Reconsidering Yarbus: A failure to predict observers’ task from eye movement patterns

In 1967, Yarbus presented qualitative data from one observer showing that the patterns of eye movements were dramatically affected by an observer’s task, suggesting that complex mental states could be inferred from scan paths. The strong claim of this very influential finding has never been rigorously tested. Our observers viewed photographs for 10 s each. They performed one of four image-based tasks while eye movements were recorded. A pattern classifier, given features from the static scan paths, could identify the image and the observer at above-chance levels. However, it could not predict a viewer’s task. Shorter and longer (60 s) viewing epochs produced similar results. Critically, human judges also failed to identify the tasks performed by the observers based on the static scan paths. The Yarbus finding is evocative, and while it is possible an observer’s mental state might be decoded from some aspect of eye movements, static scan paths alone do not appear to be adequate to infer complex mental states of an observer.     

Can reliable values of Young’s modulus be deduced from Fisher’s (1971) spinning lens measurements?

The current textbook view of the causes of presbyopia rests very largely on a series of experiments reported by R.F. Fisher some three decades ago, and in particular on the values of lens Young's modulus inferred from the deformation caused by spinning excised lenses about their optical axis (Fisher 1971) We studied the extent to which inferred values of Young's modulus are influenced by assumptions inherent in the mathematical procedures used by Fisher to interpret the test and we investigated several alternative interpretation methods. The results suggest that modelling assumptions inherent in Fisher's original method may have led to systematic errors in the determination of the Young's modulus of the cortex and nucleus. Fisher's conclusion that the cortex is stiffer than the nucleus, particularly in middle age, may be an artefact associated with these systematic errors. Moreover, none of the models we explored are able to account for Fisher's claim that the removal of the capsule has only a modest effect on the deformations induced in the spinning lens.     

What’s “up”? Working memory contents can bias orientation processing

We explored the interaction between the processing of a low-level visual feature such as orientation and the contents of working memory (WM). In a first experiment, participants memorized the orientation of a Gabor patch and performed two subsequent orientation discriminations during the retention interval. The WM stimulus exerted a consistent repulsive effect on the discrimination judgments: participants were more likely to report that the discrimination stimulus was rotated clockwise compared to the oblique after being presented with a stimulus that was tilted anti-clockwise from the oblique. A control condition where participants attended to the Gabor patch but did not memorize it, showed a much reduced effect. The repulsive effect was stable across the two discriminations in the memory condition, but not in the control condition, where it decayed at the second discrimination. In a second experiment, we showed that the greater interference observed in the WM condition cannot be explained by a difference in cognitive demands between the WM and the control condition. We conclude that WM contents can bias perception: the effect of WM interference is of a visual nature, can last over delays of several seconds and is not disrupted by the processing of intervening visual stimuli during the retention period.     

Can the magnocellular pathway read? Evidence from studies of color

A review of the neurophysiological literature suggests that the magnocellular pathway has adequate spatial-frequency and contrast sensitivity to perceive text under normal contrast conditions (>10%) and also is suppressed by red light. Results from three experiments involving color and reading show that red light impairs reading performance under normal luminance contrast conditions. However in a fourth experiment, isoluminant color text, designed to selectively activate the parvocellular pathway, is easier to read under red light. These discrepant results suggest that the magnocellular pathway is the dominant visual pathway for text perception. Implications for reading models and developmental dyslexia are discussed.     

Epidemiology of Behcet’s Disease in Taiwan: A Population-Based Study

Purpose: To study the incidence and epidemiology of Behcet’s disease in Taiwan.

Methods: This retrospective cohort study was conducted using the nationwide reimbursement database in Taiwan. One million registered beneficiaries of the Taiwan National Health Insurance system in 2000 were randomly selected. All medical claims of these persons were collected. The definition of having Behcet’s disease was based on diagnostic codes. Persons who had incomplete registry data or diagnoses prior to 2001 were excluded. Annual incidence between 2001 and 2011 was calculated and risk factors for incidence were explored using the Cox proportional regression model. Characteristics of patients with Behcet’s disease with and without uveitis were compared.

