereby rhyming stimuli provide a form of categorical similarity that allows distractors to be excluded from retrieval at recall.

The scope and control of attention: Sources of variance in working memory capacity.

Working memory capacity is a strong positive predictor of many cognitive abilities, across various domains. The pattern of positive correlations across domains has been interpreted as evidence for a unitary source of inter-individual differences in behavior. However, recent work suggests that there are multiple sources of variance contributing to working memory capacity. The current study (N = 71) investigates individual differences in the scope and control of attention, in addition to the number and resolution of items maintained in working memory. Latent variable analyses indicate that the scope and control of attention reflect independent sources of variance and each account for unique variance in general intelligence. Also, estimates of the number of items maintained in working memory are consistent across tasks and related to general intelligence whereas estimates of resolution are task-dependent and not predictive of intelligence. These results provide insight into the structure of working memory, as well as intelligence, and raise new questions about the distinction between number and resolution in visual short-term memory.

Capacity estimates in working memory: Reliability and interrelationships among tasks.

The concept of capacity has become increasingly important in discussions of working memory (WM), in so far as most models of WM conceptualize it as a limited-capacity mechanism for maintaining information in an active state, and as capacity estimates from at least one type of WM task-complex span-are valid predictors of real-world cognitive performance. However, the term capacity is also often used in the context of a distinct set of WM tasks, change detection, and may or may not refer to the same cognitive capability. We here develop maximum-likelihood models of capacity from each of these tasks-as well as from a third WM task that places heavy demands on cognitive control, the self-ordered WM task (SOT)-and show that the capacity estimates from change detection and complex span tasks are not correlated with each other, although capacity estimates from change detection tasks do correlate with those from the SOT. Furthermore, exploratory factor analysis confirmed that performance on the SOT and change detection load on the same factor, with performance on our complex span task loading on its own factor. These findings suggest that at least two distinct cognitive capabilities underlie the concept of WM capacity as it applies to each of these three tasks.

A nuanced view of the extent to which samples from narrow populations are scientifically problematic.

Psychologists have a traditional concern with participant samples from narrow populations and deleterious effects on researchers' ability to generalize findings. Recently, both individuals and authoritative organizations, such as the American Psychological Association, have merged this external validity concern with diversity and inclusion concerns. The American Psychological Association directive for researchers to include diverse samples seems obviously well-taken as it purports to mitigate these problems at once; it simultaneously increases external validity and promotes diversity and inclusion. However, we show that there are complications. These include problems with internal and external validity conceptualizations; that sometimes generalization failures can support, rather than detract from, external validity; the crucial role auxiliary assumptions play in impacting internal and external validity; Lakatosian degenerative science and its problematic application; and distinguishing between merely including diverse groups in research samples versus analyzing for group differences. These complications imply a nuanced perspective of whether samples from narrow populations are undesirable. That a sample is from a narrow population might, or might not, preclude strong support or disconfirmation for the theory, including its ability to generalize. Our nuanced perspective militates against the current trend of journal directives to require diverse samples. Sample suitability for particular researcher goals should be judged on a case-by-case basis that takes into account that sometimes samples from narrow populations can nevertheless engender impressive scientific progress and sometimes not. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Working memory for social information: chunking or domain-specific buffer?

Humans possess unique social abilities that set us apart from other species. These abilities may be partially supported by a large capacity for maintaining and manipulating social information. Efficient social working memory might arise from two different sources: chunking of social information or a domain-specific buffer. We test these hypotheses with functional magnetic resonance imaging (fMRI) by manipulating sociality and working memory load in an n-back paradigm. We observe (i) an effect of load in the frontoparietal control network, (ii) an effect of sociality in regions associated with social cognition and face processing, and (iii) an interaction within the frontoparietal network such that social load has a smaller effect than nonsocial load. These results support the hypothesis that working memory is more efficient for social information than for nonsocial information, and suggest that chunking, rather than a domain-specific buffer, is the mechanism of this greater efficiency.

The Structure of Cognitive Abilities and Associations with Problem Behaviors in Early Adolescence: An Analysis of Baseline Data from the Adolescent Brain Cognitive Development Study.

Using baseline data (n = 9875) from the Adolescent Brain Cognitive Development (ABCD) Study examining children aged 9 to 10 years, the current analyses included: (1) exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) of neurocognitive measures administered during baseline collection, and (2) linear regression analyses on the Child Behavior Checklist (CBCL), controlling for demographic and socioeconomic factors. The neurocognitive tasks measured episodic memory, executive function (EF; attention), language skills, processing speed, working memory, visuospatial ability, and reasoning. The CBCL included composite scores of parent-reported internalizing, externalizing, and stress-related behavior problems. The study reported here serves as an extension of prior research using a principal components analysis (PCA) of the ABCD baseline data. We propose an alternative solution using factor analysis. Analyses revealed a three-factor structure: verbal ability (VA), executive function/processing speed (EF/PS), and working memory/episodic memory (WM/EM). These factors were significantly correlated with the CBCL scores, albeit with small effect sizes. These findings provide a novel three-factor solution to the structure of cognitive abilities measured in the ABCD Study, offering new insights into the association between cognitive function and problem behaviors in early adolescence.

