Is working memory fractionated onto different components of intelligence? A reply to Mackintosh and Bennett (2003)

Mental counters as an online tool for assessing working memory capacity

Working memory capacity (WMC) describes an individual's ability to focus their attention in the face of interference which allows them to actively maintain and manipulate information in immediate memory. Individual differences in WMC predict a wide range of psychological constructs. The development of online measures can enable data collection from broader, more diverse samples than those typically collected in person in laboratory settings. In addition, logistical challenges brought on by the COVID-19 pandemic have mandated the need for reliable and valid remote assessments of individual differences that are both culture-fair and less susceptible to cheating. This study reports details of a new online version of a Mental Counters task that takes only 10 min to collect and provides evidence for its reliability and convergent validity with other measures including Picture Span and Paper Folding.

The role of attention control in complex real-world tasks

Working memory capacity is an important psychological construct, and many real-world phenomena are strongly associated with individual differences in working memory functioning. Although working memory and attention are intertwined, several studies have recently shown that individual differences in the general ability to control attention is more strongly predictive of human behavior than working memory capacity. In this review, we argue that researchers would therefore generally be better suited to studying the role of attention control rather than memory-based abilities in explaining real-world behavior and performance in humans. The review begins with a discussion of relevant literature on the nature and measurement of both working memory capacity and attention control, including recent developments in the study of individual differences of attention control. We then selectively review existing literature on the role of both working memory and attention in various applied settings and explain, in each case, why a switch in emphasis to attention control is warranted. Topics covered include psychological testing, cognitive training, education, sports, police decision-making, human factors, and disorders within clinical psychology. The review concludes with general recommendations and best practices for researchers interested in conducting studies of individual differences in attention control.

Working memory capacity and mental rotation: evidence for a domain-general view

Despite the existence of numerous studies that examined the relationship between working memory capacity and performance in complex cognitive tasks, it remains unclear whether this capacity is domain specific or domain general. In addition, the available empirical evidence is somewhat contradictory. In this work we have studied the role of verbal working memory capacity in a non-verbal task--mental image rotation. If this capacity were domain specific it would be expected that high and low verbal span participants would obtain similar results in the mental rotation task. We have found that this is not the case as the high span participants performed better in terms of both speed and accuracy. Moreover, these differences depended on the processing component of the mental rotation task: the higher the processing requirements the higher the differences as a function of the working memory capacity. Therefore, the evidence presented here supports the domain general hypothesis.

Contextual analysis of fluid intelligence

The nature of fluid intelligence was investigated by identifying variables that were, and were not, significantly related to this construct. Relevant information was obtained from three sources: re-analyses of data from previous studies, a study in which 791 adults performed storage-plus-processing working memory tasks, and a study in which 236 adults performed a variety of working memory, updating, and cognitive control tasks. The results suggest that fluid intelligence represents a broad individual difference dimension contributing to diverse types of controlled or effortful processing. The analyses also revealed that very few of the age-related effects on the target variables were statistically independent of effects on established cognitive abilities, which suggests most of the age-related influences on a wide variety of cognitive control variables overlap with age-related influences on cognitive abilities such as fluid intelligence, episodic memory, and perceptual speed.

General intelligence and memory span: evidence for a common neuroanatomic framework

General intelligence (g) is highly correlated with working-memory capacity (WMC). It has been argued that these central psychological constructs should share common neural systems. The present study examines this hypothesis using structural magnetic resonance imaging to determine any overlap in brain areas where regional grey matter volumes are correlated to measures of general intelligence and to memory span. In normal volunteers (N = 48) the results (p < .05, corrected for multiple comparisons) indicate that a common anatomic framework for these constructs implicates mainly frontal grey matter regions belonging to Brodmann area (BA) 10 (right superior frontal gyrus and left middle frontal gyrus) and, to a lesser degree, the right inferior parietal lobule (BA 40). These findings support the nuclear role of a discrete parieto-frontal network.

The real relationship between short-term memory and working memory

Storage-oriented memory span tasks with no explicit concurrent processing are usually referred as short-term memory (STM) tasks, whereas tasks involving storage plus concurrent processing requirements are designated as working memory (WM) tasks. The present study explores a question that remains unsolved: Do STM and WM tasks clearly tap distinguishable theoretical constructs? For that purpose, a large sample of 403 participants was tested through 12 diverse memory span tasks. Half of those tasks are widely accepted as measures of STM, whereas the other half measure WM. The results show that STM and WM share largely overlapping underlying capacity limitations, suggesting that all memory span tasks tap essentially the same construct. Some implications are discussed.

Complex span tasks, simple span tasks, and cognitive abilities: a reanalysis of key studies

There is great interest in the relationships between memory span tasks and cognitive abilities. However, the causes underlying their correlation remain unknown. In the present article, five key data sets were reanalyzed according to two criteria: They must consider complex span tasks (so-called working memory [WM] tasks) and simple span tasks (so-called short-term memory [STM] tasks), and they must comprise cognitive ability measures. The obtained results offer several points of interest. First, memory span tasks should be conceived from a hierarchical perspective: They comprise both general and specific components. Second, the general component explains about four times the variance explained by the specific components. Third, STM and WM measures are closely related. Fourth, STM and WM measures share the same common variance with cognitive abilities. Finally, the strong relationship usually found between memory span tasks and cognitive abilities could be tentatively interpreted by the component shared by STM and WM--namely, the capacity for temporarily preserving a reliable memory representation of any given information.

Armazenamento de curto prazo e velocidade de processamento explicam a relação entre memória de trabalho e o fator g de inteligência

O presente artigo constitui a apresentação e discussão das evidências empíricas derivadas da análise das relações entre dois construtos-chaves do processamento humano de informação e da psicologia das diferenças individuais, a saber: a memória de trabalho e o fator geral de inteligência (g). Os resultados publicados avaliam a presença de um isomorfismo entre ambos construtos, embora ainda se desconheça a resposta à pergunta sobre o porquê desse isomorfismo. Enquanto algumas propostas favorecem uma explicação baseada em construtos tais como o controle da atenção, outras se inclinam pelo papel da capacidade para armazenar transitoriamente a informação e, em menor grau, da velocidade de processamento. Descrevem-se as principais discussões acadêmicas e se apresentam os resultados obtidos em recentes investigações conduzidas pelos autores. Conclui-se que os componentes de armazenamento e velocidade de processamento podem constituir a fonte de explicação da relação entre o construto de memória de trabalho e o fator g.