Visuospatial Working Memory Deficits Research Articles

451 Interactions between tumor, age, and chemotherapy in cognitive impairments and neuroinflammation

OBJECTIVES/GOALS: We will use a novel syngeneic model of prostate cancer to examine impairments and uncover potential changes in inflammatory signaling in the brains of animals with and without tumors. We will then investigate the interaction between peripheral tumor, age, and chemotherapy on cognitive impairments and any accompanying neuroinflammation METHODS/STUDY POPULATION: Male Copenhagen rats (aged 3 or 10 months) were subjected to tumor fragment implantation (Dunning R2237G cells) or sham surgery. Once tumors were palpable, animals received either docetaxel (4.5mg/kg, intraperitoneal) or it’s vehicle once every other day for 5 days (3 injections total) followed by a two-week recovery period. During this time, TNFa and IL-6 was quantified in plasma samples obtained once per week for two weeks. Hippocampal-mediated visuospatial and working memories were assessed using the novel object task and percent alternation in a y-maze, respectively. Afterwards, trunk blood and hippocampal tissue were isolated. TNFa and IL-6 protein was quantified in plasma. Hippocampal tissue was probed for markers of neuroinflammation, including increases in TNFa, IL-6, and reactive microglia RESULTS/ANTICIPATED RESULTS: The presence of a tumor alone produces deficits in hippocampal-mediated visuospatial memory and working memory regardless of treatment and persistent elevations in TNFa and IL-6 in plasma. Docetaxel administration also produces impairments in hippocampal-mediated visuospatial memory, but not in working memory. We anticipate these cognitive impairments will be accompanied by hippocampal neuroinflammation. We expect age and docetaxel chemotherapy to exacerbate working memory deficits and markers in hippocampal neuroinflammation, including increases in TNFa, IL-6 and reactive microglia DISCUSSION/SIGNIFICANCE: This study will provide insight into the interaction between tumor, age, and chemotherapy in impairments in visuospatial memories. This model provides a substrate upon which interventions can be tested to ensure the efficacy of the cancer treatment is maintained when treating these cognitive impairments.

Executive functions underlie word reading and reading fluency in Chinese children with attention deficit/hyperactivity disorder, reading disabilities, and comorbid attention deficit/hyperactivity disorder and reading disabilities

ABSTRACT The current study examined the executive function (EF) deficits and their roles in reading in one hundred and four Cantonese-speaking children with typical development, reading disabilities (RD), ADHD, and comorbid ADHD and RD (ADHD + RD). Children’s EF and reading skills were measured. Analysis of variance results showed that all children with disorders manifested deficits in verbal and visuospatial short-term and working memory and behavioral inhibition. Moreover, children with ADHD and ADHD + RD also exhibited deficits in inhibition (IC and BI) and cognitive flexibility. These findings demonstrated that the EF deficits in Chinese children with RD, ADHD, and ADHD + RD are similar to those in their counterparts using alphabetic languages. However, children with ADHD + RD displayed more severe deficits in visuospatial working memory compared to children with RD and ADHD, which was inconsistent with that observed in children using alphabetic languages. Regression analysis results showed that verbal short-term memory was a significant predictor for both word reading and reading fluency in children with RD and ADHD + RD. Moreover, behavioral inhibition significantly predicted reading fluency in children with ADHD. These findings also agreed with previous studies. Collectively, the results of the current study showed that the EF deficits and their roles in reading found in Chinese children with RD, ADHD, and ADHD + RD are mainly consistent with children using alphabetic languages. However, more studies are still needed to confirm these findings, especially comparing the severity of working memory among these three disorders.

Visuospatial working memory in attention-deficit/hyperactivity disorder: Characterizing path length and path crossings as mechanisms of impairment.

