Neural circuits involved in imitation and perspective-taking

Abstract

Is it important to adopt the perspective of the model when learning a new skill? Is the "mirror system" equally involved when the teacher is facing or side-by-side with students? In this functional MRI study, we measured the cerebral hemodynamic changes in participants who watched video-clips depicting simple hand or foot actions. The participants either watched passively or imitated these actions. Half the video-clips depicted actions filmed from the perspective of the participant (1st-person perspective) and half from a frontal view as if watching someone else (3rd-person perspective). Behavioral results showed that latency to imitate was significantly shorter for the 1st-person perspective than the 3rd-person perspective. Functional imaging results demonstrate that the observation of intransitive actions engaged primary visual and extrastriate visual areas, but not the premotor cortex. Imitation vs. observation of actions yielded enhanced signal in the contralateral somatosensory and motor cortices, cerebellum, left inferior parietal lobule and superior parietal cortex, and left ventral premotor cortex. Activity in the lateral occipital cortex around the extrastriate body area was significantly enhanced during imitation, as compared to observation of actions confirming that this region involvement reaches beyond the perception of body parts. Moreover, comparisons of the two visual perspectives showed more activity in the left sensory-motor cortex for 1st-person, even during observation alone, and in the lingual gyrus for 3rd-person perspective. These findings suggest that the 1st-person perspective is more tightly coupled to the sensory-motor system than the 3rd-person perspective, which requires additional visuospatial transformation. Published by Elsevier Inc.

Transcranial alternating current stimulation to the inferior parietal lobe decreases mu suppression to egocentric, but not allocentric hand movements

“…In addition, our results support a neurophysiological advantage for self-related stimuli (Jackson, Meltzoff, & Decety, 2006;Maeda, Kleiner-Fisman, & Pascual-Leone, 2002) as subsequent to IPL-stimulation, -suppression only decreased for the egocentric hands movements. Given that we observed no effect on -suppression during observation of allocentric hands movements subsequent to stimulation, we suggest that other neural mechanisms are involved in the processing of allocentric hands movements.…”

“…Self-other relations have frequently been studied by means of perspectives or viewpoints (e.g. David et al, 2006;Frenkel-Toledo et al, 2013;Jackson et al, 2006;Vogt et al, 2003). Typically, these studies reason that the observation of a movement presented as if the observer is conducting the movement (egocentric) is more self-related than the observation of the movement observed as if facing another agent conducting the movement (allocentric).…”

“…Typically, correlational studies investigating perspectives as an indication of self-other differentiation have shown that egocentric stimuli induce greater neurophysiological and behavioural responses compared to allocentric stimuli. For example, it has been observed: greater cortical activity in the sensorymotor cortex (Jackson et al, 2006), greater visuomotor interference (Bortoletto et al, 2013;Vogt et al, 2003) and larger motor-evoked potentials (MEPs) as induced by transcranial magnetic stimulation (TMS) during the observation of egocentric movements (Maeda et al, 2002). However, these correlational reports have not always been consistent; Alaerts and colleagues (2009) reported that MEPs are not necessarily larger for egocentric movements per se; rather, MEP's are larger for an egocentric right hand and for an allocentric left hand.…”

Focusing on body sites: the role of spatial attention in action perception

“…Imaging studies have confirmed that a similar system is also present in humans (e.g. Grèzes et al 2003;Buccino et al 2001;Iacoboni et al 1999;Koski et al 2002), and this system has been linked to the automatic imitation of actions by imaging and behavioral studies (e.g., Jackson et al 2006;Leslie et al 2004;Wohlschläger and Bekkering 2002).…”

Prediction of intent in robotics and multi-agent systems

“…Formatted final version available at: http://link.springer.com/article/10.1007%2Fs10339-007-0168-9 cases (e.g. Jackson, Meltzoff, and Decety, 2006) can provide robotics researchers with useful information regarding potential implementation approaches.…”