Bryan E. Shepp

Selective Attention and the Processing of Integral and Nonintegral Dimensions: A Developmental Study.

Abstract In two experiments, first- and fourth-grade subjects (age 6 and 9 years) performed a speeded card-sorting task with either integral or nonintegral dimensions. The dimensions were so arranged that subjects sorted on three types of task: (1) single dimension, (2) correlated dimensions, and (3) orthogonal dimensions. Results of the first experiment indicate that both first- and fourth-grade subjects sorted integral dimensions in a manner not qualitatively different from that of the adult ( Garner & Felfoldy, Cognitive Psychology , 1970 , 1 , 225–241). In comparison with single-dimension tasks, performance was facilitated on the correlated-dimensions tasks and interference was observed on the orthogonal-dimensions tasks. Performances with nonintegral dimensions revealed an age-related processing difference. Fourth graders sorted nonintegral dimensions like the adult; no differences in performance were observed between the tasks. In contrast, first-graders sorted nonintegral dimensions as if they were integral. Interference was consistently observed on orthogonal-dimensions tasks. On correlated-dimensions tasks, interference was observed on easy tasks and redundancy facilitated difficult tasks. In the second experiment, first graders showed consistent facilitation on the correlated-dimensions task; all other results were indentical to those of Experiment I. The results were interpreted as consistent with perceptual learning theory ( Gibson, Principles of perceptual learning and development . New York: Appleton-Century-Crofts, 1969 ).

The development of selective attention: Holistic perception versus resource allocation☆☆☆

In two experiments, a speeded sorting task was administered to children. In each sorting, the child was instructed to sort a deck of cards according to values on one dimension while the values of a second irrelevant dimension were held constant, were correlated, or were varied orthogonally. Experiment 1 evaluated developmental changes in perceived structure as compared with such changes in the control of attention. Different groups of kindergarten, 2d-, and 5th-grade children performed the task with spatially integrated vs spatially separated dimensions. The results indicate that with spatially integrated dimensions there is a trend from holistic to featural perception and an increase in attentional control with increasing age. Spatially separate dimensions are perceived dimensionally at all ages, but show a trend in attentional development. In Experiment 2, the spatially integrated dimensions of Experiment 1 were made separable by portraying different targets within a configuration in different colors. The theoretical implications of the results are discussed.

Learning and Transfer of Mediating Responses in Discriminative Learning

Publisher Summary During the past several years, there has appeared substantial literature that reflects a growing interest in the chaining or mediating response theories of discriminative learning. This chapter discusses the learning and transfer of mediating responses in discriminative learning. It reviews research to classify experimental techniques and to relate them to the present body of data and processes that are assumed, by mediating-response theories, to underlie the learning and transfer of discriminations. The chapter describes the principal arrangements and paradigms and proposes a terminology that may be used to distinguish among them. The class of experiments discussed in the chapter consists of visual two-choice discriminations. The experiments are frequently conducted using a modified version of the Wisconsin general test apparatus.

The Relation Between Stimulus Analyzability and Perceived Dimensional Structure1

Publisher Summary This chapter discusses the relation between stimulus analyzability and perceived dimensional structure. The combination of integral dimensions yields stimuli that are phenomenologically fused or wholistic, whereas the combination of separable dimensions yields stimuli with perceptually distinct components. Operationally, integral dimensions produce a Euclidean metric in direct distance scaling, classifications based on a distance or similarity structure in a restricted classification task, a redundancy gain in speeded classification when the dimensions are correlated, and interference in a filtering task when the dimensions are orthogonal and selective attention is required. Some dimensional combinations meet these operational criteria extremely well; value and chroma of a single Munsell chip uniformly produce results that are consistent with the operational definition of integral dimensions and, similarly, size of circle and angle of radial line are clearly separable. The evaluation of the subjective independence of dimensional combinations by the algebraic properties of the additive difference model is important in drawing the distinction between integral and separable dimensions.

The Development of Perceived Structure and Attention: Evidence from Divided and Selective Attention Tasks.

