Is there a general trait of susceptibility to simultaneous contrast?

Individuals differ in their susceptibility to simultaneous contrast. Are the underlying differences in neural machinery conserved across different stimulus dimensions? We measured the extent to which 101 subjects perceived simultaneous contrast on the dimensions of luminance, colour, luminance contrast, colour contrast, orientation, spatial frequency, motion and numerosity. Individual differences showed re-test reliability for each dimension (0.32ICC(c,1)0.78, p0.05), but susceptibility to simultaneous contrast, with a few exceptions, was not correlated across dimensions. Either susceptibility to contrast arises empirically from an individual's interactions with the environment, or it is genetically determined but independently for different dimensions

A neural basis for unique hues?

SummaryThe four perceptually simple colors — red, green, yellow and blue — are a challenge to neuroscience, because no one has found cortical cells that represent color in terms of these ‘unique hues’ [1]. The chromatically selective cells at early stages of the primate visual system do not map on to the unique hues [2,3]. Recently, however, Stoughton and Conway [4] have reported that the peak sensitivities of color cells in posterior inferior temporal cortex do cluster near the unique hues. The authors plot their results as a polar histogram: at each position on a hue circle, they show the number of cells that are maximally excited by that hue. There are three peaks in the histogram: one (the largest) falls close to unique red and another falls close to unique blue, while the third (less well-defined) lies in the yellow-green region. In fact, however, if the stimuli used in the experiment are plotted in a physiological color space, they form not a circle but an obtuse triangle. The peaks identified by Stoughton and Conway [4] fall at the apices of this triangle. Because these stimuli maximize the ratios of cone signals, they would maximally excite cells earlier in the visual system. So Stoughton and Conway's polar plot does not in itself show that cells of the posterior inferior temporal cortex represent unique hues, nor that they differ qualitatively in their behavior from chromatic cells at an earlier level

Measuring the Social Impacts of Preservation on Disadvantaged Communities

This thesis explores how preservation organizations working in the United States use various strategies to make positive social impacts, in addition to physical improvements, within disadvantaged communities. By looking at the social impacts of preservation, rather than the economic advantages, this study aims to expand upon the common success measures and further expand the tools with which the preservation field can demonstrate relevance. This research, conducted through a series of case studies, focuses on preservation institutions working throughout the United States. To measure the social capital, a combination of interviews and surveys with the organizations and people in the community was balanced with nationally-available data

Performance in the MRCP(UK) Examination 2003-4: analysis of pass rates of UK graduates in relation to self-declared ethnicity and gender

Background: Male students and students from ethnic minorities have been reported to underperform in undergraduate medical examinations. We examined the effects of ethnicity and gender on pass rates in UK medical graduates sitting the Membership of the Royal Colleges of Physicians in the United Kingdom [MRCP( UK)] Examination in 2003-4. Methods: Pass rates for each part of the examination were analysed for differences between graduate groupings based on self- declared ethnicity and gender.Results: All candidates declared their gender, and 84 - 90% declared their ethnicity. In all three parts of the examination, white candidates performed better than other ethnic groups (P < 0.001). In the MRCP(UK) Part 1 and Part 2 Written Examinations, there was no significant difference in pass rate between male and female graduates, nor was there any interaction between gender and ethnicity. In the Part 2 Clinical Examination (Practical Assessment of Clinical Examination Skills, PACES), women performed better than did men (P < 0.001). Non-white men performed more poorly than expected, relative to white men or non-white women. Analysis of individual station marks showed significant interaction between candidate and examiner ethnicity for performance on communication skills (P = 0.011), but not on clinical skills (P = 0.176). Analysis of overall average marks showed no interaction between candidate gender and the number of assessments made by female examiners (P = 0.151).Conclusion: The cause of these differences is most likely to be multifactorial, but cannot be readily explained in terms of previous educational experience or differential performance on particular parts of the examination. Potential examiner prejudice, significant only in the cases where there were two non- white examiners and the candidate was non- white, might indicate different cultural interpretations of the judgements being made

