Abstract
Selecting objects for further processing is critical for producing appropriate goal-directed behaviours. The external and internal attentional framework emphasizes the targets of attention. Specifically, attention can be directed to either objects immediately present in the visual field, or to internal object representations held in memory. Our research provides the first in-depth investigation into how the breadths (narrow/broad) of internal and external attention interact. In Experiment 1, we tested whether manipulating internal attentional breadth impacts external attentional selection. Specifically, we examined if a narrow internal attentional breadth decreases interference by external flankers located outside this internal window. In each trial, a three-colour working memory array was presented. This array was either narrow (smaller items placed closely together) or broad (larger items placed further apart) to manipulate internal breadth. Then, to measure external attention, a flanker task was presented where target arrows were flanked by response compatible or incompatible distractor arrows. Finally, a change detection probe was displayed to test for colour memory. Results showed that narrow internal attention resulted in decreased flanker interference effects relative to when internal attention was broad. In Experiment 2, we tested whether external attentional breadth impacts internal attentional breadth, to determine whether their relationship is bidirectional. This was done by switching the order of the tasks; after first responding to the flanker target, a three-colour working memory array was presented, followed by a change detection probe. We did not observe any effect of external attentional breadth on working memory performance. Our research suggests that while external attentional breadth influences internal attentional breadth, this process is not necessarily bidirectional.