Covert orienting of visuospatial attention in children with developmental coordination disorder

It is still unclear whether impairments in visuospatial processing in children with developmental coordination disorder (DCD) are a consequence of their motor deficits or are independent of them. In two experiments, 20 children with DCD and 20 matched controls were tested on the covert orienting of a visuospatial attention task (COVAT). Experiment 1 used a COVAT with peripheral cues and an 80% probability that targets would appear at the cued location. While the results suggested a deficit in the disengage operation of orienting covert attention for the DCD group, they were difficult to reconcile with models of covert orienting and the results of past research. Experiment 2 tested subjects on two new versions of the COVAT: the first used peripheral cues and no probability information (exogenous mode), and the second used central cues and an 80% probability that targets would appear at the cued location (endogenous mode). The DCD group displayed attentional orienting deficits only for the endogenous mode. These results suggest that impairments in the endogenous control of visuospatial attention are independent of motor deficits in DCD.     

The nuoM arg368his mutation in NADH:ubiquinone oxidoreductase from Rhodobacter capsulatus: a model for the human nd4-11778 mtDNA mutation associated with Leber''s hereditary optic neuropathy

The patellar tendon reflex (PTR) and simple visual reaction time (RT) were fractionated and compared in 40 subjects with developmental coordination disorder (DCD) and normal coordination (NC) in two age groups. Four equal groups of subjects, 6 years DCD (6DCD), 6 years NC (6NC), 9 years DCD (9DCD), and 9 years NC (9NC) were compared using ANOVA for the main effects of coordination and age. PTR and its components of reflex latency and motor time were not significantly affected by the level of coordination; however, a significant coordination by age interaction (p < .05) revealed an increased motor time in the 6DCD group. RT, premotor time, and motor time were all significantly (p < .05) increased in children with DCD; the increased RT and premotor time support earlier findings, whereas the increased motor time has not previously been found. These findings suggest that the processing of reflexive and volitional responses by children with DCD differs from that of their NC peers.     

Development of bilateral motor control in children with developmental coordination disorders

This research examined behavioral (i.e. movement time) and neuromuscular (EMG) characteristics of unilateral and bilateral aiming movements of children with normal motor development and children with developmental coordination disorders (DCD). Two age groups of children were studied: 6 to 7, and 9 to 10 year olds. Bilateral aiming movements involved moving the two hands to targets of either (1) the same amplitude--symmetrical bilateral movements, or (2) different amplitudes--asymmetrical bilateral movements. Unilateral aiming movements involved moving one hand to either near or far targets associated with that hand. In general, unilateral and bilateral movement times were slower in younger than older children, and in children with DCD than children with normal motor development. Our neuromuscular data suggest that the faster movement times that typically accompany increasing age in children may be the result of a change in the capacity to initiate antagonist muscle contractions. The prolonged burst of agonist activity and delayed onset of antagonist activity observed in children with DCD may contribute to their inability to produce fast, accurate unilateral movements. On both symmetrical and asymmetrical bilateral aiming movements, children with DCD had more performance errors and greater temporal inconsistencies between neuromuscular (EMG) parameters and behavioral (movement time) parameters than children with normal motor development. These new neuromuscular data suggest that there are important differences in the way the motor control systems of children with and without DCD organize bilateral aiming responses.     

A dyspraxic deficit in specific language impairment and developmental coordination disorder? Evidence from hand and arm movements

The extent to which children with either specific language impairment (SLI) or developmental coordination disorder (DCD) could be considered dyspraxic was examined using three tasks involving either familiar, or unfamiliar actions. SLI is diagnosed in children who fail to develop language in the normal fashion for no apparent reason, while the DCD diagnosis is applied to a child who experiences problems with movement in the absence of other difficulties. Seventy-two children aged between 5 and 13 years participated, falling into one of four groups: (1) children with specific language impairment (SLI), (2) children with developmental coordination disorder (DCD), (3) age-matched control children, and (4) younger control children. The performance of the clinical groups resembled that of younger normally developing children. Children with SLI, DCD, and the younger controls showed significant difficulty on the task requiring the production of familiar, but not unfamiliar postures. The deficit observed in the SLI group is particularly striking because it was seen both in those with and those without recognized motor difficulties.     

