Components of executive control with advantages for bilingual children in two cultures

The present study used a behavioral version of an anti-saccade task, called the ‘faces task’, developed by [Bialystok, E., Craik, F. I. M., & Ryan, J. (2006). Executive control in a modified anti-saccade task: Effects of aging and bilingualism. Journal of Experimental Psychology: Learning, Memory, and Cognition, 32, 1341-1354] to isolate the components of executive functioning responsible for previously reported differences between monolingual and bilingual children and to determine the generality of these differences by comparing bilinguals in two cultures. Three components of executive control were investigated: response suppression, inhibitory control, and cognitive flexibility. Ninety children, 8-years old, belonged to one of three groups: monolinguals in Canada, bilinguals in Canada, and bilinguals in India. The bilingual children in both settings were faster than monolinguals in conditions based on inhibitory control and cognitive flexibility but there was no significant difference between groups in response suppression or on a control condition that did not involve executive control. The children in the two bilingual groups performed equivalently to each other and differently from the monolinguals on all measures in which there were group differences, consistent with the interpretation that bilingualism is responsible for the enhanced executive control. These results contribute to understanding the mechanism responsible for the reported bilingual advantages by identifying the processes that are modified by bilingualism and establishing the generality of these findings across bilingual experiences. They also contribute to theoretical conceptions of the components of executive control and their development.     

Logic in the study of psychiatric disorders: executive function and rule-following

Executive function has become an important concept in explanations of psychiatric disorders, but we currently lack comprehensive models of normal executive function and of its malfunctions. Here we illustrate how defeasible logical analysis can aid progress in this area. We illustrate using autism and attention deficit hyperactivity disorder (ADHD) as example disorders, and show how logical analysis reveals commonalities between linguistic and non-linguistic behaviours within each disorder, and how contrasting sub-components of executive function are involved across disorders. This analysis reveals how logical analysis is as applicable to fast, automatic and unconscious reasoning as it is to slow deliberate cogitation.

Task-switching abilities in children with autism spectrum disorder

Task-switching performance is often used as a measure of executive control functions. Various task-switching studies in children with autism spectrum disorder (ASD) found, in contrast to expectations, no impairments in cognitive flexibility. Here, we studied whether the role of memory for arbitrary task rules can explain these findings, and how studying rule memory can help to generally better understand executive control. We designed a novel task-switching paradigm to separate cognitive flexibility from demand on memory for arbitrary rules, and we compared 19 children with ASD (9 to 16 years old) with an age- and IQ-matched control group. Children with ASD had increased difficulty with task switching only when memorizing arbitrary rules was required. When no arbitrary rules needed to be memorized, they performed accurately and quickly. Nevertheless, they showed less distraction from task-irrelevant stimulus features, suggesting that they represented tasks differently from the children in the comparison group. We conclude that children with ASD have a weaker capacity of forming rule representations, which only leads to performance impairment when they need to memorize arbitrary rules. Further, executive control impairments in ASD seem more complex than hitherto hypothesized due to mutual interactions between memory demand and task representations.     

Specific and general autobiographical knowledge in adults with autism spectrum disorders: The role of personal goals

Autobiographical knowledge is stored hierarchically, at both specific and general levels of representation. It has also been proposed that the self is the structure around which autobiographical memories are organised. The current series of studies assessed whether the autobiographical memory difficulties observed in adults with autism spectrum disorders (ASD) could be due to problems in using the self as an effective memory cue. A series of cueing paradigms were used to assess the accessibility of both specific and general autobiographical knowledge relating to (i) currently pursued goals (either high or low in self–concordance) and (ii) goals that participants were not currently pursuing. Results demonstrated that while event-specific knowledge was impaired in the ASD group, general event knowledge appeared relatively intact. Moreover, while both event-specific and general event knowledge were organised around goals of the self in control participants, a corresponding relationship was only observed for general event knowledge in the ASD group.     

