Dynamic Visual Noise Does Not Affect Memory for Fonts

Author(s):  
Chrissy M. Chubala ◽  
Tyler M. Ensor ◽  
Ian Neath ◽  
Aimée M. Surprenant

Abstract. Dynamic visual noise (DVN) selectively impairs memory for some types of stimuli (e.g., colors, textures, concrete words), but not for others (e.g., matrices, Chinese characters, simple shapes). According to the image definition hypothesis, the key difference is whether the stimulus leads to images that are ill-defined or well-defined. The former will be affected because the addition of noise quickly reduces the usefulness of the image in supplying information about the item's identity. The image definition hypothesis predicts that fonts should lead to ill-defined images and therefore should be affected by DVN, and although three previous studies appear to show this result, they lack a key control condition and report only proportion correct. Two experiments reassessed whether DVN affects memory for fonts, but, unlike the previous studies, both included a static visual noise condition and both were analyzed using signal detection measures. There was no evidence that DVN affected memory for font information, thus disconfirming a prediction of the original version of image definition hypothesis. We suggest a revised version that focuses on redintegration can explain the results.

Author(s):  
Kevin Dent

In two experiments participants retained a single color or a set of four spatial locations in memory. During a 5 s retention interval participants viewed either flickering dynamic visual noise or a static matrix pattern. In Experiment 1 memory was assessed using a recognition procedure, in which participants indicated if a particular test stimulus matched the memorized stimulus or not. In Experiment 2 participants attempted to either reproduce the locations or they picked the color from a whole range of possibilities. Both experiments revealed effects of dynamic visual noise (DVN) on memory for colors but not for locations. The implications of the results for theories of working memory and the methodological prospects for DVN as an experimental tool are discussed.


1977 ◽  
Vol 17 (8) ◽  
pp. 903-910 ◽  
Author(s):  
Joseph J. Mezrich ◽  
Albert Rose

1980 ◽  
Vol 32 (3) ◽  
pp. 387-395 ◽  
Author(s):  
M. J. Morgan ◽  
Roger Ward

Brief apparent motion sequences were introduced into a dynamic visual dot display by spatially shifting selected dots between successive frames. This causes the display to look as if it is drifting continuously in one direction. When such a display is observed with an interocular delay the drifting dots appear to be displaced in depth, even though there is no conventional retinal disparity in the display. We found that the magnitude of this depth shift increased with the duration of the apparent motion sequences. With sequences of five or more frames duration the depth effect was very similar to that which would have been predicted with a continuously moving target. With briefer sequences the size of the depth effect decreased rapidly. We suggest that apparent motion cascades form the basis of Tyler's dynamic visual noise stereophenomenon, and we question his “random spatial disparity” hypothesis.


Perception ◽  
1984 ◽  
Vol 13 (5) ◽  
pp. 547-553
Author(s):  
James Thomas Enright

When the dynamic visual noise of an untuned television set is viewed with image defocusing (positive lenses) and with a narrow vertical obstruction partially blocking the pupil of one eye, the video ‘snow’ seems to separate into two stable surfaces at different depths, divided by a vertical discontinuity. The main features of this illusion can be quantitatively accounted for in terms of the optics of defocused images and the retinal disparities predicted from blur circles. A residual component of the illusion, however, which was perceived by a majority of subjects, cannot be readily explained by geometrical optics; it apparently reflects a more subtle aspect in the processing of visual images, corresponding to the Anstis–Howard–Rogers stereo-effect, in which local depth configurations can bias global stereopsis. Several novel aspects of that effect are described, based on use of this obstructed-pupil illusion as the evoking stimulus.


Nature ◽  
1974 ◽  
Vol 250 (5469) ◽  
pp. 781-782 ◽  
Author(s):  
C. WILLIAM TYLER

Perception ◽  
1989 ◽  
Vol 18 (3) ◽  
pp. 285-291 ◽  
Author(s):  
Clara Casco ◽  
Michael J Morgan ◽  
Roger M Ward

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