La comprensione delle azioni e delle emozioni altrui: correlati elettrofisiologici nella prima infanzia e in età prescolare

The research presented in the current dissertation investigates two of the most intriguing topics pertaining to the field of developmental cognitive neuroscience, namely, the development of the ability to understand others’ actions and the ability to comprehend others' emotions. Recent research suggests that the human brain is equipped with structures that are active both during first- and third-person experience of actions and emotions. These structures, known as the mirror neuron system (MNS), were originally discovered in monkeys. They have been proposed as a neural mechanism through which others’ actions, intentions, and emotions can be directly understood by bridging the gap between self and others. In fact, when we perceive someone else’s action or emotion expression we activate a network that is also active during action execution or expression of emotions. Despite recent advances in the study of the development of action and emotion processing, the neuro-cognitive correlates of these abilities in infants and children are far from being fully understood. Studies described in this dissertation attempt to fill this gap by investigating the neural correlates of the ability to perceive and understand others’ actions and emotions in preverbal infants and older children. Chapter 1 provides a review of existing models developed to tackle the developmental origins of mirroring mechanisms, and a discussion of the existing debate about the role of the motor system in action and emotion understanding. The studies reported in Chapter 2 and 3, respectively, focus on the neural correlates of 7-month-olds’ processing of human action sounds, as measured through event-related potentials (ERPs), and the neural mechanisms driving toddlers’ ability to understand others' actions, as assessed by frequency oscillation through time-frequency analysis. Furthermore, the development of the ability to understand others' emotions and the role played by the motor system in such an understanding across development will also be explored. The study described in Chapter 4 explores the neural correlates of 7-month-old infants' capability to process static and dynamic facial expressions of emotions, whereas Chapter 5 is dedicated to the investigation of the mechanisms underlying covert facial muscle reactions, as measured through surface electromyography (sEMG), elicited by the observation of emotional expressions in 3-years-old children. Results of the presented research will be discussed in Chapter 6 to provide an integrated picture of the early stages of the development of action and emotion understanding. The existing theoretical debate about the role of the motor system in action and emotion understanding processes will be addressed by proposing a developmental viewpoint.