Impaired task switching performance in children with dyslexia but not in children with autism

Problems with cognitive control in both autism and dyslexia have already been reported in different studies. The present study specifically examined task-switching performance in children with autism and dyslexia. For this purpose, a multiple-trial paradigm was used with cues for colour- and shape-matching tasks presented before a run of trials. The cue could imply a task switch (when the cue changed the task) or a task repetition (when the cue did not change the task). Both reaction times and error rates were measured for switching, restarting, and general task performance. Participants were children with autism (24) and with dyslexia (25) and healthy controls (27) with normal IQ and ages from 12 to 18 years. The main finding was that while similar switching performance was observed between children with autism and the healthy controls, children with dyslexia showed a significant switch-specific delay relative to both healthy controls and children with autism. Furthermore, no deficit in restarting performance was observed for any of the two patient groups. Finally, additional evidence is provided for a more general deficit in information processing in dyslexia. Our data suggest that children with autism are able to switch between tasks in a similar way as do normally developing children as long as the tasks are unambiguously specified. Furthermore, the data imply switch-specific deficits in dyslexia additionally to the deficits in general information processing already reported in the literature. The implications of our data are further discussed in relation to the interpretation of the Wisconsin Card Sorting Test.     

Toddlers benefit from labeling on an executive function search task

Although labeling improves executive function (EF) performance in children older than 3 years, the results from studies with younger children have been equivocal. In the current study, we assessed performance in a computerized multistep multilocation search task with older 2-year-olds. The correct search location was either (a) not marked by a familiar picture or given a distinct label, (b) marked by a familiar picture but not given a distinct label, (c) marked by a familiar picture and labeled by the experimenter, or (d) marked by a familiar picture and labeled by the participant. The results revealed that accuracy improved across conditions such that children made the fewest errors when they generated the label for the hiding location. These findings support the hierarchical competing systems model, which postulates that improved performance can be explained by more powerful representations that guide search behavior.     

Why neuroscience matters to cognitive neuropsychology

The broad issue in this paper is the relationship between cognitive psychology and neuroscience. That issue arises particularly sharply for cognitive neurospsychology, some of whose practitioners claim a methodological autonomy for their discipline. They hold that behavioural data from neuropsychological impairments are sufficient to justify assumptions about the underlying modular structure of human cognitive architecture, as well as to make inferences about its various components. But this claim to methodological autonomy can be challenged on both philosophical and empirical grounds. A priori considerations about (cognitive) multiple realisability challenge the thesis on philosophical grounds, and neuroscientific findings from developmental disorders substantiate that challenge empirically. The conclusion is that behavioural evidence alone is inadequate for scientific progress since appearances of modularity can be thoroughly deceptive, obscuring both the dynamic processes of neural development and the endstate network architecture of real cognitive systems.     

The relations between children's communicative perspective-taking and executive functioning

Two experiments investigated children’s communicative perspective-taking ability. In Experiment 1, 4- to 5-year-old children were tested on two referential communication tasks, as well as on measures of inhibitory control, working memory, and cognitive flexibility. Results document children’s emergent use of the perspective of their speaking partner to guide their communicative behaviors in both a production and comprehension task. In Experiment 2, 3- to 4-year-old children used a speaker’s perspective to guide their interpretation of instructions. In both experiments, egocentric interpretations of speaker requests were negatively correlated with children’s inhibitory control skills. Results of these studies demonstrate that young children can differentiate between information that is accessible to the speaker versus privileged knowledge, and use this information to guide their communicative behaviors. Furthermore, the results suggest that children’s inhibitory control skills allow them to inhibit their own perspective, enabling them to make use of their communicative partner’s perspective.     

Effects of the EXAT neuropsychological multilevel intervention on behavior problems in children with executive function deficits

This is a clinical intervention study of children with executive function (EF ) deficits. A neuropsychological multimodal group intervention called EXAT (rehabilitation of EX ecutive function and AT tention) was developed at the Psychology Clinic of the University of Tampere. Based on the principles of neuropsychological rehabilitation and behavioral modification, EXAT combines child group training, parent training, and teacher consultations. The aims of this study were to investigate behavior problems before and after the intervention in children attending EXAT and in controls, and to compare intervention effects in hyperactive, inattentive, and EF subgroups based on the primary deficit described in the referral. The participants were 86 children (6–12 years) with a mean IQ of 91.4 attending EXAT and 45 controls. The participants’ parents and teachers completed the Conners’ Rating Scales‐Revised. In addition, the Strengths and Difficulties Questionnaire was completed by the parents attending EXAT . The parents reported statistically significant decreases with medium effect sizes for the CPRS ‐R subscales for impulsivity, hyperactivity, and oppositional behavior. In the controls within the same time interval, there was increase in restless and impulsive behavior, and a decrease in total problems. The teachers reported positive changes after the intervention in ADHD symptoms and anxiousness/shyness, but the effects sizes were small. The intervention effects were larger in the hyperactive subgroup. Positive intervention effects were related to a younger age, lower IQ , and simultaneous learning support. In conclusion, EXAT – a structured multilevel group intervention – has positive effects on children's behavior regulation skills by decreasing impulsivity and restless behavior.     

