Developmental change in the relation between executive functions and symptoms of ADHD and co‐occurring behaviour problems

In a sample of 92 children aged 6–13 years this study investigates the normal developmental change in the relation between executive functioning (EF) and the core behavioural symptoms associated with attention deficit hyperactivity disorder (ADHD) (hyperactivity/impulsivity and inattention) as well as symptoms often co‐occurring with childhood hyperactivity (conduct‐ and internalizing problems). EF was assessed by using multiple tests grouped through prior factor analysis, resulting in cognitive measures relating to disinhibition, speed/arousal, verbal working memory, non‐verbal working memory, and fluency. The results showed that although disinhibition was positively related to hyperactivity/impulsivity and inattention mainly for the youngest age group, there were no significant age effects for these relations. Instead, age effects were found for the relations between speed/arousal and inattention as well as for the relations between verbal working memory/fluency and inattention. In the oldest age group poor performance on these cognitive measures was associated with high ratings of inattention. For the total sample a relation was obtained between disinhibition and hyperactivity/impulsivity as well as between both working memory measures and internalizing problems. In conclusion, the results from this study suggest that poor inhibition is most clearly associated with ADHD symptoms for younger children, whereas poor functioning with regard to later developing and more complex executive functions such as working memory and fluency is associated with ADHD symptoms for older children. Copyright © 2006 John Wiley & Sons, Ltd.     

Construct validity and age sensitivity of prospective memory

We administered four prospective memory tasks to 330 adults between 18 and 89 years of age to investigate the relationship among the measures of performance in the four tasks, as well as the relationship of the prospective memory measures to age, other cognitive abilities, and noncognitive factors. The four prospective memory variables were found to exhibit both convergent and discriminant validity, indicating that prospective memory ability appears to represent a distinct dimension of individual differences. The prospective memory construct was significantly related to other cognitive abilities, such as executive functioning, fluid intelligence, episodic memory, and perceptual speed, but it was only weakly related to self-ratings of (primarily retrospective) memory and to personality traits. Although a substantial proportion of the age-related variance on the prospective memory construct was shared with other cognitive abilities, we also found some evidence of unique, statistically independent, age-related influences on prospective memory.     

Effects of adult age and working memory on reasoning and spatial abilities

Three predictions were derived from the hypothesis that adult age differences in certain measures of cognitive functioning are attributable to age-related reductions in a processing resource such as working-memory capacity. Each prediction received at least some degree of empirical support in a study involving 120 males ranging between 20 and 79 years of age. First, older adults exhibited greater impairments of performance than did young adults when task complexity increased and more demands were placed on the limited processing resources; second, the magnitudes of these complexity effects were highly correlated across verbal (reasoning) and spatial (paper folding) tasks. Finally, statistical control of an index of a working-memory processing resource attenuated the effects of age on the measures of cognitive performance. It was concluded that further progress in understanding the mechanisms of the relation between age and cognitive functioning will require improved conceptualizations of the nature of working memory or other hypothesized mediating constructs.     

Using hippocampal‐dependent eyeblink conditioning to predict individual differences in spatial reorientation strategies in 3‐ to 6‐year‐olds

The hippocampus is a subcortical structure in the medial temporal lobe involved in cognitive functions such as spatial navigation and reorientation, episodic memory, and associative learning. While much is understood about the role of hippocampal function in learning and memory in adults, less is known about the relations between the hippocampus and the development of these cognitive skills in young children due to the limitations of using standard methods (e.g., MRI) to examine brain structure and function in developing populations. This study used hippocampal‐dependent trace eyeblink conditioning (EBC) as a feasible approach to examine individual differences in hippocampal functioning as they relate to spatial reorientation and episodic memory performance in young children. Three‐ to six‐year‐old children (N = 50) completed tasks that measured EBC, spatial reorientation, and episodic memory, as well as non‐hippocampal‐dependent processing speed abilities. Results revealed that when age was held constant, individual differences in EBC performance were significantly related to individual differences in performance on the spatial reorientation test, but not on the episodic memory or processing speed tests. When the relations between hippocampal‐dependent EBC and different reorientation strategies were explored, it was found that individual differences in hippocampal function predicted the use of geometric information for reorienting in space as opposed to a combined strategy that uses both geometric information and salient visual cues. The utilization of eyeblink conditioning to examine hippocampal function in young populations and its implications for understanding the dissociation between spatial reorientation and episodic memory development are discussed.     

