Advertisement

Experimental Brain Research

, Volume 187, Issue 3, pp 447–457 | Cite as

Local (focussed) and global (distributed) visual processing in hemispatial neglect

  • Andrea PeruEmail author
  • Leonardo Chelazzi
Research Article

Abstract

In the present study we set out to investigate deficits of focussed and distributed attention (and their interaction) in brain-damaged patients. To this purpose, four left brain damaged (LBD) patients without signs of hemispatial neglect and six right brain damaged (RBD) patients with variable signs of hemispatial neglect were tested by means of an experimental paradigm comprising two embedded tasks performed on the same visual array. The first task (i.e. counting the number of shapes, 1–4, briefly displayed) mainly involved distributed attention rather than focussed attention. The second task was a typical target detection task, which emphasized the detailed analysis of each element in the array, thus mainly tapping focussed attention. Results clearly showed that: (1) LBD patients are slightly impaired at directing focussed attention to the contralesional visual hemifield; (2) in comparison to LBD patients, RBD patients with mild neglect show an exaggerated difficulty in orienting focussed attention toward the contralesional side, while they are similarly unimpaired in the deployment of distributed attention, i.e. in global processing; (3) RBD patients with the most severe neglect suffer from a deficit of both local and global visual processing, i.e. of both focussed and distributed attention. Taken together, these observations indicate that focussed and distributed components of visual attentional processing may be differentially affected in left and right brain-damaged patients with and without neglect.

Keywords

Neglect Visual search Brain damaged patients Attention 

Notes

Acknowledgments

The research reported here was supported by grants to L.C. from the Italian Government (MIUR) and the Human Frontier Science Program (HFSP). We wish to thank Marco Veronese and Gianni Finizia for their invaluable help with preparing the stimuli and the figures.

