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Dysfunctions in sensory processing are widely described in individuals with autism spectrum disorder (ASD), although little is known about the developmental course and the impact of these difficulties on the learning processes during the preschool and school ages of ASD children. Specifically, as regards the interplay between visual and haptic information in ASD during developmental age, knowledge is very scarce and controversial. In this study, we investigated unimodal (visual and haptic) and cross-modal (visuo-haptic) processing skills aimed at object recognition through a behavioural paradigm already used in children with typical development (TD), with cerebral palsy and with peripheral visual impairments. Thirty-five children with ASD (age range: 5-11 years) and thirty-five age-matched and gender-matched typically developing peers were recruited. The procedure required participants to perform an object-recognition task relying on only the visual modality (black-and-white photographs), only the haptic modality (manipulation of real objects) and visuo-haptic transfer of these two types of information. Results are consistent with the idea that visuo-haptic transfer may be significantly worse in ASD children than in TD peers, leading to significant impairment in multisensory interactions for object recognition facilitation. Furthermore, ASD children tended to show a specific deficit in haptic information processing, while a similar trend of maturation of visual modality between the two groups is reported. This study adds to the current literature by suggesting that ASD differences in multisensory processes also regard visuo-haptic abilities necessary to identify and recognise objects of daily life.

Chronic stress is well known to erode cognitive functions. Yet, our understanding of how repeated stress exposure impacts one of the fundamental bases of cognition: sensory processing, remains limited. The posterior parietal cortex (PPC) is a high order visual region, known for its role in visually guided decision making, multimodal integration, attention, and working memory. Here, we used functional measures to determine how repeated exposure to multiple concurrent stressors (RMS) affects sensory processing in the PPC in adult male mice. A longitudinal experimental design, repeatedly surveying the same population of neurons using in vivo two-photon imaging, revealed that RMS disrupts the balanced turnover of visually responsive cells in layer 2/3 of the PPC. Across the population, RMS-induced changes in visual responsiveness followed a bimodal distribution suggesting idiosyncratic stress effects. In cells that maintained their responsiveness across recording sessions, we found that stress reduced visual response magnitudes and feature selectivity. While we did not observe stress-induced elimination of excitatory synapses, noise correlation statistics indicated that RMS altered visual input to the neuronal population. The impact of RMS was restricted to visually evoked responses and was not evident in neuronal activity associated with locomotion onset. Together, our results indicate that despite no apparent synaptic reorganization, stress exposure in adulthood can disrupt sensory processing in the PPC, with the effects showing remarkable individual variation.

Visual agnosia is understood as the inability to recognize an object in the absence of primary visuoperceptive sensorial deficit or significant intellectual disability due to brain damage. Traditionally, the distinction between apperceptive-associative (proposed by Lissauer in 1892) is used to characterize those patients with visual difficulties. Recently, Farah and, Milner & Goodale have formulated new models in an attempt to integrate more recent evidence. However, due to the wide variety of symptoms and topographical distribution of the lesions, it is necessary to characterize symptoms according to those locations. Such effort will allow for the formulation of more accurate models. The current systematic review included ten articles containing a complete symptomatology description and a brain imaging of the lesion. The results suggest the possibility of coexisting primary visual defects along with agnosia. The lesion analysis recognizes the role of subcortical structures like the thalamus and the parietal and temporal cortices in visual processing. In our view, these regions should be included in developing new models., A agnosia visual é entendida como a incapacidade para reconhecer objetos, na ausência de alterações visuais ou incapacidade intelectual significativa, devido a algum tipo de dano cerebral. Tradicionalmente, se emprega a distinção aperceptivo-associativo proposta por Lissauer (1982) para caracterizar as dificuldades visuais destes pacientes. Outros modelos mais recentes como os propostos por Farah ou o de Milner e Goodale tem procurado integrar novos achados relacionados com o processamento visual. No entanto, dada a ampla variedade de sintomas e a distribuição topográfica das lesões, se faz necessário contar com uma adequada caracterização de sintomas com base nestas localizações. Só assim, será possível formular teorias que integrem a evidência disponível. Nesta revisão sistemática, foram escolhidos dez artigos com uma descrição detalhada de sintomas e que incluíam uma neuroimagem que permitia localizar as lesões. Os resultados apontam que pode existir alterações visuais de base nas agnosias e apontam também para o reconhecimento do papel das estruturas subcorticais como o tálamo e as do córtex parietal e temporal no processamento visual, as quais deveriam ser consideradas dentro do desenvolvimento de novos modelos., La agnosia visual es entendida como la incapacidad para reconocer objetos, en ausencia de alteraciones visuales o discapacidad intelectual significativa, a causa de daño cerebral. Tradicionalmente, se ha empleado la distinción aperceptivo-asociativo, propuesta por Lissauer (1892), para caracterizar las dificultades visuales de estos pacientes. Otros modelos más recientes como los propuestos por Farah o el de Milner y Goodale han procurado integrar nuevos hallazgos relacionados con el procesamiento visual. Sin embargo, dada la amplia variedad de síntomas y la distribución topográfica de las lesiones, se hace necesario contar con una adecuada caracterización de síntomas con base en dichas localizaciones. Solo así, será posible formular teorías que integren la evidencia disponible. En esta revisión sistemática, se tomaron diez artículos con una detallada descripción de síntomas e incluyeran una neuroimagen que permitiera ubicar las lesiones. Los resultados apuntan a que pueden existir alteraciones visuales de base en las agnosias y a reconocer el papel de estructuras subcorticales como el tálamo y de cortezas parietales y temporales en el procesamiento visual, las cuales deberían considerarse dentro del desarrollo de nuevos modelos.

Purpose of reviewThe study aims to provide a summary of recent developments for diagnosing and managing posterior cortical atrophy (PCA). We present current efforts to improve PCA characterisation and recommendations regarding use of clinical, neuropsychological and biomarker methods in PCA diagnosis and management and highlight current knowledge gaps.Recent findingsRecent multi-centre consensus recommendations provide PCA criteria with implications for different management strategies (e.g. targeting clinical features and/or disease). Studies emphasise the preponderance of primary or co-existing Alzheimer's disease (AD) pathology underpinning PCA. Evidence of approaches to manage PCA symptoms is largely derived from small studies.SummaryPCA diagnosis is frequently delayed, and people are likely to receive misdiagnoses of ocular or psychological conditions. Current treatment of PCA is symptomatic - pharmacological and non-pharmacological - and the use of most treatment options is based on small studies or expert opinion. Recommendations for non-pharmacological approaches include interdisciplinary management tailored to the PCA clinical profile - visual-spatial - rather than memory-led, predominantly young onset - and psychosocial implications. Whilst emerging disease-modifying treatments have not been tested in PCA, an accurate and timely diagnosis of PCA and determining underlying pathology is of increasing importance in the advent of disease-modifying therapies for AD and other albeit rare causes of PCA.

The purpose of this study was to determine if stroboscopic vision significantly effects performance on the YBT-LQ in athletes 12-18 years old, as well as investigating if age or sex effect performance. Previous research has demonstrated the clinical use of stroboscopic vision for athletic performance and rehabilitation, but no study had yet established the effect of stroboscopic vision on dynamic balance. Subjects performed the Y-Balance Lower Quarter (YBT-LQ) and then repeated the YBT-LQ with stroboscopic vision at a rate of 4 hertz (Hz). A repeated measures factorial ANOVAs were used identify significant differences in performance on the YBT-LQ with and without stroboscopic vision, as well as post-hoc analyses to investigate the effects of age and sex. Results from the study revealed stroboscopic vision has a significant effect on performance of the YBT-LQ, with age playing factor in performance, but no significant difference between sexes. These findings establish the effect stroboscopic vision has on dynamic balance.

