Attention accesses multiple reference frames: Evidence from visual neglect

Research with normal participants has demonstrated that mechanisms of selec tive attention can simultaneously gain access to internal representations o f spatial information defined with respect to both location- and object-bas ed frames of reference. The present study demonstrates that patients with u nilateral spatial neglect following a right-hemisphere lesion are poorer at detecting information on the contralateral left side in both location- and object-based spatial coordinates simultaneously Moreover, the extent of th e neglect is modulated by the probability of a target's appearing in either reference frame; as the probability of sampling a target in a particular f rame of reference increases, so does the severity of neglect in that flame. These findings suggest that attention can be flexibly and strategically as signed to a reference frame depending on the contingencies of the task.