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Background: Visual problems are an under-reported sequela following stroke. The aim of this study is to report annual incidence and point prevalence of visual problems in an acute adult stroke population and to explore feasibility of early timing of visual assessment. Methods and findings: Multi-centre acute stroke unit, prospective, epidemiology study (1st July 2014 to 30th June 2015). Orthoptists reviewed all patients with assessment of visual acuity, visual fields, ocular alignment, ocular motility, visual inattention and visual perception. 1033 patients underwent visual screening at a median of 3 days (IQR 2) and full visual assessment at a median of 4 days (IQR 7) after the incident stroke: 52% men, 48% women, mean age 73 years and 87% ischaemic strokes. Excluding pre-existent eye problems, the incidence of new onset visual sequelae was 48% for all stroke admissions and 60% in stroke survivors. Three quarters 752/1033 (73%) had visual problems (point prevalence): 56% with impaired central vision, 40% eye movement abnormalities, 28% visual field loss, 27% visual inattention, 5% visual perceptual disorders. 281/1033 (27%) had normal eye exams. Conclusions: Incidence and point prevalence of visual problems in acute stroke is alarmingly high, affecting over half the survivors. For most, visual screening and full visual assessment was achieved within about 5 days of stroke onset. Crucial information can thus be provided on visual status and its functional significance to the stroke team, patients and carers, enabling early intervention. [ABSTRACT FROM AUTHOR]

Background: The majority of U.S hospitals have implemented electronic health records (EHRs). While the benefits of EHRs have been widely touted, little is known about their effects on inpatient care, including how well they meet workflow needs and support care. Objective: Assess the extent to which EHRs support care team workflow during hospital morning rounds. Design: We applied a mixed-method approach including observations of care teams during morning rounds, semi-structured interviews and an electronic survey of hospital inpatient clinicians. Structured field notes taken during observations were used to identify workflow patterns for analysis. We applied a grounded theory approach to extract emerging themes from interview transcripts and used SPSS Statistics 24 to analyze survey responses. Setting: Medical units at a major teaching hospital in New England. Results: Data triangulation across the three analyses yielded four main findings: (1) a high degree of variance in the ways care teams use EHRs during morning rounds. (2) Pervasive use of workarounds at critical points of care (3) EHRs are not used for information sharing and frequently impede intra-care team communication. (4) System design and hospital room settings do not adequately support care team workflow. Conclusions: Gaps between EHR design and the functionality needed in the complex inpatient environment result in lack of standardized workflows, extensive use of workarounds and team communication issues. These issues pose a threat to patient safety and quality of care. Possible solutions need to include improvements in EHR design, care team training and changes to the hospital room setting. [ABSTRACT FROM AUTHOR]

It is known that cortical networks operate on the edge of instability, in which oscillations can appear. However, the influence of this dynamic regime on performance in decision making, is not well understood. In this work, we propose a population model of decision making based on a winner-take-all mechanism. Using this model, we demonstrate that local slow inhibition within the competing neuronal populations can lead to Hopf bifurcation. At the edge of instability, the system exhibits ambiguity in the decision making, which can account for the perceptual switches observed in human experiments. We further validate this model with fMRI datasets from an experiment on semantic priming in perception of ambivalent (male versus female) faces. We demonstrate that the model can correctly predict the drop in the variance of the BOLD within the Superior Parietal Area and Inferior Parietal Area while watching ambiguous visual stimuli. [ABSTRACT FROM AUTHOR]

Previous research suggesting an association between maternal prenatal docosahexaenoic acid (DHA) intake and infant cognition has yet to assess whether there is a critical trimester for the observed effects. We used a comprehensive Food Frequency Questionnaire to estimate DHA levels during both the second and third trimesters of pregnancy, in a sample of 125 pregnant women. Infants were assessed at 4.5 months and 9 months post-partum using specific tests of visual acuity, habituation, and visual attention. Based on maternal DHA levels during pregnancy, mothers were subdivided into high, medium, and low groups, and their infants compared for task performance using one-way ANOVAs with maternal DHA groups. On the 9 month visual acuity test, infants whose mothers were in the medium DHA group performed significantly better than those with mothers in the low or high DHA groups (p = 0.008). However, no significant finding was found for any of the other cognitive assessment measures. Despite a number of studies reporting a positive effect of higher DHA levels on cognitive development, this study fails to support those conclusions. We can, however, conclude that it appears to be DHA intake in the third trimester specifically, which is influencing the development of visual acuity towards the end of the first postnatal year. [ABSTRACT FROM AUTHOR]

By definition, perception is a multisensory process that unfolds in time as a complex sequence of exploratory activities of the organism. In such a system perception and action are integrated, and multiple energy arrays are available simultaneously. Perception of affordances interweaves sensory and motor activities into meaningful behavior given task constraints. The present contribution offers insight into the manner in which perception and action usher the organism through competent functional apprehension of its surroundings. We propose that the tensegrity structure of the body, manifested via multifractality of exploratory bodily movements informs perception of affordances. The affordance of stand-on-ability of ground surfaces served as the experimental paradigm. Observers viewed a surface set to a discrete angle and attempted to match it haptically with a continuously adjustable surface occluded by a curtain, or felt an occluded surface set to a discrete angle then matched it visually with a continuously adjustable visible surface. The complex intertwining of perception and action was demonstrated by the interactions of multifractality of postural sway with multiple energy arrays, responses, and changing geometric task demands. [ABSTRACT FROM AUTHOR]

There has been debate about whether blue hyperlinks on the Web cause disruption to reading. A series of eye tracking experiments were conducted to explore if coloured words in black text had any impact on reading behaviour outside and inside a Web environment. Experiment 1 and 2 explored the saliency of coloured words embedded in single sentences and the impact on reading behaviour. In Experiment 3, the effects of coloured words/hyperlinks in passages of text in a Web-like environment was explored. Experiment 1 and 2 showed that multiple coloured words in text had no negative impact on reading behaviour. However, if the sentence featured only a single coloured word, a reduction in skipping rates was observed. This suggests that the visual saliency associated with a single coloured word may signal to the reader that the word is important, whereas this signalling is reduced when multiple words are coloured. In Experiment 3, when reading passages of text containing hyperlinks in a Web environment, participants showed a tendency to re-read sentences that contained hyperlinked, uncommon words compared to hyperlinked, common words. Hyperlinks highlight important information and suggest additional content, which for more difficult concepts, invites rereading of the preceding text. [ABSTRACT FROM AUTHOR]

Our objective was to examine how exercises with the second generation of the Microsoft Kinect sensor may aid in the process of motor learning in young judo practitioners. We addressed improvements in spatio-temporal accuracy during execution of three standing techniques in judo, in a simple paradigm designed to study short-term practice effects. Two groups of judokas, 12 athletes each—one aided with Kinect and our dedicated software vs a group of controls—were asked to mimic previously recorded master-level performances of the three techniques, established as benchmarks by a two times world champion in judo. In five training sessions, athletes of the aided group used a virtual-reality setup in which they trained with a virtual representation of the master displayed on a large screen with a simultaneous real-time visualisation of their own movements in the form of an avatar based on body joint localisation, as determined by Kinect, which also measured their performance. The control group used Kinect in the 1st and 5th session, which was necessary for the measurements that constituted the basis for subsequent statistical comparisons, whereas the 2nd, 3rd, and 4th session in this group was guided by a coach, without the use of the Kinect setup. In addition, athletes of the two groups had unrestricted access to a video recording of the master performing the three throws. We found statistically significant improvements (p < 0.05) in the accuracy of executing the three techniques between the 1st and the 5th training session for the aided group but not for the control group. We conclude that incorporating Kinect based exercises into a judo training programme may be a useful means to supporting motor learning, therefore enhancing training efficiency, and thus improving performance. [ABSTRACT FROM AUTHOR]

