, 2001). Activation of this area is associated with the selection among competing responses (Petrides, 2005), and the more superior portion activated here is especially involved in the spatial domain (Volle et al., 2008). During imitation, this region may serve to maintain a representation of the observed goal in short-term working memory for later execution (Chaminade et al., 2002). Co-activation of the superior frontal gyrus and posterior inferior frontal gyrus

may thus reflect Naïve reliance on kinematic simulation and top-down direction of attention to task-relevant spatial cues. When combined with the anterior inferior parietal and ventral prefrontal activations observed across all groups, these Naïve activations match the general EPZ015666 cell line expectations of a simulation model of novel action understanding (Buccino et al., 2004; Vogt et al., 2007). No activations exclusive to Trained subjects were observed in the Acheulean–Oldowan contrast. Comparison with the numerous activations observed

in the contrast of Toolmaking–Control for Trained subjects (Table 2; Fig. 2) indicates that this result derives from the presence of similar responses to Oldowan and Acheulean stimuli rather than from the absence of significant differences from Control. This is corroborated by the observation of similar activations in separate contrasts of Oldowan–Control and Acheulean–Control (Supporting Information Figs S3 and S4; Tables S1 and S2). The Trained response to both Oldowan Sirolimus nmr and Acheulean stimuli includes: (i) clusters in the anterior insula, lateral premotor cortex, frontal eye field and supplementary eye field likely related to attentional and affective engagement with the stimuli; and (ii) ventral prefrontal clusters likely associated with parsing of observed action

sequences. Insular activations Liothyronine Sodium unique to Trained subjects are in an anterior region associated with interoception, subjective feeling and perceptual awareness (Kikyo et al., 2002; Ploran et al., 2007; Craig, 2009). Activations of the left medial frontal cortex (close to y = 0) and posterior middle frontal gyrus appear to fall within the supplementary and frontal eye fields (Tehovnik et al., 2000), functional regions associated with saccades, visual attention and visual learning (Tehovnik et al., 2000; Grosbras et al., 2005). Together with activation of the precentral gyrus, a region commonly recruited during action observation (Grezes & Decety, 2001; Caspers et al., 2010), these activations likely indicate intense engagement by Trained subjects with the Toolmaking stimuli. These effects of training were not predicted, but are consistent with the pragmatic social and motivational context created by the training programme. Also unique to Trained subjects were inferior frontal gyrus activations of bilateral pars opercularis, left pars triangularis and right pars orbitalis.