Getting from neuron to checkmark: models and methods in cognitive survey research

Since the 1980s much work has been done in the field of Cognitive Survey Research. In an interdisciplinary endeavour, survey methodologists and cognitive psychologists (as well as social psychologists and linguists) have worked to unravel the cognitive processes underlying survey responses: to improve survey measurement, but also to obtain fundamental insight into the process of question answering, the nature of attitudes, the functioning of human memory, etc. Yet, despite the amount of work that has been done, less progress has been made than was deemed possible. This paper suggests ways in which to develop cognitive theories that may help to obtain an integrated understanding of question answering in surveys. One way to build better theories is to focus on model construction. Different types of cognitive models are discussed that can be used to model question answering. Second, a larger variety of methods from the cognitive toolbox can be used to further develop and test these models. An overview is given of the various tools available to researchers of cognitive aspects of survey research, with a special focus on newer methods from cognitive neuroscience. To connect different tools and methods into an integrative theory of question answering, the idea of hierarchical modelling is proposed. Copyright © 2007 John Wiley & Sons, Ltd.     

Unraveling the Aging Skein: Disentangling Sensory and Cognitive Predictors of Age‐related Differences in Decision Making

Age‐related differences in sensory functioning, processing speed, and working memory have been identified as three significant predictors of the age‐related performance decline observed in complex cognitive tasks. Yet, the assessment of their relative predictive capacity and interrelations is still an open issue in decision making and cognitive aging research. Indeed, no previous investigation has examined the relationships of all these three predictors with decision making. In an individual‐differences study, we therefore disentangled the relative contribution of sensory functioning, processing speed, and working memory to the prediction of the age‐related decline in cognitively demanding judgment and decision‐making tasks. Structural equation modeling showed that the age‐related decline in working memory plays an important predictive role, even when controlling for sensory functioning, processing speed, and education. Implications for research on decision making and cognitive aging are discussed. Copyright © 2015 John Wiley & Sons, Ltd.     

Association between biological markers of sickle cell disease and cognitive functioning amongst Cameroonian children

Background: Some of the major complications of sickle cell disease (SCD) occur in the brain and apart from overt stroke, patients also present with cognitive impairments. We sought to evaluate the prevalence of cognitive deficits as well as their biological predicting factors in young SCD patients in Cameroon.

Methods: The cognitive performances of Cameroonian SCD young patients were evaluated using a neuropsychological test battery assessing four domains of cognitive functioning (executive functions, attention, memory, and sensory-motor skills) previously adapted and normalized on healthy subjects in Yaoundé.

Findings: Up to 37.5% of the 96 SCD patients aged 6 to 24 years (M?=?13.5, SD?=?4.9) had mild-to-severe cognitive deficits. The cognitive deficits tend to increase with age. There was a significant effect of SCD on executive functions and attention, whereas SCD patients performed as well as controls on memory and sensory-motor skills tests. Structural equation models showed a significant association between (a) severe anemia and lower executive functioning, (b) low fetal hemoglobin levels and lower executive functioning and attention, (c) history of cerebrovascular accidents and lower performances in executive functioning, sensory-motor skills, and memory, (d) pathological electroencephalogram and lower attention, and (e) abnormal Transcranial Doppler and lower memory.

Conclusion: SCD patients in Cameroon presented a very high prevalence of cognitive deficits, with a specific impairment of executive functions and attention. Routine neuropsychological evaluation for early detection of cognitive deficits in SCD patients could represent a cost-effective tool to implement in resource-limited contexts such as in sub-Saharan Africa.     

