Decoding Human Visual Colour EEG Information Using Machine Learning and Visual Evoked Potentials

With the rapid development of brain-computer interfaces (BCIs), human visual decoding, one of the important research directions of BCIs, has attracted a substantial amount of attention. However, most visual decoding studies have focused on graphic and image decoding. In this paper, we first demonstrate the possibility of building a new kind of task-irrelevant, simple and fast-stimulus BCI-based experimental paradigm that relies on visual evoked potentials (VEPs) during colour observation. Additionally, the features of visual colour information were found through reliable real-time decoding. We selected 9 subjects who did not have colour blindness to participate in our tests. These subjects were asked to observe red, green, and blue screens in turn with an interstimulus interval of 1 second. The machine learning results showed that the visual colour classification accuracy had a maximum of 93.73%. The latency evoked by visual colour stimuli was within the P300 range, i.e., 176.8 milliseconds for the red screen, 206.5 milliseconds for the green screen, and 225.3 milliseconds for the blue screen. The experimental results hereby show that the VEPs can be used for reliable colour real-time decoding.

Light Forms in Urban Environment

The paper proposes a method for generalizing and understanding the achievements of modern lighting design by means of classifying light forms and their main features are specified. The variety of types and complexity of light forms are due to avant-garde experiments in the art of the early and mid 20th century and is consistent with the successive change in artistic styles. Advances in computer technology and programming have made it possible to combine lighting elements, visual, colour and optical effects in one form. The new lighting techniques were developed for illuminating the architectural environment, various buildings, structures and forms in the spaces of world exhibitions. In this paper, the following light forms of the urban environment are investigated: projection mapping, light-graphic, light-painting and installation, sculptural, media surfaces and media facades, structural and vertical, energy-saving and virtual. The classification of light forms makes it possible to identify their structure and image, their correspondence to different eras in art, to predict the possibility of their transformation in the perspective of modern visual creativity.

Do we always drink the same coffee? The effect of weight and colour on takeaway coffee perception

Purpose Beverage serving affects consumers’ taste and price perceptions. Therefore, the correct selection of the presentation cues is essential when a consumer evaluates a product. This study aims to determine how haptic (weight) and visual (colour) cues of drinking vessels affect the taste and price perception of coffee. Design/methodology/approach The authors created three different experimental designs. Given that coffee is a popular drink among the younger population, the authors invited undergraduate students in the 18–24 age group into this study. The participants tasted the same coffee from cups differ in weight (heavy and normal) and colour (congruent, incongruent and neutral), after which their opinions about the taste and price were recorded. Findings According to the results, increasing the weight of the cup creates a more positive perception of the smell and density of the coffee. Moreover, coffee served in a heavy cup was perceived to be more expensive than in other cups. The authors also found that incongruent cups received a lower score in all evaluations regarding taste perception. In the final experiment, the authors used the weight and colour manipulations together. According to the participants, the most fragrant coffee was perceived from a heavy and congruent cup. Research limitations/implications Small sample is one of the limitations of this study. Future studies could be conducted with bigger and more diverse sample using different kinds of coffee beans. Practical implications It will be appropriate for coffee producers to design the cups in light of the said results. Originality/value The paucity in the existing literature of sensory marketing studies using hot drinks is remarkable, especially takeaway coffee, which is becoming more popular with an increasing number of coffee chains, and needs to be examined in detail.

Colour me Revolutionary

Colour in China has a long history of artistic, symbolic, religious, and mythological use. This paper takes the idea of colour as a meaningful element within Chinese society and introduces the use of visual colour grammar as a new way to identify and breakdown the use of colour within political art and propaganda posters. The use of colour has been adapted by visual linguists into its own unique visual grammar component, relaying much more information than just a symbolic transfer from sign to signifier. Meaning within political posters can be derived from regularities in use, presentation, and conventional meanings. Colour as a visual grammar component is expressed through the three metafunctions: ideational, interpersonal, and textual. This paper explores how the Chinese views on colour interconnects with the metafunctions of colour to look at the political posters of the PRC. I will discuss both the approach to art as a text that can be ‘read’ through visual grammar and present colour in the Chinese context as more than a symbol making device but as a meaning component in and of itself.

Methods for restoration of ki67 antigenicity in aged paraffin tissue blocks

Pathology archives are a treasure trove of paraffin embedded tissue spanning many years and covering a wide variety of tissues and diseases. The possibility of using old archival formalin fixed paraffin embedded (FFPE) tissues for diagnostic updates and research projects is a widespread need and it requires archives of stable, well-preserved samples. Immunohistochemistry performed on old archival paraffin blocks may give unreliable results, in particular for some antigens, such as Ki67. In consideration of this phenomenon, our aim is to comprehensively test and identify methods which may be used to obtain Ki67 immunohistochemical reactions of good quality from old archival FFPE blocks. Various methods were tested in order to evaluate their possible efficacy in increasing Ki67 immunointensity in a collection of 40-year-old, archival blocks including re-embedding, with deeper sectioning of tissue from the block and increasing heat-based pretreatment times (20 cases) and re-processing (20 cases). All reactions were performed using an automated immunostainer and Ki67 stained immunosections compared using a visual colour-based scale (the first immunostained section was considered as baseline). The combination of deep sectioning (1000 µM) and prolonged heat-based pretreatment (64 min) markedly increased immunoreactivity for Ki67. Re-embedding and reprocessing did not have a significant effect. Large tissue samples showed heterogeneity of Ki67 immunoexpression between the periphery of the sample and the central area. In conclusion, the study defines a useful protocol to increase antigen retrieval applicable to dated archival tissues.

Carborane photochromism: A fatigue resistant carborane switch

A dithienylethene molecule involving carborane clusters shows remarkable fatigue resistance and high contrast visual colour changes when irradiated with alternating ultraviolet and visible light. The fluorescence of this assembly can...

Gender Difference in Colour Preference of Lighting: A Pilot Study

Gender difference has been widely reported in many research fields. However, in the topic of colour preference of lighting, such an issue has not aroused much attention. In this study, therefore, three groups of visual experiments with different illuminance (E) levels (50 lx, 200 lx, 600 lx) were conducted which investigated the preferred correlated colour temperature (CCT: 3500 K, 5000 K, 6500 K) for six single-coloured decorative artificial bird-shaped objects (red, green, yellow, blue, white and black). Twenty subjects, ten males and ten females, were invited to respond with their visual colour preference of the experimental objects. The aim of this work was to investigate if gender difference exists when the observers judge objects with different colours under different E-CCT conditions. The results indicate that there is significant difference between males and females for the 200 lx and 600 lx conditions, especially for the cases with higher CCTs (5000 K and 6500 K). In addition, it was found that under certain E-CCT conditions the preference ratings of males and females for certain colours were obviously different. Similarly, for some scenarios the subjective ratings from observers of the same gender also varied with object colour.