Effects of contour sharpness and check-size on visually evoked cortical potentials

Harter, M. Russell; White, Cameron

doi:10.1016/0042-6989(68)90044-8

Cited by 173 publications

(50 citation statements)

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“…some other reports fail to mention where that point of fixation was located with respect to certain details of the pattern (Ciganek, 1971;Harter. 1971;Harter & White, 1968, 1970. The exact location of the observer's point of fixation with respect to the checkerboard pattern could be of crucial importance in some experimental situations.…”

Section: John B Siegfriedmentioning

confidence: 99%

The effects of checkerboard pattern check size on the VECP

Siegfried

1975

Bull. Psychon. Soc.

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Section: John B Siegfriedmentioning

confidence: 99%

The effects of checkerboard pattern check size on the VECP

Siegfried

1975

Bull. Psychon. Soc.

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“…Figure 3-13 introduces another aspect of the work. This, and figure 3-14 represent work previously reported by Harter and White (1968). Subjects were presented with a checkerboard of the optimum design, elements of 10 to 15 minutes of arc.…”

mentioning

confidence: 94%

Average evoked potentials: Methods, results, and evaluations.

Donchin

Lindsley²

1969

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to discuss current problems in the study of average evoked potential. As can be seen from %he list of participants, most laboratories, in &his country and abroad, thak aotively use signal-averaging techniques in processing electroencephalographic records were represented at the conference. Our objective in organizing this conference was to provide a forum for discussing the problems involved in conducting these gtudies and in communicating the results of experiments.For this purpose, the conference was organized in the following format. Six investigators were invited to prepare critical reviews of the literature-each on one of six assigned topics. The reviews mere made available to all the conference participants 4 to 6 weeks before the conference. Each review was to serve as the text for one &hour session at the conference. The reviewer was allotted 20 minutes to restate some of the main points presented in ahis paper; then discussion was opened to all participants. The discussions were moderated in each case by an assigned discussant.Chapters 2 through 7 present the review papers and the ensuing discussion. The remarks made by the reviewer were deleted since their substance is presented in the review.All the principal speakers completed their assignment on time, and the reviews were sent to the participants. However Dr. Vaughan's report, as included in this volume, is substantially differen6 from the document that he circulated to the participants. For this reason, the discussants ignore much of the material presented in his present chapter.I n addition to the working sessions of the conference, two evening sessions featured extended presentations. I n the first one, Dr. Lindsley surveyed the evoked potential technique, its history, and achievements; in the second one, Dr. Frank Morrell discussed the neurophysiological mechanisms underlying the average evoked response. Dr. Lindsley's talk provided the material for Chapter 1. A supplement contains m IV FOREWORD reports that were submitted by participants to expand and elaborate upon some of the comments they made in the discussion.The conference would not have been possible without the support of the O5ce of Space Science and Applications, NASA Headquarters and Dr. Orr Reynolds. Dr. Norman Weissman of NASA Headquarters was instrumental in providing support, both in the organization of the conference and in the publication of the Proceedings. His patience and understanding are deeply appreciated. Ames Research Center, where at the time I held a National Research Council Resident Research Associateship, provided much necessary help. Dr. Jorge Huertas was especially considerate. The organization of the conference down to the last detail was in the very capable hands of Mrs. Mary-Frances Thompson of the American Institute of Biological Sciences. Special thanks are due her for the magnificent job she has done.Since we have deleted all the chairman's non-technical remarks, the Proceedings fail to underline the able chairmanship provided by Dr. D. B. Lindsley, who ran...

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“…Studies by Harter & White (1968) and others have shown that the size of black and white squares (i.e., contour density) comprising checkerboard pattern stimuli dramatically affect the amplitude and waveform of averaged evoked cortical potentials. These effects are related to contour sharpness, visual acuity, and possibly to the size and organization of retinal receptive fields.…”

mentioning

confidence: 98%

“…Various studies have shown that the amplitude of the averaged evoked cortical response is re1ated to the visual field in which the stimulus appears and to the pattern or contour of the stimulus (e.g., Harter & White, 1968Harter & Suitt, 1970;Spehlmann, 1965;John et al, 1967;Rietveld et al, 1967). Using a small diffuse circular flash of light as astimulus, found that larger potentials are evoked by flashes appearing in the lower visual field than in the upper.…”

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confidence: 99%

Effects of checkerboard pattern stimulation on evoked cortical responses in relation to check size and visual field

Eason¹,

White

Bartlett

1970

Psychon Sci

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Cortical evoked responses to checker board stimulation were studied as a function of check size and visual field. Stimuli were presented to the upper, central, and lower parts of the retina. Regardless of check size, largest potentials were obtained to lower-field stimulation; central-field stimulation yielded intermediate responses; upper-field stimulation produced the smallest responses. Maximal responses were obtained to intermediate check sizes during lower-field stimulation and to the smallest checks during upper-field stimulation. The results suggest that the cortical visual system is more responsive to pattemed stimuli appearing in the lower viewing field than in the upper, but that the system may be relatively more sensitive to smaller objects appearing in the upper fjeld.

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Effects of contour sharpness and check-size on visually evoked cortical potentials

Cited by 173 publications

References 9 publications

The effects of checkerboard pattern check size on the VECP

The effects of checkerboard pattern check size on the VECP

Average evoked potentials: Methods, results, and evaluations.

Effects of checkerboard pattern stimulation on evoked cortical responses in relation to check size and visual field

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