A growing body of research provides reliable evidence of moderate to large magnitude deficits in the visuospatial (VS) working memory (WM) of children with attention-deficit/hyperactivity disorder (ADHD), relative to typically developing (TD) children. Studies of ADHD-related Visuo-spatial Working Memory (VS-WM) functioning most often present sequential presentations of VS stimuli and examine general performance characteristics. Only a few studies have examined the effects of varying VS-WM task parameters on performance in children with ADHD, despite evidence from basic-cognitive research that indicates methodological heterogeneity in VS-WM task parameters yields significant performance variability that is associated with underlying mechanistic processes. This study is the first to examine the effect of the task parameters path characteristics and path crossings on performance in children with ADHD and TD children. School-aged children with ADHD (n = 50) and TD children (n = 59) completed a VS-WM task that varied by path lengths and path crossings. Multilevel analyses indicated a negative effect of relatively long paths on VS-WM performance of both TD children and children with ADHD, and a negative effect of increasing path crossings that appears to be unique to TD children and dependent on path length. Overall, findings appear to suggest that school-aged children engage in dynamic rehearsal of VS information (i.e., mental rehearsal of path sequences), rather than static rehearsal (i.e., rehearsal of a gestalt). Moreover, ADHD-related VS-WM deficits are most likely to yield real-world impairments when information is presented with relatively long path lengths. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Association between spatial working memory and Re-experiencing symptoms in PTSD

Background and objectivesFew studies have evaluated the link between working memory (WM) and post-traumatic stress disorder (PTSD). Further, it is unknown whether this relationship is accounted for by other relevant variables including negative affect, emotional dysregulation, or general non-WM-related cognitive control deficits, which are associated with PTSD. The purpose of this study was to determine the extent to which a computerized WM task could predict PTSD symptomology incrementally beyond the contribution of other relevant variables associated with PTSD. MethodsThirty veterans were eligible to complete emotional symptom questionnaires, a heart-rate variability measure, and computerized tasks (i.e., emotional Stroop and automated complex span tasks). A three-stage hierarchical regression was conducted with the PCL-5 total score and symptom clusters (i.e., re-experiencing, avoidance, hyperarousal, and negative cognition/mood) as the dependent variable. ResultsResults revealed that only the re-experiencing symptom cluster was significantly predicted by executive, verbal, and visuospatial WM tasks, which explained an additional 29.7% of the variance over and above other relevant variables. Most notably, the visuospatial task was the only WM task that significantly explained PCL-5 re-experiencing symptoms. LimitationsThis study was based on a small sample of veterans with PTSD and causality cannot be determined with this cross-sectional study. ConclusionsOverall, the results suggest that deficits in visuospatial WM are significantly associated with PTSD re-experiencing symptoms after controlling for other relevant variables. Further research should evaluate whether an intervention to improve visuospatial WM capacity can be implemented to reduce re-experiencing symptoms.

Type 1 diabetes affects the brain functional connectivity underlying working memory processing.

Visuospatial working memory (VSWM) deficits have been demonstrated to occur during the development of type-1-diabetes (T1D). Despite confirming the early appearance of distinct task-related brain activation patterns in T1D patients compared to healthy controls, the effect of VSWM load on functional brain connectivity during task performance is still unknown. Using electroencephalographic methods, the present study evaluated this topic in clinically well-controlled T1D young patients and healthy individuals, while they performed a VSWM task with different memory load levels during two main VSWM processing phases: encoding and maintenance. The results showed a significantly lower number of correct responses and longer reaction times in T1D while performing the task. Besides, higher and progressively increasing functional connectivity indices were found for T1D patients in response to cumulative degrees of VSWM load, from the beginning of the VSWM encoding phase, without notably affecting the VSWM maintenance phase. In contrast, healthy controls managed to solve the task, showing lower functional brain connectivity during the initial VSWM processing steps with more gradual task-related adjustments. Present results suggest that T1D patients anticipate high VSWM load demands by early recruiting supplementary processing resources as the probable expression of a more inefficient, though paradoxically better adjusted to task demands cognitive strategy.

Disruption in Surface-Based Functional Connectivity in the Right Posterior Hippocampal CA3 Subfield: A Probable Neural Basis of Visuospatial Working Memory Impairment in Patients With Right Temporal Lobe Epilepsy.

