Neuropsychology of Early-treated Phenylketonuria: Specific Executive Function Deficits

This study explored the hypothesis that children with early-treated phenylketonuria (PKU) are selectively impaired on executive function measures, even when still on diet. The rationale for this hypothesis is that even mild elevations in phenylalanine (Phe) can lead to lower central levels of biogenic amines, including dopamine (DA). We hypothesize that this mild DA depletion causes subtle prefrontal dysfunction, which in turn affects executive functions such as set maintenance, planning, and organized search. 11 preschool early-treated PKU children (M age = 4.64) and a sample of age- and IQ-matched unaffected peers (n = 11) were evaluated on a battery of executive function (EF) measures. In addition, a "non-executive function" task, recognition memory, was administered to all subjects. Group comparisons demonstrated that PKU children were significantly impaired on an executive function composite score; there were no group differences, however, in recognition memory. These results supported the hypothesized specific deficit in executive function. Furthermore, within the PKU group the executive function composite score was significantly negatively correlated with concurrent phenylalanine levels, even after controlling for the correlation between IQ and executive function skills. This second finding provides support for the proposed biochemical mechanism underlying the specific cognitive deficits.     

Imitation and Pantomime in High-Functioning Adolescents with Autism Spectrum Disorders

A study was designed to test 2 alternative hypotheses—a symbolic hypothesis and an executive function hypothesis—for the imitation and pantomime deficits found in previous studies of autism. The subjects were 17 adolescent high-functioning subjects with autism spectrum disorders and 15 clinical comparison subjects who were matched on chronological age and verbal IQ. Meaning and sequence were manipulated in facial and manual imitation tasks. Sequence was manipulated in the pantomime and control tasks. Recognition memory and motor control tasks were matched to the experimental tasks. The results provided no support for the symbolic deficit hypothesis; meaning aided rather than hindered the performance of the group with autism. Partial support for the executive deficit hypothesis was found. There were no group differences on motor control tasks, and few on the memory control tasks, arguing against deficits in motor initiation, basic motor coordination, or visual recognition memory.     

Cognitive mechanisms underlying achievement deficits in children with mathematical learning disability

Using strict and lenient mathematics achievement cutoff scores to define a learning disability, respective groups of children who are math disabled (MLD, n=15) and low achieving (LA, n=44) were identified. These groups and a group of typically achieving (TA, n=46) children were administered a battery of mathematical cognition, working memory, and speed of processing measures (M=6 years). The children with MLD showed deficits across all math cognition tasks, many of which were partially or fully mediated by working memory or speed of processing. Compared with the TA group, the LA children were less fluent in processing numerical information and knew fewer addition facts. Implications for defining MLD and identifying underlying cognitive deficits are discussed.     

Metamemory in children with autism

Five experiments are reported comparing metamemory abilities in children with autism, age- and language-matched mentally retarded children, and language-matched young normal controls. The mean language age of the participants in Experiment 1 was approximately 6 years, in Experiments 2, 3, and 4 approximately 8 years, and in Experiment 5 approximately 9 years. All the children were given one or more false belief tests. Experiment 1 assessed the children's understanding that a task variable (list length) and a person variable (age) will affect their own and others' performances on an immediate auditory-verbal recall task. Experiment 2 assessed the ability to utilize category cues in a picture recall task. Experiments 3 and 4 assessed the ability to verbalize strategies used in a memory span test and in one retrospective and two prospective memory situations. Experiment 5 assessed the children's knowledge and understanding of another person's memory. On the basis of available evidence and theory, we predicted that the children with autism would be impaired on all the metamemory tasks and that impairment would be associated with failure on tests of false belief. Our predictions were not supported. The children with autism were not impaired on any of the metamemory tasks, although they were less likely than controls to make spontaneous use of memory strategies involving other people. Unexpectedly few of the children failed the false belief tasks. These results are discussed in relation to theories concerning primary psychological deficits underlying autism.     

Memory Profile of Children with Nonverbal Learning Disability

The aim of this study was to compare visual and verbal memory in children with nonverbal learning disability (NLD) using the Children's Memory Scale and to identify the profile of strengths and weaknesses in visual memory abilities. Performance was significantly lower on measures of visual than verbal memory, indicating that children with NLD have deficits in visual memory despite adequate verbal memory. A unique pattern of performance emerged for the visual but not the verbal subtests. Performance on the Faces Immediate subtest was well below average, although other measures of visual memory were within the average range. Hence, it appears that children with NLD have a specific deficit on immediate memory for faces. This facial memory deficit may be linked to a deficit in right hemisphere functioning, which has already been implicated in facial processing and may also be linked with other disorders (e.g., autism spectrum disorder) in which similar facial processing deficits have been documented. More research is needed to further understand the visual memory profile of children with NLD and to inform instruction and remediation.     

