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This paper examines developmental outcomes for children prenatally exposed to methamphetamine through maternal use. PSYCHINFO, Scopus, PubMed and ERIC databases were systematically searched for studies up to December 2020. The search identified 38 articles examining cognitive, language, motor and neuroanatomical outcomes in children from birth to 16 years. Study quality was appraised using the Newcastle Ottawa Quality Assessment Scale. Findings from neuroanatomical studies suggested that prenatal methamphetamine exposure may alter whole brain microstructure and reduce subcortical volumes across multiple brain regions. Meta-analysis of 14 studies using a random-effects model revealed associations between exposure and poorer intellectual functioning (Cohen's d = 0.89, 95 % CI: 0.47-1.30), problem solving skills (Cohen's d = 0.82, 95 % CI: 0.07 -1.56), short-term memory (Cohen's d = 0.91, 95 % CI: 0.38-1.43), and language development (Cohen's d = 0.74, 95 % CI: 0.30-1.18). These results emphasise the significant impact of intrauterine methamphetamine exposure across multiple areas of child development, noting that limited total sample size, heterogeneity between studies and control for confounds suggested further studies are required. There is a need for further intervention studies to identify effective prevention and harm minimisation approaches.

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A significant proportion of trans and gender diverse (TGD) young people report membership of the gaming community and resultant benefits to wellbeing. To date their experiences and needs regarding a key feature of games, the avatar, are largely unexplored, despite increasing interest in the therapeutic role of avatars in the general population. The aim of this study was to better understand the role of the avatar in gaming, its impact on TGD young people's mental health, and their unique needs regarding avatar design. N = 17 TGD young people aged 11-22 years (M = 16.3 years) participated in four focus groups. A general inductive approach was used to thematically analyze the transcribed data. TGD young people report considerable therapeutic benefits of using avatars with positive mental health implications. Importantly, TGD young people use avatars to explore, develop and rehearse their experienced gender identities, often as a precursor to coming out in the offline world. They also report negative experiences of feeling excluded due to the constraints of conventional notions of gender that are widely reflected in game design. Participants described simple design features to better reflect gender diversity, such as increased customization. Such changes would facilitate the positive gains reported by participants and better reflect the diversity of young people who use games. The findings have important implications for both recreational and serious or therapeutic game design.

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Individuals with autistic traits (measured with Autism-spectrum Quotient, AQ) often excel in detecting shapes hidden within complex structures (e.g. on the Embedded Figures Test, EFT). This facility has been attributed to either weaker global integration of scene elements or enhanced local processing, but 'local' and 'global' have various meanings in the literature. The function of specific global visual mechanisms involved in integrating contours, similar to EFT targets was examined. High AQ scorers produced enhanced performance on the EFT and an alternative Radial Frequency Search Task. Contrary to 'generic' interpretations of weaker global pooling, this group displayed stronger pooling of contour components that was correlated with search ability. This study therefore shows a global contour integration advantage in high AQ observers.

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Global processing of form information has been studied extensively using both Glass and radial frequency (RF) patterns. Models, with common early stages, have been proposed for the detection of properties of both pattern types but human performance has not been examined to determine whether the two pattern types interact in the manner this would suggest. The experiments here investigated whether low RF patterns and concentric Glass patterns, which are thought to tap the same level of processing in form-vision, are detected by a common mechanism. Six observers participated in two series of masking experiments. First: sensitivity to the presence of either coherent structure, or contour deformation, was assessed. The computational model predicted that detection of one pattern would be masked by the other. Second: a further experiment examined position coding. The model predicted that localizing the center of form in a Glass pattern would be affected by the presence of an RF pattern: sensitivity to a change of location should be reduced and the apparent location should be drawn toward the center of the masking pattern. However, the results observed in all experiments were inconsistent with the interaction predicted by the models, suggesting that separate neural mechanisms for global processing of signal are required to process these two patterns, and also indicating that the models need to be altered to preclude the interactions that were predicted but not obtained.

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Relative to low scorers, high scorers on the autism-spectrum quotient (AQ) show enhanced performance on the embedded figures test and the radial frequency search task (RFST), which has been attributed to both enhanced local processing and differences in combining global percepts. We investigate the role of local and global processing further using the RFST in four experiments. High AQ adults maintained a consistent advantage in search speed across diverse target-distracter stimulus conditions. This advantage may reflect enhanced local processing of curvature in early stages of the form vision pathway and superior global detection of shape primitives. However, more probable is the presence of a superior search process that enables a consistent search advantage at both levels of processing.

