Curiosity is regarded as one of the most important drives in human cognition, which motivates us to explore the environment and influences our decision-making (Gottlieb & Oudeyer, 2018; Kidd & Hayden, 2015; Loewenstein, 1994). There has been increasing research interest dedicated to studying the biological function, the underlying mechanisms of curiosity and its beneficial effects on learning (Berlyne & Normore, 1972; Fandakova & Gruber, 2021; Gruber et al., 2014; Jepma et al., 2012). Yet, there is still a lack of evidence to uncover a full picture of the underlying mechanisms of curiosity and learning. On the other
hand, the majority of currently available curiosity research was conducted with and based on adult participants. Yet, infants and children, especially young infants as curious learners explore their environment actively and seek novelty, and the more nuanced aspects of curiosity in this age group are less researched. Therefore, this thesis seeks to research curiosity-based learning in infants as well as adults using a variety of methods from behaviour, and eye tracking to electroencephalogram (EEG), aiming to provide empirical evidence and new insights into the field.

In Chapter 1, a general background of the literature was first provided with highlights of the most relevant theories and empirical research in both adults and children. In Chapter 2, against the background that curiosity about uncertainty enhances attention, benefiting learning in adults, yet, it is unclear whether this stays true for young infants and what the role of curiosity resolution may play in young children. Two experiments were conducted using eyetracking method and novel, infant-friendly paradigms to investigate (1) whether curiosity induced by uncertainty enhances object learning in young infants, and (2) whether young infants seek resolution of curiosity over novelty. These two experiments provide supporting evidence that curiosity induction is associated with attentional arousal. However, given the ambiguity about the interpretations of the looking preference paradigm, further investigation is needed to examine the precise manifestation of attentional arousal during the processing of visual uncertain information. The results from this chapter also give no obvious evidence that young infants would prefer curiosity resolution over novelty, indicating that infants might not have yet developed epistemic curiosity in this age group.

In Chapter 3, an EEG study with adult participants was conducted to investigate neural oscillations in response to curiosity about visual uncertainty, as little knowledge that we know about the neural representation of curiosity driven by visual uncertainty at a cortical level. This investigation provides supporting evidence that curiosity about visual uncertainty is associated with attentional arousal as indicated by increased alpha desynchronisation. As the role of metacognitive ability in curiosity-based learning has been highlighted in the literature, in Chapter 4, an online study was designed to investigate the roles of subjective prior knowledge, confidence and curiosity in learning using a blurred image paradigm with adult participants, allowing for improving and extending the generalizability of research findings in the field.