Influences of target and nontarget shapes on target identification

The orientation of a nontarget in a location-cuing paradigm has been shown to affect accuracy of identification of target orientation when modified pl us-signs (Ts) are the stimuli. In the current study, similar effects were f ound with Landolt C (C) stimuli. Both shapes of targets were identified by orientation. Moreover, targets were affected by nontargets whether both tar get and nontarget were the same shape or if they were different shapes. A s ingle nontarget with an orientation that matched that of the target improve d accuracy of identification of target orientation, whereas a nontarget wit h an orientation that did not match that of the target impaired accuracy of identification of target orientation, even though the nontargets appeared in locations that were never cued and could never contain targets. The data are consistent with either the Variable and Permeable Filters metaphor or a response competition account.