Of the ability to engage in spontaneous imitation is suggested by the existence of this ability in human neonates (Meltzoff and Moore, 1977, 1983) and neonatal chimpanzees (Myowa-Yamakoshi et al., 2004; Ferrari et al., 2006). In humans, spontaneous imitation of simple body movements is initially observed during the first 2 years after birth, when infants develop their primal instincts and are most dependent on their parents (Piaget, 1962, 1983; Meltzoff, 1990). However, infants and children with autism spectrum disorders (ASDs) display less imitation compared with typically developing children, suggesting that a deficit in this ability may be associated with insufficient development of social skills and language in children with these disorders (Williams et al., 2004; Hamilton, 2008; De Giacomo et al., 2009; Lai et al., 2013). Two distinct processes should be considered with respect to the cognitive processes underlying spontaneous imitation: the process that enables the performance of imitation per se, which is recruited regardless of whether the imitation is spontaneous, and the process that drives imitation, which is more relevant to the issue of why infants `spontaneously’ imitate. These two processes were identified as distinct using recently proposed multi-component models of imitation (Brass and Heyes, 2005; Rumiati et al., 2005; Brugger et al., 2007; Lestou et al., 2008; Southgate and Hamilton, 2008; Catmur et al., 2009;). Previous neuroimaging studies have generally RG7800 solubility investigated the neural basis of imitation performance. Earlier studies (Iacoboni et al., 1999, 2001; Nishitani and Hari, 2002) are likely to have been motivated largely by the concept of mirror neurons (MNs), which discharge during the observation and execution of an action (Rizzolatti et al., 2001; Rizzolatti and Craighero, 2004). This common coding has typically been associated with activation in the inferior and superior parietal lobules, as well as the dorsal and ventral premotor cortices (Iacoboni et al., 1999; Buccino et al., 2004; Vogt et al., 2007). However, some of these observations (e.g. Broca’s area) may not be related to the neural processes crucial to imitation itself (Rushworth et al. 2001a; Makuuchi, 2005). In this study, functional magnetic resonance imaging (fMRI) was used to examine neural correlates of the imitation drive, which have not yet been fully investigated. More specifically, this study investigated the driving process that is activated when humans spontaneously try to imitate an unfamiliar action without explicit reasons. To achieve this, meaningless actions were prepared, and the `urge to imitate’ (Urge) was defined as a means of measuring the imitation drive. Two potential confounding factors were given particular attention during the isolation of neural correlates underlying Urge. First, in adult participants, the urge to imitate can result from explicit reasons, which may include the fact that the presented action appears familiar, challenging or interesting. Thus, attempts were made to eliminate the effects of these types of upstream cognitive processes on imitation drive by creating a questionnaire to evaluate the potential involvement of these explicit reasons and the strength of the urge to imitate. Second, the strength of the urge to imitate may be correlated with various kinematic characteristics of the perceived action, including perceptual factors such as speed or RG7800 molecular weight complexity. Therefore, various types of kinematic factors we.Of the ability to engage in spontaneous imitation is suggested by the existence of this ability in human neonates (Meltzoff and Moore, 1977, 1983) and neonatal chimpanzees (Myowa-Yamakoshi et al., 2004; Ferrari et al., 2006). In humans, spontaneous imitation of simple body movements is initially observed during the first 2 years after birth, when infants develop their primal instincts and are most dependent on their parents (Piaget, 1962, 1983; Meltzoff, 1990). However, infants and children with autism spectrum disorders (ASDs) display less imitation compared with typically developing children, suggesting that a deficit in this ability may be associated with insufficient development of social skills and language in children with these disorders (Williams et al., 2004; Hamilton, 2008; De Giacomo et al., 2009; Lai et al., 2013). Two distinct processes should be considered with respect to the cognitive processes underlying spontaneous imitation: the process that enables the performance of imitation per se, which is recruited regardless of whether the imitation is spontaneous, and the process that drives imitation, which is more relevant to the issue of why infants `spontaneously’ imitate. These two processes were identified as distinct using recently proposed multi-component models of imitation (Brass and Heyes, 2005; Rumiati et al., 2005; Brugger et al., 2007; Lestou et al., 2008; Southgate and Hamilton, 2008; Catmur et al., 2009;). Previous neuroimaging studies have generally investigated the neural basis of imitation performance. Earlier studies (Iacoboni et al., 1999, 2001; Nishitani and Hari, 2002) are likely to have been motivated largely by the concept of mirror neurons (MNs), which discharge during the observation and execution of an action (Rizzolatti et al., 2001; Rizzolatti and Craighero, 2004). This common coding has typically been associated with activation in the inferior and superior parietal lobules, as well as the dorsal and ventral premotor cortices (Iacoboni et al., 1999; Buccino et al., 2004; Vogt et al., 2007). However, some of these observations (e.g. Broca’s area) may not be related to the neural processes crucial to imitation itself (Rushworth et al. 2001a; Makuuchi, 2005). In this study, functional magnetic resonance imaging (fMRI) was used to examine neural correlates of the imitation drive, which have not yet been fully investigated. More specifically, this study investigated the driving process that is activated when humans spontaneously try to imitate an unfamiliar action without explicit reasons. To achieve this, meaningless actions were prepared, and the `urge to imitate’ (Urge) was defined as a means of measuring the imitation drive. Two potential confounding factors were given particular attention during the isolation of neural correlates underlying Urge. First, in adult participants, the urge to imitate can result from explicit reasons, which may include the fact that the presented action appears familiar, challenging or interesting. Thus, attempts were made to eliminate the effects of these types of upstream cognitive processes on imitation drive by creating a questionnaire to evaluate the potential involvement of these explicit reasons and the strength of the urge to imitate. Second, the strength of the urge to imitate may be correlated with various kinematic characteristics of the perceived action, including perceptual factors such as speed or complexity. Therefore, various types of kinematic factors we.