PubMed HealthSearch

Biomedical subjects

M E Arterberry

Publications and source records attributed to M E Arterberry.

5 recordsLinked to original sources

Effects of imagery on vernier acuity under conditions of induced depth.

Imagery interferes with visual acuity (the "Perky effect") when an image is close to a visual target and both the image and the acuity target are located in the same depth plane. Whether imagery-induced interference occurs when a mental image and a target are separated by induced depth was investigated. Participants projects an image in front of or behind a vernier acuity target on a frontal or back plan suggested by the panels of an outline cube. A drop in accuracy for the target was found when an image was projected in front of, but not behind, the target. Thus, induced depth can influence the Perky effect. By contrast, real lines interfered with the target regardless of perceived depth plane, which is inconsistent with the hypothesis that imagery and perception are equivalent. Results support the hypothesis that images interfere with perception only when the participant must see through an image to obtain information specifying the visual target.

Depth Perception

Infants perceive spatial structure specified by line junctions.

Lines in drawings can be perceived as the corners where surfaces intersect, outer boundaries of surfaces, or as markings on a surface. In this study infants' ability to distinguish between lines that indicate corners and edges and lines that indicate markings was investigated. Infants aged 7.5 months were habituated to line displays in which the lines specified a three-dimensional cube or two overlapping rectangles. Both displays contained lines indicating corners, edges, and surface markings. After habituation, infants viewed two test displays, one in which the corners or edges were deleted and one in which the surface markings were deleted. Infants looked significantly longer at the displays that lacked the corners or edges. The results suggest that infants attend to lines that depict corners and edges to a greater degree than they attend to lines that depict markings. Infants may do so because corners and edges specify the shapes of objects whereas markings do not.

Child Development

Four-month-old infants' sensitivity to binocular and kinetic information for three-dimensional-object shape.

4-month-old infants were tested for sensitivity to kinetic and binocular information for 3-dimensional-object shape. The study included 2 tests: a test for sensitivity to binocular disparity and a shape perception test. The disparity sensitivity test used a preferential looking procedure developed by Held, Birch, and Gwiazda. On the basis of the results of this test, infants were assigned to disparity-sensitive and disparity-insensitive groups. In the shape perception test, a "transfer-across-depth-cues" method was employed. Infants were habituated to a rotating object whose shape was specified by kinetic information and were then presented with stationary stereograms specifying the same object and a novel-shaped object. The disparity-sensitive infants looked significantly longer at the novel object than at the familiar object, whereas the disparity-insensitive infants showed no difference in looking time to the novel and the familiar objects. The results indicate that disparity-sensitive 4-month-old infants can perceive 3-dimensional-object shape from kinetic and binocular depth information.

Attention

Infants' sensitivity to accretion and deletion of texture as information for depth at an edge.

Based on Gibson's hypothesis that accretion and deletion of texture in the optic array provides unambiguous information for the spatial layout of surfaces, we sought evidence of early responsiveness to this information with infant subjects. 5- and 7-month-olds viewed computer-generated random-dot displays in which accretion and deletion of texture provided the only information for contours, specifying either a foreground surface moving in front of and occluding a moving background surface or 2 partially overlapping surfaces. The infants in both age groups showed significant preferences to reach for the apparently nearer regions in the displays. Since previous research has shown that infants reach more frequently for the nearer of 2 surfaces, these results indicate that 5- and 7-month-olds are sensitive to accretion and deletion of texture as information for the spatial layout of surfaces.

Depth Perception