PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 530807

A new motion illusion.

P H Schulman
View original source ↗Export metadata ↓

Abstract

Two instances of a new illusion of motion were discovered. In the first, when observers tracked a spot of light moving vertically in a field of stationary vertical lines, the lines appeared to move in the same direction as the spot. If observers did not track the spot, the lines appeared stationary. The second instance was designed to see if the same illusion would occur when the spot appeared to move as a result of induced motion. In this display a vertically moving grid of horizontal lines surrounded a stationary vertical line. A stationary spot of light could be projected on the line. If the subject fixated the spot, both spot and line appeared to move against the grid. If the spot was absent, the line appeared to move along with the grid. The implications of this illusion for theories of induced motion are discussed.

Explore related subjects

Fixation, OcularForm PerceptionHumansIllusionsMotion PerceptionOptical IllusionsOrientationJournal ArticleResearch Support, U.S. Gov't, Non-P.H.S.

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

P H Schulman. 1979. A new motion illusion.. https://doi.org/10.1068/p080659

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2006

Localization of visual targets during optokinetic eye movements.

We investigated localization of brief visual targets during reflexive eye movements (optokinetic nystagmus). Subjects mislocalized these targets in the direction of the slow eye movement. This error decreased shortly before a saccade and temporarily increased afterwards. The pattern of mislocalization differs markedly from mislocalization during voluntary eye movements in the presence of visual references, but (spatially) resembles mislocalization during voluntary eye movements in darkness. Because neither reflexive eye movements nor voluntary eye movements in darkness have explicit (visual) goals, these data support the view that visual goals support perceptual stability as an important link between pre- and post-saccadic scenes.

Fixation, Ocular↗
PubMed2006

Binocular coordination of the eyes during reading.

Saccadic eye movements and fixations are the behavioral means by which we visually sample text during reading. Human oculomotor control is governed by a complex neurophysiological system involving the brain stem, superior colliculus, and several cortical areas. A very widely held belief among researchers investigating primate vision is that the oculomotor system serves to orient the visual axes of both eyes to fixate the same target point in space. It is argued that such precise positioning of the eyes is necessary to place images on corresponding retinal locations, such that on each fixation a single, nondiplopic, visual representation is perceived. Vision works actively through a continual sampling process involving saccades and fixations. Here we report that during normal reading, the eyes do not always fixate the same letter within a word. We also demonstrate that saccadic targeting is yoked and based on a unified cyclopean percept of a whole word since it is unaffected if different word parts are delivered exclusively to each eye via a dichoptic presentation technique. These two findings together suggest that the visual signal from each eye is fused at a very early stage in the visual pathway, even when the fixation disparity is greater than one character (0.29 deg), and that saccade metrics for each eye are computed on the basis of that fused signal.

Fixation, Ocular↗