Adult age differences in task switching

Age differences in 2 components of task-set switching speed were investigated in 118 adults aged 20 to 80 years using task-set homogeneous (e.g., AAAA ...) and task-set heterogeneous (e.g., AABBAABB ... ) blocks. General switch costs were defined as latency differences between heterogeneous and homogeneous blocks. whereas specific switch costs were defined as differences between switch and nonswitch trials within heterogeneous blocks. Both types of costs generalized over verbal, figural, and numeric stimulus materials; were more highly correlated to fluid than to crystallized abilities; and were not eliminated after 6 sessions of practice, indicating that they reflect basic and domain-general aspects of cognitive control. Most important, age-associated increments in costs were significantly greater for general than for specific switch costs, suggesting that the ability to efficiently maintain and coordinate 2 alternating task sets in working memory instead of 1 is more negatively affected by advancing age than the ability to execute the task switch itself.     

Using confirmatory factor analysis to understand executive control in preschool children: I. Latent structure

Although many tasks have been developed recently to study executive control in the preschool years, the constructs that underlie performance on these tasks are poorly understood. In particular, it is unclear whether executive control is composed of multiple, separable cognitive abilities (e.g., inhibition and working memory) or whether it is unitary in nature. A sample of 243 normally developing children between 2.3 and 6 years of age completed a battery of age-appropriate executive control tasks. Confirmatory factor analysis was used to compare multiple models of executive control empirically. A single-factor, general model was sufficient to account for the data. Furthermore, the fit of the unitary model was invariant across subgroups of children divided by socioeconomic status or sex. Girls displayed a higher level of latent executive control than boys, and children of higher and lower socioeconomic status did not differ in level. In typically developing preschool children, tasks conceptualized as indexes of working memory and inhibitory control in fact measured a single cognitive ability, despite surface differences between task characteristics.     

Enriched housing reverses age-associated impairment of cognitive functions and tPA-dependent maturation of BDNF

Although tissue type plasminogen activator (tPA) and brain derived neurotrophic factor (BDNF) have been extensively described to influence brain outcomes in a number of disorders, their roles during physiological aging are poorly investigated. In the present study, we investigated whether maintenance of mice in different environmental conditions could influence age-associated changes in hippocampal tPA expression and BDNF maturation in relation with modifications of their cognitive performances. Our data indicate that maintenance in enriched housing led to a reversal of age-associated decrease in expression of hippocampal tPA. A subsequent increase in the level of mature BDNF and an improvement in emotional and spatial memories were observed. Taken together, these data suggest that the tPA–BDNF axis could play a critical role in the control of cognitive functions influenced both by the age and housing conditions.     

Age Differences in Perceived Positive Affect, Negative Affect, and Affect Balance in Middle and Old Age

Meta-analysis was used to synthesize findings from 125 studies on age differences in positive affect, negative affect, and affect balance. We found a small age-associated decline of positive affect and affect balance, and a small age-associated increase of negative affect. In addition, a quadratic age trend emerged, showing stronger declines of positive affect and stronger increases of negative affect in older subjects. Looking at changes of specific emotions, we found an age-associated decline of those positive and negative feelings that are associated with high arousal (e.g., feeling excited or upset), and an age-associated increase of positive and negative low-arousal emotions (e.g., feeling relaxed or depressed). Furthermore, older adults from the former communist Eastern European countries showed the strongest age-associated decline of positive affect and the strongest age-associated increase of negative affect. We conclude that age-associated losses in the oldest old and economic hardship make the optimization of subjective well-being increasingly difficult.     

Effects of aging on perceptual closure

Two research strategies were employed to investigate reasons for the poorer performance associated with increased age on perceptual closure tasks involving the integration and identification of incomplete pictures. One strategy consisted of examining age differences in measures designed to reflect the proficiency of processing components presumed to be involved in the closure task. The performance of older adults was significantly worse than that of young adults on each measure, suggesting that the age differences in the criterion task could not be localized in a single specific component. The second strategy involved determining whether young and old adults differed in the effects of practice or in the amount of specific and general transfer resulting from that practice. No age differences other than those in the overall level of performance were discovered, indicating that the age-associated problem may be independent of the processes contributing to the acquisition and transfer of new information. It was suggested that the age differences in perceptual closure tasks originate because of a general inefficiency in information processing due to a reduction in some type of general-purpose processing resource, and not because of a limitation in a single specific process.     

