Object knowledge and the emergence of language

Infants' spontaneous play with objects was examined for evidence of developments in object knowledge in relation to the emergence of words and the single-word period in language development. Subjects were 7 girls and 7 boys, from different ethnic and economic backgrounds, who were studied longitudinally from 9 months to 26 months of age. Two types of displacements of objects in relation to one another were identified in the children's play: separations and constructions. The development of constructions was associated with the emergence of words, and constructions increased with age while separations decreased. The development of specific constructions, which account for knowledge of the particular properties of objects, was more strongly associated with a vocabulary spurt at the end of the single-word period than with chronological age. Despite the wide variation in the infants' ages when developments in language and play were reached, relations between achievements in the two domains were consistent among them, as confirmed with the Friedman test, p<.001. The results are discussed in terms of the cognitive developments required for play with objects and saying words.     

Relationship between conjugate lateral eye movements, brain organization, and cognitive style

The relationship between individual differences in conjugate lateral eye movements (CLEMs) and inferential reasoning was investigated in two experiments. Subjects were given inference tasks in sentence and pictorial form and were later tested for recognition of correct inferences as well as literal recognition of the acquisition items. In Experiment 2, for example, subjects were given logical syllogisms during acquisition. Theoretically, right-eye movement/left-hemispheric (REM/LH) subjects should have excelled at this highly logical task but no significant differences between eye-movement groups were found. However, support for previous research showing the moderating effects of gender on hemispheric activation (measured by CLEMs) and hemispheric competence came from the memory data of Experiment 2. These data indicated that male REM/LH subjects recognized more acquisition sentences than the other eye movement/gender groups. It was suggested CLEMs and other measures of hemispheric activation and competence, coupled with data collected using complex cognitive tasks, can eventually lead to explanatory brain models of cognitive processing.     

Detection and identification thresholds for consonant-vowel syllables

Detection and identification thresholds were obtained for 6- and 10-year-old normal children and normal adults using five-formant synthesized consonant-vowel ([baHdflrfea]) stimuli. Sixyear-old children were found to have poorer detection than adults, just as they do for pure tones. For the identification task, the slopes of the performance-intensity functions were more shallow for 6-year-old children than for 10-year-olds and adults. Consequently, compared with 10-yearolds and adults, 6-year-old listeners require a greater increase in stimulus intensity above detection threshold to identify these stimuli at a high performance level. The influence of acoustic characteristics of the stimuli on all listeners is also discussed.     

Choice, relative reinforcer duration, and the changeover ratio

Relative reinforcer duration was varied in concurrent schedules with a fixed-ratio four changeover requirement. The schedule in effect after each reinforcer was randomly chosen. For all three pigeons, relative response rates overmatched relative reinforcer durations. Time allocation was less extreme and, on the average, matched relative reinforcer duration. In a subsequent manipulation, the level of preference was shown to depend on the size of the changeover requirement. These results are similar to those from related unequal reinforcement-frequency procedures.     

A multidimensional scaling model for the size-weight illusion

The kinds of individual differences in perceptions permitted by the weighted euclidean model for multidimensional scaling (e.g., INDSCAL) are much more restricted than those allowed by Tucker's Three-mode Multidimensional Scaling (TMMDS) model or Carroll's Idiosyncratic Scaling (IDIOSCAL) model. Although, in some situations the more general models would seem desirable, investigators have been reluctant to use them because they are subject to transformational indeterminacies which complicate interpretation. In this article, we show how these indeterminacies can be removed by constructing specific models of the phenomenon under investigation. As an example of this approach, a model of the size-weight illusion is developed and applied to data from two experiments, with highly meaningful results. The same data are also analyzed using INDSCAL. Of the two solutions, only the one obtained by using the size-weight model allows examination of individual differences in the strength of the illusion; INDSCAL can not represent such differences. In this sample, however, individual differences in illusion strength turn out to be minor. Hence the INDSCAL solution, while less informative than the size-weight solution, is nonetheless easily interpretable.This paper is based on the first author's doctoral dissertation at the Department of Psychology, University of Illinois at Urbana-Champaign. The aid of Professor Ledyard R Tucker is gratefully acknowledged.     

Elementary school principals assess services of school psychologists nationwide

A one-page questionnaire was sent to 400 elementary school principals nationwide to assess their opinions regarding services of the school psychologist. These elementary school principals indicated that the school psychologist was found to be most helpful when providing the traditional services of psychological testing, personality and emotional assessment, consultation, and screening. Changes in school psychological services desired by the elementary school principals were more time from the school psychologist and an increase in individual and group counseling, preventive mental health, and inservice training. If elementary principal opinion is to be regarded, gross alterations to existing services of the school psychologist are not indicated by the results of this study.     

Thyroid hormones,psychophysiological reactivity,and anxiety

Thirty-eight adults were assigned to three groups: posttreatment hyperthyroid (n=13), low euthyroid (n=12), and high euthyroid (n=13). Physiological and subjective responses to three anxiety-induction procedures—public speaking, personally distressing imagery, and threat of shock—were compared across groups. Although there were differences across stressors for physiological and subjective measures, group differences were not detected. Results are discussed with regard to the risk for residual anxiety following treatment for hyperthyroidism and the possible influence of thyroid function on the etiology or maintenance of anxiety.     

Substitutability between conditioned and primary reinforcers in discrimination acquisition.

Rats and pigeons were trained on a series of reversals of a conditional simultaneous discrimination. The percentage of reinforcement for correct trials was varied across reversals. When nonreinforced correct trials produced the same feedback as incorrect trials, the number of errors to reach an acquisition criterion was greater for smaller percentages of reinforcement, but the number of reinforcers required was either approximately constant or smaller for the smaller percentages. When a stimulus paired with food (the conditioned reinforcer) was added on nonreinforced correct trials, both measures were substantially decreased. When the same stimulus was presented, but without a history of food pairing, learning rate was similar to when no stimulus was presented on nonreinforced trials. The results provide direct evidence that conditioned reinforcers may substitute, although imperfectly, for a primary reinforcer, and that pairing with the primary reinforcer is a necessary condition for such substitutability to occur.