Behavioral, cognitive and functional particularities in autism differ according to autism subgroups and might be associated with domain-specific cognitive strengths. It is unknown whether structural ...changes support this specialization. We investigated the link between cortical folding, its maturation and cognitive strengths in autism subgroups presenting verbal or visuo-spatial peaks of abilities.
We measured gyrification, a structural index related to function, in 55 autistic participants with (AS-SOD, N = 27) or without (AS-NoSOD, N = 28) a speech onset delay (SOD) with similar symptom severity but respectively perceptual and verbal cognitive strengths, and 37 typical adolescents and young adults matched for intelligence and age. We calculated the local Gyrification Index (lGI) throughout an occipito-temporal region of interest and independently modeled age and peak of ability effects for each group.
Unique gyrification features in both autistic groups were detected in localized clusters. When comparing the three groups, gyrification was found lower in AS-SOD in a fusiform visual area, whereas it was higher in AS-NoSOD in a temporal language-related region. These particular areas presented age-related gyrification differences reflecting contrasting local maturation pathways in AS. As expected, peaks of ability were found in a verbal subtest for the AS-NoSOD group and in the Block Design IQ subtest for the AS-SOD group.
Irrespective of their direction, regional gyrification differences in visual and language processing areas respectively reflect AS-SOD perceptual and AS-NoSOD language-oriented peaks. Unique regional maturation trajectories in the autistic brain may underline specific cognitive strengths, which are key variables for understanding heterogeneity in autism.
•Subgrouping the autism spectrum (AS) partly accounts for its heterogeneity.•AS individuals with a speech onset delay (SOD) show perceptual cognitive strengths.•AS individuals without a SOD show language-related cognitive strengths.•AS subgroups show unique gyrification patterns in areas related to their strengths.•Cortical structural maturation may be related to domain-specific strengths in AS.
▸ Autistics display enhanced mental imagery abilities. ▸ Mental rotation skills aggregate with IQ and visuospatial skills in autistics only. ▸ Autistics with a Block Design peak show the best ...performance in mental rotation.
The formation and manipulation of mental images represents a key ability for successfully solving visuospatial tasks like Wechsler's Block Design or visual reasoning problems, tasks where autistics perform at higher levels than predicted by their Wechsler IQ. Visual imagery can be used to compare two mental images, allowing judgment of their relative properties. To examine higher visual processes in autism, and their possible role in explaining autistic visuospatial peaks, we carried out two mental imagery experiments in 23 autistic and 14 age and IQ matched, non-autistic adolescents and adults. Among autistics, 11 had significantly higher Block Design scores than predicted by their IQ. Experiment 1 involved imagining a letter inside a circle, followed by a decision concerning which of two highlighted portions of the circle would contain the greater proportion of the letter. Experiment 2 involved four classic mental rotation tasks utilizing two- and three-dimensional geometric figures, hands and letters. Autistics were more accurate in the formation and comparison of mental images than non-autistics. Autistics with a Block Design peak outperformed other participants in both speed and accuracy of mental rotation. Also, Performance IQ and Block Design scores were better predictors of mental rotation accuracy in autistic compared to non-autistic participants. The ability to form, access and manipulate visual mental representations may be more developed in autistics. We propose two complementary mechanisms to explain these processing advantages: (1) a global advantage in perceptual processing, discussed in the framework of the enhanced perceptual functioning model, and (2) particular strengths in veridical mapping, the ability to efficiently detect isomorphisms among entities and then to use these mappings to process stimulus characteristics, thereby facilitating judgments about their differences.
...the same ROIs were used as endpoints in DTI probabilistic tractography to examine fractional anisotropy of the pathways connecting the functionally implicated areas, as a comparison measure of ...their structural integrity across groups.
Abstract In autistic individuals, the role, performance, and autonomy of perceptual functioning are atypical. Overlapping underlying mechanisms of perception and mental imagery predict that the ...mental imagery abilities of autistic individuals should differ from those of non‐autistic individuals. While enhanced abilities to manipulate mental images have been demonstrated in autism, the other stages of mental imagery (generation, maintenance, inspection) remain to be explored. Forty‐four autistic adults and 42 typical participants performed four tasks to assess different stages of mental imagery: the Image generation task (mentally generating a letter on a grid and indicating whether it passes over a probe located in the grid), the Visual pattern test (maintaining visual patterns in memory), the Image scanning test (inspecting mental images) and the Mental rotation test (mentally manipulating representations of geometric figures). In the image generation task and the mental rotation test, autistic and typical individuals performed equivalently, both in accuracy and response time. The span observed in the visual pattern test was significantly higher in the autistic group, indicating better maintenance of mental images. In the image scanning test, response times were influenced by the distance to mentally inspect in the typical group but not in the autistic group. Autistic participants were equally fast regardless of distance to inspect. Preserved, greater or differently influenced visual mental imagery abilities are in line with an atypical perceptual functioning in autism, possibly reflecting an increased weight of perception‐based information relatively to the top‐down effect of knowledge and language‐based influence.
Lay Summary How autistic individuals perceive and manipulate what they “see” mentally differs from typical individuals. Our study found that while some aspects of mental imagery are similar between autistic and non‐autistic individuals, others, like maintaining mental images, are better in autism. Autistic individuals were also equally quick at mentally inspecting an image regardless of distance in the image which is in line with the atypical perceptual processing style in autism.
