Date of Award
Doctor of Philosophy
Selective attention has been studied extensively and it is shown, for example, that individuals with conditions such as anxiety show attention bias to threat-related stimuli. It has been proposed that humans are predisposed or that it is naturally adaptive to selectively attend to emotional stimuli (Lang, 2000). Similarly, LeDoux (1996) and others have proposed limbic brain networks allowing for quick and automatic, but sometimes inaccurate, processing of emotion which bypasses primary cortical areas. Along these lines, automatic attention bias to subliminal image cues in an adapted Posner Covert Attention Task was examined in the current study. A sample of 64 participants was used in each of three separate experiments to examine how individuals were cued subliminally by negative or positive emotional vs. neutral images and the modulation of covert attention by emotion. Due to automatic or motivated attention to emotionally salient stimuli, participants were expected to be facilitated in task performance by negative and positive emotional image cues, relative to neutral cues. Further, state anxiety and depression were expected to impact performance on emotional cueing as well. As expected in Experiment 1, subliminal images produced significant covert attentional cueing and only negative image cues compared to neutral ones produced response time (RT) reduction by valid cueing across both cue-target delay conditions. Further, cueing differences between neutral and negative images were seen only at short delays, supporting differential subliminal processing of emotional cues in attentional paradigms and supporting previous evidence of unconscious fear processing and specialized automatic fear networks. Moreover, in Experiment 2, when delays following subliminal cues were extended further, emotional cues did not differentially modulate covert attention, suggesting that subliminal emotional cueing seems to occur more immediately. Positive subliminal imagery in Experiment 3 was largely unsuccessful in differentially modulating covert attention compared to neutral cues, suggesting that positive information is either not effective in modulating covert attention or occurs over similar immediate time durations as negative cues in Experiment 1. Finally, the presence of self-reported state anxiety and depression affected task performance, especially in Experiment 1 negative for subliminal discrimination of negative vs. neutral image cues. Overall, the current study adds to the research literature which demonstrates that emotional information, especially negative imagery processed at short intervals, can be processed below awareness to modulate attention in a different manner than less salient neutral stimuli and this modulation is further influenced by state anxiety or depressive symptomatology. Implications of these findings and future directions for research are discussed.
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