Temporal resolution of auditory perception and verbal working memory in 15 children with language impairment

We investigated temporal resolution of auditory perception (TRAP), verbal working memory, and speech perception in 15 children with language impairment (LI) in comparison with a control group of 99 typical children. A computerized two-choice test was used to assess these three abilities. No deficits in TRAP were found in the LI group, and the thresholds were similar for both study groups. It was interesting that the variability was high for both groups and that the control group's performance was poorer than reported in some previously published studies. There were significant differences in the two groups' performance on speech perception and verbal working memory. Working memory was the most sensitive of these two measures.     

Relationship of executive functioning and memory to autism symptomology and adaptive functioning: Implications for reducing future underemployment

Understanding the relationship between executive functioning and its connection to working memory and adaptive functioning can inform planning and employment efforts. This study explored the relationship between memory and adaptive functioning with a sample of Autistic youths/young adults. Participant mean age was 21.3 (SD = 3.0). Of the 22 participants, 17 were male, and 19 white, non-Hispanic/Latina/o/x. All but one lived with their parent(s). Participants were administered a full battery assessing cognitive ability (WAIS-IV), memory and executive functioning (WMS-IV and DKEFS), autism symptomatology (ADOS-II), and adaptive functioning (SIB-R). A multivariate lasso regression model was used. Memory, especially as measured on the WMS-IV, was found to be significantly related to adaptive functioning and autism symptomatology. There appears to be continuing evidence that memory is highly related to adaptive functioning and autism symptomatology. Interventions involving auditory and immediate memory could be helpful in promoting more mutually effective social interactions necessary for positive employment outcomes.     

Phonological processing skills and deficits in adult dyslexics

This article presents 4 experiments aimed at defining the primary underlying phonological processing deficit(s) in adult dyslexia. 5 phonological processes, all involving spoken language, were studied: phoneme perception, phoneme awareness, lexical retrieval of phonology, articulatory speed, and phonetic coding in verbal short-term memory. 2 differently ascertained adult dyslexic groups, familial dyslexics (n = 15) and clinic dyslexics (n = 15), were the subjects in each experiment. These dyslexic groups were chosen because deficits that persist until adulthood and that are found in differently ascertained dyslexic groups are more likely to be primary. Each dyslexic group was compared to 2 control groups, chronological age (CA) controls who were similar in age and sex, and younger reading age (RA) controls who were similar in reading age and sex. The main finding was a clear deficit in phoneme awareness in both dyslexic groups, with each dyslexic group performing significantly worse than both CA and RA controls. Moreover, performance on the 2 phoneme awareness tasks together uniquely accounted for substantial variance in nonword reading. The clinic but not the familial dyslexics appeared to have an additional deficit in verbal short-term memory. No clear deficits were found in either dyslexic group in phoneme perception, lexical retrieval, or articulatory speed.     

Cognitive processing skills and developmental dyslexia in Chinese

The purpose of the present study was twofold: (a) to examine the extent to which Chinese dyslexic children experience deficits in phonological and orthographic processing skills and (b) to examine if Chinese dyslexia is associated with deficits in Planning, Attention, Simultaneous, and Successive (PASS) processing. A total of 27 Grade 4 children with dyslexia (DYS), 27 Grade 4 chronological age (CA) controls, and 27 Grade 2 reading age (RA) controls were tested on measures of phonological awareness, rapid naming, phonological memory, PASS, reading accuracy, and reading fluency. The results indicated that the DYS group performed significantly poorer than the CA and RA groups on both measures of phonological awareness and on a measure of orthographic processing but comparably to the RA group on a measure of rapid naming and both measures of phonological memory. In regard to the PASS processing skills, the DYS group performed worse than the CA controls on Successive and Simultaneous processing but comparably to the RA group on all PASS processing skills. Implications of these findings for early identification and intervention of reading difficulties are discussed.     

Executive function and language in deaf children

The relationship between language and executive function (EF) and their development in children have been the focus of recent debate and are of theoretical and clinical importance. Exploration of these functions in children with a peripheral hearing loss has the potential to be informative from both perspectives. This study compared the EF and language skills of 8- to 12-year-old children with cochlear implants (n = 22) and nonimplanted deaf children (n = 25) with those of age-matched hearing controls (n = 22). Implanted and nonimplanted deaf children performed below the level of hearing children on tests assessing oral receptive language, as well as on a number of EF tests, but no significant differences emerged between the implanted and nonimplanted deaf groups. Language ability was significantly positively associated with EF in both hearing and deaf children. Possible interpretations of these findings are suggested and the theoretical and clinical implications considered.     

