Do the mentally retarded have poor memory?

The hypothesis that mentally retarded persons have a short-term memory deficit whixh is due to inadequate rehearsal strategies is reexamined. A reevaluation of results of a number of experiments suggests that normal and retarded persons differ on short-term memory tasks, and the superiority of normals is present from the time of initial stimulus exposure. While some evidence for slope differences in retention curves is found in a few tasks, it is not strong support for memory differences. The hypothesis that “memory” differences are due to differential encoding as a result of more adequate rehearsal by the normal subjects is unacceptable. If this were the case, some differences in slope of retention curves could be expected unless rehearsal beyond the encoding stage was totally precluded. The review points to a need for an empirical reevaluation of the issue with a full recognition that deficits in particular processes may characterize some retarded persons and not others.     

Children's knowledge of the separation of variables concept

Children 8, 10, and 13 years of age were either given prior experience constructing seriations or matrices with two-dimensional stimuli, or no prior experience. Knowledge of the separation of variables concept was then assessed by examining children's use of controlled tests of a problem variable's effect (probe questions), and recognition of the inadequacy of confounded variable tests (negative counter-suggestion questions). Although many children either passed both questions or failed both questions, a significant number of children correctly used controlled variable tests, and yet failed to recognize the inadequacy of a confounded test. These results suggest that although a preliminary form of the separation of variables concept is characterized by use of controlled variable tests, subsequent refinement of the concept includes recognition of the inadequacy of confounded tests. Relative to seriation, prior experience constructing matrices facilitated recognition of a confounded test's inadequacy. Constructing matrices may have focused attention on the simultaneous variation of problem elements on multiple dimensions and thus facilitated recognition of the necessary role of both variation of stimuli on test dimensions and equality of stimuli on nontest dimensions, e.g., a controlled test.     

The availability explanation of excessive plausibility assessments

The assessment of hypotheses in hypothesis generation involves a comparison between those hypotheses that have been generated (specified) and those that are not generated (unspecified). Experiment 1 was an investigation of an “availability explanation” for subjects' overconfidence in the probability of specified hypotheses. The conjecture is that subjects have difficulty retrieving unspecified hypotheses from memory. Therefore, the underpopulated set of unspecified hypotheses is assessed as less probable then it actually is and the specified set is assessed as more probable. Two manipulations to increase the availability of unspecified hypotheses were investigated. One involved explicitly requesting subjects to populate the unspecified set; the other was a computer presentation of candidate unspecified hypotheses. Results of experiment 1 were that assessment overconfidence for both experimental groups was reduced. The results support the conjecture that the availability heuristic is at least partially responsible for subjects' overconfidence. The main result of experiment 2 was that the overconfidence bias persisted with different assessment methods for both subject-generated and experimenter-supplied hypotheses.     

Classes,collections, and distinctive features: Alternative strategies for solving inclusion problems

This study analyzed the strategies that children ages 5 through 8 years used on two modified versions of Inhelder and Piaget's (The early growth of logic in the child. New York: Norton, 1964) class inclusion task. In two experiments, children were tested on Wilkinson's (Cognitive Psychology, 1976, 8, 64–85) “percept” inclusion task in which distinctive features marked both supraordinate and subclasses. It was hypothesized that children who fail standard Piagetian inclusion tasks succeed on the “percept” task by counting and comparing mutually exclusive features rather than using features as markers for classes and subclasses. The hypothesis was supported by children's performances on “percept” tasks in which solutions based on feature counting conflicted with solutions based on consideration of class inclusion relations. In two other experiments, children answered part-whole and part-part comparison questions in which both terms were described as classes and/or subclasses, or in which one of the two terms was described as a collection (e.g., a bunch of grapes). These experiments contrasted Markman and Seibert's (Cognitive Psychology, 1976, 8, 561–577) “organization” hypothesis that the greater psychological integrity of collections facilitates reasoning on part-whole comparison problems with the hypothesis that the faciltative effect results from the “large number” connotation of collective nouns. Results on collection problems in which parts were described as collections supported the “large number” hypothesis. Results were discussed in terms of their implications for Piaget's theory.     

The role of structural components in the Mueller-Lyer illusion

In order to assess the role of the structural components of the Mueller-Lyer illusion, subjects reproduced the central extent of standard Mueller-Lyer figures and configural variations. Illusory magnitude of the underestimated wings-in and overestimated wings-out figures was examined with selective amputations of the oblique wings and central line segment (shaft). Variations were presented at 0, 45, 90, and 135 deg from vertical. Orientation had no reliable effect on illusory magnitude. Elimination of the shaft effected a decrease in the apparent extent for all variations, presumably due to the addition of the filled-unfilled space illusory effect to the standard Mueller-Lyer effect. A second study corroborated this finding The decrease in apparent extent consequent to shaft removal occurred independently of any response factor. Selective wing removal differentially decreased the illusory magnitude of the standard Mueller-Lyer figures; this was discussed with regard to a dual-illusion hypothesis. Finally, variations that contained no intersecting lines produced a significant illusion in the direction of the standard Mueller-Lyer figures, suggesting the involvement of higher level, nonperipheral distortion mechanisms.     