A Neuropsychological Approach to Intelligence

This paper proposes that current psychometric intelligence tests are limited in evaluating cognitive activity. From a neuropsychological perspective, they fail to measure some fundamental cognitive abilities such as executive functions, memory, and visuospatial abilities. The analysis of the Wechsler Intelligence Scale presented shows that the original rationale for selecting the specific subtests included in the WAIS was unclear. The concept of a g factor in cognition is also analyzed, with the conclusion that the g factor continues to be controversial. The value of intelligence tests in predicting school performance is also criticized. It is proposed that the psychometric concept of general intelligence should be deleted from cognitive and neurological sciences. Finally, it is proposed that, in the future, neuropsychological instruments sensitive to more specific cognitive abilities replace current psychometric intelligence tests.     

Altruism and health outcomes in multiple sclerosis: The effect of cognitive reserve

Despite age-associated decreases in cognitive and physical abilities, age is not associated with a decrease in ratings of well-being; this phenomenon is termed the ‘paradox of well-being.’ One potential explanation for this paradox may be that older adults place less value on cognitive abilities that have been shown to decrease with age (e.g., memory) and more value on cognitive abilities shown to increase with age (e.g., knowledge). Using online methods, 358 individuals between the ages of 18 and 88 completed a survey assessing the values placed on everyday cognitive abilities, self-ratings for those same abilities, and life satisfaction. Results indicated that there were minimal age-related differences in values placed on everyday cognitive abilities and that values generally did not moderate the relationship between perceptions of cognitive functioning and life satisfaction. Of note, values placed on cognition significantly predicted life satisfaction in younger adults, but not in middle-aged and older adults.     

Age-related differences in acquisition of perceptual-motor skills: working memory as a mediator

Aging is associated with reduced performance on information processing speed, memory, and executive functions tasks. Although older adults are also less apt in acquiring new perceptual-motor skills, it is unclear whether and how skill acquisition difficulties are associated with age-related general cognitive differences. We addressed this question by examining structural relations among measures of cognitive resources (working memory) and indices of perceptual-motor skill acquisition (pursuit rotor and mirror tracing) in 96 healthy adults aged 19-80 years of age. Three competing structural models were tested: a single (common) factor model, a dual correlated factors model, and a hierarchical dual-factor model. The third model provided the best fit to the data, indicating age differences in simple perceptual-motor skill are partially mediated by more complex abilities.     

Age-Related Differences in Acquisition of Perceptual-Motor Skills: Working Memory as a Mediator

ABSTRACT

Aging is associated with reduced performance on information processing speed, memory, and executive functions tasks. Although older adults are also less apt in acquiring new perceptual-motor skills, it is unclear whether and how skill acquisition difficulties are associated with age-related general cognitive differences. We addressed this question by examining structural relations among measures of cognitive resources (working memory) and indices of perceptual-motor skill acquisition (pursuit rotor and mirror tracing) in 96 healthy adults aged 19–80 years of age. Three competing structural models were tested: a single (common) factor model, a dual correlated factors model, and a hierarchical dual-factor model. The third model provided the best fit to the data, indicating age differences in simple perceptual-motor skill are partially mediated by more complex abilities.     

From universal laws of cognition to specific cognitive models

The remarkable successes of the physical sciences have been built on highly general quantitative laws, which serve as the basis for understanding an enormous variety of specific physical systems. How far is it possible to construct universal principles in the cognitive sciences, in terms of which specific aspects of perception, memory, or decision making might be modelled? Following Shepard (e.g., 1987 ), it is argued that some universal principles may be attainable in cognitive science. Here, 2 examples are proposed: the simplicity principle (which states that the cognitive system prefers patterns that provide simpler explanations of available data); and the scale‐invariance principle, which states that many cognitive phenomena are independent of the scale of relevant underlying physical variables, such as time, space, luminance, or sound pressure. This article illustrates how principles may be combined to explain specific cognitive processes by using these principles to derive SIMPLE, a formal model of memory for serial order ( Brown, Neath, & Chater, 2007 ), and briefly mentions some extensions to models of identification and categorization. This article also considers the scope and limitations of universal laws in cognitive science.     

