Brief report: cognitive estimation in individuals with pervasive developmental disorders

Conventional and frugal methods of estimating COVID-19-related excess deaths and undercount factors

Across the world, the officially reported number of COVID-19 deaths is likely an undercount. Establishing true mortality is key to improving data transparency and strengthening public health systems to tackle future disease outbreaks. In this study, we estimated excess deaths during the COVID-19 pandemic in the Pune region of India. Excess deaths are defined as the number of additional deaths relative to those expected from pre-COVID-19-pandemic trends. We integrated data from: (a) epidemiological modeling using pre-pandemic all-cause mortality data, (b) discrepancies between media-reported death compensation claims and official reported mortality, and (c) the "wisdom of crowds" public surveying. Our results point to an estimated 14,770 excess deaths [95% CI 9820-22,790] in Pune from March 2020 to December 2021, of which 9093 were officially counted as COVID-19 deaths. We further calculated the undercount factor-the ratio of excess deaths to officially reported COVID-19 deaths. Our results point to an estimated undercount factor of 1.6 [95% CI 1.1-2.5]. Besides providing similar conclusions about excess deaths estimates across different methods, our study demonstrates the utility of frugal methods such as the analysis of death compensation claims and the wisdom of crowds in estimating excess mortality.

Mathematics abilities associated with adaptive functioning in preschool children born preterm

It is well known that infants born very preterm (VPT) often demonstrate deficits in mathematical abilities in early childhood which are associated with poorer academic outcomes. Mathematic skills are also critical for other areas of functioning. However, it is not known whether mathematics skills are associated with adaptive functioning in children born preterm. Infants born at ≤31 weeks gestation and full term were recruited at birth and followed over time. At the 36-month corrected age assessment, children were administered the Early Number Concepts subtest of the Differential Abilities Scale, Second Edition, and caregivers completed the Adaptive Behavior Assessment System, Third Edition. After controlling for age, sex, cognitive abilities, and caregiver education, performance on the mathematics measure was uniquely and positively associated with adaptive behavior for preschool children in the VPT group only. Exploratory analyses revealed this association to be specifically related to the Practical and Social composites. Knowledge of concepts of number and quantity were associated with better adaptive functioning, particularly for behaviors related to functioning at home and in the community and play/social functioning, for children born VPT. Although replication is warranted, it would appear that mathematical skills may be an important early intervention target for children born VPT.

What determines cognitive estimation ability? Changing contributions of semantic and executive domains as a function of age

The Cognitive Estimation Test (CET) is commonly used in neuropsychological assessment. It is typically assumed to load on executive functions, although research has shown that CET performance also depends on access to semantic knowledge. It is unknown whether these contributions vary with age. It is important to examine this question as these abilities have divergent life course trajectories: executive functions tend to decline as people age but semantic knowledge continues to accrue. In addition, previous research has not examined potential contributions to CET performance from semantic control abilities, that is cognitive control processes involved specifically in the retrieval and use of semantic information. To address these questions, we investigated cognitive predictors of CET performance in healthy young and older adults. We found that better executive function was associated with more accurate estimation in both age groups. However, the effect of semantic knowledge on CET performance was significantly larger in older people, having no predictive power in the younger group. The ability to detect weak semantic associations, which is thought to index controlled search and retrieval of semantic information, also had divergent effects on CET performance in the two age groups. Our results provide empirical support for the idea that older people are more reliant on semantic knowledge when estimating quantities, which may explain why age‐related decline in CET scores is not typically found. We conclude that deficits on the CET may be indicative either of semantic or executive impairments, particularly in older age groups.

Cognitive Estimation in Non-demented Parkinson's Disease

Objective

The Cognitive Estimation Test (CET) is widely used in clinical and research settings to assess the ability to produce reasonable estimates to items that individuals would not know that the exact answer (e.g., "How fast do race horses run?"). We examined the performance of non-demented Parkinson's disease (PD) patients on the CET, because previous studies reported heterogeneous results about possible cognitive estimation impairments in PD. We also examined whether PD patients improve their performance if given the chance to reconsider their initial CET responses.

Methods

Thirty non-demented idiopathic PD patients and 30 healthy controls matched in age, gender and years of education performed the two parallel forms of Italian CET. The estimation scores for initial and final responses as well as the number of times individuals changed their answers were examined. Additional neuropsychological tests, evaluating intellectual, frontal executive, speed of processing, naming and arithmetical abilities, were also administered.

Results

The PD group were not significantly poorer than healthy controls at estimating the answers to items on either CET versions. Moreover, PD patients did not significantly differ in their initial and final responses or number of response changes. Performance on the CET was significantly related to performance on a global measure of executive function, processing speed and arithmetic. However, PD patients were impaired compared to controls on the component involving mainly, but not exclusively, length-related estimations.

Conclusions

Non-demented PD patients have mild impairments in cognitive estimation ability, which may depend on the estimations they are required to provide.

Deconstructing the Cognitive Estimation Task: A Developmental Examination and Intra-Task Contrast

The cognitive estimation task (CET) requires participants to answer estimation questions that lack definitive answers. Few studies examine CET performance in healthy populations, and even fewer in children. Previous research has not considered differences between categories within the CET. The categories differ in their reliance on units of measurement, which is significant when examining CET performance in children due to educational factors. The goal of the study was to examine CET performance in 10 and 12 year-old children and contrast the CET categories. We found a developmental effect in overall CET performance: children’s performance was more extreme than adults but no differences were found between the groups of children. Examination of the CET categories revealed differential developmental trajectories: the children’s scores were more extreme in weight and time, while comparable to adults in quantity. We conclude that CET questions that require application of units of measurement are more difficult for childern due to higher involvement of executive functions, and children have less experience applying them in daily life. The CET is not a unified construct and has the potential to shed light on how children acquire an understanding of magnitudes and units of measurement.