Visuospatial working memory (VSWM) impairment is common in patients with right temporal lobe epilepsy (rTLE). The posterior hippocampus is critical for spatial memory, but the contributions of the different subfields to VSWM deficits remain unclear. Forty-six rTLE patients and 42 healthy controls (HCs) were recruited. Resting-state fMRI (rsfMRI) and structural MRI scans were administered, followed by a VSWM_Nback test. The right posterior hippocampus was automatically segmented, and the surface-based functional connectivity (SBFC) of the subiculum (Sub), CA1, CA3, dentate gyrus (DG), hippocampal tail, and right entorhinal cortex (EC) were compared between groups. Correlation analysis was performed between the altered SBFC and VSWM_Nback scores for rTLE patients. The results showed that rTLE patients underperformed in the VSWM_Nback test, with longer mean reaction time of accurate response (ACCmeanRT) in 0back and 2back condition, lower hit rate (HR) and higher false alarm rate (FAR) in 2back condition. Compared with HCs, the rCA3 in the rTLE group exhibited decreased SBFC with inferior parietal cortex (IPC), temporal lateral cortex (TLC), and posterior visual cortex (PVC) in the right hemisphere as well as the bilateral dorsolateral prefrontal cortex (DLPFC). The SBFC of the rEC and right anterior cingulate cortex (rACC) increased in the rTLE group. Within the rTLE group, the decreased SBFC of the rCA3-rIPC and rCA3-rLTC were correlated with worse VSWM performance. Therefore, the decreased SBFC of the rCA3-rIPC and rCA3-rLTC might be the critical aberrant FC pattern reflecting VSWM impairment in rTLE patients. The mechanism might involve functional disruption between the core subsystem and the medial temporal subsystem of the default mode network (DMN).

The Fear to Move in a Crowded Environment. Poor Spatial Memory Related to Agoraphobic Disorder.

Individuals with agoraphobia exhibit impaired exploratory activity when navigating unfamiliar environments. However, no studies have investigated the contribution of visuospatial working memory (VSWM) in these individuals’ ability to acquire and process spatial information while considering the use of egocentric and allocentric coordinates or environments with or without people. A total of 106 individuals (53 with agoraphobia and 53 controls) navigated in a virtual square to acquire spatial information that included the recognition of landmarks and the relationship between landmarks and themselves (egocentric coordinates) and independent of themselves (allocentric coordinates). Half of the participants in both groups navigated in a square without people, and half navigated in a crowded square. They completed a VSWM test in addition to tasks measuring landmark recognition and egocentric and allocentric judgements concerning the explored square. The results showed that individuals with agoraphobia had reduced working memory only when active processing of spatial elements was required, suggesting that they exhibit spatial difficulties particularly in complex spatial tasks requiring them to process information simultaneously. Specifically, VSWM deficits mediated the relationship between agoraphobia and performance in the allocentric judgements. The results are discussed considering the theoretical background of agoraphobia in order to provide useful elements for the early diagnosis of this disorder.

Executive Functioning and Clinical Variables in Patients with Obsessive-Compulsive Disorder.

Background: Cognitive flexibility, response inhibition, and working memory are considered the main mechanisms responsible for executive control. This study examined differences in cognitive flexibility, inhibition, and working memory in patients with obsessive–compulsive disorder (OCD) relative to a control group. Method: A total of 62 obsessive-compulsive participants (OCD = 32; healthy control = 32) aged between 17 and 56 years old (M = 33.16, SD = 9.23) were administered the computerized Wisconsin Card Sorting Test, Stroop Color–Word Test, Go/No-Go Task, Digit Test, and Corsi Block Test. Clinician-rated and self-reported obsessive–compulsive symptom severity, and anxiety, depression, and obsessive beliefs were evaluated. Results: The control group performed better than the OCD group in tasks involving cognitive flexibility, inhibition, and visuospatial working memory. Anxiety and obsessive beliefs influenced the participants’ performance on inhibition and working memory tasks. Similarly, comorbidity also influenced inhibition and working memory. In addition, the use of pharmacotherapy and the degree of OCD symptom severity influenced verbal working memory. Conclusions: Cognitive flexibility, inhibition, and visuospatial working memory deficits may be endophenotypes of OCD but require further examination for specificity. OCD severity, comorbidity patterns, anxiety, and obsessive beliefs may influence performance.

Numeric input operation on electronic devices among individuals with visuospatial working memory impairment

ABSTRACT In human–computer interactions, higher-level visuospatial function is likely needed to effectively use the interface. The aim of this study is to clarify whether individuals with visuospatial defects can use electronic devices effectively. We quantitatively and qualitatively analyzed the ability of seven individuals with Bálint syndrome and seven individuals with left-unilateral spatial neglect (USN) to input a digit sequence into a flat touch interface. Control groups consisted of seven individuals with memory deficits and 11 healthy individuals. Participants with Bálint syndrome took longer and had more hesitations than the USN group and the two control groups to input numerical sequences (Steel-Dwass test, p < .01). In addition, participants with Bálint syndrome had a high percentage of hesitations for exploration of the button array on the interface relative to USN and the memory deficit group (Fisher’s exact test, p < .05). Regarding neuropsychological data, participants with Bálint syndrome had a lower score for visuospatial working memory than participants with USN and the memory deficits control group (Steel-Dwass test, p < .01). The results shed some light on the relation between visuospatial working memory deficits and the spatial perception of interface layouts and spatial control during electronic device operation.