Purpose: Clinical assessment of a new optical element for presbyopia correction–the Light Sword Lens. Methods: Healthy dominant eyes of 34 presbyopes were examined for visual performance in 3 trials: reference (with lens for distance correction); stenopeic (distance correction with a pinhole ϕ = 1.25 mm) and Light Sword Lens (distance correction with a Light Sword Lens). In each trial, visual acuity was assessed in 7 tasks for defocus from 0.2D to 3.0D while contrast sensitivity in 2 tasks for defocus 0.3D and 2.5D. The Early Treatment Diabetic Retinopathy Study protocol and Pelli-Robson method were applied. Within visual acuity and contrast sensitivity results degree of homogeneity through defocus was determined. Reference and stenopeic trials were compared to Light Sword Lens results. Friedman analysis of variance, Nemenyi post-hoc, Wilcoxon tests were used, p-value < 0.05 was considered significant. Results: In Light Sword Lens trial visual acuity was stable in tested defocus range [20/25–20/32], Stenopeic trial exhibited a limited range of degradation [20/25–20/40]. Light Sword Lens and reference trials contrast sensitivity was high [1.9–2.0 logCS] for both defocus cases, but low in stenopeic condition [1.5–1.7 logCS]. Between-trials comparisons of visual acuity results showed significant differences only for Light Sword Lens versus reference trials and in contrast sensitivity only for Light Sword Lens versus stenopeic trials. Conclusions: Visual acuity achieved with Light Sword Lens correction in presbyopic eye is comparable to stenopeic but exhibits none significant loss in contrast sensitivity. Such correction method seems to be very promising for novel contact lenses and intraocular lenses design. [ABSTRACT FROM AUTHOR]

Vision begins with the encoding of contrast at specific orientations. Several works showed that humans identify their conspecifics best based on the horizontally-oriented information contained in the face image; this range conveys the main morphological features of the face. In contrast, the vertical structure of the eye region seems to deliver optimal cues to gaze direction. The present work investigates whether the human face processing system flexibly tunes to vertical information contained in the eye region when processing gaze direction. Alternatively, face processing may invariantly rely on the horizontal range, supporting the domain specificity of orientation tuning for faces and the gateway role of horizontal content to access any type of facial information. Participants judged the gaze direction of faces staring at a range of lateral positions. They additionally performed an identification task with upright and inverted face stimuli. Across tasks, stimuli were filtered to selectively reveal horizontal (H), vertical (V), or combined (HV) information. Most participants identified faces better based on horizontal than vertical information confirming the horizontal tuning of face identification. In contrast, they showed a vertically-tuned sensitivity to gaze direction. The logistic functions fitting the “left” and “right” response proportion as a function of gaze direction were indeed steeper when based on vertical than on horizontal information. The finding of a vertically-tuned processing of gaze direction favours the hypothesis that visual encoding of face information flexibly switches to the orientation channel carrying the cues most relevant to the task at hand. It suggests that horizontal structure, though predominant in the face stimulus, is not a mandatory gateway for efficient face processing. The present evidence may help better understand how visual signals travel the visual system to enable rich and complex representations of naturalistic stimuli such as faces. [ABSTRACT FROM AUTHOR]

Gradient-based approaches to brain function have recently unmasked fundamental properties of brain organization. Diffusion map embedding analysis of resting-state fMRI data revealed a primary-to-transmodal axis of cerebral cortical macroscale functional organization. The same method was recently used to analyze resting-state data within the cerebellum, revealing for the first time a sensorimotor-fugal macroscale organization principle of cerebellar function. Cerebellar gradient 1 extended from motor to non-motor task-unfocused (default-mode network) areas, and cerebellar gradient 2 isolated task-focused processing regions. Here we present a freely available and easily accessible tool that applies this new knowledge to the topographical interpretation of cerebellar neuroimaging findings. LittleBrain illustrates the relationship between cerebellar data (e.g., volumetric patient study clusters, task activation maps, etc.) and cerebellar gradients 1 and 2. Specifically, LittleBrain plots all voxels of the cerebellum in a two-dimensional scatterplot, with each axis corresponding to one of the two principal functional gradients of the cerebellum, and indicates the position of cerebellar neuroimaging data within these two dimensions. This novel method of data mapping provides alternative, gradual visualizations that complement discrete parcellation maps of cerebellar functional neuroanatomy. We present application examples to show that LittleBrain can also capture subtle, progressive aspects of cerebellar functional neuroanatomy that would be difficult to visualize using conventional mapping techniques. Download and use instructions can be found at . [ABSTRACT FROM AUTHOR]

Ocular parameters have been applied to ophthalmic lens designs in order to satisfy individual wearers. An axial length (AL) of them can be used in individual ophthalmic lens designs. Our aim was to propose a reliable formula that predicts an individual’s AL using the corneal radius and refractive error, and to demonstrate the applicability of this formula. A total of 348 subjects underwent keratometry, objective and subjective refraction, and AL measurement. The formula of calculated AL for prediction obtained from the original Gullstrand simplified schematic eye: calculated AL = (24.00 × aveK/7.80)—(SE × 0.40), where aveK and SE denote average corneal radius and spherical equivalent, respectively. Calculated AL was 24.50 ± 1.83 mm, which was 0.18 ± 0.47 mm longer than the measured value of 24.32 ± 1.73 mm (p < 0.001). The proportion showing the differences between the calculated and measured ALs were 284 eyes (40.8%) for 0.00–0.25 mm, 525 eyes (75.4%) for less than 0.50 mm, 665 eyes (95.5%) for less than 1.00 mm, and 31 eyes (4.5%) for more than 1.01 mm. Correlation coefficient showed a very high correlation between calculated and measured ALs (r = 0.967, p < 0.001), and higher in the myopic than in the hyperopic group. The mean difference was 0.18 mm; the 95% limit of agreement was +1.10—-0.75 mm in all groups. Agreement was better in hyperopic eyes than myopic eyes. Prediction from calculation of AL with a formula using the corneal radius and SE provides an alternative method to direct measurements of AL, especially in the restricted environment, which can’t use biometric equipment for personalized ophthalmic lens design. [ABSTRACT FROM AUTHOR]

Alcohol mixed with energy drinks (AMED) studies have typically not shown antagonism of acute alcohol effects by energy drink (ED), particularly over relatively short time frames. This study investigated the effects of alcohol, ED, and AMED on attentional and working memory processes over a 3 h period. Twenty-four young adults took part in a randomised, double-blind, placebo-controlled, factorial, 4-arm study. They were administered 0.6g/kg alcohol and 250 ml ED (containing 80 mg caffeine), and matching placebos alone and in combination. A battery of attentional and working memory measures was completed at baseline then 45, 90 and 180 min post-treatment. Alcohol produced a characteristic shift in speed/accuracy trade-off, having little effect on reaction times while increasing errors on all attentional measures (4-choice Reaction Time, Number Pairs and Visual Search), as well as a composite Attentional error score and one working memory task (Serial Sevens). ED alone improved two working memory measures (Memory Scanning accuracy and Digit–Symbol reaction times) and improved speed of responding on a composite Working Memory score. There was no consistent pattern of AMED vs. alcohol effects; AMED produced more errors than alcohol alone on one attentional measure (Visual Search errors) at 45 min only whereas AMED resulted in fewer errors on the Serial Sevens task at 90 min and better Digit-Symbol accuracy and reaction time at 45 min. Alcohol consumption increases error rate across several attentional and working memory processes. Mutual antagonism between alcohol and ED showed no consistent pattern and likely reflects a complex interaction between caffeine and alcohol levels, phase of the blood alcohol limb, task domain and cognitive load. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the relationship between anterior capsule polish and visual function. Methods: Data were obtained from Pubmed, Embase, Web of Science, WanFang, VIP and CNKI up to the end of May 2018, without any date or language restrictions for trials. The modified Jadad scale and the newcastle-ottawa scale were used to assess the quality of included studies. Uncorrected visual acuity (UCVA) and posterior capsule opacification (PCO) were used as outcome variables. Data on anterior capsule polish were pooled using weighted, random-effect meta-analysis. Results: One randomized controlled trial and 4 observational cohort studies involving 2533 patients were included in the analyses. There was a statistically significant difference of UCVA (OR 1.92, 95% CI 1.41–2.61) between the polish group and the control group, indicating that anterior capsule polish improved UCVA. Further studies with continuous data also suggested that anterior capsule polish was associated with good UCVA (MD 0.11, 95% CI 0.06–0.16). Posterior capsule opacification rate for 1-year or longer follow-up were extracted for 2561 eyes in 3 studies. Posterior capsule opacification rate was lower in the anterior capsule polish group according to summary odds ratio on PCO rate (OR 0.42 95% CI 0.24–0.73). Conclusions: Anterior capsule polish prevents complication of modern cataract surgery and benefits on visual function in short term follow-up period. [ABSTRACT FROM AUTHOR]

