Showing papers in "Developmental Neuropsychology in 2007"
TL;DR: Findings suggest a possible failure in left hemisphere lateralization of language function involving the superior temporal gyrus in autism.
Abstract: Deficits in language are a core feature of autism. The superior temporal gyrus (STG) is involved in auditory processing, including language, but also has been implicated as a critical structure in social cognition. It was hypothesized that subjects with autism would display different size-function relationships between the STG and intellectual-language-based abilities when compared to controls. Intellectual ability was assessed by either the Wechsler Intelligence Scale for Children-Third Edition (WISC-III) or Wechsler Adult Intelligence Scale-Third Edition (WAIS-III), where three intellectual quotients (IQ) were computed: verbal (VIQ), performance (PIQ), and full-scale (FSIQ). Language ability was assessed by the Clinical Evaluation of Language Fundamentals-Third Edition (CELF-3), also divided into three index scores: receptive, expressive, and total. Seven to 19-year-old rigorously diagnosed subjects with autism (n = 30) were compared to controls (n = 39; 13 of whom had a deficit in reading) of similar age who were matched on education, PIQ, and head circumference. STG volumes were computed based on 1.5 Tesla magnetic resonance imaging (MRI). IQ and CELF-3 performance were highly interrelated regardless of whether subjects had autism or were controls. Both IQ and CELF-3 ability were positively correlated with STG in controls, but a different pattern was observed in subjects with autism. In controls, left STG gray matter was significantly (r = .42, p < or = .05) related to receptive language on the CELF-3; in contrast, a zero order correlation was found with autism. When plotted by age, potential differences in growth trajectories related to language development associated with STG were observed between controls and those subjects with autism. Taken together, these findings suggest a possible failure in left hemisphere lateralization of language function involving the STG in autism.
362 citations
TL;DR: Findings indicate a similar unfolding of the executive aspects of verbal working memory as previously demonstrated with spatial working memory in typically developing children and adolescents across the adolescent years.
Abstract: Post-mortem histological and in vivo neuroimaging findings both reveal frontal lobe development that extends beyond the adolescent years. Few studies have examined whether this protracted neurodevelopment coincides with improvements in adolescent performance on putative frontal lobe tasks. An instrumental function supported by the frontal lobes is working memory, the ability to maintain and manipulate information online. This study investigated the performance of typically developing children and adolescents on a battery of working memory tasks. Findings revealed an improvement in performance on most working memory tasks across the adolescent years. In contrast, no improvement was observed on tasks largely supported by more posterior neural substrates. Current findings indicate a similar unfolding of the executive aspects of verbal working memory as previously demonstrated with spatial working memory. Factor analysis revealed a grouping of working memory tasks based largely on task demands, irrespective of working memory domain, adding support for process-specific models of prefrontal organization. Important implications for typical and atypical frontal lobe development are discussed.
272 citations
TL;DR: Interaction effects between ADHD and EF and between EF and gender were found: At high levels of symptoms of inattention, the poorer the EF, the greater the need for special education.
Abstract: This study examined the predictive relations from symptoms of Attention-deficit/hyperactivity disorder (ADHD) and executive functioning (EF) to social and school functioning in 112 (62 girls) school children. High levels of teacher and parent ratings of ADHD symptoms at the ages of 8-8 1/2 years, and poor EF measured at the age of 8 1/2, were associated with poor social functioning measured by peer nominations and poor teacher ratings of school functioning at the age of 9 1/2. ADHD symptoms independently predicted social and school functioning, whereas EF independently predicted only school functioning. Interaction effects between ADHD and EF and between EF and gender were found: At high levels of symptoms of inattention, the poorer the EF, the greater the need for special education. At high levels of symptoms of hyperactivity/impulsivity, the poorer the EF, the higher the levels of physical aggression. Girls with poor EF were less accepted by peers than equivalent boys.
258 citations
TL;DR: Motor development appears to follow a different developmental course in girls than in boys; separate gender and age norms should be used in clinical assessment of motor function in children.