Formulaic expressions (FEs), such as conventional collocations (e.g., fresh air) and phrases (e.g., take a break), constitute a significant part of language use in our daily lives (Erman & Warren, 2000). FEs are defined as multiword units that holistically represent a single meaning, and they are likely stored and retrieved as unanalyzed wholes from memory when used (Wray & Perkins, 2000). Previous research highlights the crucial role of FEs in language comprehension and production (Conklin & Schmitt, 2008), and their usage in English is considered essential for achieving fluency, authenticity, and idiomaticity in second language (L2) learning (Boers & Lindstromberg, 2012). However, there remains a lack of empirical evidence on how American learners of Chinese process FEs holistically, and whether incorporating these expressions in Chinese L2 classrooms is pedagogically effective.Therefore, the purpose of this research project is to provide insights into the theoretical and empirical understanding of the role of FEs in learning L2 Chinese. This project aims to achieve the following objectives: (1) employ the model of Construction Grammar (Goldberg, 1995, 2006) to examine the semantic and syntactic behaviors of Chinese FEs (especially phrases) through corpus analysis; (2) investigate the visual processing of FEs by learners of Chinese to test the holistic hypothesis (Schmitt et al., 2004); and (3) explore the application of the lexical approach (Lewis, 1993) to the teaching of FEs in novice-level Chinese language classrooms. The data for this project were collected through online experimental paradigms, including the acceptability judgment task and self-paced reading task, as well as native speaker corpus analysis, online surveys, and semi-structured interviews with instructors of Chinese. The findings contribute to the cognitive understanding of Chinese FEs by connecting formulaicity with Construction Grammar, and provide evidence from L2 Chinese to support the proc

Microsaccades that occur during periods of fixation are modulated by various cognitive processes and have an impact on visual processing. A network of brain areas is involved in microsaccade generation, including the superior colliculus and frontal eye field (FEF) which are involved in modulating microsaccade rate and direction after the appearance of a visual cue (referred to as microsaccade cueing modulation). Although the neural mechanisms underlying microsaccade cueing modulations have been demonstrated in monkeys, limited research has investigated a causal role of these areas in humans. By applying continuous theta-burst transcranial magnetic stimulation (cTBS) over the right FEF and vertex, we investigated the role of human FEF in modulating microsaccade responses after the appearance of a visual target in a visual- and memory-delay saccade task. After target appearance, microsaccade rate was initially suppressed but then increased in both cTBS conditions. More importantly, in the visual-delay task, microsaccades after target appearance were directed to the ipsilateral side more often with FEF, compared to vertex stimulation. Moreover, microsaccades were directed towards the target location, then to the opposite location of the target in both tasks, with larger effects in the visual-, compared to, memory-delay task. This microsaccade direction modulation was delayed after FEF stimulation in the memory-delay task. Overall, some microsaccade cueing modulations were moderately disrupted after FEF cTBS, suggesting a causal role for involvement of the human FEF in microsaccade generation after presentation of salient stimuli, Revisión por pares

Inherited retinal degenerative diseases are a prominent cause of blindness. Although mutations causing death of photoreceptors are mostly known, the pathophysiology downstream in the inner retina and along the visual pathway is incompletely characterized in the earliest disease stages. Here, we investigated retinal, midbrain and cortical visual function using electroretinography (ERG), the optomotor response (OMR), visual evoked potentials (VEPs), respectively, and single unit electrophysiology at the primary visual cortex (V1) in light-adapted juvenile (approximately one-month-old) and young adult (three-month-old) Rho P23H/WT mice, representative of early-stage retinitis pigmentosa (RP). Photopic ERG revealed up to ∼30% hypersensitivity to light in Rho P23H/WT mice, as measured by the light intensity required to generate half-maximal b-wave (I50 parameter). Rho P23H/WT mice also showed increased OMRs toward low spatial frequency (SF) drifting gratings, indicative of visual overexcitation at the midbrain level. At the V1 level, VEPs and single-cell recordings revealed prominent hyperexcitability in the juvenile Rho P23H/WT mice. Mean VEP amplitudes for light ON stimuli were nearly doubled in one-month-old Rho P23H/WT mice compared with controls, and more than doubled for light OFF. Single-cell recordings showed a significantly increased spontaneous V1 neuron firing in the Rho P23H/WT mice, and persistent contrast and temporal sensitivities. In contrast, direction selectivity was severely compromised. Our data suggest that during early RP, the visual pathway becomes hyperexcited. This could have both compensatory and deleterious consequences for visual behavior. Further studies on the mechanisms of hyperexcitability are warranted as this could lead to therapeutic interventions for RP.

Inherited retinal degenerative diseases are a prominent cause of blindness. Although mutations causing death of photoreceptors are mostly known, the pathophysiology downstream in the inner retina and along the visual pathway is incompletely characterized in the earliest disease stages. Here, we investigated retinal, midbrain and cortical visual function using electroretinography (ERG), the optomotor response (OMR), visual evoked potentials (VEPs), respectively, and single unit electrophysiology at the primary visual cortex (V1) in light-adapted juvenile (approximately one-month-old) and young adult (three-month-old) Rho P23H/WT mice, representative of early-stage retinitis pigmentosa (RP). Photopic ERG revealed up to ∼30% hypersensitivity to light in Rho P23H/WT mice, as measured by the light intensity required to generate half-maximal b-wave (I50 parameter). Rho P23H/WT mice also showed increased OMRs toward low spatial frequency (SF) drifting gratings, indicative of visual overexcitation at the midbrain level. At the V1 level, VEPs and single-cell recordings revealed prominent hyperexcitability in the juvenile Rho P23H/WT mice. Mean VEP amplitudes for light ON stimuli were nearly doubled in one-month-old Rho P23H/WT mice compared with controls, and more than doubled for light OFF. Single-cell recordings showed a significantly increased spontaneous V1 neuron firing in the Rho P23H/WT mice, and persistent contrast and temporal sensitivities. In contrast, direction selectivity was severely compromised. Our data suggest that during early RP, the visual pathway becomes hyperexcited. This could have both compensatory and deleterious consequences for visual behavior. Further studies on the mechanisms of hyperexcitability are warranted as this could lead to therapeutic interventions for RP.

Rodent hippocampus is believed to be critically involved in generating selectivity to allocentric space, called place cells, which are abstract and prospective. Such responses are thought to require both distal visual cues and self-motion cues. In primates, however, hippocampal neurons encode object-place association without any locomotion requirements. We explored the contributions of distal visual cues and proximal olfactory and self-motion cues on hippocampal firing. Our unique VR design allowed us to dissociate the contributions of distal visual cues and head movements on hippocampal firing. We found that a third of the neurons showed selective responses with respect to head movements. This head movement selectivity was found in experiments where the animal performed navigational tasks in the VR. These results suggest that multisensory association present in the real world plays a stronger role in hippocampal firing than navigational demands tied to virtual navigation. Our work furthers the understanding of multi-sensory contributions to hippocampal firing.