In order to explore the metric structure of the space of remembered colors, a computer game was designed, where players with normal color vision had to store a color in memory, and later retrieve it by selecting the best match out of a continuum of alternatives. All tested subjects exhibited evidence of focal colors in their mnemonic strategy. We found no concluding evidence that the focal colors of different players tended to cluster around universal prototypes. Based on the Fisher metric, for each subject we defined a notion of distance in color space that captured the accuracy with which similar colors where discriminated or confounded when stored and retrieved from memory. The notions of distance obtained for different players were remarkably similar. Finally, for each player, we constructed a new color scale, in which colors are memorized and retrieved with uniform accuracy. [ABSTRACT FROM AUTHOR]

Aims: Previous studies and community information about everyday difficulties in age-related macular degeneration (AMD) have focussed on domains such as reading and driving. Here, we provide the first in-depth examination of how impaired face perception impacts social interactions and quality of life in AMD. We also develop a Faces and Social Life in AMD brochure and information sheet, plus accompanying conversation starter, aimed at AMD patients and those who interact with them (family, friends, nursing home staff). Method: Semi-structured face-to-face interviews were conducted with 21 AMD patients covering the full range from mild vision loss to legally blind. Thematic analysis was used to explore the range of patient experiences. Results: Patients reported faces appeared blurred and/or distorted. They described recurrent failures to recognise others' identity, facial expressions and emotional states, plus failures of alternative non-face strategies (e.g., hairstyle, voice). They reported failures to follow social nuances (e.g., to pick up that someone was joking), and feelings of missing out ('I can't join in'). Concern about offending others (e.g., by unintentionally ignoring them) was common, as were concerns of appearing fraudulent ('Other people don't understand'). Many reported social disengagement. Many reported specifically face-perception-related reductions in social life, confidence, and quality of life. All effects were observed even with only mild vision loss. Patients endorsed the value of our Faces and Social Life in AMD Information Sheet, developed from the interview results, and supported future technological assistance (digital image enhancement). Conclusion: Poor face perception in AMD is an important domain contributing to impaired social interactions and quality of life. This domain should be directly assessed in quantitative quality of life measures, and in resources designed to improve community understanding. The identity-related social difficulties mirror those in prosopagnosia, of cortical rather than retinal origin, implying findings may generalise to all low-vision disorders. [ABSTRACT FROM AUTHOR]

Sexually dichromatic birds often show delayed plumage maturation, but second-year (SY) males may or may not be distinguishable from females. In competitive contexts, SY males receive a reduced amount of adult males’ aggression, either by mimicking females or through signaling their sex and inexperience as subordinate males. To the human eye, reproductive dull SY male Saffron Finches are indistinguishable from females, whereas after second-year (ASY) males are golden yellow. Our aim is to establish whether SY males are sexually dichromatic with females to the eye of conspecifics. We describe plumage variation in females, SY and ASY males and, in particular, analyze assortative mating by color by comparing a previously disregarded yellow feather patch shared by the three groups. We measured plumage reflectance of the forehead, breast, belly, and axillaries, and used a two-step avian visual model analysis to estimate the ability of Saffron Finches to distinguish between SY males and females. We find that those groups are indistinguishable to conspecifics by color. Furthermore, we find non-significant evidence of assortative mating directly related to the coloration of comparable feather patches between females and each type of male, though body condition of SY males is associated to that of their mates. Our results are compatible with both the female-mimicry and the status signaling hypotheses of evolution and maintenance of delayed plumage maturation. However, the singing behavior of males reveals their presence within the breeding site; the combined effect of song and dull coloration suggest that SY males are honestly revealing their sex and status to conspecifics. [ABSTRACT FROM AUTHOR]

It has been shown that people process assortment variety more efficiently in horizontal displays than in vertical displays, owing to human visual characteristics that favor the horizontal direction. Consequently, the number and variety of products chosen tends to increase when they are arranged horizontally. I show that this horizontal display advantage can be modulated by culture, especially writing and reading habits. When Japanese participants, who write and read text vertically as well as horizontally, chose products in horizontal and vertical displays, horizontal displays did not consistently increase the variety of products chosen. In other words, the horizontal display advantage was eliminated (Experiments 1A and 1B). However, when Japanese readers initially read horizontally, it led to a robust advantage for the horizontal display. Similarly, initial vertical reading resulted in a vertical display advantage (Experiments 2 and 3). These results suggest that horizontal displays are not always advantageous, and that optimal display direction for product choice is affected by reading habits. [ABSTRACT FROM AUTHOR]

The exclusive role of the medial temporal lobe in explicit memory has been questioned by several studies reporting medial temporal lobe involvement during implicit learning. Prior studies have demonstrated that hippocampal engagement is present during the implicit learning of perceptual associations, however, it is absent during learning response-related associations. Therefore, it was hypothesized that the function of the medial temporal lobe during implicit learning is related to the extraction of perceptual associations in general. While in most implicit learning tasks visual stimuli were used, the aim of the current functional magnetic resonance imaging (fMRI) study was to detect whether activations within medial temporal lobe structures are also found during implicit learning of auditory associations. In a modified version of the classical serial reaction time task, participants reacted to the presentation of five different tones. Unbeknownst to the participants, the tones were presented with an underlying sequential regularity that could be learned. To avoid an influence of response learning on acoustic associative learning, response buttons were remapped in every trial. After learning, two different tests were used to measure participants’ conscious knowledge about the underlying sequence in order to assess the amount of implicit memory and to exclude participants with explicit knowledge acquired during learning. fMRI results revealed hippocampal activations for implicit learning of the acoustic sequence. When detecting a relation between implicit learning of acoustic associations and hippocampal activations, this study indicated a relation between hippocampal activations and memory formation of perceptual-based relational representation regardless of explicit knowledge. Thus, present findings suggest a general functional role for the formation of sequenced perceptual associations independent of the involvement of awareness. [ABSTRACT FROM AUTHOR]

When motor abilities change, people need to generate information to recalibrate their perception through active exploration. Most prior research has focused on observers’ ability to update perception by executing experimenter-specified exploratory behaviors, however, the question of how observers spontaneously choose how to explore has been overlooked. We asked how effectively adults decide to explore when adapting to changes in their ability to squeeze through doorways. Results revealed that participants made efficient decisions about when to explore by approaching and practicing—they most often explored doorways that were near the limit of their abilities, and participants explored less often as their perceptual calibration improved. However, participants made sub-optimal decisions about how to explore, which resulted in a failure to fully recalibrate. We discuss the implications of these findings for understanding the processes of perceptual-motor recalibration that underlie real-world behavior. [ABSTRACT FROM AUTHOR]

Although the visual cortex receives information at multiple temporal patterns, much of the research in the field has focused only on intervals shorter than 1 second. Consequently, there is almost no information on what happens at longer temporal intervals. We have tried to address this question recording neuronal populations of the primary visual cortex during visual stimulation with repetitive grating stimuli and intervals ranging from 1 to 7 seconds. Our results showed that firing rate and response stability were dependent of interval duration. In addition, there were collective oscillations with different properties in response to changes in intervals duration. These results suggest that visual cortex could encode visual information at several time scales using oscillations at multiple frequencies. [ABSTRACT FROM AUTHOR]

