PubMed HealthSearch

PubMed · 7400521

"Eyes on the ball" an oversimplification.

Abstract

The familiar sports axiom "Keep your eyes on the ball" is an oversimplification of what can be a difficult process. In addition to enhancing the visual performance of athletes via spectacles, contact lenses, and vision therapy, optometric advice on how to best utilize vision for better performance can be invaluable to coaches and athletes.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

J Runninger. 1980. "Eyes on the ball" an oversimplification.. https://pubmed.ncbi.nlm.nih.gov/7400521/

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

KEEP EXPLORING

Related citations

Accuracy of estimating time to collision using binocular and monocular information.

We measured both the just-noticeable difference in time to collision (TTC) with an approaching object, and the absolute accuracy in estimating TTC in the following cases: only binocular information available; only monocular information available; both binocular and monocular information available as in the everyday situation. Observers could discriminate trial-to-trial variations in TTC on the basis of binocular information alone: the just-noticeable difference in TTC (5.1-9.8%) was the same for a small (0.03 deg) target and for a large (0.7 deg) target. In line with previous reports, when only monocular information was available, the just-noticeable difference in TTC was 5.8-12% for the large target. However, observers could not reliably discriminate trial-to-trial variations in TTC with the small target when only monocular information was available. When both binocular and monocular information was available, the just-noticeable difference in TTC for the large target was not significantly different from when only binocular or only monocular information was available. Observers could make reliable estimates of absolute TTC using binocular information only. Errors ranged from 2.5 to 10% for the large target, and 2.6 to 3.0% for the small target, all being overestimates. Errors for the small target were the same or lower than errors for the large target. Observers could make reliable estimates of TTC with the large target using monocular information only. Errors ranged from 2.0 to 12%, all being underestimates. Since monocular information did not provide a basis for reliable estimates of absolute TTC with the small target we conclude that, in everyday conditions, accurate estimates of TTC with small targets are based on binocular information when the object is small and is no more than a few metres away. Errors in estimating absolute TTC were lower in the case where both binocular and monocular information were available (as in the everyday situation) than when only binocular information or only monocular information was available. Errors ranged from 1.3 to 2.7%. An error of 1.3% approaches the accuracy required to explain the +/- 2.0-2.5 msec accuracy with which top sports players can estimate the instant of impact between bat and ball.

Depth Perception

Spatio-temporal vernier acuity.

The study of space-time vernier (STV) provides information on the spatio-temporal structure of the visual system in the same way that the classical spatio-spatial vernier (SSV) provides information on its spatial structure. The transposition of a SSV task into a STV one yields the following experimental format: an object (in the present case a Gaussian Blob) drifts with a constant velocity, V, disappears at x0, t0 and reappears after a variable duration delta t at a position x1 +/- delta x with x1 the correct position (given a constant V) and delta x the minimum (positive and negative) spatial offset discriminable from x0, i.e. the STV threshold. Observer's task is to specify whether the reappearance position is ahead of, or behind x1. The STV functions of delta t measured for 1, 5 and 10 deg/s reference velocities are linear with non-zero spatial and temporal intercepts at the origin. We refer to these x and t intercepts as dynamic dmin and tmin. Dynamic dmin is the smallest instantaneous displacement (infinite velocity) discriminable from a continuous drift, V. Dynamic tmin is the shortest 'motion stop' discriminable from the same continuous drift, V. To our knowledge these quantities have not yet been assessed. Estimated dynamic dmin increases with V. whereas tmin is more or less V independent suggesting that the motion sensors presumably involved in the STV task have peak spatial frequencies inversely proportional with V and a temporal frequency characteristic independent of V (at least within the studied range). The observed STV linearity with the spatio-temporal separation implies that the STV task is equivalent to a velocity discrimination. Two additional observations yield support to this conclusion. (i) The slopes of these functions yield velocities very similar to those discriminable from the reference V in a standard V-discrimination experiment. (ii) The predicted STV performances based on a decomposition of the task into two velocity discrimination tasks run as independent experiments are reasonably accurate.

Depth Perception

The direction of retinal motion facilitates binocular stereopsis.

Visual information from binocular disparity and from relative motion provide information about three-dimensional structure and layout of the world. Although the mechanisms that process these cues have typically been studied independently, there is now a substantial body of evidence that suggests that they interact in the visual pathway. This paper investigates one advantage of such an interaction: whether retinal motion can be used as a matching constraint in the binocular correspondence process. Stimuli that contained identical disparity and motion signals but which differed in their fine-scale correlation were created to establish whether the direction, or the speed, of motion could enhance performance in a psychophysical task in which binocular matching is a limiting factor. The results of these experiments provide clear evidence that different directions of motion, but not different speeds, are processed separately in stereopsis. The results fit well with properties of neurons early in the cortical visual pathway which are thought to be involved in determining local matches between features in the two eyes' images.

Depth Perception