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Duration Judgement Deficits and Schizophrenic Liability: What Drives Them and Can They Be Manipulated / MATTHEW HOPKINS

Swansea University Author: MATTHEW HOPKINS

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DOI (Published version): 10.23889/SUthesis.65080

Abstract

Duration judgements are a critical part of human life, and interest in this criticality is as ancient as the interest in the concept of time itself (e.g., Grondin, 2008). Judging the duration of an event or of passing time is also highly malleable, subject to both individual differences and environm...

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Published: Swansea, Wales, UK 2023
Institution: Swansea University
Degree level: Doctoral
Degree name: Ph.D
Supervisor: Reppa, Irene. and Reed, Phil.
URI: https://cronfa.swan.ac.uk/Record/cronfa65080
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Abstract: Duration judgements are a critical part of human life, and interest in this criticality is as ancient as the interest in the concept of time itself (e.g., Grondin, 2008). Judging the duration of an event or of passing time is also highly malleable, subject to both individual differences and environmental factors, e.g., heat or music. Retardation of duration judgements (e.g., judging the length of durations) are a common feature of schizophrenia (Elvevåg et al., 2003; Carroll et al., 2008; Carroll et al., 2009; Reed & Randell, 2014) however, there are patent difficulties in establishing the fundamental cause of timing deficits, in schizophrenia; which remains poorly understood. For example, it is well known that pharmaceutical interventions (e.g., haloperidol) can modify duration judgements (Rammsayer, 1990) in both normal adults and schizophrenic patients; however, external stimuli, such as an auditory Click Train (e.g., a series of clicks presented before stimuli), can also be used to modify duration judgments (albeit at a smaller effect-size than pharmaceutical interventions). Whether a Click Train has a similar effect as pharmacological interventions in schizophrenia has never been investigated and thus, there remains a paucity of research in this respect. To counter the potential effects of medication on duration judgements, schizotypy can be used as a useful construct for schizophrenia liability to investigate timing deficits in schizophrenia; as well as Click Train effectiveness in manipulating timing durations. Five experiments were conducted to examine what, fundamentally, contributes to timing deficits in schizotypy and to assess whether the Click Train can manipulate duration judgements in schizotypy. The first two experiments used the popular temporal bisection tasks in both visual and auditory modalities: as well as using a Click train The second set of experiments utilised the temporal generalisation tasks, using both visual and auditory modalities; as well as the Click Train. The final experiment used the classic estimation task, in which subjects had to estimate how long a video lasted. The first set of experiments are indicative of High Schizotypy subjects showing better precision for auditory durations, and that the Click Train manipulated judgement durations in subjects, irrespective of schizotypy level. The second set of experiments suggested memory distortions are present in Schizotypy and could be driving the timing deficits reported. The final experimental also implicates better precision in identifying durations in High Schizotypy. The Click Train manipulated duration judgements, irrespective of schizotypy level. Overall, the current thesis provides evidence that (1) timing deficits in schizotypy (and potentially, schizophrenia) are the result of better precision in identifying durations (e.g., less variability) and (2)., that the Click Train can be used as an effective tool in manipulating duration judgements in schizotypy and potentially limiting some of the effects of timing deficits in schizophrenia.
Keywords: Schizophrenia, Schizotypy, Duration Judgement Deficits, Time Perception
College: Faculty of Medicine, Health and Life Sciences