Three experiments provide converging evidence for the view that both perceived structure and attention change during the elementary school years. Kindergarteners, second graders, and adults performed three speeded tasks: divided attention to conjunctions of features, selective attention to orthogonal dimensions and selective attention to correlated dimensions. The tasks were performed with sizes and shapes that were either spatially integrated or spatially separated. In the divided attention task, conjunctions were identified as quickly as single features with integrated stimuli at all ages, but conjunctions were identified more slowly than single features with separated stimuli by all age group. In the orthogonal dimensions task, interference was observed with integrated stimuli across ages, but the interference in adult performance was asymmetric. With separated stimuli, interference was gradually eliminated with increasing age. In correlated dimensions tasks, younger children showed a redundancy gain with integrated stimuli, but no gain was observed in the performances of the older subjects. With separated stimuli there was no redundancy gain at any age. These results were interpreted to mean that integrated stimuli are initially perceived as wholes by all subjects, but that features become more accessible with increasing age. Even so, attention remains constrained by stimulus structure. In contrast, separated stimuli are initially perceived as features at all ages, and the improvement in performance with increasing age is attributable to the increasing command of attentional resources that accompanies development. Our discussion of these findings focuses on three issues: multiple trends in perceptual development, the characteristics of an adequate theory of perceptual representation and processing, and a comparison of the separability hypothesis and other developmental accounts of perceptual development.

Developmental changes in attentional skills: The effect of irrelevant variations on encoding and response selection

The present experiments examine how irrelevant variations within a stimulus set interfere with performance in a selective attention task. Second graders, fifth graders, and adults were administered a discrete trial version of a selective attention task in which they were required to search for an object that matched the prime on the targeted dimension. The stimuli in the first experiment were constructed from spatially integrated dimensions whereas the second experiment used spatially separated dimensions. The results indicated that while the spatially separated dimensions were perceived independently by all age groups, developmental differences in perceived structure were evident with the spatially integrated dimensions. Problems associated with response selection were a major source of interference with both types of stimuli, but the severity of the interference varied with the age of the perceiver and the nature of the stimuli. The developmental implications of these findings were considered.

The Sources of Developmental Differences in Children's Incidental Processing during Discrimination Trials.

Abstract Crane and Ross reported that second graders learned more than sixth graders about attributes made relevant after solution of a discrimination task. Here two experiments are reported that enlighten the sources of this developmental difference. Both make use of an experimental technique whereby children verbalize their hypotheses during solution of a discrimination problem. The results indicate that ten-year-olds do not learn about incidental attributes that they tested while irrelevant in the pre-solution period, but that five-year-olds and seven-year-olds do. Children of all three ages process incidental information about attributes that they did not sample pre-solution. With some qualification, the incidentally processed information is retained throughout a five-minute delay interval. The results bear on developmental trends in the distribution of attention and on theoretical accounts of incidental learning in discrimination tasks.

Intra- and extra-dimensional shifts with constant- and variable-irrelevant dimensions in the rat1

Rats, trained on a C-I problem, exhibited no differences between IDS and EDS, whereas rats trained on a V-I problem did. Furthermore, the C-I problem was learned faster than the V-I problem originally. These data suggest that the C-I condition was not sufficient for the acquisition of a mediator in the present experiment.

Selective attention and the breadth of learning: A developmental study

Abstract Nursery school and second-grade subjects were trained on an optional intradimensional/extradimensional shift task with (1) no overtraining, (2) overtraining on the initial problem only, (3) overtraining on the shift problem only, or (4) overtraining on both the initial and the shift problems. Predictions concerning the effects of age and training conditions on the type of solution and the breadth of learning for the shift problem were derived from selective attention theory. However, the results were not consistent with the one-look assumption of such models. Instead, a multiple-look theory in which the breadth of attention varies with task demands seems most tenable.

Selective attention and dimensional learning: A logical analysis of two-stage attention theories

The argument of the present paper is that attention theories (e.g., Sutherland & Mackintosh, 1972) make logically independent assumptions of selective attention and dimensional learning. The separability of these assumptions is illustrated by a model that assumes dimensional learning but no selective attention. The model successfully predicts the results of discriminative shift studies (e.g. ID vs ED shift comparisons) and supports the conclusion that a selective attention mechanism is not necessary to explain the results of such studies.