Executive Functions in Young Children with Autism

The executive dysfunction hypothesis of autism has received support from most studies of older people with autism; however, studies of young children have produced mixed results. Two studies are presented that compare the performance of preschoolers with autism (mean = 51 months/4.3 years of age) to a control group matched on age, and verbal and nonverbal ability. The first study (n = 18 autism and 17 control) found no group differences in performance on 8 executive function tasks (A not B, Object Retrieval, A not B with Invisible Displacement, 3-Boxes Stationary and Scrambled, 6-Boxes Stationary and Scrambled, and Spatial Reversal), but did find that children with autism initiated fewer joint attention and social interaction behaviors. The second (longitudinal) study of a subset of the children (n = 13 autism and 11 control) from the first study found that neither groups' performance on Spatial Reversal changed significantly over the course of a year. The results of these studies pose a serious challenge to the executive dysfunction hypothesis of autism.     

Using neuropsychological profiles to classify neglected children with or without physical abuse

OBJECTIVE: The aim of this study is twofold: First, to investigate whether cognitive functions can contribute to differentiating neglected children with or without physical abuse compared to comparison participants; second, to demonstrate the detrimental impact of children being victimized by a combination of different types of maltreatment. METHODOLOGY: Seventy-nine children aged 6-12 years and currently receiving Child Protection Services because of one of two types of maltreatment (neglect with physical abuse, n=56; neglect without physical abuse, n=28) were compared with a control group of 53 children matched for age, gender, and annual family income. The neuropsychological assessment focused on motor performance, attention, memory and learning, visual-motor integration, language, frontal/executive functions, and intelligence. RESULTS: Discriminant analysis identified auditory attention and response set, and visual-motor integration (Function 1), and problem solving, abstraction, and planning (Function 2) as the two sets of variables that most distinguished the groups. Discriminant analysis predicted group membership in 80% of the cases. Children who were neglected with physical abuse showed cognitive deficits in auditory attention and response set, and visual-motor integration (Function 1) and problem solving, abstraction, and planning (Function 2). Children who were neglected without physical abuse differed from the control group in that they obtained lower scores in auditory attention and response set, and visual-motor integration (Function 1). Surprisingly, these same children demonstrated a greater capacity for problem solving, abstraction, and planning (Function 2) than the physically abused neglected and control children. CONCLUSION: The present study underscores the relevance of neuropsychology to maltreatment research. The results support the heterogeneity of cognitive deficits in children based on different types of maltreatment and the fact that neglect with physical abuse is more harmful than neglect alone.     

Multimedia learning and individual differences: Mediating the effects of working memory capacity with segmentation

Research in multimedia learning lacks an emphasis on individual difference variables, such as working memory capacity (WMC). The effects of WMC and the segmentation of multimedia instruction were examined by assessing the recall and application of low (n=66) and high (n=67) working memory capacity students randomly assigned to either a segmented instruction (SI) or non-segmented instruction (NSI) version of a multimedia tutorial on historical inquiry. WMC was found to have a significant, positive effect on participants' recall and application scores; however, the use of segmentation mediated the effects of WMC to allow learners with lower WMC to recall and apply equal to those with higher WMC.     

Memory for everyday information in students with learning disabilities

This study compared students with and without learning disabilities (LD) on their recall of academic information and information encountered in the students' everyday lives. The academic recall measures included a sentence listening span test, a rhyming words working memory test, and a visual matrix working memory task. Students' cued recall of all the tasks was also measured. The everyday working memory tasks included a dance episode event recall test; a library procedure recall test; and recall tests of commonly found objects, such as a coin, a telephone, and a McDonald's sign. Compared to students without LD, students with LD performed poorly on both the academic recall tasks and the everyday recall tasks. These results support the notion that some students with LD may have working memory problems that affect their performance on tasks other than reading. The results of the cued recall showed that the availability of cues significantly decreased the ability group differences on many of the academic and everyday tasks. This result replicates prior research findings that students with LD do not use retrieval strategies effectively and that some students with LD may have a production deficiency that affects their retrieval of previously encoded information.     

Genome‐Wide Association Study of Latent Cognitive Measures in Adolescence: Genetic Overlap With Intelligence and Education

Individual differences in executive functions (EF) are heritable and predictive of academic attainment (AA). However, little is known about genetic contributions to EFs or their genetic relationship with AA and intelligence. We conducted genome‐wide association analyses for processing speed (PS) and the latent EF measures of working memory (WM) and inhibitory control (IC) in 4,611 adolescents from the Avon Longitudinal Study of Parents and Children. While no loci reached genome‐wide significance, common genetic variants explained 30% of the variance in WM and 19% in PS. In contrast, we failed to find common genetic contributions to IC. Finally, we examined shared genetic effects between EFs and general intelligence, AA and ADHD. We identified significant genetic correlations between WM, intelligence, and AA. A more specific pattern was observed for PS, with modest genetic overlap with intelligence. Together these findings highlight diversity in the genetic contributions to specific cognitive functions and their genetic relationship with educational and psychiatric outcomes.     