Domain-general mechanisms of complex working memory span.

A new fMRI complex working memory span paradigm was used to identify brain regions making domain-general contributions to working memory task performance. For both verbal and spatial versions of the task, complex working memory span performance increased the activity in lateral prefrontal, anterior cingulate, and parietal cortices during the Encoding, Maintenance, and Coordination phase of task performance. Meanwhile, overlapping activity in anterior prefrontal and medial temporal lobe regions was associated with both verbal and spatial recall from working memory. These findings help to adjudicate several contested issues regarding the executive mechanisms of working memory, the separability of short-term and working memory in the verbal and spatial domains, and the relative contribution of short-term and long-term memory mechanisms to working memory capacity. The study also provides a vital bridge between psychometric and neuroimaging approaches to working memory, and constrains our understanding of how working memory may contribute to the broader landscape of cognitive performance.

Phonological similarity effects in simple and complex span tasks.

Three experiments were conducted to examine the effect of phonological similarity in simple and complex memory span tasks. In Experiment 1, participants performed either a simple or a complex span task, and the memoranda within lists were either phonologically similar or distinct. Phonologically similar lists consisted of words that rhymed.The simple span task was word span. There were two complex span tasks; one was the original reading span task, and the other was a variant of reading span in which all the sentences within a list were contextually related. The classic phonological similarity decrement was observed in word span. In contrast, phonological similarity facilitation was observed in both versions of reading span. This facilitation effect was further investigated in Experiment 2 using two new versions of reading span. In Experiment 2, the sentences in reading span were either short or long, and the memoranda were presented separately from, and were unrelated to, the sentences. Again, words within phonologically similar lists rhymed, and again, facilitation was observed. In Experiment 3, phonological similarity was operationalized in terms of feature overlap, rather than rhyme. The classic phonological similarity decrement was still observed in word span, but facilitation was not observed in complex span. The results suggest that phonological similarity, when operationalized using words that rhyme, serves as a list retrieval cue and that complex span tasks are more dependent on cue-driven memory retrieval mechanisms than are simple span tasks.

From the Incoming Editor.

First, let me say that I am honored to take on the role of Editor in Chief at the Journal of Intelligence [...].

The Relationship between Theory of Mind and Intelligence: A Formative g Approach.

Theory of Mind (ToM) is the ability understand that other people's mental states may be different from one's own. Psychometric models have shown that individual differences in ToM can largely be attributed to general intelligence (g) (Coyle et al. 2018). Most psychometric models specify g as a reflective latent variable, which is interpreted as a general ability that plays a causal role in a broad range of cognitive tasks, including ToM tasks. However, an alternative approach is to specify g as a formative latent variable, that is, an overall index of cognitive ability that does not represent a psychological attribute (Kovacs and Conway 2016). Here we consider a formative g approach to the relationship between ToM and intelligence. First, we conducted an SEM with reflective g to test the hypothesis that ToM is largely accounted for by a general ability. Next, we conducted a model with formative g to determine whether the relationship between ToM and intelligence is influenced by domain-specific tasks. Finally, we conducted a redundancy analysis to examine the contribution of each g variable. Results suggest that the relationship between ToM and intelligence in this study was influenced by language-based tasks, rather than solely a general ability.

Individual Differences in Attention and Intelligence: A United Cognitive/Psychometric Approach.

Process overlap theory (POT) is a new theoretical framework designed to account for the general factor of intelligence (g). According to POT, g does not reflect a general cognitive ability. Instead, g is the result of multiple domain-general executive attention processes and multiple domain-specific processes that are sampled in an overlapping manner across a battery of intelligence tests. POT explains several benchmark findings on human intelligence. However, the precise nature of the executive attention processes underlying g remains unclear. In the current paper, we discuss challenges associated with building a theory of individual differences in attention and intelligence. We argue that the conflation of psychological theories and statistical models, as well as problematic inferences based on latent variables, impedes research progress and prevents theory building. Two studies designed to illustrate the unique features of POT relative to previous approaches are presented. In Study 1, a simulation is presented to illustrate precisely how POT accounts for the relationship between executive attention processes and g. In Study 2, three datasets from previous studies are reanalyzed (N = 243, N = 234, N = 945) and reveal a discrepancy between the POT simulated model and the unity/diversity model of executive function. We suggest that this discrepancy is largely due to methodological problems in previous studies but also reflects different goals of research on individual differences in attention. The unity/diversity model is designed to facilitate research on executive function and dysfunction associated with cognitive and neural development and disease. POT is uniquely suited to guide and facilitate research on individual differences in cognitive ability and the investigation of executive attention processes underlying g.

Investigating the Structure of Intelligence Using Latent Variable and Psychometric Network Modeling: A Commentary and Reanalysis.