“Cerebellar lesions after low-grade tumor resection can induce memory impairment in children, similar to that observed in patients with frontal lesions”

ABSTRACTThe aim of the present study was to specify if cerebellar lesions cause memory impairment in children. The study sample consisted of 44 children with low-grade cerebellar astrocytoma, who underwent surgical treatment and 30 healthy controls, matched with regard to age and sex. Memory was tested using the Rey Auditory Verbal Learning Test AVLT, Corsi Block-Tapping Test, Digit Span, Digit Backwards and Information Subtests from the Wechsler Intelligence Scale for Children-Revised WISC-R (PL). Patients with cerebellar lesions demonstrated memory impairments, similar to those typical for patients with frontal lesions, with auditory and visuospatial working memory deficits, a disorganized learning process without mnemonic strategy (executive dysfunctions) and problems with recalling new material from long-term memory storage, while maintaining good recognition of previously learned material, preserved semantic knowledge and short-term auditory-verbal memory (digit span). Obtained results showed that memory deficits would vary according to the side of the cerebellar lesion, with more pronounced impairment of visuospatial memory tasks accompanying the left-sided cerebellar lesions and worse performance of verbal memory task, observed in the group of patients with right-sided cerebellar lesions. Although the presence of hydrocephalus significantly worsens the memory performance of the children studied, patients with cerebellar lesions without hydrocephalus still present significantly lower memory indicators in the profile described, compared to the control group of healthy children. It confirms the hypothesis that cerebellar lesion alone could result in memory dysfunctions in children.

Deficits of visuospatial working memory and executive function in single- versus multiple-domain amnestic mild cognitive impairment: A combined ERP and sLORETA study

ObjectiveAccording to recent criteria of classification, amnestic mild cognitive impairment (aMCI) could be divided into two categories: single-domain aMCI (sd-aMCI) and multiple-domain aMCI (md-aMCI). The difference between sd-aMCI and md-aMCI needs further exploration. The present study aimed to compare deficits in visuospatial working memory (VSWM) and executive function between sd-aMCI versus md-aMCI patients by use of event-related potentials (ERP) and standardized low-resolution brain electromagnetic tomography analysis (sLORETA). MethodsThe ERP data were measured and analyzed in 26 sd-aMCI, 13 md-aMCI patients and 46 healthy elderly controls (HEC) during VSWM and Go/Nogo processes. ResultsDuring VSWM task, md-aMCI patients showed decreased P300 amplitude compared to HEC and sd-aMCI patients (All p < 0.05). As compared to sd-aMCI, md-aMCI showed a hypoactivation in the right middle frontal gyrus in 1-back task during the P300 time range. During the Go/Nogo task, sd-aMCI and md-aMCI patients showed reduced N200 amplitude, compared to HEC (All p < 0.05). However, md-aMCI patients had decreased N200 amplitude, with respect to sd-aMCI patients. Further, as compared to sd-aMCI patients, md-aMCI patients showed a hypoactivation in the right superior frontal gyrus during the N200 time range. ConclusionsThese findings with a combined ERP and sLORETA study showed more severe deficits in updating operations of WM, detections of the target stimulus and conflict processes in md-aMCI, compared to sd-aMCI patients. SignificanceThe present study showed that a combined ERP and sLORETA study during the VSWM and Go/Nogo tasks could distinguish md-aMCI from sd-aMCI.