Use of factor mixture modeling to capture Spearman's law of diminishing returns

Spearman's law of diminishing returns (SLODR) posits that at higher levels of general cognitive ability the general factor (g) performs less well in explaining individual differences in cognitive test performance. Research has generally supported SLODR, but previous research has required the a priori division of respondents into separate ability or IQ groups. The present study sought to obviate this limitation through the use of factor mixture modeling to investigate SLODR in the Kaufman Assessment Battery for Children-Second Edition (KABC-II). A second-order confirmatory factor model was modeled as a within-class factor structure. The fit and parameter estimates of several models with varying number of classes and factorial invariance restrictions were compared. Given SLODR, a predictable pattern of findings should emerge when factor mixture modeling is applied. Our results were consistent with these SLODR-based predictions, most notably the g factor variance was less in higher g mean classes. Use of factor mixture modeling was found to provide support for SLODR while improving the model used to investigate SLODR.     

Placing inspection time, reaction time, and perceptual speed in the broader context of cognitive ability: The VPR model in the Lothian Birth Cohort 1936

The idea that information processing speed is related to cognitive ability has a long history. Much evidence has been amassed in its support, with respect to both individual differences in general intelligence and developmental trajectories. Two so-called elementary cognitive tasks, reaction time and inspection time, have been used to compile this evidence, but most studies have used either one or the other. Relations between speed and fluid intelligence have tended to be stronger than those between speed and crystallized intelligence, but studies testing this have confounded verbal abilities with crystallized intelligence and spatial/perceptual abilities with fluid intelligence. Questions have also been raised regarding whether speed contributes directly to general intelligence or to more specific cognitive abilities to which general intelligence also contributes. We used 18 ability and speed measures in the Lothian Birth Cohort 1936, assessed at approximately age 70, to construct alternative versions of the Verbal-Perceptual-Image Rotation (Johnson & Bouchard, 2005a) model of cognitive ability to test different hypotheses regarding these issues. Though differences in the extents to which our models fit the data were relatively small, they suggested that reaction and inspection time tasks were comparable indicators of information processing speed with respect to general intelligence, that verbal and spatial abilities were similarly related to information processing speed, and that spatial, verbal, and perceptual speed abilities were more directly related to information processing speed than was general intelligence. We discuss the theoretical implications of these results.     

The construct of general intelligence

The construct of general intelligence is discussed in a number of different contexts. The fundamental empirical basis for it is the positive trend among the smallest correlations among cognitive measures. Differences among factor models which recognize this in different ways are discussed. Evidence for the general factor in intelligence is also found in the difficulty in finding evidence for differential validity of tests from one criterion to another. Performance on Piagetian tasks reflects mainly general intelligence. Individual differences in aural comprehension of language anticipate later individual differences in intellectual development. Selective forces which produce differences among schools operate largely on the general factor. To the extent that there is a genetic contribution to individual differences on cognitive tests, it appears to be to the general factor variance. Social class differences among whites appear to be largely on the general factor, but black-white differences require other dimensions. Although the general factor is, in a sense, real, it is not interpreted as an entity within the organism. Instead it is an abstraction resulting from the many genes, the many environmental pressures, and the many neural structures involved in the wide variety of human behaviors which can be labelled cognitive or intellectual.     

Brazilian-Portuguese empathy quotient: evidences of its construct validity and reliability

Empathy is the ability to read other's mind and understand their intentions. This paper examines the psychometric properties of the Brazilian-Portuguese version of a short form of the empathy quotient (EQ, 15 items). The EQ-15 was administered to 237 participants from the general population from Jo?o Pessoa, Brazil. Confirmatory factor analyses supported the tripartite model with cognitive, emotional and social empathy factors. In line with other studies, gender differences were only observed for the first two factors, with female participants scoring higher on both, which suggests that the social factor might not constitute a truly dimension of empathy. Strong evidence for convergent and discriminant validity was only observed for the cognitive factor. The poor psychometric parameters of the emotional and social factors are argued to reflect the complexity and contrasting ideas of their items. The possibility of elaborating specific items for the emotional and social factors is also discussed.     

What cognitive and numerical skills best define learning disabilities in mathematics? / ¿Qué habilidades cognitivas y numéricas definen mejor las dificultades de aprendizaje en matemáticas?

