Recent studies have begun to test certain fundamental assumptions underlying popular models of feature perception. This research is continued here. It was discovered that every basic assumption that was open to test in the present study was disconfirmed. However, several new characteristics of line and curve feature perception were discovered: (1) Feature perception sensitivity was inversely related to the number of features present in a stimulus pattern, and the decision criteria for reporting a feature decreased with the number of features contained in a pattern; (2) the decrements in sensitivity reported in (1) were greater for features lying inside a pattern than for those on the exterior; and (3) feature perception sensitivity actually improved if another feature was known to be correctly perceived during the same trial. Likewise, feature sensitivity decreased if another feature was missed on any trial. At the present time, a system that first extracts global and then local (more detailed) featural information provides a basis that qualitatively accounts for our findings and is also compatible with several other studies in the literature.

https://link.springer.com/content/pdf/10.3758/BF03206352.pdf

Modeling feature perception in brief displays with evidence for positive interdependencies

Among mathematical models of visual confusion of letters and similar material, those that posit a feature detection process have been especially popular. The present study provides direct tests of several of the central assumptions of such models with feature-stimuli composed of the blank, one of two straight line features, or both line features positioned at a right angle. In one condition, the two features were connected when they appeared together, whereas in the other condition they were separated by a gap. A model which makes the strong assumptions that the features are sampled (‘detected’) independently and then reported in a direct, unbiased fashion, performed acceptably in both conditions. Feature dependency models and those positing a biased decision process were ruled out on the basis of poor fits or lack of parsimony. The perceptibility (d′) of a specific feature depended on the stimulus that contained it in the Gap condition but not in the Connected condition. The relative perceptibility of the horizontal vs in the vertical features was also different in the Gap vs Connected conditions. The results were compared with other recent studies, including ones in which sampling independence was falsified, apparently because of greater stimulus complexity, and employing a stimulus set that did not contain all possible combinations of features.

Perceptual sampling of orthogonal straight line features

The role of perceptual feature sampling in speeded matching and recognition was explored in 4 experiments. Experiments 1-3 involved a perceptual matching task with pictures of various objects and scenes. In Experiments 2 and 3, same-different judgments were given under time pressure. The main objective of the matching task was to obtain measures of the perceptual processing rates of different object features. Experiment 4 was an old-new recognition experiment, in which the same stimuli as those in the matching task were used. Response signals were used to limit processing time in the recognition task. The results demonstrated that it is possible to predict speeded recognition performance from performance in perceptual matching. A simple stochastic feature-sampling model provides a unified account of the data from the 4 experiments.

/pdf/perceptual-processes-in-matching-and-recognition-of-complex-4h3kajy2le.pdf

Perceptual processes in matching and recognition of complex pictures.

In our previous research on human perception of simple patterns (Townsend, Hu, & Evans, 1984), positive dependencies in the sampling of features were interpreted in terms of underlying sensory and decisional processes. Those findings suggested a model, called Blobloc here, which is further tested in the present study under various conditions of stimulus duration in Experiment 1 and feature-specific payoff ◊ stimulus duration in Experiment 2. Signal detection microanalyses generally supported Blobloc by discovering estimated d’ greater on a given feature when another feature was a "hit" or a "correct rejection." The bias, as estimated by ~, was less consistent in the microanalyses. The macroanalyses found that d’ and ~ on individual features behaved as predicted as functions of the experimental conditions. However, in contrast to previous results, the variation in number of features in a pattern was apparently too small to yield consistent d’ and ~ changes. In addition, increasing stimulus duration produced tendencies toward linear increases in/~ (significant in Experiment 2), a finding consistent with Blobloc. A plausible alternative medel (Correlated Noise model) is rejected by the results of the present and previous studies. Recent studies have begun to clarify how psychological and contextual variables influence the way we perceive simple patterns made up of elementary sets of lines and curves (e.g., Keren & Baggen, 1981; Loomis, 1982;

/pdf/feature-sensitivity-bias-and-interdependencies-as-a-function-2kca8nhsos.pdf

Feature sensitivity, bias, and interdependencies as a function of energy and payoffs

Three experiments were performed to test the hypothesis that a target line that forms an outer contour of a stimulus figure is detected better than an internal target line. In the first experiment tridimensional stimuli similar to the object stimuli of Weisstein and Harris (1974), were used. In the second and third experiments arrows and triangles were used as stimuli, composed of one of the four right angles of a square and a diagonal. In the first two experiments the diagonal lines served as targets, and external diagonal lines were detected better than internal diagonals or diagonals without context. In the third experiment the right angles served as targets; these were detected better in arrows than in triangles or without the context diagonal. In each experiment the targets formed vertices and intersections with other line segments of the stimulus. It is argued that these local configurational features facilitated target detection by automatically attracting attention, particularly if they were located at the boundaries of the stimulus figure.

Contour effects in figure perception

Dependence in visual feature processing was studied with two identification experiments using briefly exposed stimuli The basic stimuli consisted of two orthogonal line segments which formed either one of the four angles of a square, and the subject had to identify the location of the horizontal and vertical line segment making up a stimulus In the first experiment, the two orthogonal line segments were sometimes separated by a gap In the second experiment, either a 45° diagonal or a 135° diagonal or both were added to the right angles With the observed response frequencies two forms of independence in feature detection were tested Feature detection is called state independent if the detection of a feature is independent of the detection of another feature According to context independence the detection of a feature is independent of the orientation and location of other features in the stimulus Feature detection was shown to be context dependent whereas the hypothesis of state independence was not rejected, and state independence was unrelated to the size of the gap between the two orthogonal line segments in the first experiment It was argued that the context effects obtained (context dependence) had occurred early in processing during the automatic activation of representational units corresponding to features before controlled search, interpretation and decision processes became involved

U. Glowalla

Papers

Context dependence in visual feature processing