COPY AND RECALL PERFORMANCE OF 6–8-YEAR-OLD CHILDREN AFTER STANDARD VS. STEP-BY-STEP ADMINISTRATION OF THE REY-OSTERRIETH COMPLEX FIGURE

Turner syndrome (TS) is a genetic disorder in females characterized by the complete or partial absence of one X chromosome. Its most consistent physical features include short stature and ovarian dysgenesis. TS individuals demonstrate a characteristic neurocognitive profile involving weaknesses in visuospatial processing. The hypothesis of defective right hemisphere specialization has been offered to explain the visuospatial deficits in TS. In contrast, an alternative explanation proposes a more uniform dysfunction of the left and right hemispheres, based on findings of symmetrical abnormalities. This article presents an overview of the two hypotheses, along with relevant findings on hemispheric specialization with respect to TS. The impact of the genetic and hormonal mechanisms on the neurocognitive profile of TS is also discussed and directions for further empirical research are identified.     

Turner Syndrome: A Review of Genetic and Hormonal Influences on Neuropsychological Functioning

Turner syndrome (TS) is a genetic disorder in females that arises from the loss of X chromosome material. Affected individuals demonstrate a characteristic neuropsychological profile of strengths in verbal processing and weaknesses in visuospatial processing, consistent with the Nonverbal Learning Disabilities syndrome. Previous research has described a wide range of visuospatial deficits in TS; however, their verbal abilities are less extensively studied. The present paper describes the processing difficulties of a 9-year-old girl with TS who demonstrated problems in integrating details of a complex visual display and using organizational terms to describe visual scenes or events. Her specific cognitive disabilities were thought to underlie some of the social and behavioral problems she was currently experiencing. Her pattern of results is consonant with the neuropsychological pattern that others have attributed to right hemisphere dysfunction and/or white matter abnormality.     

Visual integration difficulties in a 9-year-old girl with Turner syndrome: parallel verbal disabilities?

Turner syndrome (TS) is a genetic disorder in females that arises from the loss of X chromosome material. Affected individuals demonstrate a characteristic neuropsychological profile of strengths in verbal processing and weaknesses in visuospatial processing, consistent with the Nonverbal Learning Disabilities syndrome. Previous research has described a wide range of visuospatial deficits in TS; however, their verbal abilities are less extensively studied. The present paper describes the processing difficulties of a 9-year-old girl with TS who demonstrated problems in integrating details of a complex visual display and using organizational terms to describe visual scenes or events. Her specific cognitive disabilities were thought to underlie some of the social and behavioral problems she was currently experiencing. Her pattern of results is consonant with the neuropsychological pattern that others have attributed to right hemisphere dysfunction and/or white matter abnormality.     

Turner syndrome: a review of genetic and hormonal influences on neuropsychological functioning.

Turner syndrome (TS) is a genetic disorder affecting mainly females that arises from a loss of X chromosome material, most usually one of the two X chromosomes. TS is associated with a number of characteristic physical features such as short stature and absent ovaries as well as a set of common neuropsychological deficits and social and behavioral features. This paper will serve to review the cognitive, social, and psychoeducational abilities of individuals with TS as well as neuroimaging findings. Several putative genetic mechanisms contributing to their particular neurocognitive deficits will also be described including candidate genes. In addition, the available evidence on how hormones affect specific abilities in TS will be reviewed. It will be concluded that the TS neurobehavioral profile arises from an atypical cerebral organization caused by the complex interplay of insufficient expression of certain (unknown) genes on the X chromosome and by abnormal hormonal levels; however, it is still not clear exactly how the specific genes affect broader cognitive abilities. Future research needs to identify the elemental processes that are disturbed in TS and map these both to events in early brain development and subsequent brain function and to specific gene and hormonal contributions.     

An evolutionary perspective on hemispheric asymmetries

The evolution of hemispheric specialization of function has obvious benefits in terms of overall processing capacity, but it may also have associated costs to each hemisphere in isolation. These costs are not apparent in an intact brain since information can be readily transferred between the hemispheres via the cortical commissures. We suggest that the evolution of language in the left hemisphere may have occurred at the expense of some visuospatial functions. Because the right hemisphere was still capable of performing those functions, the relative left-hemisphere impairment for visuospatial processing would be invisible. If the cortical commissures are severed, as in callosotomy patients, the costs of specialization may become more apparent. We report data supporting the idea that the left hemisphere may have lost visuospatial abilities that it once possessed, and suggest that this process may also result in right hemisphere deficits in abilities related to linguistic processing.     

