ERIC Number: ED380788
Record Type: Non-Journal
Publication Date: 1995-Apr
Reference Count: N/A
Visual Stability across Saccades While Viewing Complex Pictures. Technical Report No. 609.
McConkie, George W.; Currie, Christopher B.
A study explored the phenomenon of space constancy or visual stability of stimulus patterns across saccades (a series of small jerky movements of the eye) by making changes in natural, full-color pictures during selected saccades as observers (18 members of the University of Illinois community) examined them for 20 seconds in preparation for a recognition test. In the first experiment, the pictures were displaced up, down, left, or right by 0.3, 0.6, or 1.2 degrees. In the second experiment, the pictures were expanded or contracted in size by 10% or 20%. As a secondary task, subjects pressed a button whenever they detected a change in the picture. Three results from previous studies with simpler stimuli did not generalize to this situation. Evidence suggests that subjects' detection of image displacements as they examine complex pictures primarily involves the use of local information in the region of the saccade's landing position. Findings suggest support for a saccade target theory, which postulates that a shift of the stimulus is detected on the basis of the post-saccadic retinal location of the object to which the eyes are sent. Further research is needed to identify other sources of evidence for instability in the stimulus configuration from one fixation to the next. (Contains 42 references, 3 notes, 5 tables of data, and 4 figures of data.) (Author/RS)
Publication Type: Reports - Research
Education Level: N/A
Authoring Institution: Illinois Univ., Urbana. Beckman Inst. for Advanced Science and Technology.; Center for the Study of Reading, Urbana, IL.