 Empirical debates about the direction of the spotlight of attention have focussed mostly on the second of these points. An important source of data here is case studies contrasting the different patterns of attention failure that are shown by different unilateral neglect patients. Such studies suggest that various frames of reference are involved in the spatial allocation of attention (Behrmann and Tipper, 1999). This indicates that there is no single map of locations determining which items get attention: attention is sometimes allocated on the basis of location in egocentric space, sometimes on the basis of location in more complex frames of reference (a point that was among those raised by Allport, in his influential critique of the Broadbentian debates (see Allport, 1992, p. 197)).