Origins of empathy development in infancy

The current thesis examined the processes involved in the generation of empathy in infancy. This thesis endorses the combination of developmental and cognitive neuroscience techniques for a more comprehensive understanding of empathy. In support of this view, the current work has adopted a multi-method approach in which neuroimaging, psychophysiological and behavioral techniques have been used to examine the cognitive and affective aspects of empathy in infancy. Through a series of experimental studies, this thesis has addressed intertwined yet different aspects of the experience of empathy. Paper 1 investigated individual differences in 8-month-old infants’ neural responses to peers’ emotional non-verbal vocalizations by using event-related potential (ERP) method and parental reports of infants’ temperament. Results showed that infants responded differently to peers’ laughing and crying vocalizations, as indexed by modulations in the N100, P200 and late positive component (LPC). Of special interest, individual differences in negative emotionality were related to amplitude variations in the P200 and LPC components. Paper 2 expands on the previous results by examining frontal asymmetry patterns linked to infants’ affective and behavioral responses to a peer crying and a peer laughing. Eight-month-old infants underwent two assessment sessions on separate days, in which electroencephalography (EEG) and behavioral measures were respectively recorded in each day. EEG analysis showed that distinct neural patterns were related to the observation of a peer laughing and a peer crying, with greater right frontal activation being associated with the observation of a peer crying. Furthermore, correlational analysis suggested a positive relation between left frontal cortical activation and infants’ attempts to approach a peer crying or infants’ attempts to engage with a peer laughing. Following on from it, Paper 3 and 4 investigated potential neurocognitive mechanisms underlying affective and cognitive aspects of empathy. Paper 3 examined the role of motor mimicry and affective evaluation processes in infants’ facial matching responses to others’ emotional facial expressions by measuring spontaneous facial reactions (SFRs). In particular, 4- and 7-month old infants were presented with facial expressions of happiness, anger, and fear. Electromyography (EMG) was used to measure activation in muscles relevant for forming these expressions: zygomaticus major (smiling), corrugator (frowning), and frontalis (forehead raising). Results indicated no selective activation of the facial muscles for the expressions in 4-monthold infants. For 7-month-old infants, evidence for selective facial reactions was found especially for happy faces and fearful faces, while angry faces did not show a clear differential response. Paper 4 goes on to explore the ontogeneis of cognitive aspects of empathy by examining the neural correlates underlying false belief (FB) processing in 15-monthold infants. Using a passive non-verbal FB task, 15-month-old infants were presented with sequences of images depicting a character acting congruently (FBc) or incongruently (FBi) to her false belief about an object’s location, while EEG was continuously recorded. ERPs analysis revealed differences between conditions at frontal locations, as indexed by modulations in the N400 component. Specifically, a more negative N400 waveform was recorded for FBi as compared to FBc trials.