In a recent publication in the Journal of Intelligence, Dennis McFarland mischaracterized previous research using latent variable and psychometric network modeling to investigate the structure of intelligence. Misconceptions presented by McFarland are identified and discussed. We reiterate and clarify the goal of our previous research on network models, which is to improve compatibility between psychological theories and statistical models of intelligence. WAIS-IV data provided by McFarland were reanalyzed using latent variable and psychometric network modeling. The results are consistent with our previous study and show that a latent variable model and a network model both provide an adequate fit to the WAIS-IV. We therefore argue that model preference should be determined by theory compatibility. Theories of intelligence that posit a general mental ability (general intelligence) are compatible with latent variable models. More recent approaches, such as mutualism and process overlap theory, reject the notion of general mental ability and are therefore more compatible with network models, which depict the structure of intelligence as an interconnected network of cognitive processes sampled by a battery of tests. We emphasize the importance of compatibility between theories and models in scientific research on intelligence.

The Role of Non-Cognitive Factors in the SAT Remains Unclear: A Commentary on Hannon (2019).

In the current issue of the Journal of Intelligence, Hannon (2019) reports a novel and intriguing pattern of results that could be interpreted as evidence that the SAT is biased against Hispanic students. Specifically, Hannon's analyses suggest that non-cognitive factors, such as test anxiety, contribute to SAT performance and the impact of test anxiety on the SAT is stronger among Hispanic students than European-American students. Importantly, this pattern of results was observed after controlling for individual differences in cognitive abilities. We argue that there are multiple issues with Hannon's investigation and interpretation. For instance, Hannon did not include an adequate number or variety of measures of cognitive ability. In addition, the measure of test anxiety was a retrospective self-report survey on evaluated anxiety rather than a direct measure of situational test anxiety associated with the SAT. Based on these and other observations, we conclude that Hannon's current results do not provide sufficient evidence to suggest that non-cognitive factors play a significant role in the SAT or that they impact European-American and Hispanic students differently.

Psychometric Network Analysis of the Hungarian WAIS.

The positive manifold-the finding that cognitive ability measures demonstrate positive correlations with one another-has led to models of intelligence that include a general cognitive ability or general intelligence (g). This view has been reinforced using factor analysis and reflective, higher-order latent variable models. However, a new theory of intelligence, Process Overlap Theory (POT), posits that g is not a psychological attribute but an index of cognitive abilities that results from an interconnected network of cognitive processes. These competing theories of intelligence are compared using two different statistical modeling techniques: (a) latent variable modeling and (b) psychometric network analysis. Network models display partial correlations between pairs of observed variables that demonstrate direct relationships among observations. Secondary data analysis was conducted using the Hungarian Wechsler Adult Intelligence Scale Fourth Edition (H-WAIS-IV). The underlying structure of the H-WAIS-IV was first assessed using confirmatory factor analysis assuming a reflective, higher-order model and then reanalyzed using psychometric network analysis. The compatibility (or lack thereof) of these theoretical accounts of intelligence with the data are discussed.

Individual differences in delay discounting: relation to intelligence, working memory, and anterior prefrontal cortex.

Lower delay discounting (better self-control) is linked to higher intelligence, but the basis of this relation is uncertain. To investigate the potential role of working memory (WM) processes, we assessed delay discounting, intelligence (g), WM (span tasks, 3-back task), and WM-related neural activity (using functional magnetic resonance imaging) in 103 healthy adults. Delay discounting was negatively correlated with g and WM. WM explained no variance in delay discounting beyond that explained by g, which suggests that processes through which WM relates to delay discounting are shared by g. WM-related neural activity in left anterior prefrontal cortex (Brodmann's area 10) covaried with g, r= .26, and delay discounting, r=-.40, and partially mediated the relation between g and delay discounting. Overall, the results suggest that delay discounting is associated with intelligence in part because of processes instantiated in anterior prefrontal cortex, a region known to support the integration of diverse information.

Working memory, attention control, and the N-back task: a question of construct validity.

The N-back task requires participants to decide whether each stimulus in a sequence matches the one that appeared n items ago. Although N-back has become a standard "executive" working memory (WM) measure in cognitive neuroscience, it has been subjected to few behavioral tests of construct validity. A combined experimental- correlational study tested the attention-control demands of verbal 2- and 3-back tasks by presenting n = 1 "lure" foils. Lures elicited more false alarms than control foils in both 2- and 3-back tasks, and lures caused more misses to targets that immediately followed them compared with control targets, but only in 3-back tasks. N-back thus challenges control over familiarity-based responding. Participants also completed a verbal WM span task (operation span task) and a marker test of general fluid intelligence (Gf; Ravens Advanced Progressive Matrices Test; J. C. Raven, J. E. Raven, & J. H. Court, 1998). N-back and WM span correlated weakly, suggesting they do not reflect primarily a single construct; moreover, both accounted for independent variance in Gf. N-back has face validity as a WM task, but it does not demonstrate convergent validity with at least 1 established WM measure.