We examined 20 individuals who had worn coloured glasses (Irlen filters) for a period of at least 3 months and who claimed to find them beneficial. Sixteen had a history of reading difficulties. The performance of a variety of visual tasks was compared: (1) using the coloured lenses; (2) using neutral density filters of similar photopic transmittance; and (3) using trial lenses to correct any residual refractive error. The coloured lenses appeared to reduce discomfort and susceptibility to anomalous perceptual effects upon viewing grating patterns. They also improved the speed of visual search by a small amount. The lenses had idiosyncratic effects on ocular muscle balance and acuity. They did not affect contrast sensitivity at a spatial frequency of 4 c/deg.

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Does visual experience in judging intent to harm change our brain responses? And if it does, what are the mechanisms affected? We addressed these questions by studying the abilities of Closed Circuit Television (CCTV) operators, who must identify the presence of hostile intentions using only visual cues in complex scenes. We used functional magnetic resonance imaging to assess which brain processes are modulated by CCTV experience. To this end we scanned 15 CCTV operators and 15 age and gender matched novices while they watched CCTV videos of 16 sec, and asked them to report whether each clip would end in violence or not. We carried out four separate whole-brain analyses including 3 model-based analyses and one analysis of intersubject correlation to examine differences between the two groups. The three model analyses were based on 1) experimentally pre-defined clip activity labels of fight, confrontation, playful, and neutral behaviour, 2) participants' reports of violent outcomes during the scan, and 3) visual saliency within each clip, as pre-assessed using eye-tracking. The analyses identified greater activation in the right superior frontal gyrus for operators than novices when viewing playful behaviour, and reduced activity for operators in comparison with novices in the occipital and temporal regions, irrespective of the type of clips viewed. However, in the parahippocampal gyrus, all three model-based analyses consistently showed reduced activity for experienced CCTV operators. Activity in the anterior part of the parahippocampal gyrus (uncus) was found to increase with years of CCTV experience. The intersubject correlation analysis revealed a further effect of experience, with CCTV operators showing correlated activity in fewer brain regions (superior and middle temporal gyrus, inferior parietal lobule and the ventral striatum) than novices. Our results indicate that long visual experience in action observation, aimed to predict harmful behaviour, modulates brain mechanisms of intent recognition.

When a rapid eye movement (saccade) is made across material displayed on cathode ray tube monitors with short-persistence phosphors, various perceptual phenomena occur. The phenomena do not occur when the monitor has a long-persistence phosphor. These phenomena were observed for certain spatial arrays, their possible physiological basis noted, and their effect on the control of eye movements examined. When the display consisted simply of two dots, and a saccade was made from one to the other, a transient ghost image was seen just beyond the destination target. When the display consisted of vertical lines, tilting and displacement of the lines occurred. The phenomena were more intrusive for the latter display and there was a significant increase in the number of corrective saccades. These results are interpreted in terms of the effects of fluctuating illumination (and hence phosphor persistence) on saccadic suppression.

In recent years, the short Synacthen test (SS) has become the most widely used test to assess adrenal reserve. Despite its frequent use, there are still several areas related to the short Synacthen test (SST), which have no consensus including the optimum sampling times, that is, whether a 60 min post-Synacthen administration cortisol is necessary or not.MethodologyWe performed a retrospective data analysis of 492 SSTs performed on adult patients in a tertiary referral teaching hospital in Ireland. The SSTs were performed in the inpatient and outpatient setting and included patients across all medical disciplines and not exclusively to the endocrinology department.Results313 patients had 0, 30 and 60 min samples available for analysis. A total of 270/313 (82%) were deemed to pass the test, that is, cortisol ≥500 nmol/L at both 30 and 60 min. Of the 313 patients, 19 (6%) patients had an indeterminate response, cortisol <500 nmol/L at 30 min, but rising to ≥500 nmol/L on the 60 min sample. Of these 19 patients, only 9/19 patients had a serum cortisol level at 30 min <450 nmol/L, requiring clinical treatment with glucocorticoid replacement. All 24/313 (8%) patients who had insufficient responses at 60 min were also insufficient at 30 min sampling. No individuals passed (≥500 nmol/L) at 30 min and then failed (<500 nmol/L) at 60 min.ConclusionUsing the 30 min cortisol sample post-Synacthen administration alone identifies clinically relevant adrenal insufficiency in the majority of cases. A small subset of patients have a suboptimal response at 30 min but have a 60 min cortisol concentration above the threshold for a pass. Data regarding the long-term outcomes and management of such patients are lacking and require further study.