Human saccadic eye movements and tracking by active foveation in log polar space

One of the possible models of the human visual system (HVS) in the computer vision literature has a high resolution fovea and exponentially decreasing resolution periphery. The high resolution fovea is used to extract necessary information in order to solve a vision task and the periphery may be used to detect motion. To obtain the desired information, the fovea is guided by the contents of the scene and other knowledge to position the fovea over areas of interest. These eye movements are called saccades and corrective saccades. A two stage process has been implemented as a mechanism for changing foveation in log polar space. Initially, the open loop stage roughly foveates on the best interest feature and then the closed loop stage is invoked to accurately iteratively converge onto the foveation point. The open loop stage developed for the foveation algorithm is applied to saccadic eye movements and a tracking system. Log polar space is preferred over Cartesian space as: (1) it simultaneously provides high resolution and a wide viewing angle; and (2) feature invariance occurs in the fovea which simplifies the foveation process.

Simulated hyperopic anisometropia and reading, visual information processing, and reading-related eye movement performance in children.

Purpose: This study investigated the impact of simulated hyperopic anisometropia and sustained near work on performance of academic-related measures in children.
Methods: Participants included 16 children (mean age: 11.1 ± 0.8 years) with minimal refractive error. Academic-related outcome measures included a reading test (Neale Analysis of Reading Ability), visual information–processing tests (Coding and Symbol Search subtests from the Wechsler Intelligence Scale for Children), and a reading-related eye movement test (Developmental Eye Movement test). Performance was assessed with and without 0.75 diopters of simulated monocular hyperopic defocus (administered in a randomized order), before and after 20 minutes of sustained near work. Unilateral hyperopic defocus was systematically assigned to either the dominant or nondominant sighting eye to evaluate the impact of ocular dominance on any performance decrements.
Results: Simulated hyperopic anisometropia and sustained near work both independently reduced performance on all of the outcome measures (P < 0.001). A significant interaction was also observed between simulated anisometropia and near work (P < 0.05), with the greatest decrement in performance observed during simulated anisometropia in combination with sustained near work. Laterality of the refractive error simulation (ocular dominance) did not significantly influence the outcome measures (P > 0.05). A reduction of up to 12% in performance was observed across the range of academic-related measures following sustained near work undertaken during the anisometropic simulation.
Conclusions: Simulated hyperopic anisometropia significantly impaired academic-related performance, particularly in combination with sustained near work. The impact of uncorrected habitual anisometropia on academic-related performance in children requires further investigation. © 2014 The Association for Research in Vision and Ophthalmology, Inc.

Reduction of vividness and associated craving in personalized food imagery

This study aimed to extend recent experimental work on the efficacy of visuo-spatial working memory-based techniques for reducing food cravings by adopting a more naturalistic methodology. Fifty undergraduate women formed images of their favorite foods while performing a visuo-spatial task across six successive trials. Vividness and craving intensity were rated for each food image. Concurrent visuo-spatial processing reduced the vividness of, and craving reactivity to, personally relevant food images. Forehead tracking, a novel self-administered task, proved to be as effective in reducing vividness and craving ratings as the established visuo-spatial working memory laboratory tasks of eye movements, dynamic visual noise, and spatial tapping, and thus presents a simple, accessible technique potentially applicable in the home environment. All four tasks maintained their reducing effect over multiple trials. Individual differences in imaging ability and habitual food craving did not impact upon their effectiveness, indicating that visuo-spatial tasks can be successfully used to reduce food cravings across a range of people.

Gaze behavior among experts and trainees during optic disc examination : does how we look affect what we see?

Purpose. The authors compared the visual gaze behaviors of glaucoma subspecialists with those of ophthalmology trainees during optic disc and retinal nerve fiber layer (RNFL) examination.

Methods. Seven glaucoma subspecialists and 23 ophthalmology trainees participated in the project. Participants were shown eight glaucomatous optic disc images with varied morphology. Eye movements during examination of the optic disc photographs were tracked. For each disc image, graders were asked to assign a presumptive diagnosis for probability of glaucoma. There was no time restriction.

