Time perception in severe traumatic brain injury patients: A study comparing different methodologies

In this study, we investigated time perception in patients with traumatic brain injury (TBI). Fifteen TBI patients and 15 matched healthy controls participated in the study. Participants were tested with durations above and below 1 s on three different temporal tasks that involved time reproduction, production, and discrimination tasks. Data variables analyzed included amount of errors, relative errors, and coefficient of variation. Both groups completed a neuropsychological battery that included measures of attention, working memory, and executive functions. Results revealed significant differences between groups on the time reproduction and discrimination tasks, whereas groups showed similar performance on the time production task. Correlation analyses showed involvement of attention, working memory and executive functions on the time reproduction and time discrimination tasks, but there was no involvement on the time production task. These findings suggest that TBI does not impact specific temporal function. Rather, impairments in attention, working memory and executive function abilities may explain lower temporal performance in people with TBI.     

Age differences in working memory updating: The role of interference,focus switching and substituting information

Working memory updating (WMU) tasks require different elements in working memory (WM) to be maintained simultaneously, accessing one of these elements, and substituting its content. This study examined possible developmental changes from childhood to adulthood both in focus switching and substituting information in WM. In addition, possible age-related changes in interference due to representational overlap between the different elements simultaneously held in these tasks were examined. Children (8- and 11-year-olds), adolescents (14-year-olds) and younger adults (mean age = 22 years) were administered a numerical updating memory task, in which updating and focus switching were manipulated. As expected, response times decreased and recall performance increased with age. More importantly, the time needed for focus switching was longer in children than in adolescents and younger adults. On the other hand, substitution of information and interference due to representational overlap were not affected by age. These results suggest that age-related changes in focus switching might mediate developmental changes in WMU performance.     

Cognitive abilities explaining age-related changes in time perception of short and long durations

The current study investigated how the development of cognitive abilities explains the age-related changes in temporal judgment over short and long duration ranges from 0.5 to 30 s. Children (5- and 9-year-olds) as well as adults were given a temporal bisection task with four different duration ranges: a duration range shorter than 1 s, two duration ranges longer than 3 s (4-8 s and >15 s), and an intermediate duration range (1.25-2.5 s). Their cognitive abilities were also assessed using a series of neuropsychological tests. The results showed that temporal sensitivity improved with age for each duration range but that this improvement occurred earlier for the short durations than for the long durations. Furthermore, the results revealed that the age-related improvement in time sensitivity for the durations shorter than 1 s was explained by the development of short-term memory span, whereas that for long durations was explained by the development of attention/executive functions. To summarize, the development of the abilities required to process long durations seems to be explained mainly by the development of attentional resources.     

Math and Memory in Bilingual Preschoolers: The Relations Between Bilingualism,Working Memory,and Numerical Knowledge

ABSTRACT

Bilingual children exhibit enhanced working memory (WM) skill relative to monolingual children, which could have implications for early mathematics development. Competency in mathematics is supported by conceptual and procedural mathematical knowledge, and numerical knowledge is in turn supported by underlying cognitive processes such as WM. Building on this evidence, we investigated whether bilingual preschoolers demonstrated, relative to monolingual peers, enhanced performance on WM and greater numerical knowledge. We examined the role of WM in numerical understanding for both monolingual and bilingual children. Participants were 4- and 5-year old children (74) recruited from preschools serving families from a range of socioeconomic, racial, and ethnic backgrounds. Participants completed a nonverbal WM task and a range of numerical-knowledge measures, specifically numeral identification, addition, symbolic magnitude comparison, and nonsymbolic magnitude comparison tasks. Results revealed that bilingual children outperformed monolingual peers on WM even after controlling for age and socioeconomic status (SES). Bilingual children also demonstrated greater performance on addition and numeral identification tasks. For all tasks except numeral identification, WM predicted children’s performance on numerical knowledge measures. We discuss results in terms of the possible unique cognitive and academic advantages bilingual children may have.     

Effects of verbal information on fear-related reasoning biases in children

The present study made an attempt to induce fear-related reasoning biases by providing children with negative information about a novel stimulus. For this purpose, non-clinical children aged 9-12 years (N = 318) were shown a picture of an unknown animal for which they received either negative, ambiguous, positive, or no information. Then children completed a series of tests for measuring various types of reasoning biases (i.e., confirmation bias and covariation bias) in relation to this animal. Results indicated that children in the negative and, to a lesser extent, the ambiguous information groups displayed higher scores on tests of fear-related reasoning biases than children in the positive and no information groups. Altogether, these results support the idea that learning via negatively tinted information plays a role in the development of fear-related cognitive distortions in youths.     

