The efficient detection of information of negative valence in the environment is crucial to survival (e.g. to elicit an avoidance response). However, previous research remains inconclusive regarding the question of whether detection is more sensitive to information of negative compared to positive valence. In the present thesis I used a signal detection approach applied to an emotional-evaluation word task (requiring the participants to classify a briefly presented masked word into emotional or non-emotional categories) to address this question. The results established conclusively enhanced detection sensitivity to negative valence compared to positive valence of verbal information, under both supraliminal and subliminal conditions (Chapter 2) while ruling out any alternative accounts in terms of word frequency, idiosyncratic differences in valence ratings and different levels of arousal. The extent to which the enhanced negative valence detection depends on availability of attention was addressed in Chapter 3. Using a dual-task paradigm, participants performed the emotional detection task together with a letter-search task of either low or high perceptual load. A negative valence detection advantage was found in the low load but not high load conditions. These results established that attentional resources are critical for the enhanced detection of negative valence. The role of individual differences in trait anxiety in the effects of attention on valence detection was examined in Chapter 4. The results demonstrated that high trait anxiety was associated with enhanced detection of negative valence even under high load, whereas individuals with low trait anxiety were less sensitive to negative valence across both levels of load. The effects of monetary reward were addressed in Chapter 5. The results indicated that while reward enhanced detection sensitivity, the negative valence detection advantage remained unaffected. Overall the results establish conclusively a negative valence detection advantage that interacts with attention, trait anxiety, but not with reward.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:565209 |
| Date | January 2011 |
| Creators | Nasrallah, M. |
| Publisher | University College London (University of London) |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://discovery.ucl.ac.uk/1302396/ |
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