Visual Processing Functions Research Articles

Visual attention and processing function in relation to executive functioning in very preterm–born children aged 3 years: a prospective cohort study

The ability to orient attention to one’s environment is a prerequisite for developing executive functions (EF) from preschool age. Very preterm children are vulnerable for delays in visual orienting function (VOF) and EF deficits. This study aimed to investigate associations between objective VOF and subjective parent-reported EF in very preterm–born children at 3 years corrected age (CA). In a prospective cohort study (BOND) involving 90 children born < 30 weeks, VOF and EF were assessed using an eye tracking–based method and BRIEF-P questionnaire. Associations between abnormal VOF (viewing reaction times) and EF scores (BRIEF-P scores) were studied using multivariable regression. Using a modified Delphi method, a subset of eight items related to VOF and EF was explored. Abnormal VOF was observed in 31% of the children and abnormal global EF composite scores in 41%. Abnormal VOF was not associated with global or domain-level EF scores. However, children with abnormal VOF more frequently had EF problems related to attentional behavior: “easily sidetracked” (OR 4.18 (CI: 1.21–14.41), p = 0.02) and “short attention span” (OR 4.52 (CI: 1.34–15.22), p = 0.02). Conclusion: Although abnormal VOF was not associated with global, parent-reported, EF at 3 years CA, secondary analyses did show a relation to specific attention and concentration span items. Further research is needed to study the role of VOF in objectifying preschool EF assessments in very preterm born children. What is known:• Very preterm children are vulnerable for executive function (EF) deficits and for delays in visual orienting function, as compared to term-born children• The ability to orient attention to one’s visual environment is an important prerequisite for EF early in life and is easy to measure objectively with visual orienting function (VOF) assessmentWhat is new:• VOF measurement at 3 years of age relates to parent-reported attention and concentration span items, important aspects of executive functions• Future work should explore the clinical additional value of early VOF measurement in children at risk for EF deficits

Hue and orientation pinwheels in macaque area V4.

Area V4 is an intermediate-level area of the macaque visual cortical hierarchy that serves key functions in visual processing by integrating inputs from lower areas such as V1 and V2 and providing feedforward inputs to many higher cortical areas. Previous V4 imaging studies have focused on differential responses to color, orientation, disparity, and motion stimuli, but many details of the spatial organization of significant hue and orientation tuning have not been fully described. We used support vector machine (SVM) decoding of intrinsic cortical single-condition responses to generate high-resolution maps of hue and orientation tuning and to describe the organization of hue and orientation pinwheels in V4. Like V1 and V2, V4 contains maps of orientation that are organized as pinwheels. V4 also contains maps of hue that are organized as pinwheels, whose circular organization more closely represents the perception of hue than is observed in antecedent cortical areas. Unlike V1, where orientation is continuously mapped across the surface, V4 hue and orientation pinwheels are organized in limited numbers of pinwheel sequences. The organization of these sequences and the distance between pinwheels may provide insight into the functional organization of V4. Regions significantly tuned for hue occupy roughly four times that of the orientation, are largely separated from each other, and overlap by roughly 5%. This spatial organization is largely consistent with segregated inputs arising from V2 thin and interstripes. This modular organization of V4 suggests that further integration of color and shape might occur in higher areas in inferotemporal cortical.NEW & NOTEWORTHY The representation of hue and orientation in macaque monkey area V4 was determined by intrinsic cortical imaging of responses to isoluminant hues and achromatic grating stimuli. Vector summation of support vector machine (SVM) decoded single-condition responses was used to generate hue and orientation maps that, like V1 orientation maps, were both characterized by distinct pinwheel patterns. These data suggest that pinwheels are an important structure to represent different stimulus features across multiple visual cortical areas.

Horizontal-cell like Dm9 neurons in Drosophila modulate photoreceptor output to supply multiple functions in early visual processing.