Abstract: Few studies have contrasted performance of typically developing boys and girls on standardized motor assessment. In the present study, developmental status of the motor system was assessed in 144 typically developing children (72 boys, 72 girls, ages 7-14), using the Physical and Neurological Examination for Subtle Signs (PANESS, Denckla, 1985). Four summary variables were examined: (1) Gaits and Stations, (2) Overflow, (3) Dysrythmia, and (4) Timed Movements. For most variables, gender differences were not significant; however significant gender effects were observed for some subtle signs (involuntary movements), gaits and stations, and timed patterned movements. In all instances, girls showed fewer subtle signs and were faster and more proficient than boys. Significant age-related changes were observed for some subtle signs (dysrythmia and overflow), and for timed movements. In contrast, by age 7, many of the skills assessed by the PANESS have reached "adult" level in typically developing children. Motor development appears to follow a different developmental course in girls than in boys; separate gender and age norms should be used in clinical assessment of motor function in children.
128 citations
TL;DR: It is concluded that children with early-treated PKU exhibit a global pattern of impairment, with a particular deficit in processing speed, and offers some support for dopamine depletion in the prefrontal cortex.
Abstract: This study aimed to enhance our understanding of neuropsychological functioning in children with early-treated phenylketonuria (PKU) and assess the relative impact of white matter abnormalities (WMA) and neurotransmitter deficiencies on cognitive functions in this population. The study consisted of 33 children with early-treated PKU and 34 healthy control children aged between 7 to 18 years. All children had a neuropsychological evaluation that included measures of general intelligence, attention, processing speed, memory and learning, executive function, and academic achievement. Children in the PKU group also had a magnetic resonance (MR) brain scan. When compared with the control group, the PKU group exhibited global cognitive impairment including lower IQ, attention problems, slow information processing, reduced learning capacity, mild executive impairments, and educational difficulties. Children in the PKU group with extensive WMA (n = 14) displayed significant impairments across all cognitive domains. Metabolic control correlated weakly to moderately with attention, executive, and memory/learning factors. Within the PKU group, regressions revealed that executive function and attention factors were independently related to severity of WM pathology and age, while the memory and learning factor was independently related to metabolic control and age. It is concluded that children with early-treated PKU exhibit a global pattern of impairment, with a particular deficit in processing speed. WM pathology extending into frontal and subcortical regions correlates with the greatest deficits and a profile of impairment consistent with diffuse WM damage. Our findings also offer some support for dopamine depletion in the prefrontal cortex, however adverse consequences as a result of norepinephrine and serotonin deficiencies should not be discounted.
118 citations
TL;DR: In this article, the authors examined developmental changes in brain electrical activity during higher-order cognitive processing at infancy and early childhood using measures of EEG power and coherence with a longitudinal sample, and found that working memory was associated with changes in EEG power from baseline to task across the entire scalp.
Abstract: Using measures of EEG power and coherence with a longitudinal sample, the goal of this study was to examine developmental changes in brain electrical activity during higher order cognitive processing at infancy and early childhood. Infants were recruited at 8 months of age and performed an infant working-memory task based on a looking version of the A-not-B task. At age 4.5 years, one half of the original sample returned for a follow-up visit and were assessed with age-appropriate working-memory tasks. At infancy, working memory was associated with changes in EEG power from baseline to task across the entire scalp, whereas in early childhood, working memory was associated with changes in EEG power from baseline to task at medial frontal only. Similar results were found for the EEG coherence data. At infancy, working memory was associated with changes in EEG coherence from baseline to task across all electrode pairs and by 4.5 years of age, EEG coherence changed from baseline to working-memory task at the ...
116 citations
TL;DR: Investigation of the impact of TBI on executive function outcomes in children who sustained a TBI before the age of seven suggested that executive difficulties were present following severe TBI, however children with mild and moderate injuries were relatively unaffected.
