Stimulus and response prediction in choice reaction time: Free vs. forced reactions

Verbal predictions were combined in a 1:many mapping in order to analyze the contribution of response preparation to both stimulus and response prediction effects in choice reaction time (RT). Using a three-stimulus, two-response task in which two of the stimuli were mapped 1:1 to separate responses (forced-choice) and the third stimulus was mapped to both responses (free-choice), response frequencies and latencies were compared in two experiments. The results indicated that (1) free-choice response selections were not influenced by forced-choice stimulus predictions; (2) free-choice RTs were reduced only when the free-choice stimulus was correctly predicted; (3) free-choice responses were generally consistent with the response predicted, but RT did not depend on response prediction; (4) on forced-choice trials, the RT difference between correct and incorrect predictions was similar for stimulus and response predictions; and (5) under no-prediction conditions, no difference was found between free and forced RTs. A stimulus anticipation component was the only apparent contribution to the stimulus prediction effect, while the response prediction data suggest some prior response selection with no associated decrease in latency     

Stimulus Effects On Behavior Allocation In Three-alternative Choice

Six pigeons were trained on three-alternative concurrent variable-interval schedules that were available through a switching response and were signaled by colored stimuli. The discriminative stimuli for two of the schedules were always 560 nm and 630 nm, but the stimulus signaling the third alternative was varied across conditions over seven levels between these colors. For each third-alternative stimulus condition, the relative frequency of reinforcers was varied over three conditions with 4:1 and 16:1 reinforcer ratios between each pair of alternatives. The distribution of responses between the alternatives was dependent jointly on the third-alternative reinforcer rate and on the disparity between the stimulus signaling the third alternative and those signaling the other alternatives. A generalized matching approach was unable to provide invariant measures of the discriminability between constant stimuli, but a contingency-discriminability approach provided excellent fits and sensible and invariant stimulus discriminability measures.     

Stimulus control: part I

In his effort to distinguish operant from respondent conditioning, Skinner stressed the lack of an eliciting stimulus and rejected the prevailing stereotype of Pavlovian "stimulus-response" psychology. But control by antecedent stimuli, whether classified as conditional or discriminative, is ubiquitous in the natural setting. With both respondent and operant behavior, symmetrical gradients of generalization along unrelated dimensions may be obtained following differential reinforcement in the presence and the absence of the stimulus. The slopes of these gradients serve as measures of stimulus control, and they can be steepened without applying differential reinforcement to any two points along the test dimension. Increases and decreases in stimulus control occur under the same conditions as those leading to increases and decreases in observing responses, indicating that it is the increasing frequency and duration of observation (and perhaps also of attention) that produces the separation in performances during discrimination learning.     

Stimulus information vs processing time in auditory pattern recognition

Previous studies have shown that pitch perception improves with increases in tone duration. An increase in tone duration increases the information available in the stimulus presentation. Other recent experiments have shown that sufficient perceptual processing time is also necessary for accurate pitch perception. The present study determines the relative contribution of stimulus information and processing time in an absolute pitch indentification task. The results indicate that processing time is more critical than stimulus information. The results are described accurately by a model that describes the perceptual process in terms of the information in the stimulus and the time the information is available for perceptual processing.     

The orienting response: Stimulus factors and response measures

Integrative Psychological and Behavioral Science - This paper outlines some of the basic ideas of the orienting response (OR) that have developed from the classical writings of E.N. Sokolov, in...     

Stimulus and response factors in mirror-image discrimination

Two choice-reaction time studies assessed the influence of stimulus-response mapping, stimulus complexity, and stimulus alignment on adults’ discrimination of mirror-image and nonmirror-image stimulus pairs. Half the subjects in Experiment 1 were instructed to treat nonmiiTor pairs as “same” and mirror pairs as “different”; the other half responded in the opposite manner. The first group responded more quickly to nonmirror pairs, while the second group responded more quickly to mirror pairs. This result, which held for horizontal stimuli (side by side) as well as for vertical stimuli (one above the other), confirms the importance of experiential factors in mirror-image “confusions. “ In Experiment 2. stimuli were drawn from a population of patterns whose complexity could be objectively defined. In general, the more complex the pattern, the slower the response and complexity seemed to influence the qualitative nature of pattern processing. In both experiments, subjects responded more quickly to horizontal stimuli than to vertical stimuli.     

Probability of Stimulus Equivalence as a Function of Class Size vs. Number of Classes

The Psychological Record - Two experiments were conducted to study stimulus equivalence as a function of class size and number of classes. In the first experiment, equivalence was tested in 50...     

Stimulus selection by the retarded: list length and response requirement.

Institutionalized retardates learned paired associates of redundant trigrams and double digits (e.g., DLZ/10) and were given a transfer test to measure their stimulus selection. List length (four or six items) and response requirement (recall or recognition) were both manipulated during learning. The finding of most interest was that the retardates became more efficient at cue selection as the amount of information increased. This finding suggests that, at least to some extent, these retarded persons actively tended to choose a stimulus-processing strategy that puts a low load on memory as the overall memory requirements of the paired-associate task were increased.