Bringing the cognitive estimation task into the 21st century: normative data on two new parallel forms

The Cognitive Estimation Test (CET) is widely used by clinicians and researchers to assess the ability to produce reasonable cognitive estimates. Although several studies have published normative data for versions of the CET, many of the items are now outdated and parallel forms of the test do not exist to allow cognitive estimation abilities to be assessed on more than one occasion. In the present study, we devised two new 9-item parallel forms of the CET. These versions were administered to 184 healthy male and female participants aged 18–79 years with 9–22 years of education. Increasing age and years of education were found to be associated with successful CET performance as well as gender, intellect, naming, arithmetic and semantic memory abilities. To validate that the parallel forms of the CET were sensitive to frontal lobe damage, both versions were administered to 24 patients with frontal lobe lesions and 48 age-, gender- and education-matched controls. The frontal patients’ error scores were significantly higher than the healthy controls on both versions of the task. This study provides normative data for parallel forms of the CET for adults which are also suitable for assessing frontal lobe dysfunction on more than one occasion without practice effects.

Dysfunction of orbitofrontal and dorsolateral prefrontal cortices in children and adolescents with high-functioning pervasive developmental disorders

BACKGROUND

Several lines of evidence suggest that dysfunction of the dorsolateral prefrontal cortex (DLPFC) and orbitofrontal cortex (OFC) contributes to the pathophysiology of pervasive developmental disorders (PDD). The purpose of this study was to investigate neuropsychological dysfunctions in both the DLPFC and OFC of children and adolescents with high-functioning PDD.

METHODS

The Iowa gambling task (IGT), which reflects OFC function, and the Wisconsin Card Sorting Test (WCST), which reflects DLPFC function, were assigned to 19 children and early adolescents with high-functioning PDD and 19 healthy controls matched for gender, age, and intelligence.

RESULTS

Compared to healthy controls, patients with high-functioning PDD displayed poorer performance on the IGT and the WCST.

CONCLUSIONS

These results indicate that both the DLPFC and OFC could be impaired in children and early adolescents with high-functioning PDD.

Neuropsychological mechanisms of Digit Symbol Substitution Test impairment in Asperger Disorder

Our aim was to investigate the neurocognitive mechanisms recruited by adolescents with Asperger Disorder (AD), in comparison to controls, and to detect the underlying mechanisms during the complex information processing required for the performance of the Digit Symbol Substitution Test (DSST). Male adolescents (n=23; mean age 15.1+/-3.6 years) with a DSM-IV diagnosis of AD were compared with a normal male control group with similar demographic characteristics (n=43; mean age: 15.1+/-3.6 years). A computerized neurocognitive battery was administered and included: Inspection Time (IT), Finger Tapping Test (FTT), Simple Reaction Time (SRT), Choice Reaction Time (CRT), Digit Running task (DRT), Stroop test and Digit Symbol Substitution Test (DSST). Adolescents with AD performed significantly worse than controls on the DSST. This impaired DSST performance was related to cognitive mechanisms different from those employed by normal controls. Motor slowness and inability to deal with increased amounts of information affected the performance of the AD group, while shifting of attention was the limiting factor in the controls. Both groups were similarly dependent on response selection. This study demonstrated differences in performance in complex cognitive tasks between adolescents with AD and normal controls that may be related to differences in neurocognitive mechanisms underlying information processing. Future neuroimaging studies are needed to clarify the neural network involved in the differences in cognitive performance between AD subjects and normal controls.

Cognitive estimation in traumatic brain injury

The present study explores the construct and ecological validity of the Biber Cognitive Estimation Test (BCET) in a traumatic brain injury (TBI) sample. Participants completed the BCET in the course of a neuropsychological evaluation at 1-15 years after injury. BCET scores correlated moderately with other standard measures of executive functioning, and contrary to our hypotheses, at least as high with neuropsychological tests with minimal demands on executive functioning. Moreover, partialing out the portion of BCET variance not attributable to executive functioning markedly attenuated the former correlations. With respect to ecological validity, BCET scores did not predict concurrent functional status, as measured by the Disability Rating Scale. By comparison, standard measures of executive functioning strongly correlated with each other, correlated less strongly with nonexecutive functioning measures, and predicted functional status. In conclusion, unlike standard measures of executive functioning, the BCET demonstrated poor construct and ecological validity in TBI patients.

Executive function deficits in autism spectrum disorders and attention-deficit/hyperactivity disorder: Examining profiles across domains and ages

Deficits in 'executive function' (EF) are characteristic of several clinical disorders, most notably Autism Spectrum Disorders (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD). In this study, age- and IQ-matched groups with ASD, ADHD, or typical development (TD) were compared on a battery of EF tasks tapping three core domains: response selection/inhibition, flexibility, and planning/working memory. Relations between EF, age and everyday difficulties (rated by parents and teachers) were also examined. Both clinical groups showed significant EF impairments compared with TD peers. The ADHD group showed greater inhibitory problems on a Go-no-Go task, while the ASD group was significantly worse on response selection/monitoring in a cognitive estimates task. Age-related improvements were clearer in ASD and TD than in ADHD. At older (but not younger) ages, the ASD group outperformed the ADHD group, performing as well as the TD group on many EF measures. EF scores were related to specific aspects of communicative and social adaptation, and negatively correlated with hyperactivity in ASD and TD. Within the present groups, the overall findings suggested less severe and persistent EF deficits in ASD (including Asperger Syndrome) than in ADHD.