Abstract: Little is known about the long-term effects of traumatic brain injury (TBI) in very young children. This study used a prospective, cross-sectional design to investigate the impact of TBI on executive function (EF) outcomes in children who sustained a TBI before the age of seven. The study aimed to identify specific or global EF deficits five years post-TBI, and to explore factors that predicted outcomes. Fifty-four children with a TBI and 17 uninjured comparison children participated. Their performance on several cognitive and behavioral EF measures was examined. Results suggested that executive difficulties were present following severe TBI, however children with mild and moderate injuries were relatively unaffected. Skills that develop early appeared to be relatively robust. Injury severity was found to be most predictive of long-term EF, however other injury, child and family-related variables also contributed to outcomes.
114 citations
TL;DR: Because of their variability, ERPs are less helpful in determining whether an individual infant is developing abnormally and should be used in conjunction with behavioral tests so as to relate performance to mechanism, and with anatomical brain measurements to relate mechanism to structure.
Abstract: The complex development of the human brain during infancy can only be understood by convergent structural, functional, and behavioral measurements. The evaluation of event-related potentials (ERPs) is the most effective current way to look at infant brain function. ERP paradigms can be used to examine the simple transmission of sensory information to the cortex and the discrimination of this information within the cortex. The main developmental changes involve localization of function as the brain becomes tuned to the experienced world (related to synaptic pruning) and a speeding up of transmission as pathways become efficient (related to myelination). ERPs that occur in relation to different temporal aspects of a stimulus (onset-responses, offset-responses, sustained potentials and steady-state responses) and ERPs recorded at different stimulus rates may help track perceptual development from a temporal perspective. Particularly important in human development are the ERP changes that occur in the processing of speech sounds and human faces. At present, ERP studies can show differences between groups of subjects that can demonstrate developmental disorders or elucidate mechanisms of development. However, because of their variability, ERPs are less helpful in determining whether an individual infant is developing abnormally. Where possible, ERP measurements should be used in conjunction with behavioral tests so as to relate performance to mechanism, and with anatomical brain measurements to relate mechanism to structure.
109 citations
TL;DR: It is suggested that face processing ability and strategies in autism can be significantly improved through training.
Abstract: Typically developing individuals process faces using strategies that differ from those used for processing objects, and which tend to be holistic and based on configural information. Behavioral and neuroimaging studies suggest that individuals with autism may not utilize the same specialized strategies for face processing. The present study was designed to investigate whether computerized face-specific training, based on a modified version of Gauthier and Tarr's (1997) expertise protocol, can influence the face processing strategies and abilities of adolescents and young adults with Autism Spectrum Disorder (ASD). Ten individuals with ASD were assigned to either a training protocol designed to improve face processing (N = 5) or a control condition (N = 5). Outcomes assessed holistic processing and configural sensitivity. All trained individuals achieved a behavioral criterion of developing expertise in face recognition established in the literature. Outcome assessments indicated that the trained group showed significantly greater sensitivity to second-order configural relations compared with untrained controls, but did not differ on the measure of holistic processing. These findings suggest that face processing ability and strategies in autism can be significantly improved through training.
106 citations
TL;DR: Different forms of MLD are discussed as related to each of the cognitive and brain systems, and the former include visuospatial long-term and working memory and the intraparietal sulcus.
Abstract: A distinction between potentially evolved, or biologically-primary forms of cognition, and the culturally-specific, or biologically-secondary forms of cognition that are built from primary systems is used to explore mathematical learning disability (MLD). Using this model, MLD could result from deficits in the brain and cognitive systems that support biologically-primary mathematical competencies, or from the brain and cognitive systems that support the modification of primary systems for the creation of secondary knowledge and secondary cognitive competencies. The former include visuospatial long-term and working memory and the intraparietal sulcus, whereas the latter include the central executive component of working memory and the anterior cingulate cortex and lateral prefrontal cortex. Different forms of MLD are discussed as related to each of the cognitive and brain systems.
104 citations
TL;DR: Regression analyses yielded a complex pattern of results concerning the prediction of set-switching and set-maintenance by the performance on tasks used to assess the EF components, which were interpreted to suggest distinct developmental trends in set- Switching andSet-Maintenance abilities required by the WCST.
