A test of the unified model of vision and attention: Effects of parietal-occipital damage on visual orienting.

Visual orienting was studied in a patient (FM) with parietal-occipital damage due to oligodendroglioma and associated surgery, and in eighteen control participants. The ability of FM and control participants to shift attention in response to spatial landmark cues, and in response to cues that recruit endogenous orienting via encoding of cue identity, were assessed. According to the unified model of vision and attention (Lambert, A. et al., Journal of Experimental Psychology: Human Perception & Performance, 44, 412-432) FM should find it difficult to orient attention in response to spatial landmarks due to impaired functioning of the dorsal visual stream; but shifting attention in response to cue identity, encoded via the ventral visual stream, should be spared. Consistent with these predictions, FM was unable to shift attention in the landmark cueing task, but shifted attention effectively in response to identity cues; and her visual orienting performance differed reliably from controls. These findings complement our earlier observation of preserved orienting towards landmark cues in a patient with bilateral damage to the ventral visual stream, and add to a growing body of evidence in support of the unified model of vision and attention.