A review by Montague and Chiu and article by Tankersley et al. describe studies showing that watching a computer perform an altruistic act, earning monitary points for charity (in contrast with human subjects playing the game themselves), activates the posterior superior temporal sulcus (pSTS). This brain region is important for considering the goals and intentions of other beings and specifically for understanding the behavior of social agents as they relate to the goals of a social interaction. An important point differentiates this work from other studies: the computer is an agent only in that the human player has been instructed that it is generating a purposeful act (earning money for a cause). Without these instructions, the human participant is simply viewing a series of flashing symbols, and the experiment might as well assess questions about visual perception. The pSTS may thus be implicated in generic computations about agency, regardless of whether a social interaction is involved.
Figure: Increased right pSTC activation to action perception compared with action performance.