Executive Functions in Children and Adolescents with Turner Syndrome: A Systematic Review and Meta-Analysis

Turner syndrome (TS) is a genetic disorder, affecting 1/2500 to 1/3000 live female births, induced by partial or total deletion of one X chromosome. The neurocognitive profile of girls with TS is characterized by a normal Verbal IQ and weaknesses in visual-spatial, mathematics, and social cognitive domains. Executive functions (EFs) impairments have also been reported in these young patients. However, methodological differences across studies do not allow determination of which EFs are impaired and what is the magnitude of these impairments. The aim of this review was to clarify the EF profile of children and adolescents with TS. Sixteen samples, from thirteen studies, were included in the current meta-analysis. EFs measures used in these studies were classified into working memory, inhibitory control, cognitive flexibility, or higher-order EFs tasks in accordance with Diamond’s model, Annual Review of Psychology, 64, 135–168 (2013). Results confirmed that girls with TS had significant executive impairments with effect sizes varying from small (inhibitory control) to medium (cognitive flexibility) and large (working memory, higher-order EFs). Analyses by task revealed that cognitive inhibition may be more impaired than the other inhibitory control abilities. Heterogeneity across cognitive flexibility measures was also highlighted. Between-sample heterogeneity was observed for three tasks and the impact of participants’ characteristics on EFs was discussed. This meta-analysis confirms the necessity to assess, in patients living with TS, each EF by combining both visual and verbal tasks. Results also underline that, when studying girls with TS’ executive profile, it is important to explore the impact of moderator variables, such as IQ, parental socio-economic status, TS karyotype, psychiatric comorbidities, and hormonal treatment status.     

Neuropsychological sequelae of stroke as a function of handedness.

The preservation of visuospatial ability relative to verbal ability following right middle cerebral artery stroke was assessed in 19 left- and 19 right-handed male patients who were group-matched on the basis of age, education, and time elapsed since stroke. Analysis of covariance (covarying education) indicated that the left- and right-handed groups were significantly different with regard to the discrepancy between Verbal IQ and Performance IQ, with the left-handed patients showing a smaller difference than the right-handers. These results provide further evidence that sinistrality may be associated with less hemispheric specialization.     

The effects of different exercise types on visuospatial attention in the elderly

While the capability of visuospatial attention decreases with advanced aging, exercise is an effective primary prevention strategy to ward off the progression of such cognitive declines among the elderly. However, no studies have yet been conducted on the relationship between exercise type and visuospatial attention in the elderly. This study was thus carried out to explore the effects of open- and closed-skill exercise modes on visuospatial attention in the elderly using behavioral and cognitive electrophysiological measurements. Sixty elderly participants were divided into open-skill (n = 20), closed-skill (n = 20), or control (n = 20) groups according to their exercise-participation experience in the previous 24 months, and performed a visuospatial attention task with concomitant electrophysiological recording. The results showed that the two exercise groups (i.e., open- and closed-skill) exhibited shorter reaction times (RTs) and larger P3 amplitudes across conditions compared with the control group. Although the open- and closed-skill groups only showed approaching between-group significance on the RTs in the invalid condition and on the P3 amplitudes across conditions, only the open-skill group showed better inhibitory control of attention relative to the control group. These findings reveal the presence of neurocognitive effects on the visuospatial attention task in the two exercise groups, with significantly better performances in the open-skill group, demonstrating that regularly participating in such an exercise mode, as compared to the closed-skill one, could have more beneficial effects on visuospatial attention.     

COMT and DAT1 polymorphisms moderate the indirect effect of parenting behavior on youth ADHD symptoms through neurocognitive functioning

Although gene × environment interactions contribute to youth attention-deficit/hyperactivity disorder (ADHD) symptoms, the pathways mediating these influences are unknown. We tested genetic moderation of indirect effects from parenting behavior to youth ADHD symptoms through multiple neurocognitive factors. Two hundred and twenty-nine youth with and without ADHD were assessed at baseline (Wave 1; ages 5–10) and at a 2-year follow-up (Wave 2; ages 7–13). At Wave 1, youth completed a neurocognitive battery including measures of response inhibition, visuospatial working memory, and fluid reasoning, and a standardized parent–child interaction task yielding observational measures of positive and negative parenting. At Wave 2, youth psychopathology was rated by parents and teachers using multiple methods (i.e., structured interview, rating scale). We employed moderated multiple mediation and compared conditional indirect effects across youth genotypes at two biologically plausible genetic loci. Controlling for parent ADHD symptoms as well as youth demographic factors and co-occurring externalizing symptoms, these genetic factors moderated the indirect effect from Wave 1 parenting to multi-method/informant Wave 2 ADHD symptoms through Wave 1 neurocognitive functioning. This preliminary study is the first to identify genetic moderation of mediated effects underlying ADHD symptoms and suggests that specific gene × parenting interactions may underlie neurocognitive functioning deficits and subsequent ADHD.     

