Abstract
Dysfunctional responses to emotionally charged situations and stimuli are at the core of several psychopathologies including both internalising (e.g., anxiety) and externalising (e.g., attention-deficit hyperactivity disorder) problems that can arise as early as infancy. As such, there has been growing attention given to understanding what constitutes developmentally normative emotion responses including emotion reactivity and emotion regulation in early life, to promote early identification and intervention for the prevention of later difficulties. Measuring emotion-related responses in infancy, however, presented unique challenges. Firstly, the line between typical and atypical emotional responding isblurred due to rapid changes in emotional, attentional, and motor capacities, as well as shifts in the organisation of neural systems during infancy. Secondly, emotions are temporally dynamic and unfold continuously in response to environmental factors. These issues require a longitudinal examination of infant emotional responses. Further, an intensive and repeated collection of emotional responses while considering various contextual factors that can influence these responses is necessary. Although many observational studies in infancy collected such data under laboratory-based emotion-eliciting tasks, the dynamic and contextual nature of emotions is often overlooked by aggregating response intensity over the task or task segments.
Given these research imperatives, the current thesis aims to investigate the temporal features of negative emotion reactivity, and emotion regulation, among typically developing infants aged 6 to 12 months. Two different emotionally challenging contexts were studied – namely, the toy retraction task that is deemed to be frustrating and the mask task that is deemed to be fearful/novel contexts. In addition to developmental change, the design of the tasks also allowed us to examine what we define as task-related factors, including conditional differences between the challenge (stressor-present condition) and recovery (stressor-removed condition), and differences in the temporal order of events as a function
of time-on-task. We then expanded our aim to explore whether these temporal dynamics in observed infant emotional behaviours predict parent-rated temperament; an early marker with well-established links to later socio-emotional adjustments. To do this, we employed a microanalytic approach, coding each emotional response on a second-by-second basis, resulting in rich time series data.
Chapter 1 presents a general introduction to emotional development in infancy, as assessed using both observational measures and parent-rated questionnaires of temperament. Chapter 2 provides an overview of the aims and distinct contributions of the thesis. In Chapter 3, a pilot study with a cross-sectional design and a small number of infants (N=20) aged 6, 12, and 18 months is reported. It aimed to identify the most efficient and age-appropriate tasks to be applied in the main study. Chapter 4 presents the overall methodology for the main study.
In Chapter 5, using repeated-measures factorial design, we examined developmental and task-related changes in the intensity (quantified by statistical mean) of emotional responses during the toy retraction task and the masks task between ages 6 and 12 months. In Chapter 6, we explored developmental and task-related changes in three different temporal dynamic parameters defined as variability, lability, and persistency, again using repeated-measures factorial design. The findings revealed a complex picture with interactions between developmental and task-related differences, proposing more adaptive and flexible emotional responses with age. These were discussed for the toy retraction and the masks tasks separately. We found negative reactivity to be more intense, variable, and labile with age but only when the stressor was present in the toy retraction task. In the masks task, negative reactivity became more intense, variable, and persistent with age again only during stressor presentation. Hence, older infants reacted to the frustrating context with larger and quicker negativity, and with larger but slower negativity to the novel/threatening context. Similar to negative reactivity, older infants showed more intense emotion regulation in the toy retraction task only during the challenge condition, but less variable and labile regulation only during the recovery condition, suggesting a more stable pattern of regulation with age perhaps with the aid of improving attentional control. In the masks task, infants exhibited more variable and labile, but not more intense regulation during the challenge at both ages.
Chapter 7 investigates whether temporal dynamics in observed reactivity and regulation are associated with parent-rated temperament and whether these associations occur above and beyond measures of the intensity in that observed response. After utilising a series of multiple regressions, results indicated that less variable and more persistent emotion regulation patterns were distinctly linked to better temperamental outcomes, including increased duration of orienting and regulation. On the other hand, more persistent negative reactivity during the non-stressful situation (recovery) uniquely predicted higher temperamental negative reactivity in the toy retraction task and fear in the masks task.
Altogether, our findings provided the first empirical support for the argument that in infancy, examining not only the intensity but also the temporal characteristics of emotion responses could be important when trying to understand emotional responses. Also, our findings underscored the influential role of situational (challenge vs. recovery condition) and contextual factors (toy retraction vs. masks task) to better understand the typical development of emotional responses through the first year of life. These findings have important implications for the early identification and prevention of psychopathologies associated with emotional dysregulation. By providing a more nuanced understanding of
emotional development in infancy, this thesis can inform the design of interventions that target the specific aspects of emotional responses that are most critical for healthy socioemotional functioning.
| Date of Award | 1 Mar 2024 |
|---|---|
| Original language | English |
| Awarding Institution |
|
| Supervisor | Edmund Sonuga-Barke (Supervisor), Sam V. Wass (Supervisor), Katarzyna Kostyrka-Allchorne (Supervisor) & Chiara Nosarti (Supervisor) |