The role of executive functions in social impairment in Autism Spectrum Disorder

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterized by socio-communicative impairments. Executive dysfunction may explain some key characteristics of ASD, both social and nonsocial hallmarks. Limited research exists exploring the relations between executive function and social impairment in ASD and few studies have used a comparison control group. Thus, the objective of the present study was to investigate the relations between executive functioning using the Behavioral Rating Inventory of Executive Functioning (BRIEF), social impairment as measured by the Social Responsiveness Scale (SRS), and overall autistic symptomology as measured by the Autism Diagnostic Observation Schedule (ADOS) in children and adolescents with and without ASD. Seventy children and adolescents diagnosed with ASD and 71 typically developing controls were included in this study. Findings showed that behavioral regulation executive processes (i.e., inhibition, shifting, and emotional control) predicted social function in all children. However, metacognitive executive processes (i.e., initiation, working memory, planning, organization, and monitoring) predicted social function only in children with ASD and not in typically developing children. Our findings suggest a distinct metacognitive executive function-social symptom link in ASD that is not present in the typical population. Understanding components of executive functioning that contribute to the autistic symptomology, particularly in the socio-communicative domain, is crucial for developing effective interventions that target key executive processes as well as underlying behavioral symptoms.     

Deconstructing Frith and Snowling's homograph-reading task: Implications for autism spectrum disorders

The poor performance of autistic individuals on a test of homograph reading is widely interpreted as evidence for a reduction in sensitivity to context termed “weak central coherence”. To better understand the cognitive processes involved in completing the homograph-reading task, we monitored the eye movements of nonautistic adults as they completed the task. Using single trial analysis, we determined that the time between fixating and producing the homograph (eye-to-voice span) increased significantly across the experiment and predicted accuracy of homograph pronunciation, suggesting that participants adapted their reading strategy to minimize pronunciation errors. Additionally, we found evidence for interference from previous trials involving the same homograph. This progressively reduced the initial advantage for dominant homograph pronunciations as the experiment progressed. Our results identify several additional factors that contribute to performance on the homograph reading task and may help to reconcile the findings of poor performance on the test with contradictory findings from other studies using different measures of context sensitivity in autism. The results also undermine some of the broader theoretical inferences that have been drawn from studies of autism using the homograph task. Finally, we suggest that this approach to task deconstruction might have wider applications in experimental psychology.     

Predicting cognitive development and early symptoms of autism spectrum disorder in preterm children: The value of temperament and sensory processing

This study was the first to longitudinally explore the extent to which early temperament and sensory processing were of predictive value for cognitive development and Autism Spectrum Disorder (ASD) symptomatology in a sample of preterm children (N = 50, 22 girls, mean gestational age 27 weeks). At the corrected ages of 10, 18, and 24 months, sensory processing and temperament were assessed, as were cognitive development and ASD symptoms at 36 months. Better cognitive development was predicted by fewer hospitalisation days at birth and by lower Activity Level at 18 months. Temperamental subscales of Negative Affect showed associations with both parent-reported and observational measures of ASD symptomatology, whereas sensory processing only had predictive value for parent-reported symptoms of ASD. The usefulness of temperament and sensory processing for prediction of ASD symptom severity and cognitive outcomes became clear in the second year of life. The results indicate that this area of research is worth additional investigation in the extreme and very preterm population, to explore in further detail whether these two concepts might be able to provide information about which preterms are more likely to develop ASD or cognitive impairments.     