Epilepsy and disorders of cortical development in children with congenital cytomegalovirus infection

INTRODUCTION: Neuroimaging and experimental studies have related cytomegalovirus (CMV) to certain neuronal migration disorders. MATERIAL AND METHODS: To define the electroclinical picture of children with epilepsy associated with disorders of cortical development (DCD) and congenital CMV infection, we conducted a clinical, electroencephalographic and neuroradiological study of 10 children with this condition. RESULTS: Eighty per cent of them had dismorphic traits, or malformations outside CNS. All showed other neuroradiological signs (cerebral calcification, white matter damage, porencephaly). Six patients with bihemispheric DCD (agyria-pachigyria, 2; 'poligyria', 1; schizencephaly, 1; bilateral opercular DCD, 2) showed: Tetraparesis, severe or profound mental deficiency, early onset epilepsy (mean age at onset: 11 months) with spasms, tonic seizures, partial seizures, and multifocal paroxysms or unusual diffuse sharp Alfa-Beta EEG activity. One child developed Epilepsia Partialis Continua. Children with bilateral opercular DCD evolved to a continuous spike and wave (SW) electrical status during wakefulness and sleep, linked to a worsening of psychomotor derangement. Four patients with unilateral hemispheric DCD (pachigyric or 'poligyric') showed: Congenital hemiparesis, mild intellectual deficiency, motor seizures (orofacial, hemiclonic, generalized) beginning in the third year of live, atypical absences with focal phenomena, frequent focal rhythmic SW discharges during wakefulness, and continuous SW status during sleep (CSWS). CONCLUSIONS: A wide spectrum of DCD due to congenital CMV infection is documented. Characteristic electroclinical pictures related to the extent and topographical distribution of the DCD are recognized, which may lead to an appropriate diagnosis and prognosis.     

A test of motor (not executive) planning in developmental coordination disorder and autism.

Grip selection tasks have been used to test “planning” in both autism and developmental coordination disorder (DCD). We differentiate between motor and executive planning and present a modified motor planning task. Participants grasped a cylinder in 1 of 2 orientations before turning it clockwise or anticlockwise. The rotation resulted in a comfortable final posture at the cost of a harder initial reaching action on 50% of trials. We hypothesized that grip selection would be dominated by motoric developmental status. Adults were always biased towards a comfortable end-state with their dominant hand, but occasionally ended uncomfortably with their nondominant hand. Most 9- to 14-year-olds with and without autism also showed this “end-state comfort” bias but only 50% of 5- to 8-year-olds. In contrast, children with DCD were biased towards selecting the simplest initial movement. Our results are best understood in terms of motor planning, with selection of an easier initial grip resulting from poor reach-to-grasp control rather than an executive planning deficit. The absence of differences between autism and controls may reflect the low demand this particular task places on executive planning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Subclinical prenatal iodine deficiency negatively affects infant development in Northern China

Although mild-to-moderate levels of iodine deficiency (ID) have been associated with poor cognitive outcomes in children, little is known about subclinical prenatal ID and infant development. In this study, the association between elevated cord blood thyroid stimulating hormone (TSH, thyrotropin) and infant development was examined in Northern China. Three groups of infants with elevated cord blood TSH were compared with infants with normal TSH levels on an information processing task at 7 mo, and in cognitive and motor developmental assessments at 13 mo. Infants with elevated TSH had poorer information processing skills and lower scores on the cognitive development index. There were no differences in motor abilities. Relationships between socioenvironmental factors and iodine status were assessed. Infants from more rural settings and those whose mothers had completed fewer years of schooling and had lower paying occupations had higher cord blood TSH levels. A regression analysis indicated that maternal education was predictive of cognitive performance among infants with elevated TSH but not control infants. The findings suggest that subclinical prenatal ID has negative effects on infant development and that, in some instances, maternal education may ameliorate these effects.     

Learning disability subtypes in children with neurofibromatosis

A high incidence of learning disabilities (LD) has been reported in children with neurofibromatosis Type 1 (NF-1), and many children affected with this disease are thought to have a form of LD that is characterized by selective visuospatial and motor deficits. However, the evidence is subject to sampling biases and is limited by the clinical-inferential methods used to classify children into LD subtypes. In the present study, objective statistical methods were used to categorize LD in 105 children with NF-1 between the ages of 6 and 18 years. A cluster analysis of achievement test scores yielded 10 groups; 6 of which met our criterion for academic deficiency. An analysis of neuropsychological data for 72 children with academic deficiencies with complete neuropsychological data yielded three groups: a neuropsychologically normal group (n = 28), a group with general academic deficiencies (n = 34), and a group with visuospatial-construction deficiencies (n = 10). The low incidence of visuospatial-constructional deficits and the absence of cases involving pure linguistic deficits is notable.     