Dm9 neurons in Drosophila have been proposed as functional homologs of horizontal cells in the outer retina of vertebrates. Here we combine genetic dissection of neuronal circuit function, two-photon calcium imaging in Dm9 and inner photoreceptors, and immunohistochemical analysis to reveal novel insights into the functional role of Dm9 in early visual processing. Our experiments show that Dm9 receive input from all four types of inner photoreceptor R7p, R7y, R8p, and R8y. Histamine released from all types R7/R8 directly inhibits Dm9 via the histamine receptor Ort, and outweighs simultaneous histamine-independent excitation of Dm9 by UV-sensitive R7. Dm9 in turn provides inhibitory feedback to all R7/R8, which is sufficient for color-opponent processing in R7 but not R8. Color opponent processing in R8 requires additional synaptic inhibition by R7 of the same ommatidium via axo-axonal synapses and the second Drosophila histamine receptor HisCl1. Notably, optogenetic inhibition of Dm9 prohibits color opponent processing in all types of R7/R8 and decreases intracellular calcium in photoreceptor terminals. The latter likely results from reduced release of excitatory glutamate from Dm9 and shifts overall photoreceptor sensitivity toward higher light intensities. In summary, our results underscore a key role of Dm9 in color opponent processing in Drosophila and suggest a second role of Dm9 in regulating light adaptation in inner photoreceptors. These novel findings on Dm9 are indeed reminiscent of the versatile functions of horizontal cells in the vertebrate retina.

Differential clustering of visual and choice- and saccade-related activity in macaque V3A and CIP.

Neurons in sensory and motor cortices tend to aggregate in clusters with similar functional properties. Within the primate dorsal ("where") pathway, an important interface between three-dimensional (3-D) visual processing and motor-related functions consists of two hierarchically organized areas: V3A and the caudal intraparietal (CIP) area. In these areas, 3-D visual information, choice-related activity, and saccade-related activity converge, often at the single-neuron level. Characterizing the clustering of functional properties in areas with mixed selectivity, such as these, may help reveal organizational principles that support sensorimotor transformations. Here we quantified the clustering of visual feature selectivity, choice-related activity, and saccade-related activity by performing correlational and parametric comparisons of the responses of well-isolated, simultaneously recorded neurons in macaque monkeys. Each functional domain showed statistically significant clustering in both areas. However, there were also domain-specific differences in the strength of clustering across the areas. Visual feature selectivity and saccade-related activity were more strongly clustered in V3A than in CIP. In contrast, choice-related activity was more strongly clustered in CIP than in V3A. These differences in clustering may reflect the areas' roles in sensorimotor processing. Stronger clustering of visual and saccade-related activity in V3A may reflect a greater role in within-domain processing, as opposed to cross-domain synthesis. In contrast, stronger clustering of choice-related activity in CIP may reflect a greater role in synthesizing information across functional domains to bridge perception and action.NEW & NOTEWORTHY The occipital and parietal cortices of macaque monkeys are bridged by hierarchically organized areas V3A and CIP. These areas support 3-D visual transformations, carry choice-related activity during 3-D perceptual tasks, and possess saccade-related activity. This study quantifies the functional clustering of neuronal response properties within V3A and CIP for each of these domains. The findings reveal domain-specific cross-area differences in clustering that may reflect the areas' roles in sensorimotor processing.

Hippocampal subfields and thalamic nuclei associations with clinical outcomes in multiple sclerosis: An ultrahigh field MRI study

BackgroundPrevious studies have shown that thalamic and hippocampal neurodegeneration is associated with clinical decline in Multiple Sclerosis (MS). However, contributions of the specific thalamic nuclei and hippocampal subfields require further examination. ObjectiveUsing 7 Tesla (7T) magnetic resonance imaging (MRI), we investigated the cross-sectional associations between functionally grouped thalamic nuclei and hippocampal subfields volumes and T1 relaxation times (T1-RT) and subsequent clinical outcomes in MS. MethodsHigh-resolution T1-weighted and T2-weighted images were acquired at 7T (n=31), preprocessed, and segmented using the Thalamus Optimized Multi Atlas Segmentation (THOMAS, for thalamic nuclei) and the Automatic Segmentation of Hippocampal Subfields (ASHS, for hippocampal subfields) packages. We calculated Pearson correlations between hippocampal subfields and thalamic nuclei volumes and T1-RT and subsequent multi-modal rater-determined and patient-reported clinical outcomes (∼2.5 years after imaging acquisition), correcting for confounders and multiple tests. ResultsSmaller volume bilaterally in the anterior thalamus region correlated with worse performance in gait function, as measured by the Patient Determined Disease Steps (PDDS). Additionally, larger volume in most functional groups of thalamic nuclei correlated with better visual information processing and cognitive function, as measured by the Symbol Digit Modalities Test (SDMT). In bilateral medial and left posterior thalamic regions, there was an inverse association between volumes and T1-RT, potentially indicating higher tissue degeneration in these regions. We also observed marginal associations between the right hippocampal subfields (both volumes and T1-RT) and subsequent clinical outcomes, though they did not survive correction for multiple testing. ConclusionUltrahigh field MRI identified markers of structural damage in the thalamic nuclei associated with subsequently worse clinical outcomes in individuals with MS. Longitudinal studies will enable better understanding of the role of microstructural integrity in these brain regions in influencing MS outcomes.

