Influence of stimulus symmetry on visual scanning patterns

Eye movements of four Ss performing a complexity rating task in which the stimuli consisted of random shapes differing in symmetry, number of turns (sides) in the perimeter, and structural angularity were examined. It was found that for both symmetrical and asymmetrical shapes, the number of fixations and fixation time increased directly with structural complexity (number of sides). Distributions of fixations for symmetrical shapes clustered in one-half of the shapes, while the distributions of fixations for asymmetrical shapes did not exhibit this one-sided bias. No differences were found in the distributions of fixation time to either half of asymmetrical or symmetrical shapes. The findings suggest that S utilizes an organizing code in addition to the featural code in characterizing a given shape. The organizing code permits S to generate the feature code for a gwen shape on the basis of partial information.     

Partial differential feedback: An on-line training configuration for the optimization of multidimensional cue learning

The present paper describes a PDP-9 computer configuration arranged for experimental research into the acquisition of judgmental skill, but designed to overcome certain deficiences noted in stimulus-response-outcome (SRO) paradigms. The configuration departs radically from traditional approaches in that (a) the stimulus is placed under S control; (b) the requirement for a “response” is eliminated; (c) outcome feedback is a continuously changing function of the multiattribute stimulus settings under the control of S; and (d) the configuration makes possible the rapid learning of an essential feature of such learning tasks, namely the partial derivatives of the criterion or outcome variable with respect to each of the stimulus attributes.     

Marx on species-being and social essence

We see in the early texts of Marx a continuity of thought, where the individual essence of man is likewise regarded to be social. This concept is for Marx not abstract; that is, it is not to be understood in isolation from nature or other men.     

Repeated vs varied distractors in immediate memory

Ss heard groups of eight spoken digits presented for immediate recall. Irrelevant distractor letters were interpolated between digits, using either the same letter interpolated eight times or eight different letters. The latter condition produced significantly more errors in recall. Error scores were also affected by rate of presentation of items and by whether letter-digit sequences started with a letter or a digit. It is suggested that selective immediate recall may bear some resemblance to aspects of visual search.     

The effects of a graduated stimulus change on the acquisition of a simple discrimination in severely retarded boys

Methods were compared for teaching severely retarded boys to discriminate the position of a 0.75-in. black square and to press the response key closest to it. Seven boys were given trial-and-error training; one learned the task. The six boys who did not learn were presented with a program of graduated stimulus changes. All but one acquired the performance, and he was under appropriate control during the program. When he reached the criterion stimuli, he reverted to a position-based response learned during trial-and-error training. Six similar subjects were presented with graduated stimulus training alone. All six learned the criterion discrimination with few or no errors. Both groups were tested for retention of the criterion performance 35 days after training was completed. Two boys who had near-perfect criterion discrimination performances showed no signs of retention after 35 days. These boys had a history of trial-and-error training.     

ETHICS CONCERNING LEISURE

In the United States, non-work, or non-productive activity can produce ego anxiety within a person who considers work as the primary index of self-worth. This anxiety can become extreme when a person retires or is forced into unemployment. One cause of this anxiety is society's standards concerning acceptable activity; particularly the work-oriented attiude formulated in the “Protestant Ethic.” However, the “Protestant Ethic” is neither Protestant nor religious. Rather, it is a set of national mores, which justify our work-oriented economy in religious terms. Situational ethics, which reflect both sound counseling practice and contemporary theology, can be formulated concerning the problem of leisure. And, we propose a guideline for such an ethic.     

On the determination of appropriate dimensionality in data with error

The study deals with the problem of determining true dimensionality of data-with-error scaled by Kruskal's multidimensional scaling technique. Artificial data was constructed for 6, 8, 12, 16, and 30 point configurations of 1, 2, or 3 true dimensions by adding varying amounts of error to the true distances. Results show how stress is affected by error, number of points, and number of dimensions, and indicate that stress and the elbow criterion are inadequate for purposes of identifying true dimensionality when there is error in the data. The Wagenaar-Padmos procedure for identifying true dimensionality and error level is discussed. A simplified technique, involving a measure calledConstraint, is suggested.The authors wish to thank Dr. J. B. Kruskal for his valuable help and suggestions.Computer time for this research was supplied by the Instruction and Research Computer Center, The Ohio State University.