References

  1. Aglioti S, Smania N, Barbieri C, Corbetta M (1997) Influence of stimulus salience and attentional demands on visual search patterns in hemispatial neglect. Brain Cogn 34:388–403PubMedCrossRefGoogle Scholar
  2. Arguin M, Joanette Y, Cavanagh P (1993) Visual search for feature and conjunction targets with an attentional deficit. J Cogn Neurosci 5:436–452CrossRefGoogle Scholar
  3. Berhmann M, Ebert P, Black SE (2004) Hemispatial neglect and visual search: a large scale analysis. Cortex 40:247–263CrossRefGoogle Scholar
  4. Berti A, Rizzolatti G (1992) Visual processing without awareness: Evidence from unilateral neglect. J Cogn Neurosi 4:345–351CrossRefGoogle Scholar
  5. Bisiach E, Vallar G, Perani D, Papagno C, Berti A (1986) Unawareness of disease following lesions of the right hemisphere: anosognosia for hemiplegia and anosognosia for hemianopia. Neuropsychologia 24:471–482PubMedCrossRefGoogle Scholar
  6. Cave KR, Batty MJ (2006) From searching for features to searching for threat: drawing the boundary between preattentive and attentive vision. In: Parasuraman R (ed) The attentive brain. MIT Press, Cambridge, pp 629–646Google Scholar
  7. Chelazzi L (1999) Serial attention mechanisms in visual search: a critical look at the evidence. Psychol Res 62:195–219PubMedCrossRefGoogle Scholar
  8. Di Lollo V, Kawahara J, Zuvic SM, Visser TA (2001) The preattentive emperor has no clothes: a dynamic redressing. J Exp Psychol Gen 130:479–492PubMedCrossRefGoogle Scholar
  9. Eglin M, Robertson LC, Knight RT (1989) Visual search performance in the neglect syndrome. J Cogn Neurosci 1:372–385CrossRefGoogle Scholar
  10. Esterman M, McGlinchey-Berroth R, Milberg W (2000) Preattentive and attentive visual search in individuals with hemispatial neglect. Neuropsychology 14:599–611PubMedCrossRefGoogle Scholar
  11. Gainotti G, D’Erme P, Bartolomeo P (1991) Early orientation of attention toward the half space ipsilateral to the lesion in patients with unilateral brain damage. J Neurol Neurosurg Psychiatry 54:1082–1089PubMedGoogle Scholar
  12. Halligan PW, Marshall JC (1992) Left visuo-spatial neglect: a meaningless entity? Cortex 28:525–535PubMedGoogle Scholar
  13. Kinsbourne M (1987) Mechanisms of unilateral NSU. In: Jeannerod M (ed) Neurophsyiological and neuropsychological aspects of spatial neglect. Elsevier, Amsterdam, pp 69–86CrossRefGoogle Scholar
  14. Mattingley JB, David G, Driver J (1997) Preattentive filling in of visual surfaces in parietal extinction. Science 275:671–674PubMedCrossRefGoogle Scholar
  15. Nakayama K, Joseph JS (1998) Attention, pattern recognition and popout in visual search. In: Parasuraman R (ed) The attentive brain. MIT Press, Cambridge, pp 279–298Google Scholar
  16. Nothdurft HC (2002) Attention shifts to salient targets. Vision Res 42:1287–1306PubMedCrossRefGoogle Scholar
  17. Pavlovskaya M, Ring H, Groswasser Z, Keren O, Hochstein S (2001) Visual search in peripheral vision: learning effect and set-size dependence. Spat Vis 14:151–173PubMedCrossRefGoogle Scholar
  18. Pavlovskaya M, Ring H, Groswasser Z, Hochstein S (2002) Searching with unilateral neglect. J Cogn Neurosci 14:745–756PubMedCrossRefGoogle Scholar
  19. Peru A, Moro V, Avesani R, Aglioti S (1996) Overt and covert processing of left side information in neglect patients investigated with chimeric drawings. J Clin Exp Neuropsychol 18:621–630PubMedCrossRefGoogle Scholar
  20. Piazza M, Giacomini E, Le Bihan D, Dehaene S (2003) Single-trial classification of parallel pre-attentive and serial attentive processes using functional magnetic resonance imaging. Philos Trans R Soc Lond B Biol Sci 270:1237–1245CrossRefGoogle Scholar
  21. Ptak R, Valenza N (2005) The inferior temporal lobe mediates distracter-resistant visual search of patients with spatial neglect. J Cogn Neurosci 17:788–799PubMedCrossRefGoogle Scholar
  22. Railo H, Koivisto M, Revonsuo A, Hannula MM (2007) The role of attention in subitizing. Cognition. doi: 10.1016/j.cognition.2007.08.004
  23. Riddoch MJ, Humphreys GW (1987) Perceptual and action systems in unilateral visual neglect. In: Jeannerod M (ed) Neurophsyiological and neuropsychological aspects of spatial neglect. Elsevier, Amsterdam, pp 151–181Google Scholar
  24. Robertson IH, Mattingley JB, Rorden C, Driver J (1998) Phasic alerting of neglect patients overcomes their spatial deficit in visual awareness. Nature 395:169–172PubMedCrossRefGoogle Scholar
  25. Theeuwes J, Kramer AF, Atchley P (1999) Attentional effects on preattentive vision: spatial precues affect the detection of simple features. J Exp Psychol Hum Percept Perform 25:341–347PubMedCrossRefGoogle Scholar
  26. Treisman A (2006) How the deployment of attention determines what we see. Vis Cogn 14:411–443PubMedCrossRefGoogle Scholar
  27. Treisman A, Gelade GA (1980) A feature integration theory of attention. Cognit Psychol 12:97–136PubMedCrossRefGoogle Scholar
  28. Trick LM, Pylyshyn ZW (1994) Why are small and large numbers enumerated differently? A limited-capacity preattentive stage in vision. Psychol Rev 101:80–102 PubMedCrossRefGoogle Scholar
  29. Vuilleumier PO, Rafal RD (2000) A systematic study of visual extinction. Between- and within-field deficits of attention in hemispatial neglect. Brain 123:1263–1279PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  1. 1.Dipartimento di Scienze dell’EducazioneUniversità di FirenzeFirenzeItaly
  2. 2.Department of Neurological and Vision SciencesUniversity of VeronaVeronaItaly

Personalised recommendations