Bottom-up and top-down dynamics in young children's executive function: Labels aid 3-year-olds’ performance on the Dimensional Change Card Sort

Executive function (EF) improves between the ages of 3 and 5 and has been assessed reliably using the Dimensional Change Card Sort (DCCS), a task in which children first sort bivalent cards by one dimension (e.g., shape) and then are instructed to sort by a different dimension (e.g., color). Three-year-olds typically perseverate on the pre-switch dimension, whereas 5-year-olds switch flexibly. Labeling task stimuli can facilitate EF performance (0110 and 0060), but the nature of this effect is unclear. In 3 experiments we examined 2 hypotheses deriving from different theoretical perspectives: first, that labels facilitate performance in a more bottom-up fashion, by biasing attention to relevant task rules (Kirkham et al., 2003); and second, that labels aid performance in a more top-down fashion by prompting reflection and an understanding of the hierarchical nature of the task (Zelazo, 2004). Children performed better on the DCCS when labels referred to the relevant sorting dimension (Experiment 1). This was a function of the content of the labels rather than the change in auditory signal across phases (Experiment 2). Furthermore, labeling the opposite dimension only did not have a symmetrically negative effect on performance (Experiment 3). Together, these results suggest external, verbal labels bias children to attend to task-relevant information, likely through interaction with emerging top-down, endogenous control.     

Dissociations in visual attention deficits among persons with mild cognitive impairment

Impairments in visual attention and visual information processing have been identified as part of the neuropsychological features of Alzheimer's disease (AD), even in its earliest stages. There is increasing recognition that these deficits may be selective rather than global, with some attentional subtypes being more vulnerable than others. The few studies that have investigated attentional deficits in mild cognitive impairment (MCI), a putatively prodromal phase of AD, have not satisfactorily addressed the possible selectivity in attentional deficits in MCI. This study examined potential dissociations in visual attention deficits in MCI using a measure that assesses simple, divided, and selective attention. The results indicated a hierarchy of attentional impairments, with divided attention being the most affected and simple attention the least. Among participants with MCI, 53% showed evidence of impairment in divided attention compared to 19% of controls (OR = 4.81, p < .001). Poorer visual attention was also associated with poorer overall cognitive status. The implications of these findings for early identification of MCI, prevention of functional decline in MCI, and delay/reversal of cognitive degradation in MCI are discussed.     

Neurological subtle signs and cognitive development: A study in late childhood and adolescence

Introduction and Aim: Neurological subtle signs (NSS) are often observed during the neurological examination of children and tend to disappear with age. Their persistence into late adolescence or young adulthood has been related to psychiatric and neurocognitive disorders. To provide a better understanding of their functional basis, a longitudinal correlational study with neurocognitive measurements was performed.

Method: We conducted multiple regression and correlation analyses of NSS with demographic and cognitive measures on a subset of 341 healthy children (56% males), taking part in a longitudinal dental study. Participants, whose ages ranged between 11–15 years, at first evaluation, undertook yearly, during 5 years, a 6-item NSS exam (producing a total score ranging between 0–18) and a comprehensive battery of neurocognitive tests. Effects of age, gender, IQ, and 7 neurocognitive factors on NSS were analyzed.

Results: Over the years, NSS scores correlated consistently with selective attention (Stroop test), motor speed (finger tapping), and visuomotor speed (pegboard speed).

Discussion: These results suggest that the disappearance of NSS in late childhood and adolescence occurs primarily in parallel with the development of motor and visuomotor functions and secondarily in relation to higher order functions such as selective attention (Stroop) and executive control (B-A Trails difference).     

Differential changes in the development of motor coordination and executive functions in children with motor coordination impairments

Cognitive and motor coordination skills of children with and without motor coordination impairments were examined with a one-year follow-up investigation. Initially, children were between 4 and 6 years old. Age-appropriate tests of executive functions (updating, switching, inhibition, interference control), motor coordination (the Movement Assessment Battery for Children-2) and fitness (the Körperkoordinations-Test für Kinder) were administered in two consecutive years. Several background variables (age, socioeconomic status, medical support, clinical interventions, leisure activities) and potential moderators (nonverbal intelligence, reaction time, visual perception) were controlled. The matched sample consisted of 48 control children and 48 children with motor coordination impairments. The children’s executive functions dramatically improved during the one-year period. With regard to motor coordination performance, half of the impaired children caught up to the control children’s level (“remission group”), while the remaining half showed no improvement (“persisting group”). Compared to the persisting group, the children in the remission group showed markedly better interference control at both measurement points. The correlation between executive functions and motor coordination is significant in the persisting group, but not in the remission group. The results of the study are discussed in the light of the role of executive functions, especially inhibition processes, for the automatization of motor coordination tasks.     