A machine learning pipeline for labeling chess pieces images

Nowadays there are lots of emerging use cases and fields to artificial intelligence/machine learning technologies. One of several relevant fields is that of image recognition model training, which itself has several potential applications already in development. This project studies this field through a specific case study: a machine learning model built to recognise and differentiate between chess piece images. For models to accurately discern what they are being presented with it is pivotal to meticulously assemble and refine the data they receive. In this project, based on a previously existing dataset of chess board images, we delve with the acquisition of curated chessboard images, each representing a spectrum of game states and scenarios. This is done in two ways: firstly, by capturing images from physical chess boards during in-person tournaments, and secondly by recreating digital versions of real professional chess games in a physical artificial environment in order to enrich our dataset substantially. This foundational step furnishes the bedrock components of our data collection pipeline, which is the second part of the project. Once the previous step has been completed we proceed by constructing a preprocessing pipeline tailor-fitted for preparing data for model training, automatizing the meticulous labeling of raw data and curating data consistently. In summary, this thesis is wholly devoted to the betterment and refinement of a machine learning dataset for chess board image recognition, enhancing data collection and automatizing data preprocessing workflows. Insights gleaned from this project bear significance for the continued development of computer vision systems

THE QEDUSEN PROJECT; IMPROVING SENIORS’QUALITY OF LIFE THROUGH TO EDUCATION

Learning in later life (citizens over 65 or retired) is becoming common. The motivation and interests of the senior citizens to keep learning are mainly personal, they are not job related needs or labour market qualification requirements. These personal aims can be seen from the quality of life (QoL) perspective, where education increases well-being, integration and participation of the elderly in the present society. Institutions dealing with senior learners then face the challenge to provide a socio-educational intervention to senior learners, which has a requirements, needs and motivation different from other adults, and that specific pedagogy, courses and staff qualifications must be considered. From this need the project QEduSen (supported by the Lifelong Learning Programme of the European Commission) produced a guide and a evaluation toolki

Cerebral iconics: How are visual stimuli represented centrally in the human brain?

In the case of some sensory attributes (e.g., luminance), differential thresholds increase with the spatial separation between the stimuli to be compared, but in other cases (e.g., spatial frequency, hue) thresholds vary little whether the stimuli are close together or separated by 10 degrees of arc. To this latter class of sensory attributes, we here add two dimensions: Speed of motion and chromatic purity. Stimuli were presented too briefly for an eye movement and could fall at any positions on an imaginary circle centered on the fixation point. What neural mechanisms underlie discrimination in such tasks? We doubt discrimination depends on a large array of dedicated "comparator neurons," one for each possible pair of positions in the visual field and for each sensory attribute. Instead we suggest that information about local sensory properties is carried to the cortical site of comparison by neural connections that resemble the man-made Internet insofar as the same physical substrate from moment to moment carries different information in a symbolic code

A new Mooney test.

Since its introduction in 1957, the Mooney test has continued to see active use in studies of visual perception, in studies using brain imaging, and in clinical research. Mooney's original version is of limited length, however, and was designed to be administered by time-consuming personal interview. We have developed a new, extended version of the Mooney test that is suitable for online testing and for use in a test-retest paradigm. The Mooney-Verhallen Test (MVT) comprises 144 trials, takes on average less than 10 min to complete, and has a Spearman-Brown-corrected test-retest reliability of ρ = .89. We outline our methods for developing the stimuli and for selecting the final stimulus set, and we present the results from two rounds of testing on two independent samples of 374 participants and 505 participants, respectively. The test is freely available for scientific use.RJV is grateful for funding received from the Prins Bernhard Cultuurfonds, the Hendrik Muller Fonds, the Grindley Fund, and the Cambridge Philosophical Society.This is the author accepted manuscript. The final version is available from Springer via http://dx.doi.org/10.3758/s13428-015-0666-

Tetrachromacy: the mysterious case of extra-ordinary color vision

Recent years have witnessed a growing public interest in human tetrachromacy – the possibility that a subpopulation of women enjoy an extra dimension of color vision. Yet, by contrast, rigorous studies of this unusual phenotype are sparse. The aim here is to offer the reader a guide to the facts and myths regarding this potential‘superpower’ and to address the core methodological issues that need to be considered when investigating it