Biotin-cGMP and -cAMP are able to permeate through the gap junctions of some amacrine cells in the mouse retina despite their large size.

Gap junctions transmit electrical signals in neurons and serve metabolic coupling and chemical communication. Gap junctions are made of intercellular channels with large pores, allowing ions and small molecules to permeate. In the mammalian retina, intercellular coupling fulfills many vital functions in visual signal processing but is also implicated in promoting cell death after insults, such as excitotoxicity or hypoxia. Conversely, some studies also suggested a role for retinal gap junctions in neuroprotection. Recently, gap junctions were also advocated as conduits for therapeutic drug delivery in neurodegenerative disorders. This requires the permeation of rather large molecules through retinal gap junctions. However, the permeability of retinal networks for molecules >0.6 kDa has not been tested systematically. Here, we used the cut-loading method and probed gap junctional networks in the mouse retina for their permeability to cGMP and cAMP coupled to Biotin, using the well-characterized tracer Neurobiotin as control. Biotin-cGMP and -cAMP have a molecular weight of >0.8 kDa. We show that they cannot pass the gap junctions of horizontal cells but can permeate through the gap junctions of specific amacrine cells in the inner retina. These amacrine cells do not comprise AII amacrine cells and nitric oxide-releasing amacrine cells but some unknown type. In summary, we show that some retinal gap junctions are large enough to let molecules >0.8 kDa pass, making the intercellular delivery of therapeutic agents - already successfully exploited, for example, in cancer - also feasible in neurodegenerative diseases.

Altered intrinsic brain activity in patients with neuropathic pain after brachial plexus avulsion

ObjectiveThis study aimed to investigate brain activity changes in patients suffering from neuropathic pain (NP) following brachial plexus avulsion (BPA). MethodsFifteen patients with NP following BPA and eight healthy participants (HP) were recruited for this study. All participants underwent examination using resting-state functional MRI. The amplitude of low-frequency fluctuation (ALFF) and regional homogeneity (ReHo) were calculated and compared between the BPA group, left-BPA subgroup, right-BPA subgroup, and the HP group using independent samples t-tests. ResultsIn the BPA group, there were notable increases in ALFF/ReHo observed in the left rolandic operculum, insula, and supramarginal gyrus, while decreases were observed in the left paracentral lobule, fusiform gyrus, calcarine fissure and surrounding cortex, lingual gyrus, precuneus, as well as the bilateral anterior/median cingulate and paracingulate gyri, supplementary motor area, and cerebellum. In the left-BPA subgroup, elevated ALFF/ReHo levels were identified in the left middle/inferior frontal gyri, rolandic operculum, and supramarginal gyrus, with corresponding decreases in the left calcarine fissure and surrounding cortex, inferior occipital gyrus, fusiform gyrus, lingual gyrus, as well as the bilateral anterior/median cingulate and paracingulate gyri, postcentral gyri, supplementary motor area, paracentral lobules, and cerebellum. The right-BPA subgroup displayed increased ALFF/ReHo in the left frontal lobe, rolandic operculum, insula, fusiform gyrus, and lingual gyrus, as well as the right cerebellum. Conversely, decreases in ALFF/ReHo were observed in the bilateral anterior/median cingulate and paracingulate gyri, calcarine fissure and surrounding cortex, cuneus, and occipital lobes. ConclusionsThe NP after BPA caused spontaneous activity changes in brain regions associated with linguistic, visual, somatosensory, and motor coordination and processing function. The majority of these abnormal areas were situated in the left cerebral hemisphere, while the effect of cingulate gyri and cerebellum seemed to be bilateral.

