This thesis investigates how the presence of communicative signals such as direct gaze and infant-directed speech might help infants and young children to under- stand, anticipate, and segment actions. For this, the thesis draws upon a range of methodologies, such as electroencephalography (Chapter 2), eye tracking, pupil dilation (both Chapter 3), and behavioural research (Chapter 4).
Chapter 2 and 3 both investigate whether the presence of communicative signals, such as infant directed speech and direct gaze, increase infants’ under- standing of actions as meaningful. The ERP experiments on 9-month-old infants reported in Chapter 2 found limited evidence that the presence of communica- tive signals enhances the N400 response, a correlate of semantic understanding. Furthermore, there is limited evidence of a complex response taking into account the presence of communication and action congruency in the Pb component in the second experiment, in which referential signals were added and the structure of the presentation was changed. Meanwhile, Chapter 3 found no evidence that communicative signals enhance anticipatory looking in 7-month-old children.
Chapter 2 and 3 also investigate the possibility that communication enhances arousal. However, neither the Nc component reported in Chapter 2, nor the Pupillary Light Reflex investigated in Chapter 3 provided evidence in support of this hypothesis.