The current thesis explores the complex relationship between cognitive control and memory. A series of experiments combined task-switching paradigms with recognition memory tests to measure how switching between tasks influences effective control over long-term memory. In these experiments, participants were presented with compound stimuli consisting of a picture and an overlaid word, and were cued in each trial whether the word or the picture was relevant (attended) or irrelevant (unattended). Participants were then tested for their memory of items presented during task switching. Experiments 1-2 indicated that switching between tasks reduces the selectivity of processing: Switching was associated with impaired task performance as well as more similar memory ratings for attended and unattended items. Experiments 3-5 extended these findings by showing that enhanced top-down control positively affected task-performance as well as memory, in both cases by increasing the selectivity of processing toward task-relevant information. Experiments 6-7 replicated key effects with simple switches of visual attention, and explored the neural correlates of successful task performance and encoding using EEG. The key finding here was that previously observed ―subsequent memory‖ effects reflect, at least in part, selective encoding processes. The last chapter extended the focus of the investigation to explore the role of control in long-term memory retrieval. FMRI meta- analyses indicated considerable overlap in neural activation found during task switching and during the adoption of different retrieval sets. The results of Experiment 8 indicated that switching during task performance and later memory retrieval were both associated with decreased selectivity of processing. Collectively, the results of this thesis suggest that selectivity of processing is a critical factor in effective task performance and successful memory, with potentially very similar mechanisms underlying the two. This work demonstrates the fruitfulness of combining research on cognitive control and memory to study questions relevant for both fields.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:618432 |
| Date | January 2013 |
| Creators | Richter, Franziska Rebekka |
| Contributors | Yeung, Nick |
| Publisher | University of Oxford |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://ora.ox.ac.uk/objects/uuid:6537ad2c-107b-4517-8b37-7d5d59edbe3b |
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