Results. Overall, trainees spent more time looking at disc images than glaucoma subspecialists (21.3 [13.9–37.7] vs. 16.6 [12.7–19.7]) seconds; median [interquartile range (IQR)], respectively; P < 0.01) and had no systematic patterns of gaze behavior, and gaze behavior was unaltered by disc morphology or topographic cues of pathology. Experienced viewers demonstrated more systematic and ordered gaze behavior patterns and spent longer times observing areas with the greatest likelihood of pathology (superior and inferior poles of the optic nerve head and adjacent RNFL) compared with the trainees. For discs with focal pathology, the proportion of total time spent examining definite areas of pathology was 28.9% (22.4%–33.6%) for glaucoma subspecialists and 13.5% (12.2%–19.2%) for trainees (median [IQR]; P < 0.05). Furthermore, experts adapted their viewing habits according to disc morphology.

Conclusions. Glaucoma subspecialists adopt systematic gaze behavior when examining the optic nerve and RNFL, whereas trainees do not. It remains to be elucidated whether incorporating systematic viewing behavior of the optic disc and RNFL into teaching programs for trainees may expedite their acquisition of accurate and efficient glaucoma diagnosis skills.

Wireless-based sleep technology for monitoring sleep apnea

Abstract: This paper covers the technical aspects of the wireless-based sleep technology for monitoring sleep apnea, which is a sleep disorder that can be detected via continuous monitoring. In this paper, a wireless system testbed is designed to monitor the patients for the signs of sleep apnea. The testbed is comprised of a number of biomedical sensors, which are used to monitor the related biological parameters related to the patient's sleeping mechanism, such as: nasal airflow, snoring, abdominal, leg, chest, and eye movements, blood oxygen level, blood pressure, and body position. The goal of this paper is to characterize the and model the data traffic generated from the biomedical sensors used in the sleep apnea study and find the network-centric lower traffic limits; minimum frequency deployment and minimum bandwidth required.

Emotional responses to filmed violence and the eye blink startle response

The study assessed gender differences in emotional responses to violent film. Both subjective emotional response and eye blink startle magnitude were assessed while 20 men and 20 women viewed a series of five violent film segments and five nature scenes. Participants exhibited higher levels of curiosity, anxiety, disgust, and anger, and lower levels of positive emotion and boredom in response to the violent film segments in comparison with the nature material. Startle response was magnified during the violent film segments, indicating an aversive response. Evidence that men and women responded to the violence differently was demonstrated by men' experiencing greater positive feelings, entertainment, and curiosity in relation to the violent film, whereas women reported more disgust, boredom, anger, and experienced greater startle in relation to the violent scenes portrayed in the film. Future directions for investigating filmed violence are outlined.

Ontogeny of movements and foraging ranges in the Australian sea lion

This study tracked the movements of Australian sea lion (Neophoca cinerea) pups, juveniles, and adult females to identify home ranges and determine if young sea lions accompanied their mothers at sea. Satellite tags were deployed on nine 15- mo-old pups, nine 23-mo-old juveniles, and twenty-nine adult female Australian sea lions at Seal Bay Conservation Park, Kangaroo Island, South Australia. Females did not travel with their offspring at sea, suggesting young Australian sea lions learn foraging behaviors independently. Although home ranges increased with age,  23-mo-old juveniles had not developed adult movement capacity and their range was only 40.6% of the adult range. Juveniles traveled shorter distances (34.8 ± 5.5 km) at slower speeds (2.0 ± 0.3 km/h) than adults (67.9 ± 3.5 km and 3.9 ± 0.3 km/h). Young sea lions also stayed in shallower waters; sea floor depths of mean locations were 48±7m for juveniles and 74±2m for females. Restricted to shallow coastal waters, pups and juveniles are more likely to be disproportionately impacted by human activities. With limited available foraging habitat, young Australian sea lions appear particularly vulnerable to environmental alterations resulting from fisheries or climate change.