Preserved topographical memory following right temporal lobectomy

In an attempt to study remote memory for visuospatial information, geographical knowledge was examined in patient J.N., who had received a radical right temporal lobectomy to remove a large glioblastoma. In postoperative tests J.N. displayed severe deficits in anterograde memory for visuospatial and verbal material, visuoperceptual functions, constructions, attention, and response initiation. Despite her global cognitive deficiencies she performed normally on the WAIS Information Scale and the Fargo Map Test, a measure of geographical knowledge. In contrast, patients known to have severe amnesia exhibited impairments on tests of geographical knowledge that required precise localization of features such as cities. Assuming that J.N.'s performance is typical of patients with extensive damage to the right temporal lobe, the findings suggest that the integrity of the right temporal lobe is not essential for the retrieval of premorbidly established visuospatial memories.     

Association between aerobic fitness and visuospatial performance in healthy older adults.

This study examined whether chronic physical exercise activity is associated with better neurocognitive performance in older adults. One hundred five men participated in 1 of 3 age groups (18-28, 35-45, and 60-73). For each age group, subjects were classified as high or low in fitness on the basis of self-reported activity levels and the results of a submaximal bicycle ergometer test. A comprehensive battery of neuropsychological tests was administered to each subject, and older subjects scored significantly lower than the younger groups on most tests. Significant differences between high- and low-fit subjects were found only on tasks with heavy visuospatial demands, and these differences were most notable in the older adult group. These findings suggest that participation in aerobic exercise activity selectively preserves some cognitive functions that normally decline with age. The benefits of activity appear to be most evident on tasks that require visuospatial processing.     

Hemispheric differences in object identification

Although the right hemisphere is thought to be preferentially involved in visuospatial processing, the specialization of the two hemispheres with respect to object identification is unclear. The present study investigated the effects of hemifield presentation on object and word identification by presenting objects (Experiment 1) and words (Experiment 2) in a rapid visual stream of distracters. In Experiment 1, object images presented in the left visual field (i.e., to the right hemisphere) were identified with shorter display times. In addition, the left visual field advantage was greater for inverted objects. In Experiment 2, words presented in the right visual field (i.e., to the left hemisphere) under similar conditions were identified with shorter display times. These results support the idea that the right hemisphere is specialized with regard to object identification.     

Sex differences in cerebral laterality of language and visuospatial processing

Sex differences on language and visuospatial tasks are of great interest, with differences in hemispheric laterality hypothesized to exist between males and females. Some functional imaging studies examining sex differences have shown that males are more left lateralized on language tasks and females are more right lateralized on visuospatial tasks; however, findings are inconsistent. Here we used functional magnetic resonance imaging to study thirty participants, matched on task performance, during phonological and visuospatial tasks. For each task, region-of-interest analyses were used to test differences in cerebral laterality. Results indicate that lateralization differences exist, with males more left lateralized during the phonological task and showing greater bilateral activity during the visuospatial task, whereas females showed greater bilateral activity during the phonological task and were more right lateralized during the visuospatial task. Our data provide clear evidence for differences in laterality between males and females when processing language versus visuospatial information.     

Inhibition of return in children with Tourette's syndrome and comorbid forms: a preliminary study.

BACKGROUND: This study investigated the nature and functioning of the visual-spatial inhibition of return (IOR) phenomenon in children with "pure" Tourette's syndrome (TS), and those with comorbid forms of TS. METHOD: Children with TS-only and "TS + comorbid" (TS + ADHD +/- OCD) and matched controls performed the inhibition of return (IOR) task, which involved responding to left and right visual targets appearing on a computer screen that were preceded by congruent or incongruent exogenous visual cues. RESULTS: The TS-only group performed similarly on the IOR task to the controls. When the TS-only group was subdivided into children with mild and severe TS symptoms, a post hoc comparison between the controls and severe TS symptom children revealed that these TS children had a reduced magnitude of IOR for targets appearing in the right visual field. The comparison between the TS + comorbid and controls revealed an atypical IOR pattern for the TS + comorbid group. They displayed a loss of normal facilitatory and inhibitory effects for right visual field targets. CONCLUSIONS: The findings suggest abnormalities in attentional "disengage" and "move" mechanisms in TS when directing attention to the right visual field, which may reflect left posterior parietal, superior colliculus, and midbrain pathology.     

