Spatial and non-spatial attention deficits in neurodegenerative diseases: Assessment based on Bundesen's theory of visual attention (TVA)

PURPOSE: The aim was to present evidence that, similarly as in neglect, a combined pattern of spatial and non-spatial deficits of visual attention can also be typically observed in patients suffering from neurodegenerative disorders. METHOD: Whole and partial report of brief letter arrays, based on Bundesen's 'theory of visual attention' (TVA), was applied in patients suffering from Huntington's disease (HD), mild cognitive impairment (MCI), or Alzheimer's disease (AD). TVA-based parameter estimates were derived reflecting (a) perceptual processing speed and visual working memory storage capacity as non-spatial aspects of visual attention (determined by whole report performance), and (b) spatial attentional weighting (determined by partial report performance). RESULTS: Processing speed was severely slowed in HD, and also reduced, although to a lesser degree, in MCI and AD patients. In HD and AD patients, but not in MCI patients, a strong leftward bias of spatial attention was observed. CONCLUSION: Neglect and neurodegenerative diseases both involve a similar constellation of non-spatial and spatial deficits of visual attention. Therefore, by using TVA-based measurement, results from both fields of research may fruitfully inform each other in future studies, thus improving our understanding of the interaction of spatial and non-spatial attention deficits and its behavioral consequences.