Oculomotor and electrophysiological markers of cognitive distraction during low-level and complex visual tasks

  • Steven William Savage

    Student thesis: Doctoral ThesisDoctor of Philosophy


    Distraction during driving is one of the leading contributors to injury and mortality rates in traffic accidents. The aim of this current thesis was to consider 1) whether oculomotor and electrophysiological metrics could act as markers of cognitive distraction; 2) whether decrements in hazard perception performance caused by secondary cognitive task demand are to some extent due to cognitive load interfering with processes of alerting, orienting, inhibitory control and visual search; 3) what elements of secondary cognitive tasks have the greatest impact on hazard perception performance; and 4) whether the susceptibility of previously identified markers of cognitive distraction are affected by primary task difficulty.

    Over the course of four Experiments we recorded the effects of secondary cognitive task demand on behavioural, oculomotor and electrophysiological metrics during a variety of low-level and complex visual tasks.

    Taken together the experiments of this thesis have demonstrated that secondary cognitive task demand interferes with not just one but every component process of hazard perception performance that was examined. Next, this research has demonstrated that measures such as blink rates, saccade peak velocities, the spread of fixations along the horizontal axis as well as reductions in alpha and beta power output may be reliable indicators of secondary cognitive task demand regardless of the type of primary task. Finally we have shown that the co-registration of eye movements, EEG and ERP measures is a viable method with which to study the cognitive processes involved in visual processing within low level and complex visual tasks.
    Date of Award2015
    Original languageEnglish
    SupervisorBenjamin Tatler (Supervisor) & Douglas Potter (Supervisor)


    • Driving
    • Distraction
    • Physiological assessment
    • Eye movements
    • EEG
    • Cognitive psychology
    • Experimental psychology

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