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Adaptation in the visual system frequently results in properties of subsequently presented stimuli being repelled along identifiable axes. Adaptation to radial frequency (RF) patterns, patterns deformed from circular by a sinusoidal modulation of radius, results in a circle taking on the appearance of having modulation in opposite phase. Here we used paths of spatially localized gratings (Gabor patches) to examine the role of local orientation adaptation in this shape aftereffect. By applying the tilt aftereffect (TAE) as a function of the local orientation difference between adaptor and test, concomitant with adjustment of local position to accommodate the orientation change and preserve path continuity (Euler's method), we show that a TAE field can account for this misperception of shape. Spatial modulation is also observed spontaneously in a circular path of Gabor patches when the local patch orientations are rotated from tangential to the path. This illusory path modulation is consistent with the path orientation being attracted to the orientation of the patches. This consistent local rule implies a local explanation for the global effect and is consistent with a known illusion with a local cause, the Fraser illusion (FI). A similar analysis to that used for the TAE shows that the Fraser illusion can account for this particular alteration of perceived shape. A model which proposes that local orientations are encoded after considering the activation in a population of neurons with differing orientation tuning can accommodate both effects. It is proposed that these distinct processes rely on the same neural architecture.

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Visual adaptation results in aftereffects that exaggerate the difference between successively experienced stimuli. In the tilt aftereffect (TAE), for example, the perceived orientation of a test line is repelled from the orientation of an adapting line. This principle also applies to more complex stimuli. Adaptation to faces can displace the next face viewed along axes such as identity, gender, ethnicity and specific emotions (Webster et al., 2004). The TAE field has been proposed as a general mechanism by which perceptual differences between shapes, including faces, could be enhanced through the systematic application of local TAEs (Dickinson, Almeida, et al., 2010). In this way perception of faces could be systematically modified along any dimension of interest defined by face morphology. Because the time course of adaptation for the TAE is rapid (Sekuler & Littlejohn, 1974) the same needs to be true for shapes and faces and Experiment 1 of this study shows that it is. Moreover, the orientation selective cells in early visual cortex are retinotopically arranged with limited receptive field sizes and so are sensitive to stimuli in particular regions of the visual field. A TAE field explanation for shape and face adaptation requires, therefore, that the shape and face aftereffects are retinotopic and Experiment 2 obtains this result. Experiment 3 exploits the folded face illusion to demonstrate that adaptation to a simple orientation field can also result in a shift in the perceived emotion in a face.

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Adaptation to prevailing stimuli is a ubiquitous property of the visual system that optimizes its dynamic range. The perceived difference in orientation of successively presented lines of similar orientation is exaggerated and the perceived shape of an object is influenced by previously experienced shapes. Change in perceived shape is assumed to arise through the adaptation of shape detectors. Here we consider an alternative: adaptation within a substrate of local oriented line detectors resulting in enhanced shape contrast in similar shapes. We show that the perceived shapes of a spatially coincident circle and Cartesian grid can be manipulated independently by adaptation to geometrically transformed copies of themselves. The same transformation was applied to the circle and the grid to create the adaptors; therefore, the specificity of the effects of adaptation demonstrates that the visual system adapts to the shape of objects rather than applying transformations to the reference frame of the visual field. The tilt aftereffect predicts local changes in perceived orientation, and fields of such local effects can often account for the global change in perceived shape of complex objects, including faces.

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The Embedded Figures Test (EFT) requires detecting a shape within a complex background and individuals with autism or high Autism-spectrum Quotient (AQ) scores are faster and more accurate on this task than controls. This research aimed to uncover the visual processes producing this difference. Previously we developed a search task using radial frequency (RF) patterns with controllable amounts of target/distracter overlap on which high AQ participants showed more efficient search than low AQ observers. The current study extended the design of this search task by adding two lines which traverse the display on random paths sometimes intersecting target/distracters, other times passing between them. As with the EFT, these lines segment and group the display in ways that are task irrelevant. We tested two new groups of observers and found that while RF search was slowed by the addition of segmenting lines for both groups, the high AQ group retained a consistent search advantage (reflected in a shallower gradient for reaction time as a function of set size) over the low AQ group. Further, the high AQ group were significantly faster and more accurate on the EFT compared to the low AQ group. That is, the results from the present RF search task demonstrate that segmentation and grouping created by intersecting lines does not further differentiate the groups and is therefore unlikely to be a critical factor underlying the EFT performance difference. However, once again, we found that superior EFT performance was associated with shallower gradients on the RF search task.

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The Embedded Figure Test (EFT) requires locating a simple shape embedded within a background of overlapping target-irrelevant scene elements. Observers with autism, or those with high levels of autistic-like traits, typically outperform matched comparison groups on the EFT. This research investigated the critical visual properties which give rise to this improved performance. The EFT is a search task and so here a radial frequency (RF) search task was created to directly explore efficacy of visual search and also the influence of element overlap on performance. In all conditions, the task was to detect whether the target RF3 (a triangular shape chosen for its visual properties) was present among a number of distracter RF4 (a square shape) patterns. The conditions employed were: 'singles', where all the patterns were spatially discrete, 'pairs', where two overlapping elements formed each cluster, and 'quads', comprising four overlapping elements per cluster. Compared to students scoring low on the Autism Spectrum Quotient (AQ; n=27), those scoring high on the AQ (n=23) were faster on the EFT and also significantly less influenced by increasing set size of the stimulus array in all RF search task conditions. However, the group difference in RF search performance was unaffected by the amount of stimulus overlap. Thus a simple search task is sufficient to detect a performance advantage associated with higher levels of autistic traits and has the advantages of a solid footing in visual theory and being readily repeatable for the purpose of assessing performance variability and change with interventions.

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