Planning and execution of action in children with and without developmental coordination disorder

Ninety-five children from six English primary schools were identified on the basis of the Movement Assessment Battery for Children (Movement ABC) as having developmental coordination disorder (DCD) and, together with age- and ability-matched controls, were given three tasks that involved proprioception in the control and discrimination of limb position, and two tasks that involved planning for end state comfort after a bar was grasped and turned. The children in the DCD group performed less well on the majority of the proprioceptive tasks, but did not differ from controls in planning of grip selection. There was an improvement in grip planning with age. The results are contrasted with research indicating that people with autism do have a difficulty with planning grip selection.     

Working memory in young children: evidence for modality-specificity and implications for cerebral reorganization in early childhood

Digit span (DS) and visual-spatial memory span (VMS) tasks have been considered indices of auditory and visual spatial processing, respectively, often classified as "primary memory" or "attention". There has been limited evidence for their modality specificity, however. We present two children who showed visual spatial processing deficiencies (including VMS) and non-dominant manual inefficiency with normal visual-spatial perception, auditory-verbal processing and dominant fine manual skills. These children support a distinction between auditory and visual-spatial memory span. These findings are discussed with regard to a hypothesis that the unique expression of VMS is time-limited, that visual-spatial processing becomes more verbalized as children learn to read and that these behavioral changes produce a lateral shift in cortical processing of visual spatial information.     

Hyperactivity and attention deficits.

Substantive progress has been made in our understanding of children considered hyperactive, especially in the interpersonal sphere. Evolving conceptualizations of hyperactivity and attention deficits are reviewed briefly, including changes in clinical diagnostic practices and in knowledge about developmental course. The hypothesis is advanced that the cognitive and social difficulties of hyperactive children may be better understood in terms of motivational and self-regulatory processes than as deficiencies in basic information processing. The role of stimulant medication is emphasized, both as a controversial treatment approach and as an adjunct to research on the children's problems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developmental changes in hemispheric specialization for tactual processing in very young children: Evidence from cross-modal transfer.

Examined whether young children show any evidence of right hemispheric specialization for tactual processing. 72 1-, 2-, and 3-yr-old right-handed children were each administered 6 cross-modal tasks in which they palpated a shape with either their left or right hand for 25 sec and then viewed the familiar and a novel shape in a 10-sec test of visual recognition. Although Ss of all 3 ages showed significantly more visual fixation to novel shapes, regardless of which hand had been used for palpation, scores were enhanced among 2- and 3-yr-olds following palpation with the left as compared with the right hand. This left-hand (right hemisphere) superiority was not evident in 1-yr-olds. These results are the first to demonstrate a left-hand superiority for information processing in children as young as 2 yrs and to suggest that this adultlike pattern is developed by at least the 2nd year of life. Left-hand superiority may be due to asymmetries in tactual sensitivity, motor control, and/or information processing. (40 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Input capability and speed of processing in mental retardation.

The minimum stimulus duration for criterion accuracy and the minimum interval between presentation of a test and presentation of a masking stimulus for criterion accuracy were determined for mildly (mean IQ 55.25) and moderately (mean IQ 47.25) retarded adults and normal controls of the same MA and CA. Five groups of 8 Ss were tested: All adult Ss were in their 20s, and 2 groups of children whose mean CAs were 9.1 and 7.7 yrs served as MA controls for the milds and moderates, respectively. The procedure was replicated 3 times in 3 separate sessions. Both retarded groups required longer stimulus durations as well as longer masking intervals for criterion accuracy than did both the MA and the CA control groups. Results are consistent with deficiencies in both iconic storage and speed of information processing in mental retardation. These deficiencies, furthermore, cannot be accounted for on the basis of low MA. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive processing bias of children in a real life stress situation and a neutral situation

The aim of this study was to investigate whether nonclinically anxious children, like anxious adults, favor the processing of threatening or concern-related information. Two experiments, using an emotional Stroop task, were carried out in high anxious and low anxious children aged 8 to 9 to examine whether a medical stressor elicited a processing bias. Results indicated that, independently of the presence of the medical stressor, all children give high priority to the processing of information related to physical harm. Moreover, like anxious adults in other studies, high anxious children showed a processing bias for generally threatening information. This bias was absent in the vicinity of an acute stressor and it was only significant in girls. However, unlike low anxious adults, low anxious girls also showed this processing bias. These results are interpreted in terms of cognitive developmental differences in the ability to inhibit the processing of meaningful information.     