This study evaluates in terms of reliability, internal consistency, and validity a modification of the Adult Developmental Eye Movement (ADEM) test, ADEM with distractors (ADEMd), designed to analyse oculomotor system, visual processing and visual attentional behaviour. 302 healthy subjects participated in the study (20–86 years old). Intrasession repeatability was evaluated by analysing the correlation between the time needed to read different parts of the test. Inter-session analyses were carried in 40 subjects by calculating intraclass correlation coefficients and using the Bland–Altman method. Validity was assessed in the outcomes obtained according to age as well as investigating the correlation between ADEMd and attentional useful field of vision (UFOV) test. Correlation coefficients between times need to read each sheet were ≥ 0.95 (p < 0.001). The inter-session intraclass correlation coefficient ranged from 0.81 in the horizontal distractor sheet to 0.97 in the vertical sheet. Bland–Altman analysis showed clinically acceptable limits of agreement. Statistically significant correlations were found between age and ADEMd outcomes (r ≥ 0.55, p < 0.001). Processing velocity, divided attention and selective attention measured with the UFOV were correlated with the horizontal distractor times (r ≥ 0.32, p < 0.001). ADEMd test may be a useful clinical tool to evaluate the combined interaction of ocular movements and visual attentional behaviour.

Predictive coding provides a computational paradigm for modeling perceptual processing as the construction of representations accounting for causes of sensory inputs. Here, we developed a scalable, deep network architecture for predictive coding that is trained using a gated Hebbian learning rule and mimics the feedforward and feedback connectivity of the cortex. After training on image datasets, the models formed latent representations in higher areas that allowed reconstruction of the original images. We analyzed low- and high-level properties such as orientation selectivity, object selectivity and sparseness of neuronal populations in the model. As reported experimentally, image selectivity increased systematically across ascending areas in the model hierarchy. Depending on the strength of regularization factors, sparseness also increased from lower to higher areas. The results suggest a rationale as to why experimental results on sparseness across the cortical hierarchy have been inconsistent. Finally, representations for different object classes became more distinguishable from lower to higher areas. Thus, deep neural networks trained using a gated Hebbian formulation of predictive coding can reproduce several properties associated with neuronal responses along the visual cortical hierarchy.

Rodent hippocampus is believed to be critically involved in generating selectivity to allocentric space, called place cells, which are abstract and prospective. Such responses are thought to require both distal visual cues and self-motion cues. In primates, however, hippocampal neurons encode object-place association without any locomotion requirements. We explored the contributions of distal visual cues and proximal olfactory and self-motion cues on hippocampal firing. Our unique VR design allowed us to dissociate the contributions of distal visual cues and head movements on hippocampal firing. We found that a third of the neurons showed selective responses with respect to head movements. This head movement selectivity was found in experiments where the animal performed navigational tasks in the VR. These results suggest that multisensory association present in the real world plays a stronger role in hippocampal firing than navigational demands tied to virtual navigation. Our work furthers the understanding of multi-sensory contributions to hippocampal firing.

Predictive coding provides a computational paradigm for modeling perceptual processing as the construction of representations accounting for causes of sensory inputs. Here, we developed a scalable, deep network architecture for predictive coding that is trained using a gated Hebbian learning rule and mimics the feedforward and feedback connectivity of the cortex. After training on image datasets, the models formed latent representations in higher areas that allowed reconstruction of the original images. We analyzed low- and high-level properties such as orientation selectivity, object selectivity and sparseness of neuronal populations in the model. As reported experimentally, image selectivity increased systematically across ascending areas in the model hierarchy. Depending on the strength of regularization factors, sparseness also increased from lower to higher areas. The results suggest a rationale as to why experimental results on sparseness across the cortical hierarchy have been inconsistent. Finally, representations for different object classes became more distinguishable from lower to higher areas. Thus, deep neural networks trained using a gated Hebbian formulation of predictive coding can reproduce several properties associated with neuronal responses along the visual cortical hierarchy.

This study evaluates in terms of reliability, internal consistency, and validity a modification of the Adult Developmental Eye Movement (ADEM) test, ADEM with distractors (ADEMd), designed to analyse oculomotor system, visual processing and visual attentional behaviour. 302 healthy subjects participated in the study (20–86 years old). Intrasession repeatability was evaluated by analysing the correlation between the time needed to read different parts of the test. Inter-session analyses were carried in 40 subjects by calculating intraclass correlation coefficients and using the Bland–Altman method. Validity was assessed in the outcomes obtained according to age as well as investigating the correlation between ADEMd and attentional useful field of vision (UFOV) test. Correlation coefficients between times need to read each sheet were ≥ 0.95 (p < 0.001). The inter-session intraclass correlation coefficient ranged from 0.81 in the horizontal distractor sheet to 0.97 in the vertical sheet. Bland–Altman analysis showed clinically acceptable limits of agreement. Statistically significant correlations were found between age and ADEMd outcomes (r ≥ 0.55, p < 0.001). Processing velocity, divided attention and selective attention measured with the UFOV were correlated with the horizontal distractor times (r ≥ 0.32, p < 0.001). ADEMd test may be a useful clinical tool to evaluate the combined interaction of ocular movements and visual attentional behaviour.

Visual processing in humans is done by integrating and updating multiple streams of global and local sensory input. Interaction between these two systems can be disrupted in individuals with ASD and other learning disabilities. When this integration is not done smoothly, it becomes difficult to see the “big picture”, which has been found to have implications on emotion recognition, social skills, and conversation skills. An example of this phenomenon is local interference, which is when local details are prioritized over the global features. Previous research in this field has aimed to decrease local interference by developing and evaluating a filter to help direct ASD patients towards normative processing of the global features in images. Within this process, this research focuses on whether an image’s spatial frequency was affected by the filter and how spatial frequency impacted the filter’s functionality. Spatial frequency can be defined as a measure of the periodic distribution of light versus dark in image. In this work, we isolated “hot spots”, which are areas in the image where the eye gaze of normative individuals fixated. Using the OpenCV package in Python, I implemented an algorithm to detect hotspots and draw a contour around each one. I then drew rectangles around the contours in each image and calculated the spatial frequency within each rectangle. Statistical analysis will reveal whether the spatial frequency of hot spots had an impact on the differences in normative and ASD fixations. We plan to use these findings to improve the image filter and conduct further research in this field.

Visual processing abnormalities in schizophrenia (SZ) are poorly understood, yet predict functional outcomes in the disorder. Bipolar disorder (BD) may involve similar visual processing deficits. Converging evidence suggests that visual processing may be relatively normal at early stages of visual processing such as early visual cortex (EVC), but that processing abnormalities may become more pronounced by mid-level visual areas such as lateral occipital cortex (LO). However, little is known about the connectivity of the visual system in SZ and BD. If the flow of information to, from, or within the visual system is disrupted by reduced connectivity, this could help to explain perceptual deficits. In the present study, we performed a targeted analysis of the structural and functional connectivity of the visual system using graph-theoretic metrics in a sample of 48 SZ, 46 BD, and 47 control participants. Specifically, we calculated parallel measures of local efficiency for EVC and LO from both diffusion weighted imaging data (structural) and resting-state (functional) imaging data. We found no structural connectivity differences between the groups. However, there was a significant group difference in functional connectivity and a significant group-by-region interaction driven by reduced LO connectivity in SZ relative to HC, whereas BD was approximately intermediate to the other 2 groups. We replicated this pattern of results using a different brain atlas. These findings support and extend theoretical models of perceptual dysfunction in SZ, providing a framework for further investigation of visual deficits linked to functional outcomes in SZ and related disorders.