Although the natural haptic perception of textures includes active finger movements, it is unclear how closely perception and movements are linked. Here we investigated this question using oriented textures. Textures that are composed of periodically repeating grooves have a clear orientation defined by the grooves. The direction of finger movement relative to texture orientation determines the availability of temporal cues to the spatial period of the texture. These cues are absent during movements directed in line with texture orientation, whereas movements orthogonal to texture orientation maximize the temporal frequency of stimulation. This may optimize temporal cues. In Experiment 1 we tested whether texture perception gets more precise the more orthogonal the movement direction is to the texture. We systematically varied the movement direction within a 2IFC spatial period discrimination task. As expected, perception was more precise (lower discrimination thresholds) when finger movements were directed closer towards the texture orthogonal as compared to in parallel to the texture. In Experiment 2 we investigated whether people adjust movement directions to the texture orthogonal in free exploration. We recorded movement directions during free exploration of standard and comparison gratings. The standard gratings were clearly oriented. The comparison gratings did not have a clear orientation defined by grooves. Participants adjusted movement directions to the texture orthogonal only for clearly oriented textures (standards). The adjustment to texture orthogonal was present in the final movement but not in the first movement. This suggests that movement adjustment is based on sensory signals for texture orientation that were gathered over the course of exploration. In Experiment 3 we assessed whether the perception of texture orientation and movement adjustments are based on shared sensory signals. We determined perceptual thresholds for orientation discrimination and computed ‘movometric’ thresholds from the stroke-by-stroke adjustment of movement direction. Perception and movements were influenced by a common factor, the spatial period, suggesting that the same sensory signals for texture orientation contribute to both. We conclude that people optimize texture perception by adjusting their movements in directions that maximize temporal cue frequency. Adjustments are performed on the basis of sensory signals that are also used for perception. [ABSTRACT FROM AUTHOR]

Somatosensory feedback of the hand is essential for object identification. Without somatosensory feedback, individuals cannot reliably determine the size or compliance of an object. Electrical nerve stimulation can restore localized tactile and proprioceptive feedback with intensity discrimination capability similar to natural sensation. We hypothesized that adding artificial somatosensation improves object recognition accuracy when using a prosthesis. To test this hypothesis, we provided different forms of sensory feedback–tactile, proprioceptive, or both–to two subjects with upper limb loss. The subjects were asked to identify the size or mechanical compliance of different foam blocks placed in the prosthetic hand while visually and audibly blinded. During trials, we did not inform the subjects of their performance, but did ask them about their confidence in correctly identifying objects. Finally, we recorded applied pressures during object interaction. Subjects were free to use any strategy they chose to examine the objects. Object identification was most accurate with both tactile and proprioceptive feedback. The relative importance of each type of feedback, however, depended on object characteristics and task. Sensory feedback increased subject confidence and was directly correlated with accuracy. Subjects applied less pressure to the objects when they had tactile pressure feedback. Artificial somatosensory feedback improves object recognition and the relative importance of tactile versus proprioceptive feedback depends on the test set. We believe this test battery provides an effective means to assess the impact of sensory restoration and the relative contribution of different forms of feedback (tactile vs. kinesthetic) within the neurorehabilitation field. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the feasibility of 3D anterior segment optical coherence tomography (AS-OCT) for the detection of corneal endothelial features in patients with Fuchs’ Endothelial Corneal Dystrophy (FECD). Methods: Twenty patients with clinical diagnosis of FECD (group A), and 20 control subjects (group B) were enrolled. In all patients a complete ophthalmological examination was performed, including best corrected visual acuity (BCVA), slit lamp examination for subjective grading of FECD and corneal endothelial specular microscopy. A 512x128 AS-OCT cube centered on the corneal apex was performed, and then the inner surface of the cornea was visualized and analyzed individually. Results: Overall, the study participants were adults (mean age was 57.35 ± 8.45 years [mean ± SD] 80% female) with a BCVA ranged from 1.3 to 0 LogMAR. The OCT analysis disclosed three different patterns of the corneal endothelium (1, 2, 3) according to the signal distribution and the level of reflectivity: a homogenous, hypo-reflective surface (pattern 1); the presence of hyper-reflective orange-yellowish points (pattern 2); and a mottled appearance with a variable number of hyper-reflective areas (pattern 3). The distributions of these morphological models in the two populations were as follows: patterns 1, 2 and 3 were observed respectively in 0%, 80%, and 20% of patients in group A, and in 80%, 20% and 0% of subjects in group B. Correlation analysis unveiled a positive relationship between OCT corneal endothelium reflectivity and the clinical severity score (assessed with biomicroscopy), as well as an inverse relationship between the OCT pattern and the integrity of corneal endothelium. Conclusion: 3D AS-OCT is a useful tool in investigation of endothelial features and therefore may represent a valuable support in the setting of FECD diagnosis and staging. [ABSTRACT FROM AUTHOR]

We study a self-organising neural network model of how visual representations in the primate dorsal visual pathway are transformed from an eye-centred to head-centred frame of reference. The model has previously been shown to robustly develop head-centred output neurons with a standard trace learning rule, but only under limited conditions. Specifically it fails when incorporating visual input neurons with monotonic gain modulation by eye-position. Since eye-centred neurons with monotonic gain modulation are so common in the dorsal visual pathway, it is an important challenge to show how efferent synaptic connections from these neurons may self-organise to produce head-centred responses in a subpopulation of postsynaptic neurons. We show for the first time how a variety of modified, yet still biologically plausible, versions of the standard trace learning rule enable the model to perform a coordinate transformation from eye-centred to head-centred reference frames when the visual input neurons have monotonic gain modulation by eye-position. [ABSTRACT FROM AUTHOR]

Workplace architectural lighting conditions that are biologically dim during the day are causing healthy individuals to experience light-induced health and performance-related problems. Dynamic lighting was reported beneficial in supporting individuals’ psychological behavior and physiological responses during work period in Europe. It has yet to be investigated in workplaces with minimal/no natural daylight contribution in tropical Malaysia. Hence, an exploratory experimental study was initiated in an experimental windowless open-plan workplace in Universiti Putra Malaysia, Serdang. The aim was to identify dynamic lighting configurations that were more supportive of a morning boosting effect than the control constant lighting, to support dayshift individuals’ psychophysiological wellbeing indicators during the peak morning work period. The immediate impact of a 2-hour morning exposure to overhead white LED (6500 K) with different horizontal illuminance levels and oscillations (lighting patterns) were investigated on physiological indicator limited to urinary 6-sulfatoxymelatonin, and psychological indicators for alertness, mood, visual comfort, cognitive and visual task performance. Not all of the investigated dynamic lighting configurations were supportive of a morning boost. Only configurations 500increased to750 and 500increased to1000 lx therapeutically supported most of the indicators. Both these configurations suppressed urinary 6-sulfatoxymelatonin, and improved alertness, cognitive performance, positive affect, and visual comfort better than ‘visit 1: 500constant500’ lx (control). The increasing oscillation was observed more beneficial for the morning boost in tropical Malaysia, which is in reverse to that specified in the human rhythmic dynamic lighting protocol developed by researchers from the Netherlands for application during winter. The findings from this study present the feasibility of dynamic architectural lighting acting as an environmental therapeutic solution in supporting the individuals’ psychophysiological wellbeing indicators in windowless open-plan workplace in tropical Malaysia. Further investigations on the two prospective configurations are recommended to determine the better supportive one for the morning boosting effect in Malaysia. [ABSTRACT FROM AUTHOR]

Our work applies Universal Design criteria for producing and using Mathematics videos for primary education students, at a time when many countries are shifting towards inclusive education policies. We have focused on how the accessibility criteria used for students with visual impairments might affect non-disabled students. For this, we reviewed applicable Universal Design principles as well as best practices in multimedia learning. We took into account the roles, procedures, tools and standards involved in the multimedia lifecycle. We then undertook an experiment consisting of producing two videos about prime numbers with the same pedagogical contents; one video was accessible for students with visual impairments and the other one was not accessible to them. We conducted a trial in real world school settings with 228 non-disabled children, who were randomly assigned a version, either accessible or not accessible, and were then asked to take a test to measure objective aspects of their learning concerning retention and transfer as well as several subjective aspects, including the attractiveness of the videos. Results indicate that there were no significant differences in the scores obtained by students using either video, although the group who watched the accessible video obtained higher score medians in the retention questions. Moreover, students found the accessible video significantly more attractive (p = 0.042). Our study provides recommendations for different stakeholders and stages within the process of producing multimedia mathematics materials that are accessible to primary students with visual impairments, as well as evidence demonstrating that everybody can benefit from the recommendations for developing good quality, accessible multimedia material. [ABSTRACT FROM AUTHOR]