Results: A total of 236 newly diagnosed patients with Behcet’s disease were found between 2001 and 2011. The average incidence was 2.40 cases per 100,000 person-years (ranging from 1.29 to 3.53). Female patients and those aged between 40 and 65 years were at the highest risk of Behcet’s disease. Only 18.2% of the patients had also suffered from uveitis. The subspecialties of doctors making initial diagnoses and the number of prescribed immunomodulatory agents differed significantly between the patients with and without uveitis (p < 0.001 and <0.05, respectively).

Conclusion: Incidence of Behcet’s disease was not high in Taiwan and relatively few of the patients developed uveitis. Patients of working age or who were female were more likely to have Behcet’s disease. However, age of onset and clinical severity differed between patients with and without uveitis.     

T-cell lymphoblastic lymphoma of Tenon’s capsule: an unusual presentation

Lymphoid neoplasms of the orbit account for approximately 6–8 % of all orbital tumors and 15 % of all ocular adnexal tumors. We report an unusual case of T-cell lymphoblastic lymphoma occurring in a 30-year-old man, presenting as red, painless, firm swelling in the Tenon’s capsule of the eye.     

Classification of Duane’s Retraction Syndrome: Two Additional Electromyogram Types

Background Hubers clinical and electromyographical classifications of Duanes retraction syndrome have been considered to correspond to each other. However, cases that do not correspond to these classifications have been reported recently.Cases Retrospectively, we tried to classify the clinical types and electromyogram types of 17 eyes (15 cases) with Duanes retraction syndrome according to Hubers classification.Observations Eleven eyes could not be classified into any of Hubers electromyogram types. Among these eyes, two major additional electromyogram patterns were newly classified: a center-peak type, in which the lateral rectus or medial rectus muscle showed maximum activity in the primary position; and a type with continuous lateral rectus muscle discharge. Some minor electromyogram patterns were also recorded.Conclusion The wide variation in these electromyogram patterns may be due to the diversity of the lesions in Duanes retraction syndrome, which can be the result of muscular, nuclear, internuclear, or supranuclear failure. Jpn J Ophthalmol 2004;48:148–153 © Japanese Ophthalmological Society 2004     

A Rare Ocular Manifestation of Adult Onset Still’s Disease: Purtscher’s-like Retinopathy

Adult-onset Still’s disease (AOSD) is a rare multisystemic immune-mediated disease of unknown etiology with quotidian spiking fever, evanescent rash, arthralgia, and multiple organ involvement. The few AOSD cases that have been reported developed Purtscher’s-like retinopathy associated with thrombotic microangiopathy (TMA). Here, we report Purtscher’s-like retinopathy without TMA in a patient with AOSD. A 29-year-old-man who presented for evaluation of blurred vision was diagnosed with AOSD based on Yamaguchi criteria. He had Purtscher’s-like retinopathy in his right eye. Lesions improved after steroid treatment. Although almost all reported AOSD cases with Purtscher’s-like retinopathy are associated with TMA, in this case such a complication was not encountered.     

Eye health is everyone’s responsibility: China’s first Western-style eye hospital improves in the prevention of blindness

AIM: To investigate the relationship between China’s first Western-style eye hospital development and the prevention of blindness in China and determine the main factor influencing eye health today.METHODS: Data about eye health, blindness and cataract surgery rate of China from public website of World Health Organization (WHO), ORBIS International, Ministry of Health (MOH) of China, Pubmed center and Historical Archives of Zhongshan Ophthalmic Center (ZOC) were reviewed and analyzed.RESULTS: ZOC is China’s first Western-style eye hospital. In 2012, the ORBIS Flying Eye Hospital has chosen ZOC once again as one of its destinations, 30 years after ORBIS expanded internationally to train eye care professionals and treat underserved patients in developing countries in 1982. During the past 30 years, cataract surgery rate and public awareness of blindness prevention were improved greatly in China, in which ZOC plays a very important role.CONCLUSION: ZOC, as China’s first Western-style eye hospital,has improved in the prevention of blindness. Eye health has become everyone’s responsibility.