An objective evaluation of special class placement of elementary schoolboys with behavior problems

Behavioral checklists were employed to identify the type and degree of psychopathology observed in 90 boys who were referred for possible placement in classrooms for the socially and emotionally disturbed (SED). School behavior was assessed by teachers completing the Conners Teacher Rating Scale, while behavior at home was rated by parents with the Child Behavior Checklist. The checklist findings from both environments showed the boys to have high levels of psychological disturbance, especially for externalizing factors such as hyperactivity, aggression, and conduct disorder. This was especially true for those boys for whom SED placement was recommended. Further, the clinical usefulness of these checklists was investigated as an adjunctive method for the determination of the need for SED placement. By the use of discriminant function analysis, about three-fourths of the boys recommended for SED placement were accurately identified; correct classification was maximized when parent and teacher checklists were employed together.     

Determinism, possibility, and ethics

This essay reexamines the age-old "determinism-free will" problem from a psychoanalytic perspective. The first section recapitulates the author's (1985) earlier argument on the nature of causation in psychoanalysis; the second part examines the compatibility of determinism and freedom; and the final section looks at the ethical ramifications of the issues at hand. The author exposits his adherence to universal determinism and attempts to answer the question, "What sort of possibility and ethics are permitted in a deterministic universe?"     

A HyperCard stack for the creation of graphically organized glossaries

Many students find it difficult to transform expository text and lectures into well-organized mental constructs. Studies show that learning of this type can be enhanced by the use of graphic organizers that depict relationships among concepts by diagramming them as a tree structure. In order to incorporate all concepts taught in a course into a single graphic organizer, a HyperCard authoring shell was developed to expedite drawing tree diagrams and linking each concept in the diagram to a definition. The authoring features of the stack and its application to an abnormal psychology course are discussed in this article.     

Children’s acquisition of language: General linguistic competence or dimensions of style?

Previous studies have described children’s acquisition of language as reflecting either a referential or an expressive style. A multivariate approach, characterizing “referentiality” and “expressivity” as partially dissociable dimensions, is advantageous because it allows children to vary along one dimension as they vary along another, allowing children to have high or low degrees of both characteristics simultaneously. The present study applies multivariate techniques to an “exploratory” sample of 87 children, all of whom were 20 months old, and by subsequently validating the exploratory phase with 56 of the original children seen one month later. Using parental reports to assess children’s multiword productions, exploratory factor analyses revealed two correlated dimensions of language style which indeed reflected referential and expressive characteristics. Confirmatory factor analyses “confirmed” these factors in the test sample. This two-dimensional model of language acquisition was superior to a unidimensional, general linguistic competence model. There is also strong short-term stability for both dimensions across the one-month period.     

Effects on prism adaptation of duration and timing of visual feedback during pointing

In two experiments, we investigated the effects of duration of visual feedback of the pointing limb and the time (early to late) in the movement when the limb first becomes visible (timing of visual feedback). Timing, rather than duration of visual feedback, proved to have the greater effect on the relative magnitude of visual and proprioceptive adaptation. Visual adaptation increased smoothly with feedback delay, but corresponding decreases in proprioceptive adaptation underwent an additional sharp change when feedback was delayed until about three-fourths of the way to the terminal limb position. These results are consistent with the idea that visual and proprioceptive adaptation are mediated by exclusive processes. Change in the limb position sense (i.e., proprioceptive adaptation) may be produced by visual guidance of the pointing limb, and view of the limb early in the pointing movement seems to be critical for such visual guidance. The limb may be ballistically released as it nears the terminal position, and, thereafter, any opportunity for visual guidance (i.e., view of the limb) is not effective. On the other hand, change in the eye position sense (i.e., visual adaptation) may be mediated by proprioceptive guidance of the eye; the eyes may track the imaged position of the nonvisible limb. Such proprioceptive guidance seems to be solely a function of the distance moved before the limb becomes visible.     

An empirical note on attaining a spatial target after distorting the initial conditions of movement via muscle vibration

Can one's limb be accurately positioned to a spatial location without a veridical estimate of the initial conditions of movement? The experiment reported here examined this question by distorting perception of a limb's starting position via muscle vibration. Subjects executed rapid flexion movements under no-vibration, contralateral arm vibration, and ipsilateral arm vibration conditions. Vibration was applied to the biceps for 10 sec prior to the start of a reproduction movement. The results showed that vibration on the ipsilateral arm caused a significant increase in reproduction error, relative to the no-vibration and contralateral-vibration conditions. This finding provides additional evidence that accurate knowledge about the initial conditions of movement is a necessary component in positioning a limb.     

Computer-based systems for applying psychological knowledge

Computer-based systems have long been seen as a means for applying psychological knowledge to instructing. However, from many years of research and development on instructional design and on using computers for instructing, we learned that the current instructional techniques are based on an inadequate scientific knowledge base and are poorly implemented. In order to do better, improved techniques based on modern cognitive science must be developed, and computer-based aids are needed to assist their application. Furthermore, a standardization and distribution system is needed to identify effective instructional programs and make them available. This seems especially important if we hope to have broad impact on education and training.     

Visual control of discrete aiming movements

An experiment is reported which investigated the visual control of discrete rapid arm movements. Subjects were required to move as rapidly as possible to several target width-movement distance combinations under both visual and non-visual conditions. The movement time (MT) data were supportive of Fitts' Law in that MT was linearly related and highly correlated to the Index of Difficulty (ID). MT was also similar for different target width-distance combinations sharing the same ID value. The error rate analysis, which compared visual to non-visual perfromance, indicated that vision was only used, and to varying degrees, when MT exceeded 200 ms (3.58 ID level). There was some evidence that vision was differentially used within target width-distance combinations sharing the same ID. Estimates of endpoint variability generally reflected the results of the error rate analysis. These results do not support the discrete correction model of Fitts' Law proposed by Keele (1968).     

Sensory and motor impairment in the nerve compression block

Recently nerve compression block as a method of investigating movement control without kinaesthetic feedback has been questioned on the grounds that motor impairment (as measured by nerve conduction parameters) is a confounding factor. In order to clarify the relationship between sensory and motor function, behavioural data was obtained on both at systematic time intervals throughout the duration of the block. The findings indicated that significant decrements in tapping measures occurred somewhat earlier in the time course of the block than decreases in kinaesthetic discrimination. Also, contrary to assumption, the majority of subjects ceased to perform prior to total kinaesthetic loss. The data suggest that motor impairment is a “crucial” issue (Laszlo, 1966) in the use of this technique, and provide further behavioural support for the neurological findings of Kelso, Stelmach and Wanamaker (1974).