The Predictive Utility of a Working Memory Span Task Depends on Processing Demand and the Cognitive Task

The relationship between performance in working memory (WM) span tasks, scholastic skills and fluid intelligence was investigated to determine how WM span is related to higher order cognition. The predictive utility of two WM span tasks differing in the demand of the processing task was studied with controlled presentation times and a broad set of academic criterion tasks. Sixty‐eight adolescents (mean age 16 years) completed two WM span tasks, Raven's Progressive Matrices and several scholastic performance measures. The results showed that the more demanding WM span task predicted fluid intelligence, but did not contribute uniquely in explaining scholastic performance. In contrast, the less demanding WM task predicted scholastic performance. The results suggest that the strength of the relation between WM performance and higher order cognition varies in conjunction with both the demand of the WM span task and the type of higher order cognition measure.Copyright © 2016 John Wiley & Sons, Ltd.     

Motor planning between 4 and 7 years of age: Changes linked to executive functions

In the present study, we adopted the conceptual frameworks of Miyake et al. (2000) (organization of executive functions) and Sergeant (2000) (linking executive function to motor behaviour) to assess developmental changes in executive functions and motor behaviour, using a planning task with a sample of 4–7-years old children. More precisely, the aim of the study was to characterize the development of motor response planning between the ages of 4 and 7 as a measure of the integration of multiple executive function processes, namely inhibition, shifting and working memory, and to gain insight into the concurrent developmental contributions of these processes. Participants were divided into two groups: group 1 was composed of 24 children aged 4–5 years and group 2 was composed of 20 children aged 6–7 years. Each participant took tests for shifting, inhibition, working memory and motor planning (the egg-planning task). Our results suggest that the egg-planning task requires the inhibition of a pre-potent but inappropriate response, and to a lesser extent the manipulation of working memory strategies. These results are discussed in relation to the development of each executive function component.     

Children's working memory: Its structure and relationship to fluid intelligence

Working memory (WM) has been predominantly studied in adults. The insights provided by these studies have led to the development of competing theories on the structure of WM and conflicting conclusions on how strongly WM components are related to higher order thinking skills such as fluid intelligence. However, it remains unclear whether and to what extent the theories and findings derived from adult data generalize to children. The purpose of the present study is therefore to investigate children's WM (N = 161), who attended classes at the end of kindergarten in Luxembourg. Specifically, we examine different structural models of WM and how its components, as defined in these models, are related to fluid intelligence. Our results indicate that short-term storage capacity primarily explains the relationship between WM and fluid intelligence. Based on these observations we discuss the theoretical and methodological issues that arise when children's WM is investigated.     

Young children’s acquisition of knowledge about the Earth: A longitudinal study

This longitudinal study examined the acquisition of early knowledge of astronomy to determine whether children’s knowledge at any point in time is consistent with a naive “mental model.” Children were first assessed by means of open questions and drawing tasks at 2 and 3 years of age (N = 143). The knowledge was reassessed over the course of the following 3 years. The results showed that although a few indications of naive mental models were found, in most cases young children’s knowledge was fragmented and accurate knowledge was often expressed alongside inaccurate/synthetic ideas. Furthermore, it was shown that children need to know scientific facts before they start taking the global perspective when describing the world and, when faced with ambiguous open questions, children often experience difficulties that can induce them to change the types of answers they provide.     

Prospective and retrospective time perception are related to mental time travel: Evidence from Alzheimer’s disease

Unlike prospective time perception paradigms, in which participants are aware that they have to estimate forthcoming time, little is known about retrospective time perception in normal aging and Alzheimer’s disease (AD). Our paper addresses this shortcoming by comparing prospective and retrospective time estimation in younger adults, older adults, and AD patients. In four prospective tasks (lasting 30 s, 60 s, 90 s, or 120 s) participants were asked to read a series of numbers and to provide a verbal estimation of the reading time. In four other retrospective tasks, they were not informed about time judgment until they were asked to provide a verbal estimation of four elapsed time intervals (lasting 30 s, 60 s, 90 s, or 120 s). AD participants gave shorter verbal time estimations than older adults and younger participants did, suggesting that time is perceived to pass quickly in these patients. For all participants, the duration of the retrospective tasks was underestimated as compared to the prospective tasks and both estimations were shorter than the real time interval. Prospective time estimation was further correlated with mental time travel, as measured with the Remember/Know paradigm. Mental time travel was even higher correlated with retrospective time estimation. Our findings shed light on the relationship between time perception and the ability to mentally project oneself into time, two skills contributing to human memory functioning. Finally, time perception deficits, as observed in AD patients, can be interpreted in terms of dramatic changes occurring in frontal lobes and hippocampus.     

