Under appropriate stimulus conditions, judgments about the degree of temporal synchrony in sequences containing rapid alternations of colour and motion direction imply a large apparent delay of motion perception relative to colour perception. Whether this colour-motion asynchrony results from the relative processing delay of different visual attributes, or from inappropriate matching of time ma...

Colour changes in Gradia Direct™ composite after immersion in tea, coffee, red wine, Coca-Cola, Colgate mouthwash, and distilled water were evaluated using principal component analysis (PCA) and the CIELAB colour coordinates. The reflection spectra of the composites were used as input data for the PCA. The output data (scores and loadings) provided information about the magnitude and origin of ...

We consider an algorithm on a graph G = (V,E) with a 2-colouring of V , that is motivated from the computer-aided text-recognition. Every vertex changes simultaneously its colour if more than a certain proportion c of its neighbours have the other colour. It is shown, that by iterating this algorithm the colouring becomes either constant or 2-periodic. For c = 1 2 the presented theorem is a spe...

Synaesthesia is a condition that gives rise to unusual secondary sensations (e.g., colours are perceived when listening to music). These unusual sensations tend to be reported as being stable throughout adulthood (e.g., Simner & Logie, 2007, Neurocase, 13, 358) and the consistency of these experiences over time is taken as the behavioural hallmark of genuineness. Our study looked at the influen...

OBJECTIVE To determine whether there are changes in the peripapillary nerve fibre layer, in colour vision, contrast sensitivity, dark adaptation and electroretinography changes in these patients who do not have infectious retinitis. METHODS We studied 52 patients without ocular pathology; the mean age was 35.88 years old. RESULTS We observed less thickness in all quadrants, except the nasal...

The dual retina of humans and most vertebrates consists of multiple types of cone for colour vision in bright light and one single type of rod, leaving these animals colour-blind at night. Instead of comparing the signals from different spectral types of photoreceptors, they use one highly sensitive receptor, thus improving the signal-to-noise ratio. However, nocturnal moths and geckos can disc...

In this paper, we compare local colour descriptors to grey-value descriptors. We adopt the evaluation framework of Mikolayzcyk and Schmid. We modify the framework in several ways. We decompose the evaluation framework to the level of local grey-value invariants on which common region descriptors are based. We compare the discriminative power and invariance of grey-value invariants to that of co...

Sedimentary diatoms in inferring trophic status and limnological changes in boreal lakes Miettinen, Juha O. Sedimentary diatoms in inferring trophic status and limnological changes in boreal lakes. – Analyses of sedimentary diatoms were used for inferring reference (pre-impact) conditions and limnological changes in eastern Fennoscandian lakes. Long-term limnological variation was studied from ...

Information about colour is initially extracted by the visual system in terms of the activity within a small number of receptor types with different spectral sensitivities, and then recoded within channels that respond to different combinations of the receptor signals. Many insights have been gained about these post-receptoral transformations, yet their number and nature remain poorly defined. ...

To understand how bees, birds, and fish may use colour vision for food selection and mate choice, we reconstructed views of biologically important objects taking into account the receptor spectral sensitivities. Reflectance spectra of flowers, bird plumage, and fish skin were used to calculate receptor quantum catches. The quantum catches were then coded by “red,” “green,” and “blue” of a compu...