The Subjective Direction of Gaze Shifts Long Before the Saccade

Subjects in eye movement experiments sometimes report that they have moved their eyes to some location before their eyes have actually moved (Deubel and Schneider, 1996). We investigated this by presenting a brief test stimulus at various points in time after directing subjects to make a saccadic eye movement to a peripheral cue. The subjects had to report where they were looking when the test stimulus was presented. We found that visual stimuli presented at the saccade target location as early as 250 ms before sac-cade onset were reported as occurring after the saccade. In a second experiment subjects performed, intentionally, a saccade to a static cue. Also under this condition, subjects reported to look at the future saccade target location long before the saccade actually occurred. The data show that subjects are unaware of the time when they make even a large saccade, and that they have no explicit knowledge of the retinal position of stimuli. Rather, they mistake movements of visual attention for movements of the eyes.

[1]  G. Becker.  AGE OF A COOLING GLOBE IN WHICH THE INITIAL TEMPERATURE INCREASES DIRECTLY AS THE DISTANCE FROM THE SURFACE. , 1908, Science.

[2]  B. Bridgeman,et al.  Postsaccadic target blanking prevents saccadic suppression of image displacement , 1996, Vision Research.

[3]  J R Duhamel,et al.  The updating of the representation of visual space in parietal cortex by intended eye movements. , 1992, Science.

[4]  J. Hoffman,et al.  The role of visual attention in saccadic eye movements , 1995, Perception & psychophysics.

[5]  J. Findlay,et al.  The Relationship between Eye Movements and Spatial Attention , 1986, The Quarterly journal of experimental psychology. A, Human experimental psychology.

[6]  D. E. Irwin,et al.  A localist evaluation solution for visual stability across saccades , 1994, Behavioral and Brain Sciences.

[7]  B. Dosher,et al.  The role of attention in the programming of saccades , 1995, Vision Research.

[8]  Robert W. Kentridge,et al.  Eye movement research : mechanisms, processes and applications , 1995 .

[9]  H. Deubel,et al.  Visual attention and saccadic eye movements: Evidence for obligatory and selective spatial coupling , 1995 .

[10]  A. A. Skavenski,et al.  Contr of eye position in the dark. , 1970, Vision research.

[11]  Christopher B. Currie,et al.  Visual stability across saccades while viewing complex pictures. , 1995, Journal of experimental psychology. Human perception and performance.

[12]  H. Deubel,et al.  Saccade target selection and object recognition: Evidence for a common attentional mechanism , 1996, Vision Research.