When two faces are not better than one: Serial limited-capacity processing with redundant-target faces.

Many researchers believe that faces-whether presented alone or as part of an ensemble-are processed automatically. According to this idea, (a) the detection of single or multiple faces is resource free and does not require allocation of attention, and (b) visual search for faces is held in parallel. The current study put these hypotheses under direct scrutiny. Participants performed in a redundant target-detection task, responding according to the presence or absence of a face (or faces) on the display. I used a rigorous methodology known as the system factorial technology (SFT). The SFT methodology afforded simultaneous assessment of (a) architecture (serial vs. parallel), (b) stopping rule (exhaustive vs. self-terminating), and (c) capacity (limited, unlimited, or supercapacity). SFT analyses were held at the level of the mean RTs and at the level of the RT distributions. The analyses pointed conclusively to a serial self-terminating architecture with limited capacity. These findings cast serious doubts on the alleged automaticity of face perception.