Abstract: This study examined developmental change in set-switching and set-maintenance on the Wisconsin Card Sorting Task (WCST), and sought to determine how executive function (EF) components (i.e., Working Memory, Shifting and Inhibition) may contribute to the observed changes on WCST performance. To this end, performance in four age groups (7-year-olds, 11-year-olds, 15-year-olds, and 21-year-olds) was measured on the WCST, and on three EF tasks assumed to tap Working Memory, Shifting, and Inhibition. The results showed that adult levels of performance were reached in 11-year-olds for set-switching, and in 15-year-olds for set-maintenance. A subsequent principal component analysis revealed that set-switching and set-maintenance loaded on two factors for 7-year-olds, but a single factor in the other age groups. Finally, regression analyses yielded a complex pattern of results concerning the prediction of set-switching and set-maintenance by the performance on tasks used to assess the EF components. The results were interpreted to suggest distinct developmental trends in set-switching and set-maintenance abilities required by the WCST.
TL;DR: A cohort of pediatric MS patients is followed and cognitive function longitudinally is assessed and results indicate that a number of these patients experience further cognitive decline over time, or decline from previously normal functioning.
Abstract: Although Multiple Sclerosis (MS) occurring in childhood and adolescence has received increasing attention in recent years, the impact of the disease on cognitive function in this subgroup remains poorly understood. It has been posited that children and adolescents with MS may be particularly susceptible to cognitive dysfunction because the pathological processes, including inflammation, blood brain barrier breakdown, and demyelination, occur concurrently with ongoing myelination. Early work has documented that a number of these children present with cognitive deficits. However, there is no available information on the progression of these deficits, or on what clinical factors may predict further decline. The current article reviews what is currently known about pediatric MS and follows a cohort of pediatric MS patients and assesses cognitive function longitudinally. Participants were evaluated with a brief neuropsychological test battery on two separate occasions and correlational analyses assessed the relations between changes in cognition and several clinical variables including level of neurologic impairment, number of relapses prior to baseline assessment, number of interim relapses, age of disease onset, and disease length. The results indicate that a number of these patients experience further cognitive decline over time, or decline from previously normal functioning. Baseline level of neurologic disability was significantly correlated with changes in cognition. The number of interim relapses (i.e., relapses occurring between baseline assessment and re-evaluation) showed a modest relationship to changes in cognitive function, but this did not reach statistical significance.
TL;DR: Despite variability in the stability of individual domains of EFs, the majority (79%) of girls with ADHD that met the categorical definition of executive function deficits (EFDs, defined as two or more EF tasks impaired) at baseline continued to have EFDs at the five-year followup.
Abstract: Neuropsychological deficits in the executive system are major sources of morbidity in individuals with attention-deficit/hyperactivity disorder (ADHD) We conducted a 5-year longitudinal study of girls with (N = 140) and without (N = 122) ADHD, aged 6–18 years at baseline Neuropsychological functioning was assessed using standard neuropsychological testing assessing executive functions (EFs) Girls with ADHD were significantly more impaired than controls in all neuropsychological domains except set shifting Despite variability in the stability of individual domains of EFs, the majority (79%) of girls with ADHD that met the categorical definition of executive function deficits (EFDs, defined as two or more EF tasks impaired) at baseline continued to have EFDs at the five-year followup These findings document the stability of EFDs in girls with ADHD from childhood into adolescence
TL;DR: This article found that children with dyslexia performed faster than normal-reading children with letters, but not in normal reading children with dot patterns, and that symmetry of dot patterns facilitated performance in both children with and normal readers with letters.
Abstract: In a number of studies, children diagnosed with developmental dyslexia reached normal scores in standard visual processing tasks, and some researchers concluded that visual processing deficits are not involved in the syndrome. The tasks used, however, may be insensitive to anomalous visual information processing strategies used to compensate for an underlying deficit. To determine whether children with dyslexia use anomalous visual processing strategies, a same-different task was applied, in which 2 items identical under rotation and reflection were judged as same. Pairs of letters or dot patterns were used, which were either symmetric or asymmetric in shape. Children with dyslexia performed faster than normal-reading children--in particular, remarkably, with letters. Symmetry of dot patterns facilitated performance in both children with dyslexia and normal-reading children; symmetry of letters facilitated performance in children with dyslexia but not in normal-reading children. Children with dyslexia, therefore, fail to adequately differentiate visual processing of linguistic and non-linguistic materials; they process symmetry in letters similarly to that in shapes, which leads in this particular task to the paradoxical observation of children with dyslexia outperforming normal readers with letters.
