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H Buffart

Publications and source records attributed to H Buffart.

4 recordsLinked to original sources
PubMed1988

Sequence influence on the organization of meaningless serial stimuli: economy after all.

This article provides evidence for an extension of structural information theory, a theory which describes perceptual organization formally, into a more general theory of representation that takes the role of organizations obtained earlier into account. In eight experiments, subjects study series of colored dots. Each series contained 6-8 dots of different colors, and viewing time was between 400 ms and 60 s. In several experimental procedures, subjects recalled the series presented. The experiments systematically varied the economy of the organizations of the series as described by structural information theory as well as a number of aspects of the context in which the series were presented, like order of presentation of a series, order between the series, viewing span, viewing time, and recall procedure. Recall was influenced both by the economy as well as by the context. It is shown how the context influences the relative strength of the most economical organization as compared with rival, local organizations. A structured network model is presented that accounts for the influence of both the economy and the context.

Adult↗
PubMed1983

Analysis of ambiguity in visual pattern completion.

It is possible to construct an ambiguous line drawing representing several objects partly hidden behind another object. This article deals with two problems: (a) What are the necessary and sufficient conditions for ambiguity to occur? (b) How can the response frequencies of the completions of ambiguous drawings be explained? Whether completions occur or not, the predictions based on the coding theory, better termed the structural information theory, have been discussed in a previous article (Buffart, Leeuwenberg, & Restle, 1981). It is shown here that the theory also specifies the conditions for ambiguity to occur. The theory describes all possible interpretations of a drawing and selects those interpretations or completions to which subjects will respond. A direct relation between the response frequencies and the possible theoretical descriptions of each response is shown to exist. Two one-parameter models describing the behavior of subjects each fit the response frequencies measured in two experiments with 25 drawings. It is argued that the type of ambiguity that is studied in both experiments generally appears during the perceptual process. The character of the theoretical descriptions indicates that guidance of perceptual behavior by interpretations might occur.

Adolescent↗
PubMed1981

Coding theory of visual pattern completion.

It is possible to construct a line drawing that represents one object partly hidden behind another, and most subjects complete the interrupted figure and see the hidden object as whole. This article is addressed to two problems: (a) What are the necessary and sufficient conditions for such figural completion to occur, and (b) exactly what will be seen behind the occluding figure---that is, what completion will be made? Leeuwenberg's coding model for line drawings was used to analyze a number of such figures, along with the hypothesis that figural completion occurs whenever it results in a simplification of final code of the whole figure. Data from previous experiments along with results from two new experimental studies were collected and shown to agree with this hypothesis. Of various possible figural completions or "mosaic" interpretations, subjects chose the ones resulting in the simplest overall code. However, the above conclusions are correct only if "simple" is precisely defined as the smallest information load in a completely reduced code. Other possible theories of figural completion, both structuralist and Gestalt, may invoke familiarity, particular "cues," like T-shaped intersections, simplicity of the hidden figure, symmetry, and good continuation. All such possibilities were considered in the experiments and shown to fail, wrongly predicting at least one figure. The coding-theory analysis, on the other hand, made correct predictions for all of the 25 figures used.

Cues↗