scholarly journals Global stimulus configuration modulates crowding

10.1167/9.2.5 ◽  
2009 ◽  
Vol 9 (2) ◽  
pp. 5-5 ◽  
Author(s):  
T. P. Saarela ◽  
B. Sayim ◽  
G. Westheimer ◽  
M. H. Herzog
Keyword(s):  
Stimulus Configuration

Reproduction of Object Shape is More Accurate without the Continued Availability of Visual Information

Perception ◽  
1998 ◽  
Vol 27 (1) ◽  
pp. 69-86 ◽  
Author(s):  
Michel-Ange Amorim ◽  
Jack M Loomis ◽  
Sergio S Fukusima
Keyword(s):  
Visual Information ◽  
Internal Representation ◽  
Stimulus Configuration ◽  
The Other ◽  
Additional Information ◽  
Distant Stimulus ◽  
Perspective Change ◽  
Visual Presence ◽  
Viewpoint Change ◽  
Actual Change

An unfamiliar configuration lying in depth and viewed from a distance is typically seen as foreshortened. The hypothesis motivating this research was that a change in an observer's viewpoint even when the configuration is no longer visible induces an imaginal updating of the internal representation and thus reduces the degree of foreshortening. In experiment 1, observers attempted to reproduce configurations defined by three small glowing balls on a table 2 m distant under conditions of darkness following ‘viewpoint change’ instructions. In one condition, observers reproduced the continuously visible configuration using three other glowing balls on a nearer table while imagining standing at the distant table. In the other condition, observers viewed the configuration, it was then removed, and they walked in darkness to the far table and reproduced the configuration. Even though the observers received no additional information about the stimulus configuration in walking to the table, they were more accurate (less foreshortening) than in the other condition. In experiment 2, observers reproduced distant configurations on a nearer table more accurately when doing so from memory than when doing so while viewing the distant stimulus configuration. In experiment 3, observers performed both the real and imagined perspective change after memorizing the remote configuration. The results of the three experiments indicate that the continued visual presence of the target configuration impedes imaginary perspective-change performance and that an actual change in viewpoint does not increase reproduction accuracy substantially over that obtained with an imagined change in viewpoint.

Stimulus configuration, long-term potentiation, and the hippocampus

1997 ◽  
Vol 20 (4) ◽  
pp. 629-631 ◽  
Author(s):  
Nestor A. Schmajuk
Keyword(s):  
Neural Network ◽  
Computer Simulations ◽  
Neural Network Model ◽  
Long Term Potentiation ◽  
Stimulus Configuration ◽  
Association Cortex ◽  
Hippocampal Function ◽  
Term Potentiation ◽  
External Stimuli

Shors & Matzel propose that hippocampal LTP increases the effective salience of discrete external stimuli and thereby facilitates the induction of memories at distant places. In line with this suggestion, a neural network model of associative learning and hippocampal function assumes that LTP increases hippocampal error signals to the cortex, thereby facilitating stimulus configuration in association cortex. Computer simulations show that under these assumptions the model correctly describes the effect of LTP induction and blockade in classical discriminations and place learning.

Effects of Peripheral Gradient of Color Saturation on the Feeling of Being Dazzled

Perception ◽  
2019 ◽  
Vol 48 (5) ◽  
pp. 412-427
Author(s):  
Mitsuhiko Hanada
Keyword(s):  
Opposite Effect ◽  
Peripheral Region ◽  
Stimulus Configuration ◽  
Color Saturation

The feeling of being dazzled that is evoked by images consisting of an achromatic uniform center surrounded by regions with a luminance gradient was investigated. The effects of type of color saturation gradient in the peripheral region on the feeling of being dazzled were examined. Stimulus configuration was also varied. For the stimulus configuration of a disk-annulus, the feeling of being dazzled was lower for an increasing saturation gradient from the center to the periphery than for decreasing and no-saturation gradients when the center and the periphery maximum luminances were the same. This suggests that the presence of a chromaticity difference between the disk and the surrounding annulus strengthens the feeling of being dazzled. Similar results were obtained for the stimulus configuration of a star shape. For the stimulus configuration of a cross shape, quite different results were obtained; the chromaticity discontinuity had little or opposite effect. These results suggest that chromaticity border and stimulus configurations are factors in the feeling of being dazzled that is evoked by images with luminance gradient.

Stimulus configuration determines the detectability of motion signals in noise

2000 ◽  
Vol 17 (9) ◽  
pp. 1525 ◽  
Author(s):  
Preeti Verghese ◽  
Suzanne P. McKee ◽  
Norberto M. Grzywacz
Keyword(s):  
Stimulus Configuration

Navigational range lights: effect of stimulus configuration on alignment accuracy

Ergonomics ◽  
1995 ◽  
Vol 38 (7) ◽  
pp. 1360-1367
Author(s):  
STANLEY COREN ◽  
LORNE A. WHITEHEAD ◽  
MICHAEL J. BACA ◽  
RICHARD PATTEN
Keyword(s):  
Stimulus Configuration ◽  
Alignment Accuracy

Stimulus configuration and location in the visual field affect appetitive responses by the praying mantis, Sphodromantis lineola (Burr.)

1993 ◽  
Vol 10 (6) ◽  
pp. 997-1005 ◽  
Author(s):  
Frederick R. Prete
Keyword(s):  
Visual Field ◽  
Adult Female ◽  
Stimulus Configuration ◽  
Retinal Location ◽  
White Background ◽  
Praying Mantis ◽  
Field Center ◽  
Moving Stimuli ◽  
Upward Moving

AbstractAdult female praying mantises, Sphodromantis lineola (Burr.), were presented with computer-generated black rectangular stimuli that moved horizontally or vertically at 82 deg/s against a homogeneous white background. Both stimulus configuration (orientation in relation to direction) and the retinal location of the stimulus image affected the rate at which mantises responded appetitively (approached or struck at the stimulus). Mantises responded most to square stimuli (12.5 deg × 12.5 deg) when they moved horizontally or vertically through, or horizontally at 24.5 deg below the center of their visual field. Mantises also responded most to vertically (vs. horizontally) oriented rectangular stimuli (12.5 deg × 47 deg) that moved through their visual-field center, irrespective of whether the stimuli moved downward or horizontally. Upward moving stimuli elicited intermediate amounts of behavior with no configuration preference. Mantises did not demonstrate a configuration preference when rectangular stimuli moved ≥24.5 deg outside of the visual-field center. Furthermore, mantises responded very little and demonstrated no configuration preferences to stimuli that moved less than ≈83 deg through their visual field even if the stimuli moved through the visual-field center.

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