Rapid and Parallel Allocation of Attention to Shapes.

In real-world visual environments, many objects can appear simultaneously or in rapid succession and often guide attention based on features such as colour and shape. There is continuing debate as to whether attention is allocated in serial or in parallel; however, previous research by Eimer and Grubert (2014) used event-related brain potential (ERP) markers of attentional allocation to show that attention could be allocated rapidly and in parallel to new items. Since colour is known to be a particularly strong guiding feature (Wolfe, 2007), it is possible that this effect is unique to colour. The current research aimed to replicate these findings using targets defined by shape in order to generalise this attentional phenomenon. Participants were presented with trials containing two rapidly presented displays with a stimulus-onset asynchrony (SOA) that varied between conditions (10, 20 and 50ms). Each display contained one target shape and one distractor shape. Participants were instructed to compare the orientations of lines presented inside the target shapes. EEG data were collected from each participant and the N2pc ERP component was analysed as a marker for the deployment of attention to a location in the contralateral visual hemifield. As found by Eimer and Grubert, differences between N2pc onset latencies in each of the two displays closely matched the objective SOA in each condition, demonstrating that attention can also be allocated rapidly to new target objects when they are defined by shape, and two separate foci of attention can be maintained in parallel. These results suggest that the ability to maintain attention at one location whilst allocating it to a new location is not confined to colour, but may in fact be a phenomenon that exists also for other attention-guiding features. Meeting abstract presented at VSS 2015.