TL;DR: Early cognitive, motor, and language skills were evaluated in 165 children, 91 with Spina Bifida (SB) and 74 developing typically as mentioned in this paper, at five time points (6, 12, 18, 24, and 36 months of age).
Abstract: Early cognitive, motor, and language skills were evaluated in 165 children, 91 with Spina Bifida (SB) and 74 developing typically Assessments were given at 5 time points (6, 12, 18, 24, and 36 months of age) Three latent growth curve models were conducted to evaluate the development of these early skills, with social economic status and etiology as predictors of growth Lesion level and shunting effects were included for group comparison Children with SB exhibited lower levels of functioning in all areas, with slower rates of growth in cognition and language, but more acceleration in growth of motor skills The impact of lesion level and shunting significantly related to growth in cognition and motor skills but not in language
TL;DR: An auditory event-related potential (ERP) component called mismatch negativity (MMN) was examined in three groups of children aged 8–14 years and showed no systematic difference in the MMN peak latencies or amplitudes between the groups.
Abstract: An auditory event-related potential (ERP) component called mismatch negativity (MMN) was examined in three groups of children (n = 63) aged 8-14 years. A control group comprised healthy children in second or sixth grade of comprehensive school (n = 21). The two clinical groups included children with reading disability (RD) (n = 21) and children with attention deficit (AD) (n = 21). MMN was elicited in a passive oddball paradigm by duration changes in a continuous sound, consisting of two alternating (600 and 800 Hz) 100 msec tones. The deviant tones were either 30 or 50 msec in duration. Both deviants elicited a clear MMN in all groups. Statistical analyses showed no systematic difference in the MMN peak latencies or amplitudes between the groups. A significant difference between the RD group and the control group was observed in the lateralization of the MMN peak amplitudes.
TL;DR: Comparative results suggest that the visual go/no-go task may be more sensitive cognitive measure than the flanker task of mistakes made by children, and the peak amplitude of ERN for 9–11 year old children is larger than that of 7–8 year olds, with no difference overall between young adults and children.
Abstract: Thirteen young adults (ages 21-25) and nine children (ages 7-11) were tested on a visual go/no-go task comparing response times (RTs), error rates, and amplitude and latency changes of error-related negativity (ERN). All experimental conditions were identical for both age groups. Results are consistent with the previous flanker task research showing an increase in ERN amplitude as children age. However, the present results indicate that the peak amplitude of ERN for 9-11 year old children is larger than that of 7-8 year old children, with no difference overall between young adults and children. ERN responses elicited by the flanker task continue to develop until late adolescence. Comparative results suggest that the visual go/no-go task may be more sensitive cognitive measure than the flanker task of mistakes made by children. Differences in time pressure to respond, complexity of the task, and feedback are discussed as possible explanations of differences in the two paradigms.
TL;DR: It appears that the development of P3a in children represents the start of processes that later continue in the adult life-span, but that the automatic processes indexed by P 3a seems to mature earlier than the controlled processes reflected by P3b.
Abstract: The relationship of visual P3a and P3b to age and neuropsychological performance was investigated in 26 healthy children (6.8-15.8 years) and 129 adult volunteers (20.0-88.8 years). Within the sample of children, an effect of age on midline topography was observed, with higher frontal amplitudes in the youngest compared to the oldest children. Increasing age was associated with lower P3a and P3b amplitude and shorter P3b latency at Fz. Performance on neuropsychological tests (matrix reasoning from WASI, digit span from WAIS, word order and hand movement from Kaufman) was only weakly associated with measures of P3a and P3b. The analyses were then repeated with the full life-span sample (n = 155). It was found that for P3a, amplitude decreased and latency increased with age. For P3b, the pattern was more complex, with a nonlinear amplitude reduction and no latency change with age. It appears that the development of P3a in children represents the start of processes that later continue in the adult life-span, but that the automatic processes indexed by P3a seems to mature earlier than the controlled processes reflected by P3b. Finally, it was demonstrated that the relationships between neuropsychological test scores (matrix reasoning, digit span) and P3 parameters were complex, following a mix of linear and nonlinear patterns. It is suggested that the neuropsychological significance of the different P3a and P3b parameters may change from childhood to the adult life-span.