The role of working memory sub-components in food choice and dieting success

Evidence suggests a role for self-reported working memory (WM) in self-reported food intake, but it is not known which WM sub-components are involved. It is also important to consider how individual differences in dietary restraint and disinhibition influence WM and the impact of this on food choice. The current study assessed the relationship between WM sub-components and food choice, using computerised measures of WM sub-components and a direct assessment of food intake. The role of dieting success (measured by restraint and disinhibition) as a distal predictor of food choice that influences food choices via WM, and the role of WM more generally in dieting success were investigated. Female undergraduate students (N = 117, mean age: 18.9 years, mean BMI: 21.6 kg/m2) completed computer tasks assessing three components of WM (updating, phonological loop and visuospatial sketchpad) and a snack food taste-test. Greater visuospatial WM span was associated with a higher (lower) percentage of food intake that was low (high) energy dense. It was also found that unsuccessful dieters (high restraint, high disinhibition) had poorer visuospatial WM span and consumed a lower (higher) percentage of low (high) energy dense food. Visuospatial WM span significantly mediated the relationship between dieting success and percentage of low energy dense food intake. Further, dietary restraint was associated with poorer updating ability, irrespective of disinhibition. These findings suggest that better visuospatial WM is associated with a greater (reduced) preference for low (high) energy dense foods, and that deficits in visuospatial WM may undermine dieting attempts. Future work should assess whether the ability to deal with food cravings mediates the relationship between visuospatial WM and dieting success and investigate how WM may influence the mechanisms underlying behavioural control.

The Effect of Apolipoprotein E ε4 (APOE ε4) on Visuospatial Working Memory in Healthy Elderly and Amnestic Mild Cognitive Impairment Patients: An Event-Related Potentials Study.

Background: Apolipoprotein E (APOE) ε4 is the only established risk gene for late-onset, sporadic Alzheimer’s disease (AD). Previous studies have provided inconsistent evidence for the effect of APOE ε4 status on the visuospatial working memory (VSWM).Objective: The aim was to investigate the effect of APOE ε4 on VSWM with an event-related potential (ERP) study in healthy controls (HC) and amnestic mild cognitive impairment (aMCI) patients.Methods: The study recorded 39 aMCI patients (27 APOE ε4 non-carriers and 12 APOE ε4 carriers) and their 43 matched controls (25 APOE ε4 non-carriers and 18 APOE ε4 carriers) with an 64-channel electroencephalogram. Participants performed an N-back task, a VSWM paradigm that manipulated the number of items to be stored in memory.Results: The present study detected reduced accuracy and delayed mean correct response time (RT) in aMCI patients compared to HC. P300, a positive component that peaks between 300 and 500 ms, was elicited by the VSWM task. In addition, aMCI patients showed decreased P300 amplitude at the central–parietal (CP1, CPz, and CP2) and parietal (P1, Pz, and P2) electrodes in 0- and 1-back task compared to HC. In both HC and aMCI patients, APOE ε4 carriers showed reduced P300 amplitude with respect to non-carriers, whereas no significant differences in accuracy or RT were detected between APOE ε4 carriers and non-carriers. Additionally, standardized low-resolution brain electromagnetic tomography analysis (s-LORETA) showed enhanced brain activation in the right parahippocampal gyrus (PHG) during P300 time range in APOE ε4 carriers with respect to non-carriers in aMCI patients.Conclusion: It demonstrated that P300 amplitude could predict VSWM deficits in aMCI patients and contribute to early detection of VSWM deficits in APOE ε4 carriers.

The effect of apolipoprotein E ɛ4 (APOE E4) on visuospatial working memory in healthy elders and amnestic mild cognitive impairment patients: An event-related potentials study

IntroductionPrevious studies provided inconsistent evidences for the effect of apolipoprotein E ɛ4 (APOE ɛ4) status on the visuospatial working memory (VSWM). Our study was the first investigation with event-related potential (ERP) to explore the effect of APOE ɛ4 on VSWM in healthy elders and aMCI patients.ObjectiveThe aim was to investigate the effect of APOE ɛ4 on VSWM with event-related potential (ERP) study in healthy elders and aMCI patients.MethodsThirty-nine aMCI patients (27 APOE ɛ4 non-carriers and 12 APOE ɛ4 carriers) and 43 their matched control (25 APOE ɛ4 non-carriers and 18 APOE ɛ4 carriers) performed an N-back task, a VSWM paradigm that manipulated the number of items to be stored in memory.ResultsOur study detected reduced accuracy and delayed mean correct response time in aMCI patients than healthy elders. P300 was elicited by VSWM and its amplitude was lower in aMCI patients at the central-parietal and parietal electrodes than healthy controls. In healthy elders, P300 amplitude declined prior to task performance change in APOE ɛ4 carriers than non-carriers. Regarding aMCI patients, P300 amplitude result revealed exacerbated VSWM deficits in APOE ɛ4 carriers than APOE ɛ4 non-carriers. Additionally, standardized low-resolution brain electromagnetic tomography analysis (s-LORETA) result showed enhanced brain activation in right parahippocampal gyrus during P300 time range in APOE ɛ4 carriers than non-carriers in aMCI patients (Fig. 1, Tables 1 and 2).ConclusionsIt demonstrated that P300 amplitude might serve as a biomarker for recognizing aMCI patients and contribute to early detection of worse VSWM in APOE ɛ4 carriers than non-carriers.Disclosure of interestThe author has not supplied his/her declaration of competing interest.

