Via generative adversarial networks (GANs), artificial intelligence (AI) has influenced many areas, especially the artistic field, as symbol of a human task. In humancomputer interaction (HCI) studies, perception biases against AI, machines, or computers are generally cited. However, experimental evidence is still lacking. This paper presents a wide-scale experiment in which 565 participants are asked to evaluate paintings (which were created by humans or AI) on four dimensions: liking, perceived beauty, novelty, and meaning. A priming effect is evaluated using two between-subject conditions: artworks presented as created by an AI, and artworks presented as created by a human artist. Finally, the paintings perceived as being drawn by human are evaluated significantly more highly than those perceived as being made by AI. Thus, using such a methodology and sample in an unprecedented way, the results show a negative bias of perception towards AI and a preference bias towards human systems.