Cognitive functioning in healthy older adults aged 64-81: a cohort study into the effects of age, sex, and education

The objective of this study was to determine a possible differential effect of age, education, and sex on cognitive speed, verbal memory, executive functioning, and verbal fluency in healthy older adults. A group of 578 healthy participants in the age range of 64-81 was recruited from a large population study of healthy adults (Maastricht Aging Study). Even in healthy individuals in this restricted age range, there is a clear, age-related decrease in performance on executive functioning, verbal fluency, verbal memory, and cognitive speed tasks. The capacity to inhibit information is affected most. Education had a substantial effect on cognitive functioning: participants with a middle or high level of education performed better on cognitive tests than did participants with a low level of education. Women performed better than men on verbal memory tasks. Therefore, education and sex must be taken into account when examining an older individual's cognitive performance.     

Executive functioning and prospective memory in young children

The current study examined the role of executive functioning (EF) in children's prospective memory (PM) by assessing the effect of delay and number of intentions to-be-remembered on PM, as well as relations between PM and EF. Ninety-six 4-, 5-, and 6-year-olds completed a PM task and two executive function tasks. The PM task required children to interrupt an ongoing card game to perform one action (single intention) or two actions (dual intention) with target cards after a short delay (1 min) or a long delay (5 min). There was no main effect of number of intentions or delay on the PM task. However, performance improved with age, and age and delay interacted such that 4-year-olds’ performance remained the same after a long delay whereas 5-year-olds’ performance improved after a long delay. We suggest that the age by delay interaction is a product of age differences in cognitive monitoring. Working memory but not inhibitory control predicted PM with age controlled. We argue that an executive function framework permits an integrative understanding of many processes involved in young children's prospective memory.     

Social Network Size and Cognitive Functioning in Middle-Aged Adults: Cross-Sectional and Longitudinal Associations

The objective of the present study was to examine relations between social network size and three cognitive abilities (episodic memory, semantic memory, visuospatial ability) in middle-aged adults. We analyzed cross-sectional data on social network size and cognitive functioning that were available for 804 participants aged 40–60 years. In addition, we examined 5- and 10-year follow-up measurements of cognitive functioning that were available for 604 and 255 participants, respectively. Cross-sectional analyses revealed a positive association between social network size and each of the three cognitive abilities. Baseline network size was positively related to 5-year changes in semantic memory, and to 10-year changes in semantic as well as episodic memory, but was unrelated to changes in visuospatial performance. A minor portion of the sample (n = 131) had 10-year follow-up data on network size. Cross-lagged panel correlations revealed that baseline network size was associated with follow-up measurement in cognitive functioning (episodic memory, semantic memory), whereas baseline cognitive performance was unrelated to future network size. Together, the results demonstrate a small but positive relation between network size and declarative memory abilities, in line with models proposing a cognitive reserve built up by factors such as the increased cognitive stimulation associated with a more extensive social network.     

On the specificity of face cognition compared with general cognitive functioning across adult age

Face cognition is considered a specific human ability, clearly differentiable from general cognitive functioning. Its specificity is primarily supported by cognitive-experimental and neuroimaging research, but recently also from an individual differences perspective. However, no comprehensive behavioral data are available, which would allow estimating lifespan changes of the covariance structure of face-cognition abilities and general cognitive functioning as well as age-differences in face cognition after accounting for interindividual variability in general cognition. The present study aimed to fill this gap. In an age-heterogeneous (18-82 years) sample of 448 adults, we found no factorial dedifferentiation between face cognition and general cognition. Age-related differences in face memory were still salient after taking into account changes in general cognitive functioning. Face cognition thus remains a specific human ability compared with general cognition, even until old age. We discuss implications for models of cognitive aging and suggest that it is necessary to include more explicitly special social abilities in those models.     

Decomposing the relationship between cognitive functioning and self-referent memory beliefs in older adulthood: what’s memory got to do with it?

