What drives memory-based attentional capture? An investigation on category-based working memory guidance of visual attention
Degree GrantorUniversity of Canterbury
Degree NameMaster of Arts
Previous neurophysiological and behavioural studies have shown that attention can be guided by the contents of working memory (WM), and that such guidance can be involuntary even when it is detrimental to the task at hand. In three experiments, this thesis investigated whether the guidance of visual attention from WM could be generalized from a specific stimulus or a task to a category. Experiment 1 tested whether maintaining a set of stimuli of a specific category in WM would influence participants' deployment of visual attention to favour other stimuli that belonged to the same category. Experiment 2 further manipulated the interval between the onset of a critical prime (i.e., a stimulus in the same category as the stimuli held in WM) and the target to determine whether the results of Experiment 1 were associated with the lack of time for attention to be focused onto the critical prime. In both experiments, the stimuli held in WM never appeared in the prime display. In Experiment 3, the identity of the prime was manipulated so that it matched the stimuli held in WM on half of the trials. The results showed that when the stimuli held in WM never reappeared in the prime display (Experiments 1 and 2) there was no evidence that maintaining specific stimuli in WM biased the distribution of attention to other stimuli within the same category. However, when the stimuli held in WM could reappear in the prime display on some trials (Experiment 3), the participants whose reaction times were relatively fast showed evidence for category-based WM guidance of attention when the critical prime item was a new stimulus in the same category as the stimuli held in WM. In contrast, the participants whose reaction times were relatively slow showed a non-spatially specific cost when the critical prime was one of the WM items than when it was a new item in the same category. These results showed that category-based WM could guide the deployment of visual attention under certain conditions. It further suggests that the relationship between WM and attention is more complex than what is outlined by the biased competition theory and related theories of attention.