Hungry for colours? Attentional bias for food crucially depends on perceptual information.

Attentional bias has been consistently investigated with both threatening and rewarding stimuli, such as food. Several studies demonstrated the presence of an attentional bias for high-calorie food cues compared to neutral (non-food) cues. Authors have interpreted this effect in the context of top-down processes (e.g. the food draws attention thanks to the experience we have with it). The aim of the present study is to test whether perceptual features (bottom-up processes) can modulate the attentional bias effect of food stimuli. Using a dot-probe task, we investigated the relevance of colours in the occurrence of the attentional bias. We compared two different categories of naturalistic food images (high-calorie versus low-calorie) both coloured (Exp. 1) and greyscale (Exp. 2). While we found the occurrence of the attentional bias with high-calorie food coloured images, we did not obtain any significant differences with greyscale images. In Experiments 3 and 4, we compared greyscale office items images, respectively, with greyscale high-calorie food images (Exp. 3) and greyscale low-calorie food images (Exp. 4). In both these last experiments, we did not find any attentional bias. Thus, taken together, our results show that colours convey crucial identity information that could orient our attention. We interpret these results as linked to the relevance of visual appearance in our experience of food.