Experimental Brain Research

, Volume 155, Issue 3, pp 320–333 | Cite as

Distractor modulation of saccade trajectories: spatial separation and symmetry effects

Research Article


The trajectories of saccadic eye movements can be modulated by the presence of a competing visual distractor. In the present study the trajectories of vertical saccades curved away from a single visual distractor presented in one visual field, but tended to be straight when two distractors were presented at mirror symmetric locations in both visual fields. The spatial nature of the mirror distractor effect was examined by presenting a second distractor at mirror and non-mirror locations. Saccade trajectories also tended to be straight with both mirror and non-mirror symmetrical distractors. The relationship between the distractor location and saccade curvature was examined in a third experiment by manipulating the distractor-to-target spatial separation. Although there was a tendency for greater curvature when the distractor was presented in the same hemifield as the target there was no clear relationship between curvature and distractor location. The results show that the distractor modulation of saccade trajectory is not highly spatially specific and that it can be balanced by a second bilateral distractor in the opposite visual field. The results are interpreted in terms of a model in which the initial saccade direction and curvature back towards the saccade goal are controlled by separate processes. Initial saccade direction is modulated by the inhibition of distractor locations within a ‘motor map’ specifying saccade direction. Curvature back towards the saccade goal may be attributed to a feedback system, with a separate representation of the visual target location, that enables an on-line correction of the saccade during mid-flight.


Saccade Curvature Trajectory Superior colliculus Salience map 



The authors would like to thank Sam Clark for his assistance with running some of the earlier experiments and Richard Amlôt for his comments on an earlier draft of this manuscript. This work was funded by a grant from the Leverhulme Trust awarded to RW and PH.