Understanding the role of biological aging on cognitive vulnerability among individuals at risk of Alzheimer’s disease

AbstractBackgroundLeukocyte telomere length (LTL) is an objective biomarker of biological aging and has been proposed to play a crucial role in AD progression by impairing cognitive resilience. However, a limited number of studies have evaluated the role of LTL in cognition, showing inconsistent results, particularly in the context of AD pathology. The main objective of this study was to evaluate the association between LTL and cognitive performance in middle‐aged cognitively unimpaired individuals at increased risk of AD.MethodThe study included 1,532 participants from the ALFA cohort. LTL was determined by qPCR in peripheral blood leukocytes. LTL values were log‐transformed, normalized by computing z‐scores and residualized (rLTL) against age and sex using a linear regression model. A cognitive battery was administered to assess verbal memory, psychomotor speed, visual processing, and executive function. Episodic memory (EM), executive function, and global cognitive composites were calculated by averaging normalized raw scores of all subtests in each domain. Generalized linear models were implemented to assess the cross‐sectional association between rLTL and cognitive performance. Association analyses were performed separately in the accelerated aging group (rLTL &lt; percentile 50th) and decelerated aging group (rLTL &gt; percentile 50th). Stratified analyses by sex were conducted.ResultIndividuals at accelerated aging had higher systolic blood pressure and a different distribution of familiar history of AD than those at decelerated aging [Table 1]. Longer rLTL was associated with better performance in the EM domain only among individuals within the accelerated aging group. Remarkably, only free recall measurements remained significant after correction for multiple comparisons. Conversely, longer rLTL was associated with worse psychomotor speed in the whole sample and among individuals in the decelerated group [Table 2]. Women mainly drove these results. Among men, longer rLTL had a beneficial effect on semantic fluency but a detrimental effect on cued recall among those at decelerated aging [Table 3].ConclusionrLTL has a differential effect on cognitive domains among cognitively unimpaired individuals at accelerated/decelerated biological aging. Moreover, results differed depending on sex and cognitive domain. Our results suggest a complex heterogeneity in biological aging mechanisms that appear to change in individuals at increased risk of AD.

Sex differential effects on the joint contribution of air pollution and biological aging on cognitive performance in individuals at risk of Alzheimer’s disease

AbstractBackgroundAir pollution is associated with cognitive performance, risk for AD and may accelerate biological aging. Biological aging due to telomere shortening has been associated with cognitive impairment. However, few studies have looked at the link between air pollution, telomere length, and cognitive performance among sexes. In this study, we investigated the joint effect of sex, air pollution, and leukocyte telomere length (LTL), on cognitive performance in cognitively unimpaired (CU) individuals at risk of AD.MethodThe study included 1,472 middle‐aged CU adults with increased risk of AD from the ALFA study [Table 1]. Residential exposure to air pollutants including nitrogen dioxide (NO2) and particulate matter (PM2.5, PM10) was estimated by land use regression models. LTL was determined by qPCR from DNA extracted from peripheral blood leukocytes. LTL was residualized against chronological age and sex (rLTL). A cognitive battery was administered to assess verbal memory, psychomotor speed, visual processing and executive function. Further, episodic memory (EM), executive function and Preclinical Alzheimer Cognitive Composite (PACC) composites were calculated by averaging normalized raw scores of the subtests. Models were corrected by chronological age, years of education and APOE‐ε4 status. Sex‐specific effects were investigated by adjusting interaction models.ResultThere was no overall effect of neither rLTL nor air pollution on cognitive performance, but crossover interactions with sex were found. Exposure to higher levels of NO2 and PM2.5 were associated with worse EM only in men [Figure 1]. Three‐way interaction models revealed longer rLTL and lower levels of air pollution were associated with better performance on PACC (for PM2.5, PM10 and NO2) and EM (for PM10 and NO2) among men. In women, these associations were only observed at higher exposure levels of air pollution [Figure 2].ConclusionThe results show that lower levels of air pollution allow for the protective effect of rLTL on cognitive performance only in men for whom air pollution had a stronger negative impact. In women, the results show different mechanisms through which air pollution and rLTL affect cognitive performance. Further analyses will be conducted to gain insight into the observed effects.