Differentiating students with mathematical learning disabilities (MLD) from those with low achievement (LA) is still an unresolved issue. This study explored whether the specific combination of certain cognitive and numerical skills can classify students with MLD, with LA, and without MLD. In order to do this, an analysis was carried out of the performance of 756 Spanish students in grades two to six, on different numerical and cognitive tasks. Two factors were extracted using a principal component analysis of the tasks: a semantic-cognitive factor and a verbal-automation factor. The results obtained from comparing the groups showed that students with MLD and LA demonstrated significant differences in the semantic-cognitive factor, and that these differences were consistent across grade levels. In contrast, there were no differences between groups in the automatic-verbal factor. These results confirm that the groups are not only quantitatively different but also qualitatively different.     

Effects of divided attention in the word-fragment completion task with unique and multiple solutions

A study with 114 young adults investigated the correlations of intelligence factors and working-memory capacity with reaction time (RT) tasks. Within two sets of four-choice RT tasks, stimulus–response compatibility was varied over three levels: compatible, incompatible, and arbitrary mappings. Two satisfactory measurement models for the RTs could be established: A general factor model without constraints on the loadings and a nested model with two correlated factors, distinguishing compatible from arbitrary mappings, with constraints on the loadings. Structural models additionally including factors for working memory and intelligence showed that the nested model with correlated factors is superior in fit. Working-memory capacity and fluid intelligence were correlated strongly with the nested factor for the RT tasks with arbitrary mappings, and less with the general RT factor. The results support the hypothesis that working memory is needed to maintain arbitrary bindings between stimulus representations and response representations, and this could explain the correlation of working-memory capacity with speed in choice RT tasks.     

Prospective evaluation of the etiology of anxiety sensitivity: test of a scar model

A large body of research has suggested that anxiety sensitivity (AS) acts as a specific vulnerability factor in the development of anxiety pathology. More recently, attention has turned to the etiology of AS per se. The present study represents a specific test of a Scar model of AS. A Scar model posits that the experience of distress will affect the vulnerability factor. We were specifically interested in evaluating the effects of a specific stressor (spontaneous panic) as well as general distress on changes in AS over time. A large nonclinical sample of young adults (N = 1296) was prospectively followed over a five week highly stressful period of time (i.e. military basic training). Findings were consistent with the Scar model and suggested that the specific stressor of experiencing a panic attack as well as general stressors creating significant anxiety symptoms uniquely contributed to increased levels of AS (regardless of prior history of panic). Moreover, the experience of spontaneous panic in the context of generally low levels of distress (both anxiety and depression) appeared to be particularly pernicious in terms of resulting in greater increases in AS. In sum, anxiety-related stressors appear to have the potential to 'scar' individuals in regard to this cognitive vulnerability factor.     

Relating inter-individual differences in metacognitive performance on different perceptual tasks

Human behavior depends on the ability to effectively introspect about our performance. For simple perceptual decisions, this introspective or metacognitive ability varies substantially across individuals and is correlated with the structure of focal areas in prefrontal cortex. This raises the possibility that the ability to introspect about different perceptual decisions might be mediated by a common cognitive process. To test this hypothesis, we examined whether inter-individual differences in metacognitive ability were correlated across two different perceptual tasks where individuals made judgments about different and unrelated visual stimulus properties. We found that inter-individual differences were strongly correlated between the two tasks for metacognitive ability but not objective performance. Such stability of an individual’s metacognitive ability across different perceptual tasks indicates a general mechanism supporting metacognition independent of the specific task.     

Is thought-action fusion specific to obsessive-compulsive disorder?: a mediating role of negative affect

Thought-action fusion (TAF) is a cognitive bias presumed to underlie the development of obsessional problems (i.e. obsessive-compulsive disorder; OCD). Previous studies have found that TAF is related to not only OCD, but also to other anxiety disorders. In the present study we compared levels of TAF in OCD patients and in patients with other anxiety disorders, depression, and healthy controls to examine whether TAF is characteristic of individuals with emotional distress in general, as opposed to anxiety disorders per se. We also examined whether negative affect (i.e. anxiety and depression) mediates the relationship between OCD and TAF. Results indicated that OCD patients were characterized by higher scores on likelihood-self and likelihood-other TAF, but that this difference was predominately due to differences in negative affect. These findings support a model in which negative affect mediates the relationship between OCD and TAF.