  1. Aizawa H, Wurtz RH (1998) Reversible inactivation of monkey superior colliculus. I. Curvature of saccadic trajectory. J Neurophysiol 79:2082–2096PubMedGoogle Scholar
  2. Burr DC, Ross J (1982) Contrast sensitivity at high velocities. Vision Res 22:479–484CrossRefPubMedGoogle Scholar
  3. Dodge R (1917) The laws of relative fatigue. Psychol Rev XXIV:89–113Google Scholar
  4. Doyle M, Walker R (2001) Curved saccade trajectories: voluntary and reflexive saccades curve away from irrelevant distractors. Exp Brain Res 139:333–344CrossRefPubMedGoogle Scholar
  5. Doyle M, Walker R (2002) Multisensory interactions in saccade target selection: curved saccade trajectories. Exp Brain Res 142:116–130CrossRefPubMedGoogle Scholar
  6. Findlay JM, Walker R (1999) A model of saccade generation based on parallel processing and competitive inhibition. Behav Brain Sci 22:661–721PubMedGoogle Scholar
  7. Frens MA, Van Opstal AJ, Van der Willigen RF (1995) Spatial and temporal factors determine auditory-visual interactions in human saccadic eye movements. Percept Psychophys 57:802–816Google Scholar
  8. Godijn R, Theeuwes J (2002) Parallel programming of saccades: evidence for a competitive inhibition model. J Exp Psychol Hum Percept Perform 28:1039–1054CrossRefPubMedGoogle Scholar
  9. Hallett PE, Adams WD (1980) The predictability of saccadic latency in a novel oculomotor task. Vision Res 20:329–339PubMedGoogle Scholar
  10. Hanes DP, Wurtz RH (2001) Interaction of the frontal eye field and superior colliculus for saccade generation. J Neurophysiol 85:804–815PubMedGoogle Scholar
  11. Honda H, Findlay JM (1992) Saccades to targets in three-dimensional space: dependence of saccadic latency on target location. Percept Psychophys 52:167–174PubMedGoogle Scholar
  12. Houghton G, Tipper SP (1996) Inhibitory mechanisms of neural and cognitive control: applications to selective attention and sequential action. Brain Cogn 30:20–43CrossRefPubMedGoogle Scholar
  13. Houghton G, Tipper SP (1999) Attention and the control of action. An investigation of the effects of selection on population coding of hand and eye movements. In: Heinke D, Humphreys GW, Olson A (eds) Connectionist models in cognitive neuroscience. Proceedings of the 5th neural computational and psychological workshop. Springer, Berlin Heidelberg New YorkGoogle Scholar
  14. Ludwig CJH, Gilchrist IG (2002) Measuring saccade curvature: a curve fitting approach. Behav Res Methods Instrum Comput 34:618–624PubMedGoogle Scholar
  15. Ludwig CJH, Gilchrist ID (2003) Target similarity affects saccade curvature away from irrelevant onsets. Exp Brain Res (in press)Google Scholar
  16. Mays LE, Sparks DE (1980) Saccades are spatially, not retinotopically, coded. Science 208:1163–1165PubMedGoogle Scholar
  17. McIlwain JT (1986) Point images in the visual system: new interest in an old idea. Trends Neurosci 354–358Google Scholar
  18. McIlwain JT (1991) Distributed spatial coding in the superior colliculus: a review. Vision Neurosci 6:3–13Google Scholar
  19. McPeek RM, Keller EL (2001) Short-term priming, concurrent processing, and saccade curvature during a target selection task in the monkey. Vision Res 41:785–800PubMedGoogle Scholar
  20. McPeek RM, Skavenski AA, Nakayama K (2000) Concurrent processing of saccades in visual search. Vision Res 40:2499–2516Google Scholar
  21. McPeek RM, Han JH, Keller EL (2003) Competition between saccade goals in the superior colliculus produces saccade curvature. J Neurophysiol 89 (in press)Google Scholar
  22. McSorley E, Findlay JM (2003) Saccade target selection in visual search: accuracy improves when more distractors are present. J Vision (in press)Google Scholar
  23. Munoz DP, Istvan PJ (1998) Lateral inhibitory interactions in the intermediate layers of the monkey superior colliculus. J Neurophysiol 79:1193–1209PubMedGoogle Scholar
  24. Munoz DP, Wurtz RH (1995) Saccade-related activity in monkey superior colliculus 2. Spread of activity during saccades. J Neurophysiol 73:2334–2348PubMedGoogle Scholar
  25. Optican LM (1995) A field theory of saccade generation: temporal-to-spatial transform in the superior colliculus. Vision Res 35:3313–3320CrossRefPubMedGoogle Scholar
  26. Quaia C, Aizawa H, Optican LM, Wurtz RH (1998) Reversible inactivation of monkey superior colliculus. II. Maps of saccadic deficits. J Neurophysiol 79:2097–2110PubMedGoogle Scholar
  27. Quaia C, Lefévre P, Optican LM (1999) Model of the control of saccades by superior colliculus and cerebellum. J Neurophysiol 82:999–1018PubMedGoogle Scholar
  28. Robinson DA (1975) Oculomotor control signals. In: Lennerstrand G, Bach-y-Rita P (eds) Basic mechanisms of ocular motility and their clinical implications. Pergamon, Oxford, pp 337–374Google Scholar
  29. Robinson FR, Fuchs AF (2001) The role of the cerebellum in voluntary eye movements. Annu Rev Neurosci 24:981–1004CrossRefPubMedGoogle Scholar
  30. Ross LE, Ross SM (1980) Saccade latency and warning signals: stimulus onset, offset, and change as warning events. Percept Psychophys 27:251–257PubMedGoogle Scholar
  31. Schiller PH, True SD, Conway JL (1980) Deficits in eye movements following frontal eye-field and superior colliculus ablations. J Neurophysiol 44:1175–1189PubMedGoogle Scholar
  32. Schlag-Rey M, Schlag J, Dassonville P (1992) How the frontal eye field can impose a saccade goal on superior colliculus neurons. J Neurophysiol 67:1003–1005PubMedGoogle Scholar
  33. Sheliga BM, Riggio L, Craighero L, Rizzolatti G (1995a) Spatial attention-determined modifications in saccade trajectories. Neuroreport 6:585–588PubMedGoogle Scholar
  34. Sheliga BM, Riggio L, Rizzolatti G (1995b) Spatial attention and eye movements. Exp Brain Res 105:261–275PubMedGoogle Scholar
  35. Sheliga BM, Craighero L, Riggio L, Rizzolatti G (1997) Effects of spatial attention on directional manual and ocular responses. Exp Brain Res 114:339–351PubMedGoogle Scholar
  36. Soetedjo R, Kaneko CRS, Fuchs AF (2002) Evidence against a moving hill in the superior colliculus during saccadic eye movements in the monkey. J Neurophysiol 87:2778–2789PubMedGoogle Scholar
  37. Theeuwes J, Kramer AF, Hahn S, Irwin DE (1998) Our eyes do not always go where we want them to go: capture of the eyes by new objects. Psychol Sci 9:379–385CrossRefGoogle Scholar
  38. Theeuwes J, Kramer AF, Hahn S, Irwin DE, Zelinsky GJ (1999) Influence of attentional capture on oculomotor control. J Exp Psychol Hum Percept Perform 25:1595–1608PubMedGoogle Scholar
  39. Tipper SP, Howard LA, Houghton G (2000) Behavioural consequences of selection from neural population codes. In: Monsell S, Driver J (eds) Control of cognitive processes: attention and performance XVIII. MIT Press, Cambridge, MAGoogle Scholar
  40. Tipper SP, Howard LA, Paul MA (2001) Reaching affects saccade trajectories. Exp Brain Res 136:241–249PubMedGoogle Scholar
  41. Von Helmholtz H (1962) Helmholtz’s treatise on physiological optics. Dover, New YorkGoogle Scholar
  42. Walker R, Kentridge RW, Findlay JM (1995) Independent contributions of the orienting of attention, fixation offset and bilateral stimulation on human saccadic latency. Exp Brain Res 103:294–310PubMedGoogle Scholar
  43. Walker R, Deubel H, Schneider WX, Findlay JM (1997) Effect of remote distractors on saccade programming: evidence for an extended fixation zone. J Neurophysiol 78:1108–1119PubMedGoogle Scholar
  44. Walker R, Walker D, Husain M, Kennard C (2000) Control of voluntary and reflexive saccades. Exp Brain Res 130:540–544CrossRefPubMedGoogle Scholar
  45. Wurtz RH (2000) Vision for the control of movement. In: Gazzaniga MS (ed) Cognitive neuroscience: a reader. Blackwell, MA, pp 341–365Google Scholar
  46. Yarbus A (1967) Eye movements and vision. Plenum Press, New YorkGoogle Scholar

Copyright information

© Springer-Verlag 2004

Authors and Affiliations

  • Eugene McSorley
    • 1
  • Patrick Haggard
    • 2
  • Robin Walker
    • 1
  1. 1.Department of Psychology, Royal HollowayUniversity of LondonEghamUK
  2. 2.Institute of Cognitive Neuroscience, Department of PsychologyUniversity College LondonLondonUK

Personalised recommendations