Spread of inhibition across an object's surface

For efficient visual search it is critical that attention is inhibited from returning to previously examined loci. It has been demonstrated that this inhibition can be associated both with the location and the object towards which attention was oriented. However, it is not known whether, after atten ding to one part of an object, the inhibition spreads to the entire object, or remains localized at the attended site. This study demonstrates that in hibition can spread across an object's surface. This confirms that the pres ence of objects in a display is sufficient to observe an object-based inhib itory attentional effect. However, it is also noted that this spread of inh ibition appears to decline with exposure to the task, being generally non-s ignificant in the second half of the study. The study suggests that the mag nitude of pure object-based Inhibition of Return (TOR) effect may be modula ted by the subjective salience of the objects and that, when not directly r elevant to a subject's behavioural goals, object-based representations can have minimal impact on attentional orienting processes.