Individual differences in visual salience vary along semantic dimensions

Abstract

What determines where we look? Theories of attentional guidance hold that image features and task demands govern fixation behaviour, while differences between observers are ‘noise’. Here, we investigated the fixations of > 100 human adults freely viewing a large set of complex scenes. We found systematic individual differences in fixation frequencies along six semantic stimulus dimensions. These differences were large (> twofold) and highly stable across images and time. Surprisingly, they also held for first fixations directed towards each image, commonly interpreted as ‘bottom-up’ visual salience. Their perceptual relevance was documented by a correlation between individual face salience and recognition skills. The dimensions of individual salience and their covariance pattern replicated across samples from three different countries, suggesting they reflect fundamental biological mechanisms of attention. Our findings show stable individual salience differences along semantic dimensions, with meaningful perceptual implications. Salience reflects features of the observer as well as the image.