Imitation of hand and tool actions is effector-independent

Following the theoretical notion that tools often extend one’s body, in the present study, we investigated whether imitation of hand or tool actions is modulated by effector-specific information. Subjects performed grasping actions toward an object with either a handheld tool or their right hand. Actions were initiated in response to pictures representing a grip at an object that could be congruent or incongruent with the required action (grip-type congruency). Importantly, actions could be cued by means of a tool cue, a hand cue, and a symbolic cue (effector-type congruency). For both hand and tool actions, an action congruency effect was observed, reflected in faster reaction times if the observed grip type was congruent with the required movement. However, neither hand actions nor tool actions were differentially affected by the effector represented in the picture (i.e., when performing a tool action, the action congruency effect was similar for tool cues and hand cues). This finding suggests that imitation of hand and tool actions is effector-independent and thereby supports generalist rather than specialist theories of imitation

Mindreading as social expertise

In recent years, a number of approaches to social cognition research have emerged that highlight the importance of embodied interaction for social cognition (Reddy, How infants know minds, 2008; Gallagher, J Conscious Stud 8:83–108, 2001; Fuchs and Jaegher, Phenom Cogn Sci 8:465–486, 2009; Hutto, in Seemans (ed.) Joint attention: new developments in psychology, philosophy of mind and social neuroscience, 2012). Proponents of such ‘interactionist’ approaches emphasize the importance of embodied responses that are engaged in online social interaction, and which, according to interactionists, present an alternative to mindreading as a source of social understanding. We agree that it is important to take embodied interaction seriously, but do not agree that this presents a fundamental challenge to mainstream mindreading approaches. Drawing upon an analogy between embodied interaction and the exercise of expert skills, we advocate a hierarchical view which claims that embodied social responses generally operate in close conjunction with higher-level cognitive processes that play a coordinative role, and which are often sensitive to mental states. Thus, investigation of embodied responses should inform rather than conflict with research on mindreading