The purpose of the current study was to examine the relationship between expertise, performance, and gaze behavior in a complex error-detection cockpit task. Twenty-four pilots and 26 non-pilots viewed video-clips from a pilot’s viewpoint and were asked to detect malfunctions in the cockpit instrument panel. Compared to non-pilots, pilots detected more malfunctioning instruments, had shorter dwell times on the instruments, made more transitions, visited task-relevant areas more often, and dwelled longer on the areas between the instruments. These results provide evidence for three theories that explain underlying processes for expert performance: The long-term working memory theory, the information-reduction hypothesis, and the holistic model of image perception. In addition, the results for generic attentional skills indicated a higher capability to switch between global and local information processing in pilots compared to non-pilots. Taken together, the results suggest that gaze behavior as well as other generic skills may provide important information concerning underlying processes that can explain successful performance during flight in expert pilots. [ABSTRACT FROM AUTHOR]

The McGurk effect is a classic audiovisual speech illusion in which discrepant auditory and visual syllables can lead to a fused percept (e.g., an auditory /bɑ/ paired with a visual /gɑ/ often leads to the perception of /dɑ/). The McGurk effect is robust and easily replicated in pooled group data, but there is tremendous variability in the extent to which individual participants are susceptible to it. In some studies, the rate at which individuals report fusion responses ranges from 0% to 100%. Despite its widespread use in the audiovisual speech perception literature, the roots of the wide variability in McGurk susceptibility are largely unknown. This study evaluated whether several perceptual and cognitive traits are related to McGurk susceptibility through correlational analyses and mixed effects modeling. We found that an individual’s susceptibility to the McGurk effect was related to their ability to extract place of articulation information from the visual signal (i.e., a more fine-grained analysis of lipreading ability), but not to scores on tasks measuring attentional control, processing speed, working memory capacity, or auditory perceptual gradiency. These results provide support for the claim that a small amount of the variability in susceptibility to the McGurk effect is attributable to lipreading skill. In contrast, cognitive and perceptual abilities that are commonly used predictors in individual differences studies do not appear to underlie susceptibility to the McGurk effect. [ABSTRACT FROM AUTHOR]

This study investigated whether visual stimuli (FACES vs. CARS) combined with the presence of maternal scent can influence suck patterning in healthy infants. Fifteen healthy full-term infants (six months and younger) were exposed to their mother’s scent during a visual preference paradigm consisting of FACES vs. CARS stimuli while sucking on a custom research pacifier. Infants looked significantly longer to the FACES compared to CARS, p = .041. Repeated Measures ANOVA revealed a significant main effect for non-nutritive suck (NNS) bursts and visual stimuli (p = .001) with the largest differences evident between FACES and when the infant looked away from the visual stimuli (p = 0.008) as well as between FACES and CARS (p = 0.026). These preliminary findings suggest that infants have more suck attempts when looking at FACES in the presence of maternal scent thereby indicating potent links between visual preference and suck behavior. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate, through (OCT), alterations in retinal thickness, secondary to use of ethambutol in the treatment of patients with tuberculosis. In addition to studying the use of simpler semiological tools, such as Amsler and Ishihara, in the screening of these cases. Methods: Thirty patients with ethambutol were recruited from the reference service of tuberculosis treatment at the Federal University of Espírito Santo from May 2015 to July 2016. After clinical history, the following parameters were analyzed; best corrected visual acuity, biomicroscopy, tonometry, photomotor reflex testing, Ishihara test, Amsler’s grid test, color digital retinography and optical coherence tomography with CIRRUS HD-OCT (Humphrey-Zeiss) every 2 months during treatment with ethambutol. They were divided into two groups according to the treatment: (1) standard group, two months of ethambutol; (2) extended group, nine to twelve months of ethambutol. Results: There was a significant reduction in OCT thickness between the pre and post treatment times in ten eyes of the extended group, mean reduction of 7,8 microns and in seven eyes of the standard group, with an average of 5.57 microns. During the study, a significant reduction of retinal thickness was observed in both groups at two months of treatment, and the delta percentage was higher in those patients who presented reduction of visual acuity and / or change in the Ishihara test. Conclusion: There was a significant reduction in the thickness of the nerve fiber layer by OCT in the patients studied, being more pronounced in those submitted to the extended treatment regimen. This reduction was observed two months after the start of therapy, and was more significant in the cases that presented changes in the Ishihara test. [ABSTRACT FROM AUTHOR]

Cerebellar ataxia is a neurological disorder due to dysfunction of the cerebellum that affects coordination of fine movement, gait, and balance. Although ataxic patients commonly exhibit abnormal eye movement and have difficulties with saccadic reading, quantification of ocular motor abilities during reading in the clinical setting is rarely done. In this study, we assess visual performance with simple reading tests that can be used in the clinical setting and performed video infrared oculography in 11 patients with hereditary or acquired cerebellar ataxia and 11 age-matched controls. We found that compared with controls, ataxic patients read significantly slower on regularly and irregularly spaced 120 single-digit number reading tasks (read aloud) (p = 0.02 for both) but not on a word reading task (read silently), although there was large variability on the word reading task. Among the 3 reading tasks, the regularly spaced number reading task had the greatest difference (44%) between ataxic patients and controls. Analysis of oculography revealed that ataxic patients had slower reading speeds on the regularly spaced number reading task because of significantly higher saccade and fixation counts, impairment of small amplitude progressive saccades as well as large amplitude, line-changing saccades, greater fixation dispersion, and irregularity of scan paths and staircase gaze patterns. Our findings show that infrared oculography remains the gold standard in assessment of ocular motor difficulties during reading in ataxic patients. In the absence of this capability in the clinical setting, a simple 120 regularly spaced single-digit saccadic number reading test, which most patients can perform in less than 2 minutes, can be a possible biomarker for ocular motor abilities necessary for reading. [ABSTRACT FROM AUTHOR]

The intrinsic factors (IF) influencing visual attention performance (VAP) might cause potential human errors, such as “error/mistake”, “forgetting” and “omission”. It is a key issue to develop a systematic assessment of IF in order to distinguish the levels of VAP. Motivated by the Stimulus-Response (S-R) model, we take an interactive cancellation test—Neuron Type Test (NTT)—to explore the IF and present the corresponding systematic assessment. The main contributions of this work include three elements: a) modeling the IF on account of attention span, attention stability, distribution-shift of attention with measurable parameters by combining the psychological and statistical concepts; b) proposing quantitative analysis methods for assessing the IF via its computational representation—intrinsic qualities (IQ)—in the sense of computational model; and c) clustering the IQ of air traffic control (ATC) students in the feature space of interest. The response sequences of participants collected with the NTT system are characterized by three parameters: Hurst exponent, normalized number of decisions (NNoD) and error rate of decisions (ERD). The K-means clustering is applied to partition the feature space constructed from practical data of VAP. For the distinguishable clusters, the statistical inference is utilized to refine the assessment of IF. Our comprehensive analysis shows that the IQ can be classified into four levels, i.e., excellent, good, moderate and unqualified, which has a potential application in selecting air traffic controllers subject to reducing the risk of the inadequacy of attention performances in aviation safety management. [ABSTRACT FROM AUTHOR]