BACKGROUND: An increasing number of children are suffering from brain damage-related visual processing dysfunctions (VPD). There is currently a lack of evidence-based intervention methods that can be used early in development. We developed a visual intervention protocol suitable from 1 year of age. The protocol is structured, comprehensive and individually adaptive, and is paired with quantitative outcome assessments. Our aim is to investigate the effectiveness of this first visual intervention program for young children with (a risk of) VPD. METHODS: This is a single-blind, placebo-controlled trial that is embedded within standard clinical care. The study population consists of 100 children born very or extremely preterm (< 30 weeks) at 1 year of corrected age (CA), of whom 50% are expected to have VPD. First, children undergo a visual screening at 1 year CA. If they are classified as being at risk of VPD, they are referred to standard care, which involves an ophthalmic and visual function assessment and a (newly developed) visual intervention program. This program consists of a general protocol (standardized and similar for all children) and a supplement protocol (adapted to the specific needs of the child). Children are randomly allocated to an intervention group (starting upon inclusion at 1 year CA) or a control group (postponed: starting at 2 years CA). The control group will receive a placebo treatment. The effectiveness of early visual intervention will be examined with follow-up visual and neurocognitive assessments after 1 year (upon completion of the direct intervention) and after 2 years (upon completion of the postponed intervention). DISCUSSION: Through this randomized controlled trial we will establish the effectiveness of a new and early

La literatura científica reciente sobre el procesamiento de la información visual en el Trastorno del Espectro Autista (TEA), ha puesto en entredicho el déficit en la coherencia central del procesamiento de la información visual, aportando evidencias de su capacidad para el procesamiento global de la información, pero con una tendencia al procesamiento local o fragmentado. En el presente estudio se ha empleo la tarea de copia del Test de la Figura Compleja de Rey-Osterrieth con una muestra de 14 niños de entre 8 y 10 años con diagnóstico de TEA grado 1, Síndrome de Asperger. El objetivo ha sido examinar el rendimiento general en el test, así como las estrategias organizativas para la reproducción del diseño con respecto al procesamiento local versus global. Los resultados indican que los niños con TEA emplean un estilo de copia por yuxtaposición por detalles y tienen una tendencia a fragmentar los elementos de diseño global, llamados elementos de configuración. La conclusión del presente estudio es que la definición de yuxtaposición por detalles podría contribuir a la hora de corregir la figura, así como para obtener evidencias acerca del estilo de procesamiento de la información visual. Por tanto, esta nueva definición de yuxtaposición por detalles, se podría considerar como una variable significativa para el diagnóstico del TEA., Recent scientific literature focusing on the processing of visual information regarding Autism Spectrum Disorder (ASD) has called into question the shortfall in rationality of processing visual information, contributing evidence of this capacity for global information processing but with an inclination to local or fragmented processing. In this study, the Rey- Osterrieth Complex Figure Test was used, with a sample size of 14 children between 8 and 10 years old of whom were diagnosed with grade one ASD, Asperger’s Syndrome; to examine the general performance of the test, as well as the organisational strategies for the reproduction of the design with regards to local versus global processing by obtaining as a result, style copies by association of details and a propensity to fragment the global design elements called configuration elements. In addition, a new contribution has been made to the definition of juxtaposition by details that could contribute when correcting the figure, as well as obtaining evidence about the visual information processing style of the evaluated person. Therefore, this new definition of juxtaposition by details could be considered a significant variable for the diagnosis of ASD.

Visual processing abnormalities in schizophrenia (SZ) are poorly understood, yet predict functional outcomes in the disorder. Bipolar disorder (BD) may involve similar visual processing deficits. Converging evidence suggests that visual processing may be relatively normal at early stages of visual processing such as early visual cortex (EVC), but that processing abnormalities may become more pronounced by mid-level visual areas such as lateral occipital cortex (LO). However, little is known about the connectivity of the visual system in SZ and BD. If the flow of information to, from, or within the visual system is disrupted by reduced connectivity, this could help to explain perceptual deficits. In the present study, we performed a targeted analysis of the structural and functional connectivity of the visual system using graph-theoretic metrics in a sample of 48 SZ, 46 BD, and 47 control participants. Specifically, we calculated parallel measures of local efficiency for EVC and LO from both diffusion weighted imaging data (structural) and resting-state (functional) imaging data. We found no structural connectivity differences between the groups. However, there was a significant group difference in functional connectivity and a significant group-by-region interaction driven by reduced LO connectivity in SZ relative to HC, whereas BD was approximately intermediate to the other 2 groups. We replicated this pattern of results using a different brain atlas. These findings support and extend theoretical models of perceptual dysfunction in SZ, providing a framework for further investigation of visual deficits linked to functional outcomes in SZ and related disorders.

Several fundamental aspects of motion vision circuitry are prevalent across flies and mice. Both taxa segregate ON and OFF signals. For any given spatial pattern, motion detectors in both taxa are tuned to speed, selective for one of four cardinal directions, and modulated by catecholamine neurotransmitters. These similarities represent conserved, canonical properties of the functional circuits and computational algorithms for motion vision. Less is known about feature detectors, including how receptive field properties differ from the motion pathway or whether they are under neuromodulatory control to impart functional plasticity for the detection of salient objects from a moving background. Here, we investigated 19 types of putative feature selective lobula columnar (LC) neurons in the optic lobe of the fruit fly Drosophila melanogaster to characterize divergent properties of feature selection. We identified LC12 and LC15 as feature detectors. LC15 encodes moving bars, whereas LC12 is selective for the motion of discrete objects, mostly independent of size. Neither is selective for contrast polarity, speed, or direction, highlighting key differences in the underlying algorithms for feature detection and motion vision. We show that the onset of background motion suppresses object responses by LC12 and LC15. Surprisingly, the application of octopamine, which is released during flight, reverses the suppressive influence of background motion, rendering both LCs able to track moving objects superimposed against background motion. Our results provide a comparative framework for the function and modulation of feature detectors and new insights into the underlying neuronal mechanisms involved in visual feature detection.

Background: Early-stage visual processing deficits are evident in chronic schizophrenia. Consistent with a cascade model of information processing, whereby early perceptual processes have downstream effects on higher-order cognition, impaired visual processing is associated with deficits in social cognition in this clinical population. However, the nature of this relationship in the early phase of illness is unknown. Here, we present data from a study of early visual processing and social cognitive performance in recent-onset schizophrenia (ROSz). Method: Thirty-two people with ROSz and 20 healthy controls (HC) completed a visual backward masking task using stimuli of real world objects (Object Masking) to assess early-stage (i.e., 0–125 ms post-stimulus onset) visual processing. Subjects also completed two tasks of social cognition, one assessing relatively low-level processes of emotion identification (Emotion Biological Motion, EmoBio), and another assessing more complex, higher-order theory of mind abilities (The Awareness of Social Inference Test, TASIT). Group differences were tested with repeated measures ANOVAs and t-tests. Bivariate correlations and linear regressions tested the strength of associations between early-stage visual processing and social cognitive performance in ROSz. Results: For Object Masking, the mask interfered with object identification over a longer interval for ROSz than for HC [F (3.19, 159.35) = 8.51, p < 0.001]. ROSz were less accurate on the EmoBio task [t (50) = −3.36, p = 0.001] and on the TASIT compared to HC [F (1, 50) = 38.37, p < 0.001]. For the TASIT ROSz were disproportionately impaired on items assessing sarcasm detection [F (1, 50) = 4.30, p = 0.04]. In ROSz, better Object Masking performance was associated with better social cognitive performance [r EmoBio = 0.45, p < 0.01; r TASIT = 0.41, p < 0.02]. Regression analyses did not provide significant support for low-level social cognition mediating the relations

