Real-world moving objects are usually defined by correlated information in multiple sensory modalities such as vision and hearing. The aim of our study was to assess whether simultaneous auditory supra-threshold motion introduces a bias or affects the sensitivity in a visual motion detection task. We demonstrate a bias in the perceived direction of visual motion that is consistent with the direction of the auditory motion (audio-visual motion capture). This bias effect is robust and occurs even if the auditory and visual motion signals come from different locations or move at different speeds. We also show that visual motion detection thresholds are higher for consistent auditory motion than for inconsistent motion, provided the stimuli move at the same speed and are co-localised.

We use multivoxel pattern analysis (MVPA) to study the spatial clustering of color-selective neurons in the human brain. Our main objective was to investigate whether MVPA reveals the spatial arrangements of color-selective neurons in human primary visual cortex (V1). We measured the distributed fMRI activation patterns for different color stimuli (Experiment 1: cardinal colors (to which the LGN is known to be tuned), Experiment 2: perceptual hues) in V1. Our two main findings were that (i) cone-opponent cardinal color modulations produce highly reproducible patterns of activity in V1, but these were not unique to each color. This suggests that V1 neurons with tuning characteristics similar to those found in LGN are not spatially clustered. (ii) Unique activation patterns for perceptual hues in V1 support current evidence for a spatially clustered hue map. We believe that our work is the first to show evidence of spatial clustering of neurons with similar color preferences in human V1.

Background: Accurate skin colour measurements are important for numerous medical applications including the diagnosis and treatment of cutaneous disorders and the provision of maxillofacial soft tissue prostheses.Methods: In this study, we obtained accurate skin colour measurements from four different ethnic groups (Caucasian, Chinese, Kurdish, Thai) and at four different body locations (Forehead, cheek, inner arm, back of hand) with a view of establishing a new skin colour database for medical and cosmetic applications. Skin colours are measured using a spectrophotometer and converted to a device‐independent standard colour appearance space (CIELAB) where skin colour is expressed as values along the three dimensions: Lightness L*, Redness a* and Yellowness b*. Skin colour differences and variation are then evaluated as a function of ethnicity and body location.Results: We report three main results: (1) When plotted in a standard colour appearance space (CIELAB), skin colour distributions for the four ethnic groups overlap significantly, although there are systematic mean differences. Between ethnicities, the most significant skin colour differences occur along the yellowness dimension, with Thai skin exhibiting the highest yellowness (b*) value and Caucasian skin the lowest value. Facial redness (a*) is invariant across the four ethnic groups. (2) Between different body locations, there are significant variations in redness (a*), with the forehead showing the highest redness value and the inner arm the lowest. (3) The colour gamut is smallest in the Chinese sample and largest in the Caucasian sample, with the Chinese gamut lying entirely the Caucasian gamut. Similarly, the largest variability in skin tones is found in the Caucasian group, and the smallest in the Chinese group.Conclusion: Broadly speaking, skin colour variation can be explained by two main factors: individual differences in lightness and yellowness are mostly due to ethnicity, whereas differences in redness are primarily due to different body locations. Variations in lightness are more idiosyncratic probably reflecting the large influence of environmental factors such as exposure to sun.