Deficits in executive functions among youths with autism spectrum disorders: an age-stratified analysis.

Impaired executive function (EF) is suggested to be one of the core features in individuals with autism spectrum disorders (ASD); however, little is known about whether the extent of worse EF in ASD than typically developing (TD) controls is age-dependent. We used age-stratified analysis to reveal this issue. We assessed 111 youths with ASD (aged 12.5 ± 2.8 years, male 94.6%) and 114 age-, and sex-matched TD controls with Digit Span and four EF tasks of the Cambridge Neuropsychological Test Automated Battery (CANTAB): Spatial Span (SSP), Spatial Working Memory (SWM), Stockings of Cambridge (SOC), and Intradimensional/Extradimensional Shift Test (I/ED). Compared to TD controls, youths with ASD performed poorer on the Digit Span, SWM, SOC, and I/ED tasks. The performance of all the tasks improved with age for both groups. Age-stratified analyses were conducted due to significant age × group interactions in visuospatial planning (SOC) and set-shifting (I/ED) and showed that poorer performance on these two tasks in ASD than TD controls was found only in the child (aged 8-12 years) rather than the adolescent (aged 13-18 years) group. By contrast, youths with ASD had impaired working memory, regardless of age. The increased magnitude of group difference in visuospatial planning (SOC) with increased task demands differed between the two age groups but no age moderating effect on spatial working memory. Our findings support deficits in visuospatial working memory and planning in youths with ASD; however, worse performance in set-shifting may only be demonstrated in children with ASD.

Correlation between visuo-spatial working memory and brain Magnetic Resonance Imaging (MRI) lesion five years after Traumatic Brain Injury (TBI)

To describe the changes in fractional anisotropy (FA) measured with Diffusion Tensor Imaging (DTI) and the changes in Regional Homogeneity (ReHo) signal measured with resting state functional MRI on patients with visuo-spatial working memory deficit, 5 years after a severe TBI. We included TBI patients from a neurosurgical intensive care cohort of the Pitié-Salpêtrière Parisian Hospital. Patients were hospitalized between 2005 and 2011. A French version of the Glasgow Outcome Scale Extended (GOSE) assessed the global functional outcome. A large neuropsychological assessment including working memory tests was performed. We present here the results of the backward visuo-spatial span as standard notes. FA were measured on DTI and ReHo were extracted from resting state functional MRI acquisition on a voxel-based approach. Fifty-four patients were included 65 months after their TBI. The median age at evaluation time was 34 years [19–71]. Median Glasgow Coma Score was 8 [3–15]. Seventeen patients had a GOSE score below 6, 18 had a GOSE at 6 and 19 had a GOSE higher than 6. Thirty patients had a standard note on backward visuo-spatial span inferior to 7, which corresponds to a deficit. In this group, FA was lower in the left hemisphere, in the anterior limb of the internal capsule and in the external capsule. Patients also had an increased ReHo in the right hemisphere in the superior temporal gyrus, Heschl's gyrus, putamen, medium frontal gyrus and inferior frontal gyrus triangularis. Despite the fact that axonal lesions observed after TBI are diffuse, decreased FA was predominant in the left hemisphere of patients with the most severe working memory deficits and in whom ReHo appeared higher in the right hemisphere. These observations should open the discussion about contralateral inhibition of hemispheres.

Developmental Dyscalculia

Developmental dyscalculia (DD) is a specific learning disorder that affects the acquisition of arithmetic skills and number processing in children. A high comorbidity between DD and other neurodevelopmental disorders (e.g., dyslexia, attention-deficit/hyperactivity disorder [ADHD]) as well as substantial heterogeneity in cognitive profiles have been reported. Current studies indicate that DD is persistent, has a genetic component, and is related to functional and structural alterations of brain areas involved in magnitude representation. Recent neuronal and behavioral evidence is presented, showing that DD entails (a) impairments in two preverbal core systems of number, an approximate system for estimating larger magnitudes and an exact system for representing small magnitudes, (b) deficits in symbolic number processing, (c) aberrant and nonadaptive neuronal activation in basic magnitude processing and calculation, (d) dysfunctional arithmetic fact retrieval and persistent use of counting strategies in calculation, and (e) deficits in visuospatial working memory and the central executive. Finally, open research questions, including the role of domain-general cognitive resources in DD, causes and developmental consequences of comorbidity, as well as design and evaluation of interventions for DD, are briefly discussed.