TL;DR: The results suggest that the nature of learning and memory deficits in children with TBI is related to working memory impairment.
Abstract: Working memory (WM), the ability to monitor, process and maintain task relevant information on-line to respond to immediate environmental demands, is controlled by frontal systems (D'Esposito et al., 2006), which are particularly vulnerable to damage from a traumatic brain injury (TBI). This study employed the adult-based Working Memory model of Baddeley and Hitch (1974) to examine the relationship between working memory function and new verbal learning in children with TBI. A cross-sectional sample of 36 school-aged children with a moderate to severe TBI was compared to age-matched healthy Controls on a series of tasks assessing working memory subsystems: the Phonological Loop (PL) and Central Executive (CE). The TBI group performed significantly more poorly than Controls on the PL measure and the majority of CE tasks. On new learning tasks, the TBI group consistently produced fewer words than Controls across the learning and delayed recall phases. Results revealed impaired PL function related to poor encoding and acquisition on a new verbal learning task in the TBI group. CE retrieval deficits in the TBI group contributed to general memory dysfunction in acquisition, retrieval and recognition memory. These results suggest that the nature of learning and memory deficits in children with TBI is related to working memory impairment.
TL;DR: The results indicate a minor spatial working memory deficit in preterm born adolescents without major disability and with normal cognitive capacity, and indicate only minor neuropsychological consequences due to very preterm birth.
Abstract: The working memory functions and processing speed of 35 adolescents born preterm (< or = 32 weeks of gestation) and those of 31 control adolescents were assessed at the age of 16 years. All study participants were free from major disabilities. There were no statistically significant differences in verbal IQ between the study groups. Adolescents born preterm performed less well in complex spatial span compared to their peers born full term, even when verbal IQ and processing speed were allowed to covary. Both groups performed equally well in other working memory tasks and processing speed. Gestational age was the primary contributor to spatial span performance. These results indicate a minor spatial working memory deficit in preterm born adolescents without major disability and with normal cognitive capacity. Our results are encouraging and indicate only minor neuropsychological consequences due to very preterm birth.
TL;DR: Structural equation modeling revealed that the effect of CP on arithmetic accuracy is mediated by intelligence, working memory, early numeracy, and instruction time.
Abstract: The development of addition and subtraction accuracy was assessed in first graders with cerebral palsy (CP) in both mainstream (16) and special education (41) and a control group of first graders in mainstream education (16). The control group out-performed the CP groups in addition and subtraction accuracy and this difference could not be fully explained by differences in intelligence. Both CP groups showed evidence of working memory deficits. The three groups exhibited different developmental patterns in the area of early numeracy skills. Children with CP in special education were found to receive less arithmetic instruction and instruction time was positively related to arithmetic accuracy. Structural equation modeling revealed that the effect of CP on arithmetic accuracy is mediated by intelligence, working memory, early numeracy, and instruction time.
TL;DR: The results find that the PF tumor, hydrocephalus, white matter injury and radiation therapy have various impacts on intelligence, attention and information processing skills, and contribute to the long term outcome in children treated for PF tumor.
Abstract: Cognitive deficits are frequently reported in children treated for posterior fossa (PF) tumors. A range of tumor, treatment, medical and treatment complications have been implicated in causing a variety of cognitive deficits. The aim of this study is to identify factors that influence intelligence, attention and information processing in these children. Thirty-five children (aged 4-16) with PF tumors attending the Royal Children's Hospital Melbourne, Australia, were enrolled into a prospective, repeated measures design. Neuropsychological assessments were conducted at diagnosis and at 12 month intervals for three years. The results find that the PF tumor, hydrocephalus, white matter injury and radiation therapy have various impacts on intelligence, attention and information processing skills, and contribute to the long term outcome in children treated for PF tumor. The neurological structures that subserve the efficient function of attention and information processing are particularly vulnerable to those factors.
