Timing the senses and sensing the time: Individual differences in subjective duration

Although the experimental investigation of the perception of time dates back to around 1864 (Lejeune & Wearden, 2009) the reasons for variation between individuals are still poorly understood. Advancing in this area has been identified as one of the most important issues for the modern investigation of time perception (Hancock & Block, 2012). Although various individual differences in time perception have been identified, these are usually based on comparisons between different groups depending on characteristics such as age or gender; clinical conditions such as schizophrenia or autism; or induced differences such as temperature or pharmacology. In this thesis we seek to investigate whether, and how, intrinsic individual differences in sensory processing within the general population influence individual timing behaviour. This is accomplished over four experiments. The first seeks a relationship between the EEG alpha rhythm, which is strongly associated with visual and audio-visual temporal integration, and behaviour on four timing tasks; while trends are in the expected directions no significant relationship emerges. The second responds to this null result by seeking a relationship between audio-visual integration and estimated, sub-second, durations in a purely behavioural paradigm, in this case the results show a significant association. The final two experiments are concerned with individual differences in interoceptive accuracy (sensitivity to ones own bodily signals), and how these influence the effect of arousal on time judgement. The first experiment, using supra-second durations, finds no effects, but the second, using shorter durations (under 1200ms) and addressing some methodological concerns, does find a significant moderation, by interoception, of the effect of emotional arousal upon time. We conclude that this provides substantial evidence that exteroceptive and interoceptive primary sensory processes play a role in individual variation in timing tasks, a finding that provides many further avenues of investigation.