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H K Rodewald

Publications and source records attributed to H K Rodewald.

9 recordsLinked to original sources
PubMed1978

Concurrent random-interval schedules and the matching law.

In Experiment I, a group of eight pigeons performed on concurrent random-interval schedules constructed by holding probability equal and varying cycle time to produce ratios of reinforcer densities of 1:1, 3:1, and 5:1 for key pecking. Schedules for a second group of seven were constructed with equal cycle times and unequal probabilities. Both groups deviated from simple matching, but the two forms of the schedules appeared to produce no consistent patterns of deviation. The data were found to be consistent with those obtained in concurrent variable-interval situations. The parameters of the matching equation in the form of Y=k X(a) were estimated; the value of k was unity and a was 0.84. In Experiment II, six pigeons were exposed to two conc RI RI schedules in which one component increasingly approximated an FI schedule. The value of k was not 1.0. Concurrent RI RI schedules were shown to represent a continuum from conc FI VI to conc VI VI schedules. The use of the exponential equation in testing "matching laws" suggests that a<1 will continue to be observed, and this will set limits on the form of new laws and the assumed or rational values of the component variables in these laws.

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PubMed1974

All-or-none-acquisition in matching-to-sample and a test of two models.

Three pigeons learned to match three colors in a matching-to-sample procedure. The sample hue was presented on the center one of three keys, and the comparison hues were presented on the side keys. Forty responses on the center key produced the stimuli on the side keys and left the sample on the center key. A single response on the correct side key produced 3-sec access to grain, which was followed by a 25-sec intertrial interval. A correction procedure was employed when an error was committed. Before attaining asymptotic levels, there was no evidence of learning, responses were independent of the preceding response, and distributions of errors in four-trial blocks were binomial. Distributions of error runs, runs of various lengths, autocorrelations of errors of several lags, alternations of correct responses and errors, etc., were shown to fit Bower's (1961) all-or-none model better than a gradual learning model of Bush and Sternberg (1959). A transfer test employing a novel color showed only transitory degradation of performance.

Journal Article↗
PubMed1973

Application of Bower's one-element model to paired-associate learning by pigeons.

Bower's (1961) all-or-none model of human paired-associate learning was applied to individual data supplied by three pigeons. When the center one of three keys was illuminated with red light or with three white dots in a vertical array on a black ground, pecking on the left key was reinforced. When the center key was lighted green or with a horizontal array of three white dots on a black ground, pecking on the right key was reinforced. The left and right keys were illuminated with white light. The task was considered to be analogous to learning a paired-associate list of four pairs involving four stimulus items and two response items. The model was evaluated by comparing the following model predictions with values obtained from each animal: trials-to-criterion, standard deviation of trials-to-criterion, standard deviation of errors-to-criterion, mean error runs, mean error runs of lengths one to four, and autocorrelations of errors of lags one to three. Most of the predictions based upon the model were in close agreement with the obtained data.

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