A dual look at spontaneous cooperative play in the preschool: Free play versus structured environment

An observational study was conducted during free play among preschool children (N = 36) to identify the component skills of spontaneous cooperative play. Early techniques of spontaneous cooperation were found to be action-oriented and/or self-referenced statements contributing to thematic dialogue. Advanced techniques informed partners of abstract use of props and advised them on how to interact. A reliability study introduced dyads of older preschoolers (N = 60) to structured sets of play materials. In addition to supporting the display of components revealed in Study I, results indicated that 5-year-olds were better able than 4-year-olds to respond to the demand characteristics of the structured setting. Comparisons by sex, partnerships, and types of play materials were also analyzed.     

Contrast and undermatching as a function of reinforcer duration and quality during multiple schedules

Eight pigeons pecked keys under multiple variable-interval two-minute variable-interval two-minute schedules. In Experiment 1, the reinforcers were 2, 4, or 8 seconds access to a food magazine. In Experiments 2 and 3, the reinforcers were grains that had been determined to be most-, moderately-, or non-preferred. Both positive and negative behavioral contrast occurred when the reinforcers in one component were held constant and the duration or type of reinforcer obtained in the other component varied. Undermatching occurred when the relative rate of responding during a component was plotted as a function of the relative duration of the reinforcers in that component.     

Personality Characteristics and Self-esteem in Pet Owners and Non-owners

Previous research suggests that pet owners are psychologically different than non-owners in terms of self-esteem and other personality characteristics. In this study, 82 pet owners and 48 non-owners were tested on self-esteem, extraversion, neuroticism, and social self-esteem. Special emphasis was placed on highly attached pet owners compared with non-owners. Level of attachment was determined by scores from the CENSHARE pet attachment survey. No significant differences were found between the groups using analysis of variance and multivariate analysis of variance statistical procedures. It was concluded that pet owners and non-owners may not be different in terms of personality but may have become victims of stereotyping by both the general population and scientific researchers. Discussion was given to related significant findings and recommendations for further research.     

“Paramount reality” in Schutz and Gurwitsch

Conclusion Both Schutz and Gurwitsch describe reality as having a manifold character: Schutz speaks of multiple realities and Gurwitsch of orders of existence. Both hold that one realm of reality has a privileged status compared to the others: common everyday experience. However, in spite of this apparent convergence in their views, a closer reading of their various works reveal the important difference in what they understand under common everyday experience.For Schutz, it is the world of social action, characterized by him as paramount reality because of the constitutive processes of the experiences of time, space, sociality and meaning involved in action. For Gurwitsch, the realm of common everyday experience represents the counterpart and the origin of the constructed realm of science: therein lies its status of paramount reality. But what it really refers to is not ordinary experience, as most of his statements suggest, but pre-predicative experience, wherefrom the categories of the natural sciences, namely space and time, originate. Gurwitsch speaks of this pre-predicative experience, which he also calls primordial experience, as being essentially perceptual experience. However, he limits perceptual experience to sensory perception, leaving out the symbolic, social and action-related components of perception and becomes thus inconsistent with his adherence to the dismissal of the constancy hypothesis in his field theory of consciousness. The dismissal of the constancy hypothesis implies the recognition of the appresentational structures involving symbols, action and Others as inherent components of every perception. Schutz disagrees with Gurwitsch's reduction of the life-world Erlebnisse to sensory perception and this issue becomes the core of their debate on the phenomenon of paramount reality.     

Aversive procedures: The minnesota experience

Aversive and deprivation procedures for controlling and reducing challenging behaviors have received increasing attention. Many states have adopted guidelines on the use of these procedures treating persons with developmental disabilities. The Minnesota state rule promulgated in October, 1987 requires reviews from both local and state-wide review committees on permitted, but controlled procedures. Data generated from state-wide committees revealed that (a) state operated regional treatment centers (RTCs) employed individual habilitative training programs with controlled procedures more frequently than community-based agencies (b) a higher proportion of RTC submissions were for treatment of self-injury than submissions from community services, and (c) RTCs had a higher usage of mechanical restraints than community facilities with both services settings using manual restraints more frequently than all other controlled procedures combined. Reasons for the above differences in the two service settings were discussed.