Differential effects of emotional arousal on memory-guided attention

Arousal-Biased Competition (ABC) Theory suggested that emotional arousal helps to prioritise salient information, whereas it impairs non-salient information. The first purpose of this dissertation was to test the prediction of ABC theory on attention by prior knowledge (i.e., memory). Its second purpose was to investigate the effects of different emotional manipulation techniques using similar experimental tasks (i.e., memory-guided attention task) across three studies. The aims of the first study were to test the prediction of ABC theory and the effects of the fear-conditioning manipulation technique via white-noise burst on memory-guided attention. Thirty-eight participants recruited and experiment was completed with 34 participants. A visual-search task (i.e., memory-guided attention task) included training and testing sessions was employed. Results showed that manipulation technique, fear-conditioning with white-noise burst, was not effective to elicit emotional arousal and ABC theory was not confirmed. Therefore, short sound clips were employed as manipulation to test their effects on memory-guided attention and the prediction of ABC theory in the second study. Fifty-five participants took part in the experiment completed with 47 participants. The same visual-search task as study 1 was employed. According to the results, contrary to the ABC theory, emotional arousal enhanced participants' attention towards low-priority (i.e., non-salient) information than high-priority (i.e., salient) information. In the third study, a different manipulation technique which were image presentation was employed to test the effects of images on memory-guided attention and the prediction of ABC theory. Experiment was completed with 51 participants although 56 participants were recruited. Identical to the study 1 and 2, a visual-search task was employed. The results illustrated that emotional arousal enhanced participants' attention on the salient information compared to the non-salient information. In these studies, it was expected that the use of different techniques to elicit emotional arousal would result in different outcomes. Supporting this hypothesis, results from the three experiments showed that each manipulation technique has different effects on memory-guided attention. Specifically, the technique of white-noise burst employed in Study 1 was not strong enough to elicit emotional arousal. Importantly, Study 3, with image presentation as emotional manipulation, confirmed the hypothesis of ABC theory, whereas short sound clips in Study 2 resulted in an opposing effect. Thus, the findings of this thesis suggest that all manipulation methods in eliciting arousal would give somewhat different results in the testing of theories. Therefore, selection of an appropriate emotional manipulation technique is important when designing experiments.