Object-based attention

Object based attention is a process of selective attention that allows us to selectively process objects on the basis of their relevance. A visual scene contains a vast amount of information which means that we must focus our attention in order to selectively process the relevant information.

Attention to objects can direct attention to stimuli, even when those stimuli are not goal oriented. Binding information to a single object can facilitate manipulations of information in working memory.

An object is commonly defined as the elements in the visual scene organised by one of more gestalt principles of grouping and/or uniform connectedness.

When object based attention effects are more observable

A number of factors make object effects more observable, for example, object effects are more likely to be observed when perceptual load of the task is low, participants are young, motor responses require grasping rather than pointing, and when it is the left, rather than the right hemisphere receiving object related information. Object based attention effects are commonly demonstrated more readily with exogenous (peripheral) cues rather than endogenous (central) cues. Some studies have even struggled to find exogenous object based attention effects at all . This makes sense, as participants are more likely to adopt a broad attentional focus with exogenous cues, as they are peripheral. For enogenous cues, a narrow attentional focus is likely to be adopted and the object representation is therefore likely to be weakened if the stimulus objects are large or located peripherally, object effects are more difficult to find with endogenous cues. Object effects were therefore more reliable when the task at hand encouraged a wide (rather than narrow) deployment of attention.

The formation of object representations

The formation of an object representation is a critical factor in the deployment of object based attention. For example, Chen (1998) presented participants with displays that resembled two “v”’s, partially superimposed at the base. (pics?) When the stimulus was described to participants as two Vs, observers were faster to switch attention between two arms of the same V, compared with switching between two arms of different Vs. Slower switching between different objects indicates object based attention. However, when the same stimulus configuration was described as an X made up of two different colours, the object based attention effect was eliminated.