Degree Name

Doctor of Philosophy (Clinical Psychology)


School of Psychology


Cognitive processes have traditionally been studied objectively within controlled environments, and how they unfold for different individuals in the flow of everyday life remains unexplored. This is partially due to the difficulty of studying cognition in real world settings. Capturing subjective perceptions of cognition may be of use. Selfreported cognitive failures, being minor slips and errors during routine activities, are a construct of interest. Cognitive failures are associated with schizotypy, a constellation of personality traits thought to represent psychosis-proneness. It has been posited that subjective impairment represents a cognitive marker of psychosis risk. However, there is a “gap” between objectively normal performance and subjectively impaired cognition in schizotypy which is not understood. Additionally, cognitive failures are poorly defined, and there is debate concerning the validity of subjective complaints as a measure of cognition.

The aims of this thesis were to develop a clearer conceptualisation of cognitive failures, and to consider the nature of the relationship between failures and schizotypy. Two systematic reviews were initially undertaken to inform further empirical research. Review 1 involved the examination of cognitive failures in healthy populations, and highlighted that a range of trait and state factors co-occur to shape the likelihood cognitive failures will occur. Ongoing concerns regarding the validity of self-reported cognition were also evident. It was proposed that cognitive failures capture capacity in the real world; aspects of cognition separate to objectively-determinable ability. In Review 2, cognitive failures were examined in psychologically disordered and substance user populations, both of whom were found to experience heightened failures.

Directed by these findings, Study 1 addressed the impact of self-awareness on selfreported cognitive failures. Self and observer ratings of neuroticism and cognitive failures were compared for 409 healthy target participants and were moderately correlated. Neither high nor low neuroticism or self-awareness corresponded with a reduced correlation between self and observer reports of cognitive failures. This supported that groups who report heightened failures genuinely experience more errors in day-to-day life.

Studies 2 and 3 focused on the schizotypy-cognitive failures relationship. Study 2 aimed to examine self-reports of 863 healthy participants and found increased failures in high schizotypes relative to low schizotypes. In addition, it was found that negative affect mediates this relationship, suggesting that emotion contributes to the experience of failures in schizotypy.

Study 3 involved the assessment of both subjective and objective cognition in 127 healthy participants. Cognitive failures and schizotypy were moderately correlated. Deficits were evident for emotional but not neutral content on a working memory task. Fearful stimuli combined with high task difficulty elicited the most errors. However, self-reported cognitive failures did not correlate with objective cognition even when incorporating emotional processes. It seems that high schizotypes demonstrate normal cognition until overwhelmed with high levels of cognitive load and emotion.

Together the results underscore the significance of self-reported cognitive failures as reflecting aspects of cognition distinct from objective ability. Cognitive failures warrant further attention from both researchers and clinicians as potentially reflecting dysfunction of emotion regulation and increased risk for psychological disorders including psychosis.

This thesis is unavailable until Saturday, January 12, 2019