Multi‐Functional Platform for In‐Memory Computing And Sensing Based on 2D Ferroelectric Semiconductor α‐In2Se3

Abstract2D layered semiconductors with excellent light−matter interaction and atomic‐scale thickness have been envisioned as promising candidates for more than Moore and beyond Moore technologies. Here, for the first time, a multi‐functional platform is reported that is fabricated entirely from wrinkle‐free 2D ferroelectric semiconductor α‐In2Se3 integrated with a photodetector, reconfigurable logic switching, and visual perception processing functions. The intensity‐ and wavelength‐dependent resistance is used to demodulate broadband optical information into electrical signals and perform reconfigurable logic switching. Moreover, the platform offers dynamically modulated photosensitive visual sensing in different working modes at the pixel level. Using photo‐assisted piezoresponse force microscopy, the optical‐engineered ferroelectric polarization switch behavior is explored. The platform has excellent sensitivity to both optical and electrical stimuli and can respond to lights in the visible to short‐wavelength infrared region in volatile/non‐volatile manner under gate voltage modulation, with a response of 98 mA W−1 (to 1800 nm light), a current on/off ratio of over 106, and a high field‐effect mobility of 137.55 cm2 V−1 s−1. With its simple structure, unique photoelectric interaction, and controllable operating mechanism, the platform has the potential to simplify the complexity of neuromorphic computing circuitry systems, paving the way for high‐performance hybrid technologies suitable for artificial intelligence applications.

Biomaterial-Based Biomimetic Visual Sensors: Inkjet Patterning of Bacteriorhodopsin.

Biomimetic visual sensors utilizing bacteriorhodopsin (bR) were fabricated by using an inkjet method. The inkjet printer facilitated the jetting of the bR suspension, allowing for the deposition of bR films. The resulting inkjet-printed bR film exhibited time-differential photocurrent response characteristics similar to those of a dip-coated bR film. By adjusting the number of printed bR film layers, the intensity of the photocurrent could be easily controlled. Moreover, the inkjet printing technique enabled unconstrained patterning, facilitating the design of various visual information processing functions, such as visual filters. In this study, we successfully fabricated two visual filters, namely, a two-dimensional Difference of Gaussian (DOG) filter and a Gabor filter. The printed DOG filter demonstrated edge detection capabilities corresponding to contour recognition in visual receptive fields. On the other hand, the printed Gabor filter proved effective in detecting objects of specific sizes as well as their motion and orientation. The integration of bR and the inkjet method holds significant potential for the widespread implementation of highly functional biomaterial-based visual sensors. These sensors have the capability to provide real-time visual information while operating in an energy-efficient manner.

Research on brain functions related to visual information processing and body coordination function of pilots based on the low-frequency amplitude method.

Research on the differences in physiological and psychological mechanisms of practitioners in different occupations is a current hot spot, such as pilots. This study explores the frequency-dependent changes of pilots' low-frequency amplitudes in the classical frequency band and sub-frequency band between pilots and general occupations. The goal of the current work is to provide objective brain images for the selection and evaluation of outstanding pilots. Twenty-six pilots and 23 age-, sex-, and education-matched healthy controls were included in this study. Then the mean low-frequency amplitude (mALFF) of the classical frequency band and sub-frequency band was calculated. The two-sample t-test was performed on SPM12 to analyze the differences between the flight group and control group in the classic frequency band. To explore the main effects and the inter-band effects of the mean low-frequency amplitude (mALFF), the mixed design analysis of variance was applied in the sub-frequency bands. Compared with the control group, left cuneiform lobe and the right cerebellum six area of pilots show significant difference in the classic frequency band. And the main effect results in the sub-frequency bands show that the area with higher mALFF in the flight group is located on the left middle occipital gyrus, the left cuneiform lobe, the right superior occipital gyrus, the right superior gyrus, and the left lateral central lobule. However, the area where the value of mALFF decreased is mainly located on the left rectangular cleft with surrounding cortex and the right dorsolateral superior frontal gyrus. Besides, compared with the slow-4 frequency band, the mALFF of the left middle orbital middle frontal gyrus of the slow-5 frequency band was increased, while the mALFF value of the left putamen, left fusiform gyrus, and right thalamus was decreased. The sensitivity of the slow-5 frequency band and the slow-4 frequency band to the pilots' different brain areas was also different. Also, the different brain areas in the classic frequency band and the sub-frequency band were significantly correlated with pilots' flight hours. Our findings showed that the left cuneiform brain area and the right cerebellum of pilots changed significantly during resting state. And there was a positive correlation between the mALFF value of those brain area and flight hours. The comparative analysis of sub-frequency bands found that the slow-5 band could elucidate a wider range of different brain regions, providing new ideas for exploring the brain mechanisms of pilots.