TL;DR: The optimal digital filtering freed the MMN from this rhythmic activity, improved the signal-to-noise ratio (SNR), and thus stabilized the quantitative amplitude and latency analyses of theMMN.
Abstract: Conventionally, mismatch negativity (MMN) is analyzed through the calculation of the difference waves. This helps to eliminate some exogenous event-related potential (ERP) components. However, this reduces the signal-to-noise ratio (SNR). This study aims to test whether or not the optimal digital filtering performs better than the difference waves procedure in quantitative ERP analyses in an uninterrupted sound paradigm. The participants were 102 children aged 8-16 years. The MMN was elicited in a passive oddball paradigm presenting an uninterrupted sound consisting of two alternating tones (600 and 800 Hz) of the same duration (100 msec) with infrequent shortenings of one of the 600 Hz tones (50 or 30 msec). In the grand average, both the 50 and 30 msec tones showed a clear MMN-like activity. Each 100 msec tone elicited some rhythmic activity with relatively consistent ERP waveforms. The difference waves calculated from the offset of the deviant stimuli (time correction due to shortening of the deviant stimuli) failed to separate the MMN from this activity, and produced spurious ERPs at early latencies. The optimal digital filtering freed the MMN from this rhythmic activity, improved the SNR, and thus stabilized the quantitative amplitude and latency analyses of the MMN. The frequency range for optimal extraction of the MMN in this paradigm was 2-8.5 Hz.
TL;DR: The absence of significant relationships between hemispheric specialization and holding biases does not support directly the emotional hypothesis for infant holding but can be interpreted according to the nature of the holding relationship.
Abstract: Infant holding biases of 202 mothers were studied in four French maternity hospitals. The study collected laterality for holding in mother/child dyads as a means of testing the emotional hypothesis (Manning & Chamberlain, 1991). Maternal holding side preferences and handedness were collected through questionnaires. In addition, hemispheric specialization for perceiving visual and auditory emotional cues was examined using a chimeric figure and dichotic listening task. The mothers displayed a significant left holding bias as well as a general perceptual bias in favor of the left side/right hemisphere. However, no significant associations were found between holding biases and emotional perceptual asymmetry. The absence of significant relationships between hemispheric specialization and holding biases does not support directly the emotional hypothesis for infant holding but can be interpreted according to the nature of the holding relationship.
TL;DR: Findings indicate that that the WHCT is a valid test of hand preference in both children and adults and offers a robust alternative method for measuring hand preference.
Abstract: The current study was performed to assess the WatHand Cabinet Test (WHCT), a newly developed multidimensional observational test of handedness. Because the test is observational, it is ideal for assessing children, as it does not require a high degree of verbal comprehension on the part of the participants. 548 individuals participated in the present study on a voluntary basis. Individuals of varying ages were examined (including 3 to 5, 6, 7, 8, 9, 10, and 11-year-olds, and 19-to 24-year-olds). Each participant was asked to complete the WHCT, the Annett Pegboard (Annett, 1985), and the Waterloo Handedness Questionnaire (WHQ) (M.P. Bryden, 1977). Overall, the total score on the WHCT was significantly correlated with both the WHQ, r =.795, p < .01, and the Annett Pegboard, r = .542, p < .01. Sub-scores measuring skilled performance, bimanual performance, and internal consistency were also examined, as well as performance on the three tests as a function of age. Overall, findings indicate that that the WHCT...
TL;DR: Overall, selective learning efficiency was not related to the total number of words recalled, and the measure of selective learning was linear with age, which differed in developmental trajectory.
Abstract: Using incentive-based auditory word recall we studied the efficiency of selective learning in children ages 6-18 years. We found effects of age for both selective learning efficiency and for total words recalled, which differed in developmental trajectory. The number of words recalled showed a nonlinear component, reflecting a negatively accelerated increase with age. In contrast, the measure of selective learning was linear with age. Overall, selective learning efficiency was not related to the total number of words recalled. The findings provide a framework for interpretation of studies of selective learning in clinical populations.