When interacting with virtual environments, feedback delays between making a movement and seeing the visual consequences of that movement are detrimental for the subjective quality of the VR experience. Here we used standard measures of subjective experiences such as ownership, agency and presence to investigate whether prolonged exposure to the delay, and thus the possibility to adapt to it, leads to the recovery of the qualitative experience of VR. Participants performed a target-tracking task in a Virtual Reality environment. We measured the participants’ tracking performance in terms of spatial and temporal errors with respect to the target in both No-Delay and Delay conditions. Additionally, participants rated their sense of “ownership” of holding a virtual tool, agency and presence on each trial using sliding scales. These single trial ratings were compared to the results of the more traditional questionnaires for ownership and agency and presence for both No-Delay and Delay conditions. We found that the participants’ sliding scales ratings corresponded very well to the scores obtained from the traditional questionnaires. Moreover, not only did participants behaviourally adapt to the delay, their ratings of ownership and agency significantly improved with prolonged exposure to the delay. Together the results suggest a tight link between the ability to perform a behavioural task and the subjective ratings of ownership and agency in virtual reality. [ABSTRACT FROM AUTHOR]

Background: Vision plays an important role in controlling posture and balance in children. Reduced postural control has been reported in children with strabismus, but little has been reported specifically in amblyopia. Objective: To investigate whether children with amblyopia have reduced balance compared to both children with strabismus without amblyopia and healthy controls. Study design and methods: In this cross-sectional study, a total of 56 patients and healthy controls were recruited from the Ophthalmology and Otolaryngology Clinics at The Hospital for Sick Children, Toronto. Participants were divided into three groups: (1) 18 with unilateral amblyopia (strabismic amblyopia or mixed mechanism); (2) 16 with strabismus only without amblyopia; and (3) 22 visually-normal controls. The primary outcome was the balance performance as measured by the balance subtest of the Bruininks-Oseretsky Test of Motor Proficiency 2 [BOT2]. Results: The age and gender-adjusted BOT2 balance scores were significantly reduced in the amblyopia group (mean score 9.0 ± 3.1 SD) and the strabismus without amblyopia group (mean score 8.6 ± 2.4 SD) compared to visually normal controls (mean score 18.9 ± 4.2) (p<0.0001), but no statistical difference was demonstrated between the two patient groups (p = 0.907). Further subgroup analysis of the strabismus only group did not reveal a statistically significant difference in performance on BOT2 balance score between strabismus only patients with good stereopsis 60 sec or better (BOT2 mean score 9.8±3.0 SD) to patients with 3000 sec or no stereopsis (BOT2 mean score 7.9±1.7) (p = 0.144). Conclusion: Our findings suggest that normal vision plays an important role in the development and maintenance of balance control. When normal binocular vision is disrupted in childhood in strabismus and/or amblyopia, not only is the vision affected, but balance is also reduced. Our results indicate that the presence of even mild binocular discordance/dysfunction (patients with intermittent strabismus and good stereopsis) may lead to postural instability. [ABSTRACT FROM AUTHOR]

In vision science, cascades of Linear+Nonlinear transforms are very successful in modeling a number of perceptual experiences. However, the conventional literature is usually too focused on only describing the forward input-output transform. Instead, in this work we present the mathematics of such cascades beyond the forward transform, namely the Jacobian matrices and the inverse. The fundamental reason for this analytical treatment is that it offers useful analytical insight into the psychophysics, the physiology, and the function of the visual system. For instance, we show how the trends of the sensitivity (volume of the discrimination regions) and the adaptation of the receptive fields can be identified in the expression of the Jacobian w.r.t. the stimulus. This matrix also tells us which regions of the stimulus space are encoded more efficiently in multi-information terms. The Jacobian w.r.t. the parameters shows which aspects of the model have bigger impact in the response, and hence their relative relevance. The analytic inverse implies conditions for the response and model parameters to ensure appropriate decoding. From the experimental and applied perspective, (a) the Jacobian w.r.t. the stimulus is necessary in new experimental methods based on the synthesis of visual stimuli with interesting geometrical properties, (b) the Jacobian matrices w.r.t. the parameters are convenient to learn the model from classical experiments or alternative goal optimization, and (c) the inverse is a promising model-based alternative to blind machine-learning methods for neural decoding that do not include meaningful biological information. The theory is checked by building and testing a vision model that actually follows a modular Linear+Nonlinear program. Our illustrative derivable and invertible model consists of a cascade of modules that account for brightness, contrast, energy masking, and wavelet masking. To stress the generality of this modular setting we show examples where some of the canonical Divisive Normalization modules are substituted by equivalent modules such as the Wilson-Cowan interaction model (at the V1 cortex) or a tone-mapping model (at the retina). [ABSTRACT FROM AUTHOR]

It is currently not well understood whether people experience themselves to be located in one or more specific part(s) of their body. Virtual reality (VR) is increasingly used as a tool to study aspects of bodily perception and self-consciousness, due to its strong experimental control and ease in manipulating multi-sensory aspects of bodily experience. To investigate where people self-locate in their body within virtual reality, we asked participants to point directly at themselves with a virtual pointer, in a VR headset. In previous work employing a physical pointer, participants mainly located themselves in the upper face and upper torso. In this study, using a VR headset, participants mainly located themselves in the upper face. In an additional body template task where participants pointed at themselves on a picture of a simple body outline, participants pointed most often to the upper torso, followed by the (upper) face. These results raise the question as to whether head-mounted virtual reality might alter where people locate themselves making them more “head-centred”. [ABSTRACT FROM AUTHOR]

Motion in a distorted virtual 3D space may cause visually induced motion sickness. Geometric distortions in stereoscopic 3D can result from mismatches among image capture, display, and viewing parameters. Three pairs of potential mismatches are considered, including 1) camera separation vs. eye separation, 2) camera field of view (FOV) vs. screen FOV, and 3) camera convergence distance (i.e., distance from the cameras to the point where the convergence axes intersect) vs. screen distance from the observer. The effect of the viewer’s head positions (i.e., head lateral offset from the screen center) is also considered. The geometric model is expressed as a function of camera convergence distance, the ratios of the three parameter-pairs, and the offset of the head position. We analyze the impacts of these five variables separately and their interactions on geometric distortions. This model facilitates insights into the various distortions and leads to methods whereby the user can minimize geometric distortions caused by some parameter-pair mismatches through adjusting of other parameter pairs. For example, in postproduction, viewers can correct for a mismatch between camera separation and eye separation by adjusting their distance from the real screen and changing the effective camera convergence distance. [ABSTRACT FROM AUTHOR]

Objective: Comparison of conventional Penetrating Keratoplasty (PKP), posterior mushroom PKP and Descemet's Stripping Automated Endothelial Keratoplasty (DSAEK) regarding overall graft survival of primary corneal transplants for Fuchs´ endothelial dystrophy (FED), best spectacle-corrected visual acuity (BSCVA) and astigmatism. Methods: Single centre study using prospectively collected data from the national database for follow-up of corneal transplants. Main outcome parameters: 10 years graft survival, astigmatism at 24 months, pre- and post-operative BSCVA. Results: In total, 721 cases were included: PKP, n = 171; posterior mushroom PKP, n = 91; and DSAEK, n = 459. There was no significant difference in graft survival between PKP, posterior mushroom PKP and the DSAEK technique (log-rank test, P = 0.12). The overall post-operative BSCVA improvement in all treatment groups was significant (paired t-test, P<0.001). Pre-operative BSCVA was better for the DSAEK group (0.68 ± 0.41 logMAR) as compared to the PKP (0.89 ± 0.53) and posterior mushroom PKP group (0.90 ± 0.58); ANOVA, P<0.001. After 24 months, BSCVA was significantly better for the DSAEK group (0.25 ± 0.26 logMAR) compared to the PKP (0.35 ± 0.29) and posterior mushroom PKP group (0.41 ± 0.42); ANOVA, P<0.001. A significant difference in astigmatism was found (median test, P<0.001) between the DSAEK (1.7 ± 1.1 D), PKP (4.6 ± 2.7 D) and posterior mushroom PKP group (4.5 ± 3.3 D). The significantly lower DSAEK-induced astigmatism was confirmed by vector analysis. Conclusion: There was no difference in graft survival and BSCVA improvement between conventional PKP, inverted mushroom PKP and DSAEK in this study. The significantly lower changes in astigmatism, wound stability and faster visual rehabilitation with DSAEK surgery are favourable aspects of this technique. The benefits of posterior lamellar keratoplasty warrant earlier intervention, which may contribute to preserve better vision for a prolonged period of remaining lifetime. [ABSTRACT FROM AUTHOR]