La literatura científica reciente sobre el procesamiento de la información visual en el Trastorno del Espectro Autista (TEA), ha puesto en entredicho el déficit en la coherencia central del procesamiento de la información visual, aportando evidencias de su capacidad para el procesamiento global de la información, pero con una tendencia al procesamiento local o fragmentado. En el presente estudio se ha empleo la tarea de copia del Test de la Figura Compleja de Rey-Osterrieth con una muestra de 14 niños de entre 8 y 10 años con diagnóstico de TEA grado 1, Síndrome de Asperger. El objetivo ha sido examinar el rendimiento general en el test, así como las estrategias organizativas para la reproducción del diseño con respecto al procesamiento local versus global. Los resultados indican que los niños con TEA emplean un estilo de copia por yuxtaposición por detalles y tienen una tendencia a fragmentar los elementos de diseño global, llamados elementos de configuración. La conclusión del presente estudio es que la definición de yuxtaposición por detalles podría contribuir a la hora de corregir la figura, así como para obtener evidencias acerca del estilo de procesamiento de la información visual. Por tanto, esta nueva definición de yuxtaposición por detalles, se podría considerar como una variable significativa para el diagnóstico del TEA., Recent scientific literature focusing on the processing of visual information regarding Autism Spectrum Disorder (ASD) has called into question the shortfall in rationality of processing visual information, contributing evidence of this capacity for global information processing but with an inclination to local or fragmented processing. In this study, the Rey- Osterrieth Complex Figure Test was used, with a sample size of 14 children between 8 and 10 years old of whom were diagnosed with grade one ASD, Asperger’s Syndrome; to examine the general performance of the test, as well as the organisational strategies for the reproduction of the design with regards to local versus global processing by obtaining as a result, style copies by association of details and a propensity to fragment the global design elements called configuration elements. In addition, a new contribution has been made to the definition of juxtaposition by details that could contribute when correcting the figure, as well as obtaining evidence about the visual information processing style of the evaluated person. Therefore, this new definition of juxtaposition by details could be considered a significant variable for the diagnosis of ASD.

Two themes have puzzled the research on developmental and learning disorders for decades. First, some of the risk and protective factors behind developmental challenges are suggested to be shared and some are suggested to be specific for a given condition. Second, language-based learning difficulties like dyslexia are suggested to result from or correlate with non-linguistic aspects of information processing as well. In the current study, we investigated how adults with developmental dyslexia or ADHD as well as healthy controls cluster across various dimensions designed to tap the prominent non-linguistic theories of dyslexia. Participants were 18–55-year-old adults with dyslexia (n = 36), ADHD (n = 22), and controls (n = 35). Non-linguistic theories investigated with experimental designs included temporal processing impairment, abnormal cerebellar functioning, procedural learning difficulties, as well as visual processing and attention deficits. Latent profile analysis (LPA) was used to investigate the emerging groups and patterns of results across these experimental designs. LPA suggested three groups: (1) a large group with average performance in the experimental designs, (2) participants predominantly from the clinical groups but with enhanced conditioning learning, and (3) participants predominantly from the dyslexia group with temporal processing as well as visual processing and attention deficits. Despite the presence of these distinct patterns, participants did not cluster very well based on their original status, nor did the LPA groups differ in their dyslexia or ADHD-related neuropsychological profiles. Remarkably, the LPA groups did differ in their intelligence. These results highlight the continuous and overlapping nature of the observed difficulties and support the multiple deficit model of developmental disorders, which suggests shared risk factors for developmental challenges. It also appears that some of the risk factors suggested by the prominent no, SCOPUS: ar.j, info:eu-repo/semantics/published

Visual information is crucial for postural control. Visual processing in children with autism spectrum disorder (ASD) was hypothesized to be less efficient and thus they would display a less stable standing posture than typically developing children. The present study compared the static standing responses and attentional demands of 15 children with ASD and 18 control participants in conditions of eyes open and eyes closed. The results showed that postural responses and attention invested in standing were similar between the participant groups in the two visual conditions. Both groups displayed a more stable posture when their eyes were open in comparison to eyes closed. The finding suggests that normal postural control development could occur in children with ASD., Article type: Brief Report.

This article used an empirical experiment and a computationalmodel to test the hypothesis that humans rely on the visualsystem to solve the traveling salesperson problem (TSP). Wetested two consequences of this hypothesis: (1) humans shouldperform better on Euclidean TSP than not–Euclidean TSP; (2)a model of the visual system should account for performance inEuclidean TSP. Participants were asked to solve Euclidean ornot–Euclidean TSP, and a pyramid model of the visual systemwas used to solve the same tours as the humans. The resultsshow that deviations from the optimal tour were smaller in Eu-clidean problems than in not–Euclidean problems, and the fitof the pyramid model to human performance was worse onnot–Euclidean problems then on Euclidean problems. Theseresults suggest that participants solve Euclidean problems withthe visual system, but that other mechanisms are needed to suc-cesfully solve non–visual problems.

The purpose of this research is to address the nature of high-level processing within visual perception. In particular, results from the visual processing of biological motion will be used to discuss the role of attention in high-level vision and visual consciousness. Original results from 3 priming experiments indicate “automatic” high-level semantic activation in biological motion perception. The view presented here is discussed in the context of Prinz’s (2000, 2003) AIR-theory. AIR stands for Attended Intermediate-level Representations and claims that visual consciousness resides at the level of intermediate-level representations. In contrast, the view presented here is that results from behavioral and neuroscientific studies of biological motion suggest that visual consciousness occurs at high cortical levels. Moreover, the Reverse Hierarchy Theory of Hochstein and Ahissar (2002) asserts that spread attention in high cortical areas is indicative of what they term “vision at a glance.” The gist of their theory is that explicit high-level visual processing involves initial feedforward mechanisms that implicitly follow a bottom-up hierarchical pathway. The end product of the processing, and the beginning of explicit visual perception, is conscious access to perceptual content in high-level cortical areas. Finally, I discuss the specific claims in AIR and present objections to Prinz’s arguments for why high-level visual processors are not good candidates for the locale of consciousness. In conclusion, the central claim of AIR with an emphasis on the connection between intermediate level representations and perceptual awareness seems to be too strong, and the arguments against high-level perceptual awareness are not convincing

First published: 09 December 2019, In order to extract the regularities underlying a continuous sensory input, the individual elements constituting the stream have to be encoded and their transitional probabilities (TPs) should be learned. This suggests that variance in statistical learning (SL) performance reflects efficiency in encoding representations as well as efficiency in detecting their statistical properties. These processes have been taken to be independent and temporally modular, where first, elements in the stream are encoded into internal representations, and then the co-occurrences between them are computed and registered. Here, we entertain a novel hypothesis that one unifying construct—the rate of information in the sensory input—explains learning performance. This theoretical approach merges processes related to encoding of events and those related to earning their regularities into a single computational principle. We present data from two large-scale experiments with over 800 participants tested in support for this hypothesis, showing that rate of information in a visual stream clearly predicts SL performance, and that similar rate of information values leads to similar SL performance. We discuss the implications for SL theory and its relation to regularity learning.