Exploration of static functional connectivity and dynamic functional connectivity alterations in the primary visual cortex among patients with high myopia via seed-based functional connectivity analysis.

This study was conducted to explore differences in static functional connectivity (sFC) and dynamic functional connectivity (dFC) alteration patterns in the primary visual area (V1) among high myopia (HM) patients and healthy controls (HCs) via seed-based functional connectivity (FC) analysis. Resting-state functional magnetic resonance imaging (fMRI) scans were performed on 82 HM patients and 59 HCs who were closely matched for age, sex, and weight. Seed-based FC analysis was performed to identify alterations in the sFC and dFC patterns of the V1 in HM patients and HCs. Associations between mean sFC and dFC signal values and clinical symptoms in distinct brain areas among HM patients were identified via correlation analysis. Static and dynamic changes in brain activity in HM patients were investigated by assessments of sFC and dFC via calculation of the total time series mean and sliding-window analysis. In the left anterior cingulate gyrus (L-ACG)/left superior parietal gyrus (L-SPG) and left V1, sFC values were significantly greater in HM patients than in HCs. In the L-ACG and right V1, sFC values were also significantly greater in HM patients than in HCs [two-tailed, voxel-level P < 0.01, Gaussian random field (GRF) correction, cluster-level P < 0.05]. In the left calcarine cortex (L-CAL) and left V1, dFC values were significantly lower in HM patients than in HCs. In the right lingual gyrus (R-LING) and right V1, dFC values were also significantly lower in HM patients than in HCs (two-tailed, voxel-level P < 0.01, GRF correction, cluster-level P < 0.05). Patients with HM exhibited significantly disturbed FC between the V1 and various brain regions, including L-ACG, L-SPG, L-CAL, and R-LING. This disturbance suggests that patients with HM could exhibit impaired cognitive and emotional processing functions, top-down control of visual attention, and visual information processing functions. HM patients and HCs could be distinguished from each other with high accuracy using sFC and dFC variabilities. These findings may help to identify the neural mechanism of decreased visual performance in HM patients.

Change Point Detection Methods for Locating Activations in Functional Neuronal Images

The most common analysis for fMRI images is activation detection, in which the purpose is to find the locations in the brain that respond to specific functions, such as visual processing or motor functions by providing related stimuli as tasks in the experiment. On the other hand, it is also important to detect the instance the activation is triggered. One of the powerful techniques that can analyze the abnormal behavior of any data is change point (CP) analysis. We suggest that CP detection algorithms also can be used to locate the activations in functional magnetic resonance imaging (fMRI) sequences, as well. Our paper presents a two-fold innovative study in that respect. First, we propose to use CP detection algorithms to locate the activations in fMRI signals as a state-of-art topic. Furthermore, we propose and compare a set of change point analysis methods, a regression-based method (RBM), a statistical method (SM), and a mean difference of double sliding windows method (MDSW)) to locate such points. Second, we apply these methods to the fMRI signals, which are acquired from the real subjects, while they were performing fMRI tasks. Proposed methods were applied to three different fMRI experiments with a motor task, a visual task, and a linguistic task. The analysis shows that the methods find activations in accordance with established methods such as statistical parametric maps (SPM). The acquired up to 94 % results also show that the proposed methods can be used effectively to locate the activation times on fMRI time series.

Impact of visual impairment on balance and visual processing functions in students with special educational needs.