Hyperactivity in Boys with Attention-Deficit/Hyperactivity Disorder (ADHD): A Ubiquitous Core Symptom or Manifestation of Working Memory Deficits?

Hyperactivity is currently considered a core and ubiquitous feature of attention-deficit/hyperactivity disorder (ADHD); however, an alternative model challenges this premise and hypothesizes a functional relationship between working memory (WM) and activity level. The current study investigated whether children’s activity level is functionally related to WM demands associated with the domain-general central executive and subsidiary storage/rehearsal components using tasks based on Baddeley’s (Working memory, thought, and action. New York: Oxford University Press 2007) WM model. Activity level was objectively measured 16 times per second using wrist- and ankle-worn actigraphs while 23 boys between 8 and 12 years of age completed control tasks and visuospatial/phonological WM tasks of increasing memory demands. All children exhibited significantly higher activity rates under all WM relative to control conditions, and children with ADHD (n = 12) moved significantly more than typically developing children (n = 11) under all conditions. Activity level in all children was associated with central executive but not storage/rehearsal functioning, and higher activity rates exhibited by children with ADHD under control conditions were fully attenuated by removing variance directly related to central executive processes.

Aberrant neural mediation of verbal fluency in autism spectrum disorders

Objective

Contrasts of verbal fluency and automatic speech provide an opportunity to evaluate the neural underpinnings of generativity and flexibility in autism spectrum disorders (ASD).

Method

We used functional magnetic resonance imaging (fMRI) to contrast brain activity in high functioning ASD (n = 17, mean verbal IQ = 117) and neurotypical (NT; n = 20, mean verbal IQ = 112) adolescent and young adult males (12–23 years). Participants responded to three word generation conditions: automatic speech (reciting months), category fluency, and letter fluency.

Results

Our paradigm closely mirrored behavioral fluency tasks by requiring overt, free recall word generation while controlling for differences in verbal output between the groups and systematically increasing the task demand. The ASD group showed reduced neural response compared to the NT participants during fluency tasks in multiple regions of left anterior and posterior cortices, and sub-cortical structures. Six of these regions fell in cortico-striatal circuits previously linked to repetitive behaviors (Langen, Durston, Kas, van Engeland, & Staal, 2011), and activity in two of them (putamen and thalamus) was negatively correlated with autism repetitive behavior symptoms in the ASD group. In addition, response in left inferior frontal gyrus was differentially modulated in the ASD, relative to the NT, group as a function of task demand.

Conclusions

These data indicate a specific, atypical brain response in ASD to demanding generativity tasks that may have relevance to repetitive behavior symptoms in ASD as well as to difficulties generating original verbal responses.     

Temperament moderates the effect of the verbal threat information pathway on children's heart rate responses to novel animals

Temperamental variables such as trait anxiety are risk factors in children for the development of anxiety disorders. This experiment aimed to test whether temperament moderates the effect of verbal threat information on the physiological component of the fear emotion. An experiment is reported in which 6-10 year old children's (N = 54) fear beliefs about novel animals were measured. They were then given threat, positive or no verbal information about these animals following which their heart rate was recorded while they placed their hands in boxes that they believed these animals inhabited. Children also completed a questionnaire measure of trait anxiety. Child-reported temperament moderated the effect that threat information has on the physiological component of the fear emotion. Fear information is, therefore, a possible mechanism through which temperament leads children to acquire animal fears.     

Visual perspective taking impairment in children with autistic spectrum disorder

Evidence from typical development and neuroimaging studies suggests that level 2 visual perspective taking - the knowledge that different people may see the same thing differently at the same time - is a mentalising task. Thus, we would expect children with autism, who fail typical mentalising tasks like false belief, to perform poorly on level 2 visual perspective taking as well. However, prior data on this issue are inconclusive. We re-examined this question, testing a group of 23 young autistic children, aged around 8 years with a verbal mental age of around 4 years and three groups of typical children (n = 60) ranging in age from 4 to 8 years on a level 2 visual perspective task and a closely matched mental rotation task. The results demonstrate that autistic children have difficulty with visual perspective taking compared to a task requiring mental rotation, relative to typical children. Furthermore, performance on the level 2 visual perspective taking task correlated with theory of mind performance. These findings resolve discrepancies in previous studies of visual perspective taking in autism, and demonstrate that level 2 visual perspective taking is a mentalising task.     