The influence of age on reproductive success and diet in Australasian gannets (Morus Serrator) breeding at Pope's Eye, Port Phillip Bay, Victoria

The influence of age on reproductive success and diet was examined in ‘old’ (experienced; 12 years and older) and ‘young’ (5–8 years of age) Australasian gannets (Morus serrator) breeding at Pope’s Eye, Port Phillip Bay, Victoria during the 2002–2003 breeding period. Although food availability, as indicated by commercial fish catches, throughout this breeding period was low, there were no significant differences in breeding success or chick growth between groups. Nevertheless, old birds tended to have higher reproductive success, replacing more lost eggs and fledging chicks of a greater mass. However, old birds also laid more eggs that failed to hatch. Five fish species, including jack mackerel (Trachurus declivis), barracouta (Thyrsites atun), redbait (Emmelichthys nitidus), anchovy (Engraulis australis) and red mullet (Upeneichthys vlamingii), were important in the gannet diet during this breeding period. There were no significant differences in dietary parameters, including range of species and size of prey, between old and young gannets, nor were there any differences between those of the chicks and their parents, suggesting that adults do not forage selectively for their chicks. This study showed that even during a period of presumed low food availability, when experienced (older) birds might be expected to have enhanced success, the differences between these and less experienced (younger) birds may not be apparent.

Social inclusion, social movements, and the characteristics of late modernity

In discussing the ideology of social inclusion, this paper demonstrates that the composition of community groups in a period of late modernity is worthy of consideration. Although it would appear, on the surface at least, that previously stable community institutions, such as family, organised religion, trade unions, occupation and residential stability, and so on, are being challenged by a broad rejection of the once powerful tool of tradition, society's attachment to a belief in the symbolic value of community remains strong. In an environment however, in which the interaction and interdependence of human activity is subject to continual re-evaluation as the current processes of industrialisation and globalisation unfold, the template of what constitutes 'community' may need to be re-defined. It is to this end that the present paper is concerned, in that it seeks to identify new community formations. Of particular interest, is the rise and reach of modern day 'social movements', and why, when analysing the subject from a macro-sociological perspective, they have come to assume such a pivotal role in occupying community spaces left vacant by the demise of traditional social institutions. The paper is exploratory in its focus, using relevant literature to posit some broad theoretical themes, with the aim of presenting such themes to encourage a shift in community debates away from traditional concerns about 'who' and 'how many', towards questions of why new community forms are emerging.

Banding and radio-tracking juvenile powerful owls in Melbourne, Victoria : trials and tribulations

The Powerful Owl (Ninox strenua) is Australia's largest owl. Considering their large size they are a very cryptic species, with limited sexual dimorphism, silent fight and a highly camouflaged presence amongst secluded canopy vegetation. These features enable Powerful Owl presence to often go unnoticed and even for the trained eye, extremely difficult to study. Our research has focused on monitoring the behaviour of individual Powerful Owls in urban Melbourne, Australia.
The leg banding of Powerful Owls is a somewhat contentious issue in Australia and here we report on the suitability of different types of legs bands placed on the tarsus of juvenile Powerful Owls. There has been some debate over the band size that should be used and the consequent effects bands may pose for the owls as they mature. We also investigate the usefulness of bands as a technique to identify Powerful Owls once they have dispersed from the natal territory.
Radio-tracking juvenile Powerful Owls was also undertaken during this study, primarily to determine individual behaviour from post fledging until dispersal. This is the first study in Australia to attempt radio-tracking juvenile Powerful Owls and the results from this research highlight behavioural characteristics, mortality rates post fledging and dispersal movements for the twelve months post fledging.
Overall we found that aluminium legs bands are a useful tool for individual identification of juvenile Powerful Owls post fledgling, however, their presence is somewhat difficult to determine on mature adults as the tarsus feathers tend to cover the band and make vision from the ground difficult. Aluminium leg bands are also useful as an identification tool for deceased birds. Leather leg bands are more suitable than aluminium bands when attaching radio-transmitters as these provide more flexibility and can be removed by the owl if they become irritating.
Radio-tracking juvenile Powerful Owls provided invaluable information relating to juvenile behaviour and movements, showing that juveniles actually remain in territories adjacent to their natal territory for the twelve months post fledging. This information is vital for the successful conservation of this species, particularly in relation to habitat conservation and home-range modelling.