Intelligence and task structure complexity: a neurocognitive investigation of goal neglect in children and adults

The PhD investigates the hypothesis that individual differences in intelligence (more specifically, fluid g) is intimately related to the construction of mental programs, during problem solving or action planning (Duncan, 2010) – termed the mental program hypothesis. A series of experiments explores the cognitive and electrophysiological mechanisms behind goal neglect—a disregard of task requirements that while understood and remembered, fail to guide behaviour at real-time execution. This PhD takes an interdisciplinary approach to the study of goal-directed behaviour and its relationship with intelligence - drawing on the fields of developmental psychology, cognitive psychology, electrophysiology, artificial intelligence, and individual differences research. The PhD uses two main approaches: the investigation of goal neglect in typically developing children using new experimental paradigms, and the investigation of goal neglect using modern Electroencephalographic (EEG) analysis methods. Both approaches investigate how task structure complexity can be increased by manipulations of the task instructions presented to participants. All studies found that task structure complexity causes poorer task performance and increases goal neglect. Moreover, experimental conditions that cause participants to maintain a more complex task structure, increase the relationship between goal neglect and fluid g. EEG analysis reveals task structure complexity disrupts two processes: an early (~200 ms) evaluation process of stimuli for task relevance, and later occurring phasic interactions between theta, alpha and beta oscillatory activities.