Ensemble Representation of Animacy Is Based on Mid-level Visual Features

Studies suggest that mid-level features could underlie object animacy perception. In the current research, we tested whether ensemble animacy perception is based on high or mid-level features. We used five types of images of animals and inanimate objects: color, greyscale, silhouettes, texforms – unrecognizable images which preserve mid-level texture and shape information – and scrambled images. In the series of Experiments 1, we asked participants to evaluate the animacy of single images and sets of eight images using a 10-point scale. In the series of Experiments 2, participants were shown two sets of eight images and had to choose a more animate one in the 2AFC task. We found that in both paradigms, observers could report the mean animacy of the set of texform images without direct access to information about high- level features. We hypothesize that ensemble animacy perception can be explained only by mid-level features such as shape and texture.