Localized attentional interference reflects competition for reentrant processing

Visual performance is compromised when attention is divided between objects that are near one another in the visual field. It has been postulated that this effect, termed localized attentional interference (LAI), reflects competition between visual-object representations for the control of cortical neural responses. To determine whether LAI arises during feedforward processing or during reentrant processing, the present study examined the influence of poststimulus pattern and four-dot masks on the strength of the effect. Experiment 1 found that pattern masks, which are believed to compromise feedforward processing, do not produce stronger LAI than do four-dot masks, which are believed to leave feedforward processing undisrupted. Experiment 2 found that LAI is weaker when reentrant processing is interrupted shortly after initiation than it is when reentrant processing is allowed to run to completion. The results suggest that LAI emerges from competition between objects during reentrant processing.