IntroductionVision is critical for children’s development. However, prevalence of visual impairment (VI) is high in students with special educational needs (SEN). Other than VI, SEN students are prone to having functional deficits. Whether visual problems relate to these functional deficits is unclear. This study aimed to assess the impact of vision on visual processing functions and balance in SEN students through a community service.MethodsVisual acuity (VA) and contrast sensitivity were measured in a total of 104 (aged 14.3±4.3) SEN students as the visual outcomes, followed by retinoscopy. Visual processing function assessment included facial expression recognition by card matching examiner’s facial expression matching, and visual orientation recognition. Dynamic balance, by Timed Up and Go test, and static standing balance (postural sway in double-legged standing with feet-together and tandem-stance for open-eye and closed-eye conditions) were assessed. Static balance was presented in terms of the maximal medial-lateral and antero-posterior sways.ResultsOf the 104 students, 62 (59.6%) were classified as visually impaired according to WHO classification of visual impairment based on presenting distance acuity. Ocular problems (e.g. optic nerve anomaly, uncorrected/ under-corrected refractive errors) and neurological anomalies were the major causes of vision loss. VA was positively associated with visual processing functions (all p ≤ 0.01), as SEN students with better vision tended to perform better in visual orientation and facial expression recognition tasks, as well as dynamic balance function (p = 0.04). For the static balance, postural sway and VA showed a positive relationship under open-eye and tandem stance conditions. However, the relationship between postural sway and VA became negative under closed-eye and tandem stance conditions.ConclusionThis study found a high prevalence of SEN students with visual impairment, in which many of them were undetected. Optometric examination is important to improve their visual function to minimize the effect of vision on functional performance. Vision is critical in visual processing as well as playing an important role in maintaining balance in SEN students.

Association between telomere length and cognitive function among cognitively unimpaired individuals at risk of Alzheimer’s disease

AbstractBackgroundTelomere length (TL) is an objective biomarker of biological aging and it has been proposed to play a crucial role in Alzheimer's disease (AD) progression by impairing cognitive resilience. However, published studies show inconsistent results and a very limited number of studies have evaluated the role of TL in aging and midlife individuals. The main objective of this study was to evaluate the association between TL and cognitive performance in middle‐aged cognitively unimpaired individuals at increased risk of AD.MethodsThe study included 1,079 participants from the ALFA (ALzheimer and FAmilies) cohort. Relative TL was determined by qPCR from DNA extracted from peripheral blood leukocytes. TL values were normalized by computing z‐scores. A cognitive battery was administered to assess verbal memory, psychomotor speed, visual processing and executive function. Further, episodic memory, executive function and global cognitive composites were calculated by averaging normalized raw scores of all subtests in each domain. Generalized linear models with Poisson/quasi‐binomial distributions and linear regression models were implemented to assess the cross‐sectional association between TL and cognitive subtests as well as TL and cognitive composites, respectively. All models were adjusted by sex and age. Additionally, stratified analyses by APOE‐ɛ4 status were conducted. Statistical significance was set at P≤0.05.ResultsLonger TL at baseline was associated with better performance on executive function subtests related to visual processing, attention/working memory and reasoning only in APOE‐ɛ4 non‐carriers [Table 1]. Similarly, APOE‐ɛ4 non‐carriers showed a significant association between longer TL and better scores on executive function composites [Table 2]. In contrast, no associations between TL and memory‐related tests were observed.ConclusionsOur results suggest a potential role for telomeres on maintaining cognition in aging, specifically in individuals at low genetic risk of AD. Further longitudinal analyses are warranted to better understand the role of the APOE‐ɛ4 genotype on these associations and their potential impact on cognitive resilience in the context of the AD continuum.

Altered functional brain dynamics in chromosome 22q11.2 deletion syndrome during facial affect processing