This study identifies and applies methods for evaluating the human response to pedestrian lighting applications intended for future use by the municipality of Malmö, Sweden. The methods employed provide a supplementary perspective to that given by the photometric properties of the lighting applications. The study involved 89 participants from two age groups (Young: N: 43, 19–31 yrs.; Elderly: N: 46, 62–77 yrs.). Data were collected in a full-scale laboratory using a mock-up pedestrian pathway. Three lighting applications (one ceramic metal halide and two LED) were presented and the participants’ behavior (walking speed), perception (ability to perform visual tasks–recognize facial expressions, detect obstacles, read street signpost), affective response, and evaluation of the lighting quality were assessed. The three lighting applications significantly differed with regard to the human response. The facial expression recognition distance, sign reading distance and the obstacle detection task, along with the evaluation of lighting quality and level of arousal, distinguished one of the LEDs (Correlated Color Temperature: 3810, Color Rendering Index: 75, Scotopic/Photopic ratio: 1.48) from the other two lighting applications–the participants performed better on the visual tasks, and the lighting was perceived as brighter, more arousing and less pleasant. Methods to capture human perception, evaluation and behavior in relation to outdoor lighting, provide a valuable perspective that should be systematically applied when municipalities consider different pedestrian lighting applications. [ABSTRACT FROM AUTHOR]

When people carry out cognitive tasks, they sometimes suffer from distractions, that is, drops in performance that occur close in time to task-irrelevant stimuli. In this research, we examine how the pursuit of rewards contributes to distractions. In two experiments, participants performed a math task (in which they could earn monetary rewards vs. not) while they were exposed to task-irrelevant stimuli (that were previously associated with monetary rewards vs. not). In Experiment 1, irrelevant cues that were previously associated with rewards (vs. not) impaired performance. In Experiment 2, this effect was only replicated when these reward-associated distractors appeared relatively early during task performance. While the results were thus somewhat mixed, they generally support the idea that reward associations can augment the negative effect of distractors on performance. [ABSTRACT FROM AUTHOR]

Purpose: Ellipsoid zone (EZ) and outer retinal integrity are strongly linked to visual prognosis, but quantitative normative data is lacking. This study evaluates the EZ, outer retina, and inner retina in eyes without macular disease across a wide age spectrum. Methods: An IRB-approved study was performed for eyes without macular pathology undergoing Spectral Domain Optical Coherence Tomography (SD-OCT) scans on the Cirrus HD-OCT system (Carl Zeiss Meditec, Oberkochen, Germany). Scans were analyzed using a previously described automated EZ mapping tool with line-by-line manual verification. Segmentation included internal limiting membrane (ILM), outer nuclear layer/Henle fiber layer complex (ONL/HFL), EZ, and the retinal pigment epithelium (RPE). The output included metrics for the inner retina (ILM-OPL/HFL), outer retina (ONL/HFL-RPE), EZ-RPE area and volume, and en face EZ mapping. EZ-RPE attenuation on en face mapping was defined as EZ-RPE thickness < 20 um, and total attenuation was 0 um. Imaging parameters were assessed for the group and compared to age, sex, visual acuity and spherical equivalent. Results: 167 eyes from 167 subjects were included. Mean age was 49.7 years (range 10–84 years). The mean foveal retinal thickness was 200.58 ± 19.22 um. Mean inner retinal thickness was 21.47 ± 13.60 um. Mean outer retinal thickness was 179.11 ± 18.52 um. Mean EZ-RPE thickness was 50.58 ± 6.01um. The mean EZ-RPE volume was 1.20 ± 0.10 mm3. Mean EZ attenuation percentage per macular map area was 0.87% ± 1.13% and mean percentage total attenuation was 0.12% ± 0.14%. Total and inner retinal thickness metrics decreased with age. Mean outer retinal thickness increased with age. EZ-RPE parameters were unchanged with age. However, EZ attenuation was negatively correlated with age. Conclusion: This study provides important information for inner and outer retinal parameters. Future research on quantitative EZ integrity can utilize this data for comparison. [ABSTRACT FROM AUTHOR]

Neuroscience investigations are most often focused on the prediction of future perception or decisions based on prior brain states or stimulus presentations. However, the brain can also process information retroactively, such that later stimuli impact conscious percepts of the stimuli that have already occurred (called “postdiction”). Postdictive effects have thus far been mostly unimodal (such as apparent motion), and the models for postdiction have accordingly been limited to early sensory regions of one modality. We have discovered two related multimodal illusions in which audition instigates postdictive changes in visual perception. In the first illusion (called the “Illusory Audiovisual Rabbit”), the location of an illusory flash is influenced by an auditory beep-flash pair that follows the perceived illusory flash. In the second illusion (called the “Invisible Audiovisual Rabbit”), a beep-flash pair following a real flash suppresses the perception of the earlier flash. Thus, we showed experimentally that these two effects are influenced significantly by postdiction. The audiovisual rabbit illusions indicate that postdiction can bridge the senses, uncovering a relatively-neglected yet critical type of neural processing underlying perceptual awareness. Furthermore, these two new illusions broaden the Double Flash Illusion, in which a single real flash is doubled by two sounds. Whereas the double flash indicated that audition can create an illusory flash, these rabbit illusions expand audition’s influence on vision to the suppression of a real flash and the relocation of an illusory flash. These new additions to auditory-visual interactions indicate a spatio-temporally fine-tuned coupling of the senses to generate perception. [ABSTRACT FROM AUTHOR]

It is very important to automatically detect violent behaviors in video surveillance scenarios, for instance, railway stations, gymnasiums and psychiatric centers. However, the previous detection methods usually extract descriptors around the spatiotemporal interesting points or extract statistic features in the motion regions, leading to limited abilities to effectively detect video-based violence activities. To address this issue, we propose a novel method to detect violence sequences. Firstly, the motion regions are segmented according to the distribution of optical flow fields. Secondly, in the motion regions, we propose to extract two kinds of low-level features to represent the appearance and dynamics for violent behaviors. The proposed low-level features are the Local Histogram of Oriented Gradient (LHOG) descriptor extracted from RGB images and the Local Histogram of Optical Flow (LHOF) descriptor extracted from optical flow images. Thirdly, the extracted features are coded using Bag of Words (BoW) model to eliminate redundant information and a specific-length vector is obtained for each video clip. At last, the video-level vectors are classified by Support Vector Machine (SVM). Experimental results on three challenging benchmark datasets demonstrate that the proposed detection approach is superior to the previous methods. [ABSTRACT FROM AUTHOR]

Perception of verticality is required for normal daily function, yet the typical human detection error range has not been well characterized. Vertical misperception has been correlated with poor postural control and functionality in patients after stroke and after vestibular disorders. Until now, all the published studies that assessed Subjective Postural Vertical (SPV) in the seated position used small groups to establish a reference value. However, this sample size does not represent the healthy population for comparison with conditions resulting in pathological vertical. Therefore, the primary objective was to conduct a systematic review with meta-analyses of Subjective Postural Vertical (SPV) data in seated position in healthy adults to establish the reference value with a representative sample. The secondary objective was to investigate the methodological characteristics of different assessment protocols of SPV described in the literature. A systematic literature search was conducted using Medline, EMBASE, and Cochrane libraries. Mean and standard deviation of SPV in frontal and sagittal planes were considered as effect size measures. Sixteen of 129 identified studies met eligibility criteria for our systematic review (n = 337 subjects in the frontal plane; n = 187 subjects in sagittal plane). The meta-analyses measure was estimated using the pooled mean as the estimator and its respective error. Mean reference values were 0.12°±1.49° for the frontal plane and 0.02°±1.82° for the sagittal plane. There was a small variability of the results and this systematic review resulted in representative values for SPV. The critical analysis of the studies and observed homogeneity in the sample suggests that the methodological differences used in the studies did not influence SPV assessment of directional bias in healthy subjects. These data can serve as a reference for clinical studies in disorders of verticality. [ABSTRACT FROM AUTHOR]