Reinforcement probability modulates temporal memory selection and integration processes

We have previously shown that rats trained in a mixed-interval peak procedure (tone = 4 s, light = 12 s) respond in a scalar manner at a time in between the trained peak times when presented with the stimulus compound (Swanton & Matell, 2011). In our previous work, the two component cues were reinforced with different probabilities (short = 20%, long = 80%) to equate response rates, and we found that the compound peak time was biased toward the cue with the higher reinforcement probability. Here, we examined the influence that different reinforcement probabilities have on the temporal location and shape of the compound response function. We found that the time of peak responding shifted as a function of the relative reinforcement probability of the component cues, becoming earlier as the relative likelihood of reinforcement associated with the short cue increased. However, as the relative probabilities of the component cues grew dissimilar, the compound peak became non-scalar, suggesting that the temporal control of behavior shifted from a process of integration to one of selection. As our previous work has utilized durations and reinforcement probabilities more discrepant than those used here, these data suggest that the processes underlying the integration/selection decision for time are based on cue value.     

The Emotionality Activity Sociability Temperament Survey: Factor analysis and temporal stability in a longitudinal cohort

We investigated Buss and Plomin’s Emotionality Activity Sociability (EAS) Temperament Survey for Children, used to assess temperament. Temperament is believed to comprise stable traits that change little over time. We examined stability of EAS temperament in the Avon Longitudinal Study of Parents and Children, in which 7429 mothers completed the EAS when their children were 3, 5 and 6 years old. Factor analysis was conducted at each time point, and stability over time was assessed using correlation and mixed effects regression modelling, accounting for differences within and between individuals. A four-factor model provided the best fit, with 19–20 of the 20 items loading onto the dimensions predicted by Buss and Plomin. Test–retest correlations ranged from 0.52–0.64 (3–5 years), 0.59–0.74 (5–6 years) and 0.46–0.58 (3–6 years). Mixed effects regression modelling suggested good stability over time: differences between, rather than within, individuals accounted for between 69% and 82% of the variance. This study demonstrates the stability of temperament over time, a vital pre-requisite to investigating childhood temperament as a predictor of outcomes.     

Working memory and vocabulary development in Greek preschool and primary school children

The present research investigated the relative contributions of verbal short-term memory (STM) and working memory (WM) to vocabulary development in the early years among Greek-speaking children. Participants were 5.5-, 7.5-, 8.5- and 9.5-year-old (N = 216) native speakers of Greek, a language differing from English in which most investigations have been conducted. Children were assessed with a receptive vocabulary task, four verbal STM measures (word, digit, and non-word list recall, as well as word list matching), and three verbal WM tasks (listening, counting, and backward digit recall). Results offer support to the view that both STM and WM influence vocabulary development in early stages. Vocabulary was associated with verbal STM at 7.5 and 8.5 years, but only with verbal WM at 5.5 years. Associations declined with age (by 9.5 years), earlier than in English-speaking children. Findings are discussed in relation to Greek language characteristics, demonstrating the importance of cross-cultural investigations.     

Attention and executive functioning in infancy: Links to childhood executive function and reading achievement

This study provides the first analyses connecting individual differences in infant attention to reading achievement through the development of executive functioning (EF) in infancy and early childhood. Five‐month‐old infants observed a video, and peak look duration and shift rate were video coded and assessed. At 10 months, as well as 3, 4, and 6 years, children completed age‐appropriate EF tasks (A‐not‐B task, hand game, forward digit span, backwards digit span, and number Stroop). Children also completed a standardized reading assessment and a measure of verbal intelligence (IQ) at age 6. Path analyses on 157 participants showed that infant attention had a direct statistical predictive effect on EF at 10 months, with EF showing a continuous pattern of development from 10 months to 6 years. EF and verbal IQ at 6 years had a direct effect on reading achievement. Furthermore, EF at all time points mediated the relation between 5‐month attention and reading achievement. These findings may inform reading interventions by suggesting earlier intervention time points and specific cognitive processes (i.e. 5‐month attention).     

Associations of coping and appraisal styles with emotion regulation during preadolescence

We investigated the associations of appraisal and coping styles with emotion regulation in a community sample of preadolescents (N = 196, 9-12 years of age), with appraisal, coping styles, and emotion regulation measured at a single time point. In a previous study, we identified five frustration and four anxiety emotion regulation profiles based on children’s physiological, behavioral, and self-reported reactions to emotion-eliciting tasks. In this study, preadolescents’ self-reported appraisal and coping styles were associated with those emotion regulation profiles. Overall, findings revealed that children who were more effective at regulating their emotions during the emotion-eliciting tasks had higher levels of positive appraisal and active coping when dealing with their own problems. Conversely, children who regulated their emotions less effectively had higher levels of threat appraisal and avoidant coping.