Selective attention and executive functions deficits among criminal psychopaths

The present study examined whether psychopaths exhibit deficits in selective attention and executive functions. Prison inmates were assigned to either a “psychopath” group or a “control” group according to their scores on the PCL‐R [Hare, 1991: Toronto, Multi‐Health Systems]. The two groups were compared in terms of performance on the following tests: (1) D‐II cancellation, (2) Porteus Maze, (3) Modified Wisconsin Card Sorting, (4) Stroop Color Word Interference, (5) Trail Making, and (6) Tower of London. The results support the hypothesis of selective attention and specific executive function deficits among psychopaths. Specifically, psychopaths' abilities to maintain a plan and to inhibit irrelevant information were inferior to those of control participants. Aggr. Behav. 29:393–405, 2003. © 2003 Wiley‐Liss, Inc.     

Representational and executive selection resources in 'theory of mind': evidence from compromised belief-desire reasoning in old age

Effective belief-desire reasoning requires both specialized representational capacities-the capacity to represent the mental states as such-as well as executive selection processes for accurate performance on tasks requiring the prediction and explanation of the actions of social agents. Compromised belief-desire reasoning in a given population may reflect failures in either or both of these systems. We report evidence supporting this two-process model from belief-desire reasoning tasks conducted with younger and older adult populations. When task inferential complexity is held constant, neither group showed specific difficulty with reasoning about mental state content as compared with non-mental state content. However, manipulations that systematically increase executive performance demands within belief-desire reasoning caused systematic decreases in task performance in both older and younger adult groups. Moreover, the effect of increasing executive demands was disproportionately greater in the older group. Regression analysis indicated that measures of processing speed and inhibition contributed most to explaining variance in accuracy and response times in the belief-desire reasoning tasks. These results are consistent with the idea that compromised belief-desire reasoning in old age is likely the result of age-related decline in executive selection skills that supplement core mental state representational abilities, rather than as a result of failures in the representational system itself.     

Cognitive imitation in typically-developing 3- and 4-year olds and individuals with autism

Individuals diagnosed with autism suffer from numerous social, affective and linguistic impairments. It has also been suggested that they have a global imitation deficit. That hypothesis, however, is compromised by the fact that individuals with autism suffer from various motor impairments. Here we describe an experiment on cognitive imitation, a type of imitation that doesn’t require motor learning. Nine male autistic subjects and 20 typically-developing 3- and 4-year olds were trained to respond, in a prescribed order, to different lists of photographs that were displayed simultaneously on a touch-sensitive monitor. Because the position of the photographs varied randomly from trial to trial, sequences could not be learned by motor imitation. In three different imitation treatments, including a ghost control, autistic subjects learned new sequences more rapidly after observing a model execute those sequences than when they had to learn new sequences entirely by trial and error. Moreover, the performance of autistic subjects did not significantly differ from the performance of typically-developing controls. The result of this and other studies suggests that individuals with autism suffer from a specific novel motor imitation deficit.     

Caregiver ratings and performance-based indices of executive function among preschoolers with and without maltreatment experience

Despite the well-documented impact of early maltreatment on children’s executive function (EF), there has been limited consensus about how to best assess this neurocognitive domain in high-risk, vulnerable preschool-aged children. Relevant studies have generally utilized either performance-based tests or caregiver ratings of EF, yet multi-method research has been rare. This study examined the EF profiles of preschoolers exposed to maltreatment, as indexed by the Behavior Rating Inventory of Executive function – Preschool Version (BRIEF-P), and investigated associations between caregiver ratings and performance-based measures (Happy–Sad Stroop, Tapping Test, and Dimensional Change Card Sort – DCCS) of EF in this population. Maltreatment status was further tested as a moderator of associations between these measures. Participants were (n = 107) children aged 4–5 years (M = 4.75; SD = 0.57; 39% female), with various levels of exposure to maltreatment. Children exposed to maltreatment were found to exhibit significantly more caregiver-rated deficits in EF than non-maltreated children, with greater fluctuations apparent across all scales of the BRIEF-P. Consistent with previous research in neurologically impaired children, there were only limited and weak to moderate correlations between BRIEF-P scales and performance-based measures of EF. Furthermore, maltreatment status was found to moderate the association between scores on the BRIEF-P Inhibit Scale and the DCCS, such that the association between these indices was weaker among children exposed to higher levels of maltreatment.