With advancing age, episodic memory performance shows marked declines along with concurrent reports of lower subjective memory beliefs. Given that normative age-related declines in episodic memory co-occur with declines in other cognitive domains, we examined the relationship between memory beliefs and multiple domains of cognitive functioning. Confirmatory bi-factor structural equation models were used to parse the shared and independent variance among factors representing episodic memory, psychomotor speed, and executive reasoning in one large cohort study (Senior Odyssey, N = 462), and replicated using another large cohort of healthy older adults (ACTIVE, N = 2802). Accounting for a general fluid cognitive functioning factor (comprised of the shared variance among measures of episodic memory, speed, and reasoning) attenuated the relationship between objective memory performance and subjective memory beliefs in both samples. Moreover, the general cognitive functioning factor was the strongest predictor of memory beliefs in both samples. These findings are consistent with the notion that dispositional memory beliefs may reflect perceptions of cognition more broadly. This may be one reason why memory beliefs have broad predictive validity for interventions that target fluid cognitive ability.     

The roles of different executive functioning skills in young children’s mental computation and applied mathematical problem-solving

This study investigated the relationships of four executive functioning skills (including verbal working memory, spatial working memory, inhibitory control, and cognitive flexibility) with young children’s mental computation and applied mathematical problem-solving. Two hundred and twenty-five Chinese kindergarteners were tested with a battery of general cognitive, executive functioning and mathematics skills. Results showed that when children’s age, gender, non-verbal intelligence, and listening comprehension skills were controlled, verbal working memory and cognitive flexibility were significant correlates of mental computation, whereas verbal working memory, spatial working memory, and cognitive flexibility were significant correlates of applied mathematical problem-solving. Inhibitory control was not significantly associated with the two domains of mathematics under investigation. The findings highlight the differential roles of different executive functioning skills in early mathematical skills and offer practical implication for helping young children in learning complex mathematical skills.     

Mediators of the Relationship Between Life Events and Memory Functioning in a Community Sample of Adults

The present study examines the association of frequency and severity of life events with memory functioning in a community sample of adults. We tested the hypothesis that stress‐related cognitive interference mediated the effects of recent life events on cognition, in addition to examining the potential roles of fatigue, sleep disturbances, and depression. The sample consisted of 310 adults (age range 19–83 years) who received a battery of cognitive tests assessing their primary memory, episodic memory, and working memory. Individuals rated how stressful previous life events were when they occurred, as well as how stressful the events were for them currently. Ratings of current but not past severity were negatively associated with working memory performance. Both stress‐related cognitive interference and depressive symptoms independently mediated this association. These findings highlight the importance of intrusive and avoidant thinking as a potential focus of psychosocial treatment for remediating stress‐related memory dysfunction. Copyright © 2014 John Wiley & Sons, Ltd.     

Event memory and suggestibility in abused and neglected children: trauma-related psychopathology and cognitive functioning

This study examined event memory and suggestibility in 3- to 16-year-olds involved in forensic investigations of child maltreatment. A total of 322 children were interviewed about a play activity with an unfamiliar adult. Comprehensive measures of individual differences in trauma-related psychopathology and cognitive functioning were administered. Sexually and/or physically abused children obtained higher dissociation scores than neglected children, and sexually abused children were more likely to obtain a diagnosis of posttraumatic stress disorder than physically abused children, neglected children, and children with no substantiated abuse histories. Overall, older children and children with better cognitive functioning produced more correct information and fewer memory errors. Abuse status per se did not significantly predict children’s memory or suggestibility whether considered alone or in interaction with age. However, among highly dissociative children, more trauma symptoms were associated with greater inaccuracy, whereas trauma symptoms were not associated with increased error for children who were lower in dissociative tendencies. Implications of the findings for understanding eyewitness memory in maltreated children are discussed.     

Predictors of time-based prospective memory in children

This study identified age differences in time-based prospective memory performance in school-aged children and explored possible cognitive correlates of age-related performance. A total of 56 7- to 12-year-olds performed a prospective memory task in which prospective memory accuracy, ongoing task performance, and time monitoring were assessed. Additional tests of time estimation, working memory, task switching, and planning were performed. Results showed a robust relationship between age and prospective memory performance even after controlling for ongoing task performance. Developmental differences in time monitoring were also observed, with older children generally adopting a more strategic monitoring strategy than younger children. The majority of age-related variance in prospective memory task performance could be explained by cognitive resources, in particular planning and task switching. In contrast, no further independent contribution of time estimation was observed. Findings are in line with the development of strategic behavior, as well as executive functioning, in school-aged children.     