Studies of context effects in speech production have shown that semantic feature overlap produces interference in naming of categorically related objects. In neuroimaging studies, this semantic interference effect is consistently associated with involvement of left superior and middle temporal gyri. However, at least part of this effect has recently been shown to be attributable to visual form similarity, as categorically related objects typically share visual features. This fMRI study examined interference produced by visual form overlap in the absence of a category relation in a picture–word interference paradigm. Both visually similar and visually dissimilar distractors led to increased BOLD responses in the left inferior frontal gyrus compared with the congruent condition. Naming pictures in context with a dis- tractor word denoting an object visually similar in form slowed RTs compared with unrelated words and was associated with reduced activity in the left posterior middle temporal gyrus. This area is reliably observed in lexical level processing during language production tasks. No significant differential activity was observed in areas typically engaged by early perceptual or conceptual feature level processing or in areas proposed to be engaged by postlexical language processes, suggesting that visual form interference does not arise from uncertainty or confusion during perceptual or conceptual identification or after lexical processing. We conclude that visual form interference has a lexical locus, consistent with the predictions of competitive lexical selection models.

First published: 09 December 2019, In order to extract the regularities underlying a continuous sensory input, the individual elements constituting the stream have to be encoded and their transitional probabilities (TPs) should be learned. This suggests that variance in statistical learning (SL) performance reflects efficiency in encoding representations as well as efficiency in detecting their statistical properties. These processes have been taken to be independent and temporally modular, where first, elements in the stream are encoded into internal representations, and then the co-occurrences between them are computed and registered. Here, we entertain a novel hypothesis that one unifying construct—the rate of information in the sensory input—explains learning performance. This theoretical approach merges processes related to encoding of events and those related to earning their regularities into a single computational principle. We present data from two large-scale experiments with over 800 participants tested in support for this hypothesis, showing that rate of information in a visual stream clearly predicts SL performance, and that similar rate of information values leads to similar SL performance. We discuss the implications for SL theory and its relation to regularity learning.

The purpose of this research is to address the nature of high-level processing within visual perception. In particular, results from the visual processing of biological motion will be used to discuss the role of attention in high-level vision and visual consciousness. Original results from 3 priming experiments indicate “automatic” high-level semantic activation in biological motion perception. The view presented here is discussed in the context of Prinz’s (2000, 2003) AIR-theory. AIR stands for Attended Intermediate-level Representations and claims that visual consciousness resides at the level of intermediate-level representations. In contrast, the view presented here is that results from behavioral and neuroscientific studies of biological motion suggest that visual consciousness occurs at high cortical levels. Moreover, the Reverse Hierarchy Theory of Hochstein and Ahissar (2002) asserts that spread attention in high cortical areas is indicative of what they term “vision at a glance.” The gist of their theory is that explicit high-level visual processing involves initial feedforward mechanisms that implicitly follow a bottom-up hierarchical pathway. The end product of the processing, and the beginning of explicit visual perception, is conscious access to perceptual content in high-level cortical areas. Finally, I discuss the specific claims in AIR and present objections to Prinz’s arguments for why high-level visual processors are not good candidates for the locale of consciousness. In conclusion, the central claim of AIR with an emphasis on the connection between intermediate level representations and perceptual awareness seems to be too strong, and the arguments against high-level perceptual awareness are not convincing

Two types of mammalian direction-selective ganglion cells (DSGCs), ON and ONOFF, operate over different speed ranges. The directional axes of the ON-DSGCs are thought to align with the axes of the vestibular system and provide sensitivity at rotational velocities that are too slow to activate the semicircular canals. ONOFF-DSGCs respond to faster image velocities. Using natural images that simulate the natural visual inputs to freely moving animals, we show that simulated visual saccades suppress responses in ON-DSGCs but not ONOFF-DSGCs recorded in retinas of domestic rabbits of either gender. Analysis of the synaptic inputs shows that this saccadic suppression results from glycinergic inputs that are specific to ON-DSGCs and are absent in ONOFF-DSGCs. When this glycinergic input is blocked, both cell types respond similarly to visual saccades and display essentially identical speed tuning. The results demonstrate that glycinergic circuits within the retina can produce saccadic suppression of retinal ganglion cell activity. The cell-type-specific targeting of the glycinergic circuits further supports the proposed physiological roles of ON-DSGCs in retinal-image stabilization and of ONOFF-DSGCs in detecting local object motion and signaling optical flow.SIGNIFICANCE STATEMENT In the mammalian retina, ON direction-selective ganglion cells (DSGCs) respond preferentially to slow image motion, whereas ONOFF-DSGCs respond better to rapid motion. The mechanisms producing this different speed tuning remain unclear. Here we show that simulated visual saccades suppress ON-DSGCs, but not ONOFF-DSGCs. This selective saccadic suppression is because of the selective targeting of glycinergic inhibitory synaptic inputs to ON-DSGCs. The different saccadic suppression in the two cell types points to different physiological roles, consistent with their projections to distinct areas within the brain. ON-DSGCs may be critical for providing the visual feedback signals that contribute to

First published: 09 December 2019, In order to extract the regularities underlying a continuous sensory input, the individual elements constituting the stream have to be encoded and their transitional probabilities (TPs) should be learned. This suggests that variance in statistical learning (SL) performance reflects efficiency in encoding representations as well as efficiency in detecting their statistical properties. These processes have been taken to be independent and temporally modular, where first, elements in the stream are encoded into internal representations, and then the co-occurrences between them are computed and registered. Here, we entertain a novel hypothesis that one unifying construct—the rate of information in the sensory input—explains learning performance. This theoretical approach merges processes related to encoding of events and those related to earning their regularities into a single computational principle. We present data from two large-scale experiments with over 800 participants tested in support for this hypothesis, showing that rate of information in a visual stream clearly predicts SL performance, and that similar rate of information values leads to similar SL performance. We discuss the implications for SL theory and its relation to regularity learning.

The purpose of this research is to address the nature of high-level processing within visual perception. In particular, results from the visual processing of biological motion will be used to discuss the role of attention in high-level vision and visual consciousness. Original results from 3 priming experiments indicate “automatic” high-level semantic activation in biological motion perception. The view presented here is discussed in the context of Prinz’s (2000, 2003) AIR-theory. AIR stands for Attended Intermediate-level Representations and claims that visual consciousness resides at the level of intermediate-level representations. In contrast, the view presented here is that results from behavioral and neuroscientific studies of biological motion suggest that visual consciousness occurs at high cortical levels. Moreover, the Reverse Hierarchy Theory of Hochstein and Ahissar (2002) asserts that spread attention in high cortical areas is indicative of what they term “vision at a glance.” The gist of their theory is that explicit high-level visual processing involves initial feedforward mechanisms that implicitly follow a bottom-up hierarchical pathway. The end product of the processing, and the beginning of explicit visual perception, is conscious access to perceptual content in high-level cortical areas. Finally, I discuss the specific claims in AIR and present objections to Prinz’s arguments for why high-level visual processors are not good candidates for the locale of consciousness. In conclusion, the central claim of AIR with an emphasis on the connection between intermediate level representations and perceptual awareness seems to be too strong, and the arguments against high-level perceptual awareness are not convincing