A case report of an epidermal papilloma in Mustelus canis

The performances of 12 EMR and 12 nonretarded sixth-grade children on a perceptual learning task were compared to investigate the information processing of visually presented stimuli in individuals with different intelligence levels. A minicomputer flashed either familiar (lowercase) or unfamiliar letters (Gibson-like figures) in either a stimultaneous or successive mode on a same-different matching task. The computer automatically calculated accuracy and latency data for each subject. Results showed that accuracy was superior in the nonretarded group and that mean latencies for the EMR group was consistently higher than those of the nonretarded group. However, when latencies were corrected for differences in basic reaction time, there were no significant differences between the groups in the speed of processing the information.     

Current management of anorectal anomalies

A significant amount of new information has been obtained concerning the early management of anorectal malformations. The surgical approach also has changed and improved the functional prognosis of children with these defects. Recommendations are made based on a series of 632 cases. A simplified approach to avoid the most common errors in the management of these defects is emphasized. Yet, there are still many children born with severe anatomic deficiencies who cannot expect normal bowel function; however, for this group, a bowel management program is available to help improve their quality of life.     

Motor activation from visible speech: Evidence from stimulus response compatibility.

In speech perception, phonetic information can be acquired optically as well as acoustically. The motor theory of speech perception holds that motor control structures are involved in the processing of visible speech, whereas perceptual accounts do not make this assumption. Motor involvement in speech perception was examined by showing participants response-irrelevant movies of a mouth articulating /bΛ/ or /dΛ/ and asking them to verbally respond with either the same or a different syllable. The letters "Ba" and "Da" appeared on the speaker's mouth to indicate which response was to be performed. A reliable interference effect was observed. In subsequent experiments, perceptual interference was ruled out by using response-unrelated imperative stimuli and by preexposing the relevant stimulus information. Further, it was demonstrated that simple directional features (opening and closing) do not account for the effect. Rather, the present study provides evidence for the view that visible speech is processed up to a late, response-related processing stage, as predicted by the motor theory of speech perception. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Congenital ocular motor apraxia: imaging findings

PURPOSE: To determine the frequency of cerebellar and cerebral abnormalities on brain imaging studies in children with congenital ocular motor apraxia. METHODS: Brain imaging studies were performed in 19 children with typical congenital ocular motor apraxia who were in the care of a visual impairment program at a children's hospital. Independent clinical review categorized the subjects as having partial (n = 10) or expanded (n = 9) congenital ocular motor apraxia on the basis of extent of associated speech or neurodevelopmental problems. Fifteen CT studies and 13 MR examinations of the brain performed in these children were reviewed independently by two pediatric neuroradiologists. Radiologic findings were agreed on by consensus. RESULTS: Cerebellar abnormalities were found in 12 of 19 cases. The cerebellar vermis was small in 10 children. A small cerebellar vermis was the only abnormality in five of 10 children with partial congenital ocular motor apraxia and in two of nine children with expanded congenital ocular motor apraxia. Among seven children with a small vermis examined with high-resolution MR imaging, the inferior portion of the vermis was preferentially involved in each case. Of these seven subjects, none of four with partial congenital ocular motor apraxia but two of three with expanded congenital ocular motor apraxia had an abnormality of the superior portion of the vermis. Miscellaneous supratentorial lesions affecting both gray and white matter were found in six subjects. Five of the 19 children had normal imaging findings. CONCLUSION: Inferior vermian hypoplasia is the most common abnormality in children with congenital ocular motor apraxia.     

Cognitive reactivity and depressotypic information processing in children of depressed mothers.

Although high-risk research suggests that children of depressed mothers are at increased risk for psychological disorders, the mechanisms of this risk are not well understood. In the current study, the information processing of children of depressed mothers was compared with that of children whose mothers were not depressed. Half of each group received a priming induction designed to activate cognitive schemas prior to assessment. All children then completed a self-referent processing task that examined the recall of negative and positive information. Results indicate that when primed, at-risk children showed a less positive self-concept and more negative information processing than did the children in the other groups. These data may offer potential clues into the mechanisms of cognitive vulnerability in at-risk children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)