When focused on a specific internal task like calculating a multiplication in mind we are able to ignore sensory distraction. This may be achieved by effective perceptual decoupling during internally directed cognition. The present study investigated whether decoupling from external events during internally directed cognition represents an active shielding mechanism that adapts to expected external distraction or a passive/automatic shielding mechanism that is independent of external distraction. Participants performed multiplications in mind (e.g. 26 x 7), a task that required to turn attention inward as soon as the problem was encoded. At the beginning of a block of trials, participants were informed whether or not distractors could appear during the calculation period, thereby potentially allowing them to prepare for the distractors. We tracked their eye behavior as markers of perceptual decoupling and workload. Turning attention inward to calculate the multiplication elicited evidence of perceptual decoupling for five of six eye parameters: blink rate, saccade and microsaccade rate increased, gaze was less constricted to the center, and pupils dilated. Although participants perceived blocks with distractors as more challenging, performance and eye behavior markers of both perceptual decoupling and workload were unaffected. This result supports the notion of perceptual decoupling as an automatic mechanism: focusing inward induces desensitization to external events independent of external distraction. [ABSTRACT FROM AUTHOR]

Aim: The present study utilizes perceptual hysteresis effects to compare the ambiguity of Mona Lisa’s emotional face expression (high-level ambiguity) and of geometric cube stimuli (low-level ambiguity). Methods: In two experiments we presented series of nine Mona Lisa variants and nine cube variants. Stimulus ambiguity was manipulated by changing Mona Lisa’s mouth curvature (Exp. 1) and the cubes’ back-layer luminance (Exp. 2). Each experiment consisted of three conditions, two with opposite stimulus presentation sequences with increasing and decreasing degrees of ambiguity, respectively, and a third condition with a random presentation sequence. Participants indicated happy or sad face percepts (Exp. 1) and alternative 3D cube percepts (Exp. 2) by key presses. We studied the influences of a priori perceptual biases (long-term memory) and presentation order (short-term memory) on perception. Results: Perception followed sigmoidal functions of the stimulus ambiguity morphing parameters. The morphing parameter for the functions’ inflection points depended strongly on stimulus presentation order with similar effect sizes but different signs for the two stimulus types (positive hysteresis / priming for the cubes; negative hysteresis / adaptation for Mona Lisa). In the random conditions, the inflection points were located in the middle between those from the two directional conditions for the Mona Lisa stimuli. For the cube stimuli, they were superimposed on one sigmoidal function for the ordered condition. Discussion: The hysteresis effects reflect the influence of short-term memory during the perceptual disambiguation of ambiguous sensory information. The effects for the two stimulus types are of similar size, explaining up to 34% of the perceptual variance introduced by the paradigm. We explain the qualitative difference between positive and negative hysteresis with adaptation for Mona Lisa and with priming for the cubes. In addition, the hysteresis paradigm allows a quantitative determination of the impact of adaptation and priming during the resolution of perceptual ambiguities. The asymmetric shifts of inflection points in the case of the cube stimuli is likely due to an a priori perceptual bias, reflecting an influence of long-term memory. Whether corresponding influences also exist for the Mona Lisa variants is so far unclear. [ABSTRACT FROM AUTHOR]

Despite a large body of research on response properties of neurons in the inferior temporal (IT) cortex, studies to date have not yet produced quantitative feature descriptions that can predict responses to arbitrary objects. This deficit in the research prevents a thorough understanding of object representation in the IT cortex. Here we propose a fragment-based approach for finding quantitative feature descriptions of face neurons in the IT cortex. The development of the proposed method was driven by the assumption that it is possible to recover features from a set of natural image fragments if the set is sufficiently large. To find the feature from the set, we compared object responses predicted from each fragment and responses of neurons to these objects, and search for the fragment that revealed the highest correlation with neural object responses. Prediction of object responses of each fragment was made by normalizing Euclidian distance between the fragment and each object to 0 to 1 such that the smaller distance gives the higher value. The distance was calculated at the space where images were transformed to a local orientation space by a Gabor filter and a local max operation. The method allowed us to find features with a correlation coefficient between predicted and neural responses of 0.68 on average (number of object stimuli, 104) from among 560,000 feature candidates, reliably explaining differential responses among faces as well as a general preference for faces over to non-face objects. Furthermore, predicted responses of the resulting features to novel object images were significantly correlated with neural responses to these images. Identification of features comprising specific, moderately complex combinations of local orientations and colors enabled us to predict responses to upright and inverted faces, which provided a possible mechanism of face inversion effects. (292/300). [ABSTRACT FROM AUTHOR]

Multi-focus image fusion is an effective approach to obtain the all-in-focus image. Focus detection is the key issue of multi-focus image fusion. Aiming at the shortcoming of spatial domain and transform domain algorithms for multi-focus image fusion, a novel multi-focus image fusion algorithm is proposed by combing focus detection in spatial domain and non-subsampled contourlet transform (NSCT) domain. At first, the focused pixels are detected by the sum-modified-Laplacian algorithm in spatial domain. At the same time, the focus detection method is proposed in NSCT domain, namely by MPCNN and voting fusion methods for high-frequency subbands of NSCT. Then, the morphological operation is utilized to correct the focus detection results in spatial domain and NSCT domain. At last, synthesis of detection results is implemented and the fused image can be obtained. Experimental results verified that the proposed algorithm outperformed some state-of-the-art fusion algorithms in terms of both subjective observation and objective evaluations. [ABSTRACT FROM AUTHOR]

A common measure of multisensory integration is the McGurk effect, an illusion in which incongruent auditory and visual speech are integrated to produce an entirely different percept. Published studies report that participants who differ in age, gender, culture, native language, or traits related to neurological or psychiatric disorders also differ in their susceptibility to the McGurk effect. These group-level differences are used as evidence for fundamental alterations in sensory processing between populations. Using empirical data and statistical simulations tested under a range of conditions, we show that published estimates of group differences in the McGurk effect are inflated when only statistically significant (p < 0.05) results are published. With a sample size typical of published studies, a group difference of 10% would be reported as 31%. As a consequence of this inflation, follow-up studies often fail to replicate published reports of large between-group differences. Inaccurate estimates of effect sizes and replication failures are especially problematic in studies of clinical populations involving expensive and time-consuming interventions, such as training paradigms to improve sensory processing. Reducing effect size inflation and increasing replicability requires increasing the number of participants by an order of magnitude compared with current practice. [ABSTRACT FROM AUTHOR]

Purpose: The internal limiting membrane (ILM) is a normal part of the retina, and the outcomes of ILM removal have not been fully investigated. ILM flap inversion is a recently developed technique that increases the success rate of macular hole (MH) surgery. Thus, we compared the anatomical closure rate and visual outcome in patients undergoing microincision vitrectomy surgery (MIVS) with ILM flap inversion or conventional ILM peeling for the treatment of MH. Methods: The medical records of 90 eyes with MH were reviewed retrospectively. The patients were classified into two groups based on MIVS procedure (group 1: ILM flap inversion, 46 eyes; group 2: ILM peeling, 44 eyes). Results: Preoperative characteristics were similar in the two groups, and there were no significant differences in 1 month- or 6 month-postoperative VA between the groups (P = 0.25 and P = 0.42, respectively). However, the surgical success rate was significantly higher in group 1 than group 2 (P = 0.04; 46/46: 100% and 41/44: 93%, respectively). Multiple regression analysis revealed that axial length and MH diameter were independent factors predicting 6-month postoperative BCVA in group 2 (P = 0.001 and P = 0.03, respectively), and that MH diameter was an independent factor predicting 6-month postoperative VA in group 1 (P = 0.03). Logistic regression analysis revealed that axial length (OR = 2.11; P = 0.02; area under the curve: 0.94; cut off score: 28.4 mm) was an independent factor indicating surgical failure in group 2. Conclusion: Our results suggest that MIVS with ILM flap inversion might be best suited to treat MH, particularly in patients with high myopia. [ABSTRACT FROM AUTHOR]