Effects of gender and executive function on visuospatial working memory in adult obsessive-compulsive disorder.

Visuospatial working memory (VSWM) is the ability of the brain to transiently store and manipulate visual information. VSWM deficiencies have been reported in obsessive-compulsive disorder (OCD), but not consistently, perhaps due to variability in task design and clinical patient factors. To explore this variability, this study assessed effects of the design factors task difficulty and executive organizational strategy and of the clinical factors gender, OCD symptom dimension, and duration of illness on VSWM in OCD. The CANTAB spatial working memory, spatial recognition memory, delayed matching to sample, and stop signal tasks were administered to 42 adult OCD patients and 42 age- and sex-matched healthy controls. Aims were to detect a possible VSWM deficit in the OCD sample, to evaluate influences of the above task and patient factors, to determine the specificity of the deficit to the visuospatial subdomain, and to examine effects of sustained attention as potential neurocognitive confound. We confirmed previous findings of a VSWM deficit in OCD that was more severe for greater memory load (task difficulty) and that was affected by task strategy (executive function). We failed to demonstrate significant deficits in neighboring or confounding neurocognitive subdomains (visual object recognition or visual object short-term memory, sustained attention). Notably, the VSWM deficit was only significant for female patients, adding to evidence for sexual dimorphism in OCD. Again as in prior work, more severe OCD symptoms in the symmetry dimension (but no other dimension) significantly negatively impacted VSWM. Duration of illness had no significant effect on VSWM. VSWM deficits in OCD appear more severe with higher task load and may be mediated through poor task strategy. Such deficits may present mainly in female patients and in (male and female) patients with symmetry symptoms.

Nature and origins of mathematics difficulties in very preterm children: a different etiology than developmental dyscalculia

Children born very preterm (<32 wk) are at high risk for mathematics learning difficulties that are out of proportion to other academic and cognitive deficits. However, the etiology of mathematics difficulties in very preterm children is unknown. We sought to identify the nature and origins of preterm children's mathematics difficulties. One hundred and fifteen very preterm children aged 8-10 y were assessed in school with a control group of 77 term-born classmates. Achievement in mathematics, working memory, visuospatial processing, inhibition, and processing speed were assessed using standardized tests. Numerical representations and specific mathematics skills were assessed using experimental tests. Very preterm children had significantly poorer mathematics achievement, working memory, and visuospatial skills than term-born controls. Although preterm children had poorer performance in specific mathematics skills, there was no evidence of imprecise numerical representations. Difficulties in mathematics were associated with deficits in visuospatial processing and working memory. Mathematics difficulties in very preterm children are associated with deficits in working memory and visuospatial processing not numerical representations. Thus, very preterm children's mathematics difficulties are different in nature from those of children with developmental dyscalculia. Interventions targeting general cognitive problems, rather than numerical representations, may improve very preterm children's mathematics achievement.

Identifying developmental coordination disorder: MOQ-T validity as a fast screening instrument based on teachers' ratings and its relationship with praxic and visuospatial working memory deficits.

The present study was devoted to test the validity of the Italian adaptation of the Motor Observation Questionnaire for Teachers (MOQ-T, Schoemaker, Flapper, Reinders-Messelink, & De Kloet, 2008) as a fast screening instrument, based on teachers' ratings, for detecting developmental coordination disorders symptoms and to study its relationship with praxic and visuospatial working memory deficits. In a first study on a large sample of children, we assessed the reliability and structure of the Italian adaptation of the MOQ-T. Results showed a good reliability of the questionnaire and a hierarchical structure with two first-order factors (reflecting motor and handwriting skills), which are influenced by a second-order factor (general motor function) at the top. In a second study, we looked at the external validity of the MOQ-T and found that children with symptoms of Developmental Coordination Disorder (children with high scores on the MOQ-T) also had difficulty reproducing gestures, either imitating others or in response to verbal prompts. Our results also showed that children with high MOQ-T scores had visuospatial WM impairments. The theoretical and clinical implications of these findings are discussed.