Chromosome 22q11.2 deletion syndrome (22q11.2DS) is a multisystem disorder associated with multiple congenital anomalies, variable medical features, and neurodevelopmental differences resulting in diverse psychiatric phenotypes, including marked deficits in facial memory and social cognition. Neuroimaging in individuals with 22q11.2DS has revealed differences relative to matched controls in BOLD fMRI activation during facial affect processing tasks. However, time-varying interactions between brain areas during facial affect processing have not yet been studied with BOLD fMRI in 22q11.2DS. We applied constrained principal component analysis to identify temporally overlapping brain activation patterns from BOLD fMRI data acquired during an emotion identification task from 58 individuals with 22q11.2DS and 58 age-, race-, and sex-matched healthy controls. Delayed frontal-motor feedback signals were diminished in individuals with 22q11.2DS, as were delayed emotional memory signals engaging amygdala, hippocampus, and entorhinal cortex. Early task-related engagement of motor and visual cortices and salience-related insular activation were relatively preserved in 22q11.2DS. Insular activation was associated with task performance within the 22q11.2DS sample. Differences in cortical surface area, but not cortical thickness, showed spatial alignment with an activation pattern associated with face processing. These findings suggest that relative to matched controls, primary visual processing and insular function are relatively intact in individuals with 22q11.22DS, while motor feedback, face processing, and emotional memory processes are more affected. Such insights may help inform potential interventional targets and enhance the specificity of neuroimaging indices of cognitive dysfunction in 22q11.2DS.

Application and research of robot sorting system based on LabVIEW

Sorting robot is a kind of artificial intelligence robot which has certain sense ability and can classify items. In the sorting industry, its appearance not only reduces the labor input, but also improves the production efficiency of the sorting industry. In this paper, a production line composed of linear Delta robot and 3-DOF robot is studied. The forward and inverse solutions are calculated by MATLAB and simulated by Solid Works. Through the visual processing function, communication function and axle card driving function of Lab VIEW software, the servo motor rotation is controlled to achieve the purpose of the end moving along the predetermined trajectory, and finally the visual sorting function is realized.

A Direct Comparison of Spatial Attention and Stimulus-Response Compatibility between Mice and Humans.

Mice are becoming an increasingly popular model for investigating the neural substrates of visual processing and higher cognitive functions. To validate the translation of mouse visual attention and sensorimotor processing to humans, we compared their performance in the same visual task. Mice and human participants judged the orientation of a grating presented on either the right or left side in the visual field. To induce shifts of spatial attention, we varied the stimulus probability on each side. As expected, human participants showed faster RTs and a higher accuracy for the side with a higher probability, a well-established effect of visual attention. The attentional effect was only present in mice when their response was slow. Although the task demanded a judgment of grating orientation, the accuracy of the mice was strongly affected by whether the side of the stimulus corresponded to the side of the behavioral response. This stimulus-response compatibility (Simon) effect was much weaker in humans and only significant for their fastest responses. Both species exhibited a speed-accuracy trade-off in their responses, because slower responses were more accurate than faster responses. We found that mice typically respond very fast, which contributes to the stronger stimulus-response compatibility and weaker attentional effects, which were only apparent in the trials with slowest responses. Humans responded slower and had stronger attentional effects, combined with a weak influence of stimulus-response compatibility, which was only apparent in trials with fast responses. We conclude that spatial attention and stimulus-response compatibility influence the responses of humans and mice but that strategy differences between species determine the dominance of these effects.

Functional, molecular and morphological heterogeneity of superficial interneurons in the larval zebrafish tectum.

The superficial interneurons, SINs, of the zebrafish tectum, have been implicated in a range of visual functions, including size discrimination, directional selectivity, and looming-evoked escape. This raises the question if SIN subpopulations, despite their morphological similarities and shared anatomical position in the retinotectal processing stream, carry out diverse, task-specific functions in visual processing, or if they have simple tuning properties in common. Here we have further characterized the SINs through functional imaging, electrophysiological recordings, and neurotransmitter typing in two transgenic lines, the widely used Gal4s1156t and the recently reported LCRRH2-RH2-2:GFP. We found that about a third of the SINs strongly responded to changes in whole-field light levels, with a strong preference for OFF over ON stimuli. Interestingly, individual SINs were selectively tuned to a diverse range of narrow luminance decrements. Overall responses to whole-field luminance steps did not vary with the position of the SIN cell body along the depth of the tectal neuropil or with the orientation of its neurites. We ruled out the possibility that intrinsic photosensitivity of Gal4s1156t+ SINs contribute to the measured visual responses. We found that, while most SINs express GABAergic markers, a substantial minority express an excitatory neuronal marker, the vesicular glutamate transporter, expanding the possible roles of SIN function in the tectal circuitry. In conclusion, SINs represent a molecularly, morphologically, and functionally heterogeneous class of interneurons, with subpopulations that detect a range of specific visual features, to which we have now added narrow luminance decrements.