Armstrong, Gleitman, and Gleitman (1983) reported shorter categorization times for members of well-defined categories judged more typical. They concluded that these effects could not originate in a ...graded, similarity-based category representation and consequently that the typicality effects obtained with natural categories might not be indicative of such a structure either. In this article, we re-examine this conclusion, focusing first on the performance obtained with well-defined categories of different sizes. Only the larger categories used showed variations in typicality ratings and produced typicality effects on categorization times. However, multiple regression analyses showed the effects on categorization times to be better explained by a measure of associative strength, called category dominance. The range of various predictor variables was equated in a follow-up experiment involving large, natural, and well-defined categories. Results obtained with well-defined categories showed pronounced dominance effects when typicality was controlled, but no reliable typicality effect when category dominance and instance familiarity were controlled. Results were opposite for natural categories. By showing that well-defined categories fail to produce unbiased typicality effects, our results bring added support to the hypothesis that the effects obtained with natural categories originate in a graded, similarity-based category structure.
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DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
INTRODUCTION: Spaceflight can expose astronauts to a wide range of environmental stresses that adversely affect brain function, including radiation, hypercarbia, and sleep deprivation. Functional ...neuroimaging studies have shown that sleep deprivation causes prefrontal cortical activity changes during performance of cognitively demanding tasks, even in the absence of performance deficits. Thus, neuroimaging may allow sensitive, early detection of impending physiological or performance decline. There are, however, no practical methods to assess brain physiology during missions, as current imaging systems cannot meet the operational constraints of small size, low power, and reliability. Our goal is to develop reliable methods, based on functional near-infrared neuroimaging (NIN), to monitor brain function during spaceflight.
Tumor proportion score (TPS) and combined positive score (CPS includes immune cells), 2 methods for scoring programmed death ligand 1 (PD-L1) expression, have been used in clinical trials ...investigating the immune checkpoint inhibitor pembrolizumab in head and neck squamous cell carcinoma (HNSCC). These trials resulted in regulatory approval for pembrolizumab in the first- and second-line setting outside the United States. We performed a post hoc analysis of the KEYNOTE-040 study (NCT02252042) to determine whether CPS is a practical and suitable alternative scoring method to TPS. In KEYNOTE-040, patients with metastatic HNSCC received pembrolizumab or investigator choice of standard of care (SOC). The relative utility and equivalence of CPS ≥ 50 and TPS ≥ 50% for defining PD-L1 expression status in patients with HNSCC and comparability of scoring methods by tandem receiver operating characteristic (ROC) analysis were analyzed. The cutoff for each method was also evaluated. CPS ≥ 50 appeared equivalent to TPS ≥ 50% for predicting objective response rate (ORR), overall survival, and progression-free survival. ORR for pembrolizumab versus SOC was 26.2 versus 8.5% for TPS ≥ 50%, 28.1 versus 7.7% for CPS ≥ 50, 10.6 versus 11.6% for TPS < 50%, and 10.0 versus 12.0% for CPS < 50. Tandem ROC analysis showed that TPS 50% and CPS 50 maximized delta Youden index and suggested that CPS is more sensitive than TPS at lower cutoffs (i.e., CPS ≥ 1). In conclusion, CPS 50 can be used interchangeably with TPS 50% to determine PD-L1 status in patients with HNSCC. CPS may be more sensitive than TPS at lower cutoffs.
Among patients with advanced renal-cell carcinoma, overall survival and progression-free survival were longer among patients who received pembrolizumab and axitinib than among those who received ...sunitinib, and more patients in the pembrolizumab–axitinib group than in the sunitinib group had a response.
The cognitive profile and measured intellectual level vary according to assessment tools in children on the autism spectrum, much more so than in typically developing children. The recent inclusion ...of intellectual functioning in the diagnostic process for autism spectrum disorders leads to the crucial question on how to assess intelligence in autism, especially as some tests and subtests seem more sensitive to certain neurodevelopmental conditions. Our first aim was to examine the cognitive profile on the current version of the most widely used test, the Wechsler Intelligence Scales for Children (WISC-IV), for a homogenous subgroup of children on the autism spectrum, i.e. corresponding to DSM-IV diagnosis of "autism". The second aim was to compare cognitive profiles obtained on the third edition versus 4th edition of WISC, in order to verify whether the WISC-IV yields a more distinctive cognitive profile in autistic children. The third aim was to examine the impact of the WISC-IV on the cognitive profile of another subgroup, children with Asperger's Syndrome. 51 autistic, 15 Asperger and 42 typically developing children completed the WISC-IV and were individually matched to children who completed the WISC-III. Divergent WISC-IV profiles were observed despite no significant intelligence quotient difference between groups. Autistic children scored significantly higher on the Perceptual Reasoning Index than on the Verbal Comprehension Index, a discrepancy that nearly tripled in comparison to WISC-III results. Asperger children scored higher on the VCI than on other indexes, with the lowest score found on the Processing Speed Index. WISC-IV cognitive profiles were consistent with, but more pronounced than WISC-III profiles. Cognitive profiles are a valuable diagnostic tool for differential diagnosis, keeping in mind that children on the autism spectrum might be more sensitive to the choice of subtests used to assess intelligence.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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