A Structural Modeling Examination of the Executive Decline Hypothesis of Cognitive Aging Through Reanalysis of Crawford et al.'s (2000) Data

This study presents a new analysis of data previously published by Crawford, Bryan, Luszcz, Obansawin, and Stewart (2000) examining the role of executive function in age-related declines in general cognitive ability and memory. Although the original authors' question is relevant to understanding the role of executive function in aging, this paper argues that the methods used can be substantially improved to more accurately answer the question. Thus, Crawford et al.'s data are here analyzed using a more parsimonious methodological approach (structural equation modeling), and the results obtained depart from the authors' results but are in line with their original hypotheses. First, for younger individuals, age was differently associated with verbal measures of cognitive ability than with performance measures. Although the relation of age to executive function was stronger than the relation of age to verbal abilities, this difference was not apparent with regard to performance abilities. Second, across samples (i.e., younger and older individuals), memory was not accounted for by cognitive ability but was related to age and executive function. Finally, also across samples, executive function was strongly linked to recall and recognition measures, accounting for the largest variance in memory. These results are discussed in relation to previous findings as well as their theoretical significance for aging research.     

Age differences in prospective memory for everyday life intentions: A diary approach

The age benefit found in many naturalistic prospective memory (PM) tasks has been taken as evidence that PM performance in real life may be spared from aging. However, this conclusion lacks empirical confirmation. Hence, the aim of the present study was to examine possible age differences in the content of everyday PM intentions and their performance. Everyday PM was assessed in young and older adults using a diary approach. Results confirmed a general age benefit for real-life PM tasks. Importantly, this finding was qualified by revealing that the benefit only held true for specific types of intentions such as health and social intentions. Further, moderation analyses showed that the relationships between cognitive functioning and everyday PM were different for young and older adults. While better inhibition, short-term and long-term memory were related with successful PM performance in the young, this was not the case in the older adults. The present findings suggest that the age benefit found in naturalistic experimenter-given tasks extends to real-life PM performance, but may differ depending on the type of intention. Furthermore, cognitive functioning predicts performance in the young, but not in the older adults.     

Executive functioning as a mediator of the relationship between age and episodic memory in healthy aging

The extent to which age-related differences in executive functioning account for age-related differences in recall from episodic memory was examined in a group of healthy older adults. Fifty-one subjects between the ages of 60 and 91 years were given tests of general cognitive abilities, episodic memory, and executive functioning. A mediational model was proposed with executive functioning as the mediator of the relationship between age and delayed recall. Consistent with this model, regression analyses indicated that, when considered alone, age was a significant predictor of recall (p <.001); however, age was not a significant predictor of recall when the effect of executive functioning was partialled out of the equation (p=.37). Furthermore, the unique contribution of executive functioning accounted for 36% of the variance in recall performance. A significant portion of age-related differences in episodic memory recall, therefore, may be due to age-related differences in the executive skills required for optimal performance on such tests.     

Cognitive Performance and the Role of Control Beliefs in Midlife

Midlife has been touted as being a time of peak performance in many different areas of functioning. In the present study, we investigated whether this was true for cognitive functioning on tasks assessing speed, reasoning, short-term memory, and vocabulary. We also explored the extent to which levels of cognitive functioning could be attributed to individual differences in general control beliefs. Middle-aged adults showed little or no cognitive declines on speed, reasoning, and short-term memory measures relative to the young and outperformed the young on vocabulary. Relative to the elderly, middle-aged adults scored higher on all tasks except vocabulary, for which there were no differences. Adults in midlife, on the other hand, had lower scores on measures of general control beliefs compared to younger adults. Thus, although midlife is a time of high cognitive functioning, it is also a time of lower beliefs about control. To investigate the relationship between control beliefs and cognitive performance, we used structural equation modeling. The models showed that for adults in midlife, control beliefs were predictive of performance but only for the reasoning task after background variables were considered. Specifically, high levels of control beliefs were associated with better cognitive performance. More work is needed to identify mediational processes linking control beliefs and cognitive performance for various age groups and to determine whether some cognitive processes are more controllable than others.