Enhanced detection sensitivity to negative emotional valence: the role of awareness, attention, anxiety, and reward

摘要

The efficient detection of information of negative valence in the environment is crucial to survival (e.g. to elicit an avoidance response).udHowever, previous research remains inconclusive regarding the question of whether detection is more sensitive to information of negative compared toudpositive valence. In the present thesis I used a signal detection approach appliedudto an emotional-evaluation word task (requiring the participants to classify audbriefly presented masked word into emotional or non-emotional categories) toudaddress this question. The results established conclusively enhanced detectionudsensitivity to negative valence compared to positive valence of verbaludinformation, under both supraliminal and subliminal conditions (Chapter 2)udwhile ruling out any alternative accounts in terms of word frequency,udidiosyncratic differences in valence ratings and different levels of arousal. Theudextent to which the enhanced negative valence detection depends on availabilityudof attention was addressed in Chapter 3. Using a dual-task paradigm,udparticipants performed the emotional detection task together with a letter-searchudtask of either low or high perceptual load. A negative valence detectionudadvantage was found in the low load but not high load conditions. These resultsudestablished that attentional resources are critical for the enhanced detection ofudnegative valence. The role of individual differences in trait anxiety in theudeffects of attention on valence detection was examined in Chapter 4. The resultsuddemonstrated that high trait anxiety was associated with enhanced detection ofudnegative valence even under high load, whereas individuals with low traitudanxiety were less sensitive to negative valence across both levels of load. The effects of monetary reward were addressed in Chapter 5. The results indicatedudthat while reward enhanced detection sensitivity, the negative valence detectionudadvantage remained unaffected. Overall the results establish conclusively audnegative valence detection advantage that interacts with attention, trait anxiety,udbut not with reward.