TL;DR: Comparisons of different aspects of verbal memory using standard and constructed measures of the Rey auditory verbal learning test suggest that memory problems in adults with ADHD may be caused by deficient executive processes that support retrieval from memory.
Abstract: Attention-deficit hyperactivity disorder (ADHD) is associated with memory deficiencies. In the current study we compared different aspects of verbal memory using standard and constructed measures of the Rey auditory verbal learning test (RAVLT). Performance on learning and recognition measures of RAVLT was similar in both ADHD and control groups. In contrast, adults with ADHD committed more double recalls and intrusion errors, indicating inaccurate recall processes. These findings suggest that memory problems in adults with ADHD may be caused by deficient executive processes that support retrieval from memory.
TL;DR: Data reveal a body-scaling problem in children in estimating reach in extrapersonal space, which should focus on possible developmental differences in use of visual information and state of confidence.
Abstract: This study explored the developmental nature of action processing via estimation of reach in peripersonal and extrapersonal space. Children 5 to 11 years of age and adults were tested for estimates of reach to targets presented randomly at seven midline locations. Target distances were scaled to the individual based on absolute maximum reach. While there was no difference between age groups for total error, a significant distinction emerged in reference to space. With children, significantly more error was exhibited in extrapersonal space; no difference was found with adults. The groups did not differ in peripersonal space; however, adults were substantially more accurate with extrapersonal targets. Furthermore, children displayed a greater tendency to overestimate. In essence, these data reveal a body-scaling problem in children in estimating reach in extrapersonal space. Future work should focus on possible developmental differences in use of visual information and state of confidence.
TL;DR: In this paper, the age-dependent development of visual object recognition abilities in 115 children aged 6 to 11 years, using a battery of neuropsychological tests based on Marr's model (Efron test, Warrington's Figure-Ground Test, Street Completion Test, Poppelreuter-Ghent Test, a selection of stimuli from the Birmingham Object Recognition Battery, a series of color photographs of objects presented from unusual perspectives or illuminated in unusual ways).
Abstract: This study documents the age-dependent development of visual object recognition abilities in 115 children aged 6 to 11 years, using a battery of neuropsychological tests based on Marr's model (Efron test, Warrington's Figure-Ground Test, Street Completion Test, Poppelreuter-Ghent Test, a selection of stimuli from the Birmingham Object Recognition Battery, a series of color photographs of objects presented from unusual perspectives or illuminated in unusual ways). The results suggest a maturation of complex visual perceptual abilities, possibly related to the development of the cerebral processes involved in object recognition, and could be the starting point for future investigations of these skills in impaired populations.
TL;DR: Within normocephalic individuals, those with autism had a smaller CC genu and midbody than either non-autistic controls or RD individuals, adding to the literature implicating problems of interhemispheric connectivity being present in individuals with autism.
Abstract: Previous investigations have reported decreased size of the corpus callosum (CC) in autism. However, little is known of the regional distribution of these callosal abnormalities. Additional uncertainty exists regarding the role of head size with respect to variations in callosal size in individuals with autism. This study investigated the size of the CC in 5 groups of high functioning individuals: (1) normocephalic autistic individuals; (2) autism with macrocephaly; (3) non-autistic normocephalic controls; (4) non-autistic participants with benign macrocephaly; and (5) a reading disordered (RD) group, comprised of non-autistic individuals with a deficit in reading. The CC was traced from midsaggital MRIs and the outlines partitioned into 99 equidistant width measures. Factor analysis of the 99 widths revealed 10 contiguous callosal regions. Individuals with macrocephaly (autistic and non-autistic) had larger total CC size. Regional analysis revealed a significantly larger CC midbody in macrocephaly, regardless of presence or absence of autism. Within normocephalic individuals, those with autism had a smaller CC genu and midbody than either non-autistic controls or RD individuals. These results underscore the importance of considering head size in studies of CC morphology in autism. These findings add to the literature implicating problems of interhemispheric connectivity being present in individuals with autism.