The purpose of this research is to address the nature of high-level processing within visual perception. In particular, results from the visual processing of biological motion will be used to discuss the role of attention in high-level vision and visual consciousness. Original results from 3 priming experiments indicate “automatic” high-level semantic activation in biological motion perception. The view presented here is discussed in the context of Prinz’s (2000, 2003) AIR-theory. AIR stands for Attended Intermediate-level Representations and claims that visual consciousness resides at the level of intermediate-level representations. In contrast, the view presented here is that results from behavioral and neuroscientific studies of biological motion suggest that visual consciousness occurs at high cortical levels. Moreover, the Reverse Hierarchy Theory of Hochstein and Ahissar (2002) asserts that spread attention in high cortical areas is indicative of what they term “vision at a glance.” The gist of their theory is that explicit high-level visual processing involves initial feedforward mechanisms that implicitly follow a bottom-up hierarchical pathway. The end product of the processing, and the beginning of explicit visual perception, is conscious access to perceptual content in high-level cortical areas. Finally, I discuss the specific claims in AIR and present objections to Prinz’s arguments for why high-level visual processors are not good candidates for the locale of consciousness. In conclusion, the central claim of AIR with an emphasis on the connection between intermediate level representations and perceptual awareness seems to be too strong, and the arguments against high-level perceptual awareness are not convincing

The purpose of this research is to address the nature of high-level processing within visual perception. In particular, results from the visual processing of biological motion will be used to discuss the role of attention in high-level vision and visual consciousness. Original results from 3 priming experiments indicate “automatic” high-level semantic activation in biological motion perception. The view presented here is discussed in the context of Prinz’s (2000, 2003) AIR-theory. AIR stands for Attended Intermediate-level Representations and claims that visual consciousness resides at the level of intermediate-level representations. In contrast, the view presented here is that results from behavioral and neuroscientific studies of biological motion suggest that visual consciousness occurs at high cortical levels. Moreover, the Reverse Hierarchy Theory of Hochstein and Ahissar (2002) asserts that spread attention in high cortical areas is indicative of what they term “vision at a glance.” The gist of their theory is that explicit high-level visual processing involves initial feedforward mechanisms that implicitly follow a bottom-up hierarchical pathway. The end product of the processing, and the beginning of explicit visual perception, is conscious access to perceptual content in high-level cortical areas. Finally, I discuss the specific claims in AIR and present objections to Prinz’s arguments for why high-level visual processors are not good candidates for the locale of consciousness. In conclusion, the central claim of AIR with an emphasis on the connection between intermediate level representations and perceptual awareness seems to be too strong, and the arguments against high-level perceptual awareness are not convincing

Sensory processing difficulties affect the development of sensorimotor skills in individuals with autism spectrum disorder (ASD). However, the effect of sensory information on postural control is unclear in the ASD adult population. The present study examined the effect of visual information on postural control as well as the attentional demands associated with postural control in fourteen adults with ASD and seventeen typically developed adults. The results showed that postural sway and attention demands of postural control were larger in adults with ASD than in typically developed adults. These findings indicate that visual processing used for postural control may be different in adults with ASD. Further research in visual field processing and visual motion processing may elucidate these sensorimotor differences.

The purpose of this research is to address the nature of high-level processing within visual perception. In particular, results from the visual processing of biological motion will be used to discuss the role of attention in high-level vision and visual consciousness. Original results from 3 priming experiments indicate “automatic” high-level semantic activation in biological motion perception. The view presented here is discussed in the context of Prinz’s (2000, 2003) AIR-theory. AIR stands for Attended Intermediate-level Representations and claims that visual consciousness resides at the level of intermediate-level representations. In contrast, the view presented here is that results from behavioral and neuroscientific studies of biological motion suggest that visual consciousness occurs at high cortical levels. Moreover, the Reverse Hierarchy Theory of Hochstein and Ahissar (2002) asserts that spread attention in high cortical areas is indicative of what they term “vision at a glance.” The gist of their theory is that explicit high-level visual processing involves initial feedforward mechanisms that implicitly follow a bottom-up hierarchical pathway. The end product of the processing, and the beginning of explicit visual perception, is conscious access to perceptual content in high-level cortical areas. Finally, I discuss the specific claims in AIR and present objections to Prinz’s arguments for why high-level visual processors are not good candidates for the locale of consciousness. In conclusion, the central claim of AIR with an emphasis on the connection between intermediate level representations and perceptual awareness seems to be too strong, and the arguments against high-level perceptual awareness are not convincing

Although vision is the dominant sense in humans, the brain's capacity to process visual information is severely limited. We use visual attention to dynamically allocate the limited processing capacity to the most relevant information at any given time. Doing so, we prioritize its processing by concentrating neural resources on the attended information Attentional selection of visual information can be based on the spatial location of information (spatial attention) or based on a visual feature, like color, orientation or numerosity, i.e. the amount of a items in a set (feature attention). A recent computational model of attention, the attention field model, predicts that attentional selection acts both like a spotlight by increasing neural responses to the attended information and like a magnifying glass by enlarging the neural representation of the attended information. However, although the spotlight concept has received sufficient empirical support, the empirical evidence supporting the concept of attention as a magnifying glass in humans is currently limited. In this thesis we investigate attentional magnification in humans. In Chapter 2 we use spatial attention to demonstrate that it indeed acts like a magnifying glass on visual information. We show that spatial attention attracts population receptive fields (pRFs; Dumoulin and Wandell, 2008) towards its location across the entire visual field and hierarchy. Doing so, more receptive fields cover the attended information, which enlarges its neural representation. Furthermore, the results from this chapter also raise the possibility that spatial attention acts like a constant influence on visual processing across the entire visual cortex. In Chapter 3 we show that both a feed forward and feedback mechanism underlies this attentional magnification. As feed forward and feedback processes are segregated across cortical depth in human V1, we use high-resolution fMRI to measure attentional magnification a

This study examined the processing of derivational morphology and its association with measures of morphological awareness and literacy outcomes in 30 Dutch-speaking high-functioning dyslexics, and 30 controls, matched for age and reading comprehension. A masked priming experiment was conducted where the semantic overlap between morphologically related pairs was manipulated as part of a lexical decision task. Measures of morphological awareness were assessed using a specifically designed sentence completion task. Significant priming effects were found in each group, yet adults with dyslexia were found to benefit more from the morphological structure than the controls. Adults with dyslexia were found to be influenced by both form (morpho-orthographic) and meaning (morphosemantic) properties of morphemes while controls were mainly influenced by morphosemantic properties. The reports suggest that morphological processing is intact in high-functioning dyslexics and a strength when compared to controls matched for reading comprehension and age. Thus, reports support morphological processing as a potential factor in the reading compensation of adults with dyslexia. However, adults with dyslexia performed significantly worse than controls on morphological awareness measures.