Psychosocial adjustment in adolescent child molesters

This study compared adolescent child molesters (n = 31) with nonsex offending delinquents (n = 34) and normal adolescents (n = 71) on standardized measures of social competence and psychological adjustment. The measures included the Adolescent Assertiveness Scale, the Survey of Heterosocial Interactions, the Self-Consciousness Scale, the Social Anxiety and Distress Scale, the Revised UCLA Loneliness Scale, the Coopersmith Self-Esteem Inventory, the Beck Depression Inventory, the Norwicki-Strickland Locus of Control Scale, and the Jesness Inventory. Results were consistent with predictions. Molesters showed significantly more global maladjustment than normals and were more socially anxious and threatened by heterosocial interactions than nonsex offending delinquents. A discriminant function analysis suggested that molesters, more than delinquents, were likely to perceive themselves as socially inadequate and to be externally oriented in their attributional style. Results support the hypothesis that social skill deficits and social isolation are risk factors that may predispose some adolescents to commit sexual crimes against children.     

注意缺陷多动障碍儿童执行功能的延迟眼跳研究

眼跳任务常用于研究额叶纹状体环路的机能,使用延迟眼跳任务可有效分离抑制空间工作记忆,深入探究注意缺陷多动障碍(ADHD)儿童的执行功能损伤.48名儿童(ADHD-I型11人,ADHD-C型19人,对照组18人)完成2种实验任务:正向眼跳和延迟眼跳.结果发现:(1)ADHD儿童存在抑制功能损伤,延迟眼跳中对照组错误率的成绩优势非常显著,延迟时间的加长使ADHD组的错误率显著提高,但不影响对照组错误率.(2)ADHD儿童存在一定的空间工作记忆损伤,延迟眼跳中ADHD组有较差的精确性,且延迟时间越长组间差异越显著.(3)ADHD儿童有较长的反应时和较慢的眼跳速度.     

The role of orthographic flexibility in Chinese word reading among kindergarten children

Abstract

The present study aimed to examine the potential importance of orthographic flexibility for Chinese reading acquisition. Orthographic flexibility is a novel concept that represents the ability to manage and switch attention among multiple aspects of orthographic information. A total of 92 Chinese kindergarten children at age 6 were assessed on measures of orthographic flexibility, orthographic knowledge, executive functions (EF) skills (i.e. cognitive flexibility and working memory) and Chinese word reading. Results of hierarchical regressions showed that orthographic flexibility uniquely and significantly contributed to word reading beyond the effects of established predictors, namely orthographic knowledge and EF skills. Path analysis further indicated that orthographic flexibility significantly mediated the contribution of EF skills to word reading. These findings provided theoretical insights into the linkage between domain-general EF skills and domain-specific reading ability. The present study also provided practical implication that training on orthographic flexibility in addition to orthographic knowledge could be beneficial to early acquisition of Chinese word reading.     

Kindergarten Children's Executive Functions Predict Their Second-Grade Academic Achievement and Behavior

Whether and to what extent kindergarten children's executive functions (EF) constitute promising targets of early intervention is currently unclear. This study examined whether kindergarten children's EF predicted their second-grade academic achievement and behavior. This was done using (a) a longitudinal and nationally representative sample (N = 8,920, M_age = 97.6 months), (b) multiple measures of EF, academic achievement, and behavior, and (c) extensive statistical control including for domain-specific and domain-general lagged dependent variables. All three measures of EF—working memory, cognitive flexibility, and inhibitory control—positively and significantly predicted reading, mathematics, and science achievement. In addition, inhibitory control negatively predicted both externalizing and internalizing problem behaviors. Children's EF constitute promising targets of experimentally evaluated interventions for increasing academic and behavioral functioning.     

Behavioral problems in alleged sexual abuse victims.

This study was conducted to compare the parental assessments of problem behaviors, using the Achenbach Child Behavior Checklist, among alleged sexual abuse victims (n = 81) and an age, race, and gender matched group of nonabused comparison subjects (n = 90). Alleged sexual abuse victims demonstrated significantly higher mean total behavior problem, internalizing and externalizing scores than the comparison sample. Subscale profiles were all in the direction consistent with withdrawal, impairment in social interaction, and sexual problems. Item comparison indicated that sexual abuse victims were more likely to be assessed as having some problem behaviors that have been reported as being indicative of sexual abuse. A significant difference was not obtained on several behaviors that have been previously reported as indicative of sexual abuse. These findings support concerns that sexual abuse victims do exhibit more problem behaviors, but caution must be exercised when interpreting individual behaviors because of their frequency in a nonabused sample.