- Title
- Behavioural and Electrophysiological Correlates of Anticipatory Task-Set Reconfiguration
- Creator
- Nicholson, Rebecca Anne
- Relation
- University of Newcastle Research Higher Degree Thesis
- Resource Type
- thesis
- Date
- 2006
- Description
- The concept of a unitary cognitive control system has increasingly come under question. Numerous paradigms have emerged that aim to dissect cognitive control into its constituent processes, including task-switching paradigms that require alternation between multiple tasks. A switch in task is associated with increased reaction time (RT) as compared to a repeat in task, which is proposed to at least partially reflect processes associated with reconfiguration of the currently active task-set. Previous event-related brain potential studies show a differential positivity emerging prior to a switch in task that appears to reflect anticipatory task-set reconfiguration. Six experiments were conducted that investigated the behavioural and ERP correlates of task-switching, and in particular, the cognitive control processes involved in anticipatory task-set reconfiguration. Experiment 1 dissociated the effects of passive dissipation of task-set interference from anticipatory task-set reconfiguration. In Experiment 2, it was further verified that the switch-related differential positivity reflects processes associated with anticipatory task-set reconfiguration, particularly initiation of the new task-set. A simplified paradigm was developed in Experiment 3 that maximised engagement in anticipatory task-set reconfiguration, reducing mean RT switch cost. Experiment 4 demonstrated that the RT switch cost and differential positivity in cueing paradigms are associated with task-set reconfiguration rather than a cue repetition benefit. Consistent with previous brain imaging studies, Experiment 5 revealed that anticipatory task-set reconfiguration is associated with increased activation in the prefrontal cortex and parietal lobe. These findings show that task-set reconfiguration processes are activated when switching between tasks and that this consists of multiple components including the active utilisation of cognitive control processes in anticipatory task-set reconfiguration. Task-switching paradigms are thus a useful tool for investigating control processes in healthy populations and as Experiment 6 demonstrates, in clinical populations that have deficits in control processes, such as patients with schizophrenia.
- Description
- Research Doctorate - Doctor of Philosophy (PhD)
- Subject
- task-switching; cognitive control processes; ERPs
- Identifier
- http://hdl.handle.net/1959.13/24736
- Identifier
- uon:725
- Rights
- http://www.newcastle.edu.au/copyright.html, Copyright 2006 Rebecca Anne Nicholson
- Language
- eng
- Full Text
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| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | DS2 | Abstract | 47 KB | Adobe Acrobat PDF | View Details Download | ||
| View Details Download | DS3 | Thesis-chapter1-4.pdf | 1 MB | Adobe Acrobat PDF | View Details Download | ||
| View Details Download | DS4 | Thesis-chapter5-11.pdf | 2 MB | Adobe Acrobat PDF | View Details Download |