Inhibition of Return in children with Tourette's syndrome and comorbid forms: A Preliminary Study

Background: This study investigated the nature and functioning of the visual-spatial inhibition of return (IOR) phenomenon in children with “pure” Tourette's syndrome (TS), and those with comorbid forms of TS. Method: Children with TS-only and “TS + comorbid” (TS + ADHD +/- OCD) and matched controls performed the inhibition of return (IOR) task, which involved responding to left and right visual targets appearing on a computer screen that were preceded by congruent or incongruent exogenous visual cues. Results: The TS-only group performed similarly on the IOR task to the controls. When the TS-only group was subdivided into children with mild and severe TS symptoms, a post hoc comparison between the controls and severe TS symptom children revealed that these TS children had a reduced magnitude of IOR for targets appearing in the right visual field. The comparison between the TS + comorbid and controls revealed an atypical IOR pattern for the TS + comorbid group. They displayed a loss of normal facilitatory and inhibitory effects for right visual field targets. Conclusions: The findings suggest abnormalities in attentional “disengage” and “move” mechanisms in TS when directing attention to the right visual field, which may reflect left posterior parietal, superior colliculus, and midbrain pathology.     

Higher functioning children with prenatal alcohol exposure: Is there a specific neurocognitive profile?

Recent attempts to identify a neurocognitive profile of children with prenatal alcohol exposure (PAE) have led to an emerging “generalized deficit” conceptualization marked by diffuse information processing and integration difficulties as opposed to a specific profile. This study examines whether this conceptualization can be extended to higher functioning children with PAE who are without intellectual disability and addresses several limitations of previous research. One hundred twenty-five children aged 6–12 years with social skills deficits, 97 of whom met diagnostic criteria for a Fetal Alcohol Spectrum Disorder (FASD), underwent a comprehensive, multi-informant assessment of neurocognitive, emotional, social, behavioral, and adaptive functioning. Multivariate analyses of variance examined differences in functioning between the PAE group and a nonexposed comparison group with and without controlling for child IQ. Results indicated that the PAE group returned significantly poorer scores than the nonexposed group on every construct assessed, including executive functioning, attention, working/visuospatial memory, linguistic abstraction, adaptive behavior, emotional/behavioral functioning, and social cognition. These differences largely maintained after controlling for IQ and were similar regardless of informant, although teachers reported somewhat fewer group differences. Within the PAE group, no differences were found across FASD subtypes. These results provide evidence extending the emerging generalized deficit conceptualization of children with PAE to those higher functioning individuals without global intellectual disability.     

视觉空间伪忽视与表征伪忽视神经机制的异同

伪忽视（pseudoneglect）是指个体存在的轻微偏左的不对称空间注意,而视觉空间伪忽视（visuo-spatial pseudoneglect）和表征伪忽视(representational pseudoneglect)是其两种主要表现形式。研究初期,研究者认为两种伪忽视基于相同的注意定向左偏机制,但近年来研究发现,它们仍存在神经机制的差异。本文主要从两种伪忽视神经机制的异同出发,梳理分析近期研究结果,以期增进对伪忽视的理解。未来研究可以从认知时间进程角度或设计更为完善的研究范式进一步探讨这两种伪忽视神经机制的异同。     

Obstructive Sleep Apnea Syndrome in Prader-Willi Syndrome: An Unrecognized and Untreated Cause of Cognitive and Behavioral Deficits?

Prader-Willi Syndrome (PWS) is a rare genetic disorder characterized by a range of physical, psychological, and physiological abnormalities. It is also distinguished by the high prevalence of obstructive sleep apnea syndrome (OSAS), i.e., repetitive upper airway collapse during sleep resulting in hypoxia and sleep fragmentation. In non-PWS populations, OSAS is associated with a range of neurocognitive and psychosocial deficits. Importantly, these deficits are at least partly reversible following treatment. Given the findings in non-PWS populations, it is possible that OSAS may contribute to neurocognitive and psychosocial deficits in PWS. The present review examines this possibility. While acknowledging a primary contribution from the primary genetic abnormality to central neural dysfunction in PWS, we conclude that OSAS may be an important secondary contributing factor to reduced neurocognitive and psychosocial performance. Treatment of OSAS may have potential benefits in improving neurocognitive performance and behavior in PWS, but this awaits confirmatory investigation.     

Heritability in cognitive performance: evidence using computer-based testing

There is overwhelming evidence of genetic influence on cognition. The effect is seen in general cognitive ability, as well as in specific cognitive domains. A conventional assessment approach using face-to-face paper and pencil testing is difficult for large-scale studies. Computerized neurocognitive testing is a suitable alternative. A total of 267 parent-child dyads were selected from a larger database of computerized neurocognitive test results. Correlations were determined between parent-child dyads, as well as matched parent-child dyads. Univariate regression analyses were estimated to determine the extent to which children's performance could be accounted for by that of their parents, compared with matched control parents. Multiple significant positive correlations in neurocognitive test performance were found in parent-child dyads. Parent performance accounted for a greater proportion of variability in every case. These findings indicated that a computerized neurocognitive battery is an effective tool for studying heritability in cognitive performance in a large sample.