Electrophysiological correlates of event segmentation: how does the human mind process ongoing activity?

The human mind decodes, processes, and makes sense of a continual flow of dynamic information, taken from an array of sensory inputs. Compelling behavioural and neuroimaging evidence reveals that humans segment activities into meaningful chunks for processing, and this phenomenon has profound implications for learning, memory and understanding the world around us (Newtson, 1973; Zacks and Tversky, 2001; Zacks et al., 2001). Whilst the existence of event segmentation is widely accepted, it remains unclear what cognitive mechanisms drive this ability.This thesis constitutes a series of behavioural and neuroimaging experiments that investigate top-down and bottom-up influences on event segmentation. The neuroimaging studies presented here are novel; they extend the field by investigating event segmentation using scalp-recorded electroencephalography (EEG). Event Related Potentials (ERPs, derived from EEG using signal-averaging procedures) showed that the perceptual processing of event boundaries is differentially sensitive to the segmentation of activities into small or large chunks, consistent with findings from previous neuroimaging research (Zacks et al., 2001). In contrast with previous findings, the electrophysiological investigations elicited responses that were clearly affected by manipulating top-down information (e.g., participant's knowledge about the activity being segmented). The results from the studies reported in the thesis support an account of the perceptual processing of event boundaries, which incorporates both top-down and bottom-up influences