Full Text, Thesis (PhD Doctorate), Doctor of Philosophy (PhD), School of Applied Psychology, Griffith Health, Declines in performance on complex visual tasks have been shown to predict declines in functional independence and mobility in older adults, but the specific perceptual processing mechanisms that decline with age and lead to functional declines are not well understood. Two measures of perception shown to predict functional outcomes (e.g. safe driving) in older adults are measures of the Functional Field of View (FFOV) and of global coherent motion. Age-related change in capacity for the deployment of visual attention and sensitivity of the sub-cortical magnocellular (M) pathway were hypothesised to explain the FFOV and motion processing in older adults. The thesis therefore had four aims: 1) to investigate differences in the capacity of older and younger adults to use bottom-up and top-down attention in the performance of a FFOV task; 2) to investigate the association between FFOV performance and the sensitivity of the M pathway, particularly in older adults; 3) to investigate differences in the capacity of older and younger adults to use top-down attention to facilitate the perception of coherent motion; 4) to investigate the association between motion coherence thresholds and the sensitivity of the M pathway, particularly in older adults. Study 1 (Chapter 4) aimed to explore how manipulating attentional demands impacted the error rates for a FFOV task in older adults, and how the effect of age on the FFOV varied under different attentional conditions. A specially designed FFOV task with differing levels of bottom-up and top-down attentional demands was conducted using a sample of 42 younger (M = 27.38 years, SD = 5.41 years, 21 women) and 42 older (M = 72.11 years, SD = 5.92 years, 23 women) adults. Older adults had higher error rates in all conditions and the effect of age did not vary across conditions indicating similar capacity to attend to and ignore salient peripheral stimuli in older and younger adults. The performance cost of dividing attention between cen

Vision research has been shaped by the seminal insight that we can understand the higher-tier visual cortex from the perspective of multiple functional pathways with different goals. In this paper, we try to give a computational account of the functional organization of this system by reasoning from the perspective of multi-task deep neural networks. Machine learning has shown that tasks become easier to solve when they are decomposed into subtasks with their own cost function. We hypothesize that the visual system optimizes multiple cost functions of unrelated tasks and this causes the emergence of a ventral pathway dedicated to vision for perception, and a dorsal pathway dedicated to vision for action. To evaluate the functional organization in multi-task deep neural networks, we propose a method that measures the contribution of a unit towards each task, applying it to two networks that have been trained on either two related or two unrelated tasks, using an identical stimulus set. Results show that the network trained on the unrelated tasks shows a decreasing degree of feature representation sharing towards higher-tier layers while the network trained on related tasks uniformly shows high degree of sharing. We conjecture that the method we propose can be used to analyze the anatomical and functional organization of the visual system and beyond. We predict that the degree to which tasks are related is a good descriptor of the degree to which they share downstream cortical-units.

ObjectiveIndividuals with anorexia nervosa (AN) and body dysmorphic disorder (BDD) exhibit distorted perception and negative evaluations of their own appearance; however, little is known about how they perceive others' appearance, and whether or not the conditions share perceptual distortions.MethodThirty participants with BDD, 22 with AN, now weight-restored, and 39 healthy comparison participants (HC) rated photographs of others' faces and bodies on attractiveness, how overweight or underweight they were, and how much photographs triggered thoughts of their own appearance. We compared responses among groups by stimulus type and by level-of-detail (spatial frequency).ResultsCompared to HCs, AN and BDD had lower attractiveness ratings for others' bodies and faces for high-detail and low-detail images, rated bodies as more overweight, and were more triggered to think of their own appearance for faces and bodies. In AN, symptom severity was associated with greater triggering of thoughts of own appearance and higher endorsement of overweight ratings for bodies. In BDD, symptom severity was associated with greater triggering of thoughts of own appearance for bodies and higher overweight ratings for low-detail images. BDD was more triggered to think of own facial appearance than AN.DiscussionAN and BDD show similar behavioral phenotypes of negative appearance evaluations for others' faces and bodies, and have thoughts of their own appearance triggered even for images outside of their primary appearance concerns, suggesting a more complex cross-disorder body-image phenotype than previously assumed. Future treatment strategies may benefit from addressing how these individuals evaluate others in addition to themselves. © 2016 Wiley Periodicals, Inc.(Int J Eat Disord 2017; 50:127-138).

Vision research has been shaped by the seminal insight that we can understand the higher-tier visual cortex from the perspective of multiple functional pathways with different goals. In this paper, we try to give a computational account of the functional organization of this system by reasoning from the perspective of multi-task deep neural networks. Machine learning has shown that tasks become easier to solve when they are decomposed into subtasks with their own cost function. We hypothesize that the visual system optimizes multiple cost functions of unrelated tasks and this causes the emergence of a ventral pathway dedicated to vision for perception, and a dorsal pathway dedicated to vision for action. To evaluate the functional organization in multi-task deep neural networks, we propose a method that measures the contribution of a unit towards each task, applying it to two networks that have been trained on either two related or two unrelated tasks, using an identical stimulus set. Results show that the network trained on the unrelated tasks shows a decreasing degree of feature representation sharing towards higher-tier layers while the network trained on related tasks uniformly shows high degree of sharing. We conjecture that the method we propose can be used to analyze the anatomical and functional organization of the visual system and beyond. We predict that the degree to which tasks are related is a good descriptor of the degree to which they share downstream cortical-units.

Declines in performance on complex visual tasks have been shown to predict declines in functional independence and mobility in older adults, but the specific perceptual processing mechanisms that decline with age and lead to functional declines are not well understood. Two measures of perception shown to predict functional outcomes (e.g. safe driving) in older adults are measures of the Functional Field of View (FFOV) and of global coherent motion. Age-related change in capacity for the deployment of visual attention and sensitivity of the sub-cortical magnocellular (M) pathway were hypothesised to explain the FFOV and motion processing in older adults. The thesis therefore had four aims: 1) to investigate differences in the capacity of older and younger adults to use bottom-up and top-down attention in the performance of a FFOV task; 2) to investigate the association between FFOV performance and the sensitivity of the M pathway, particularly in older adults; 3) to investigate differences in the capacity of older and younger adults to use top-down attention to facilitate the perception of coherent motion; 4) to investigate the association between motion coherence thresholds and the sensitivity of the M pathway, particularly in older adults. Study 1 (Chapter 4) aimed to explore how manipulating attentional demands impacted the error rates for a FFOV task in older adults, and how the effect of age on the FFOV varied under different attentional conditions. A specially designed FFOV task with differing levels of bottom-up and top-down attentional demands was conducted using a sample of 42 younger (M = 27.38 years, SD = 5.41 years, 21 women) and 42 older (M = 72.11 years, SD = 5.92 years, 23 women) adults. Older adults had higher error rates in all conditions and the effect of age did not vary across conditions indicating similar capacity to attend to and ignore salient peripheral stimuli in older and younger adults. The performance cost of dividing attention between cen, Thesis (PhD Doctorate), Doctor of Philosophy (PhD), School of Applied Psychology, Griffith Health, Full Text

Real-world scenes contain low-level visual features (e.g., edges, colors) and high-level semantic features (e.g., objects and places). Traditional visual perception models assume that integration of low-level visual features and segmentation of the scene must occur before high-level semantics are perceived. This view implies that low-level visual features of a scene alone do not carry semantic information related to that scene. Here we present evidence that suggests otherwise. We show that high-level semantics can be preserved in low-level visual features, and that different high-level semantics can be preserved in different types of low-level visual features. Specifically, the ‘disorder’ of a scene is preserved in edge features better than color features, whereas the converse is true for ‘naturalness.’ These findings suggest that semantic processing may start earlier than thought before, and integration of low-level visual features and segmentation of the scene may occur after semantic processing has begun, or in parallel.