Language development after unilateral brain injury.

This longitudinal study describes the growth of syntactic abilities and vocabulary size in nine children with unilateral antepartum or perinatal brain injury. Five children with left hemisphere damage (LHD) and four with right hemisphere damage (RHD), ages 15 to 48 months, were evaluated on three or more occasions. Language samples generated from parent-child interaction were transcribed, coded, and analyzed using the Child Language Data Exchange System. Individual growth trajectories were constructed by graphing three dependent variables--MLU, scores on the Index of Productive Syntax (IPSYN), and number of different words--as a function of the child's age. One subject remained in a prelinguistic stage throughout the study. Simple linear functions best described the growth of MLU, IPSYN scores, and vocabulary in the other eight children. The slopes of the individual growth trajectories, the graphic representations of rates of progress, were comparable in the eight children. Seven children showed developmental delays in initial word use and five in the onset of multiword utterances. However, by age 24 months, four children with LHD and two children with RHD had syntactic capabilities comparable to those of children without brain injuries. The developmental patterns suggested that both cerebral hemispheres may play critical roles in the very earliest stages of language acquisition. Some unilateral lesions caused little discernible effect on language outcome in the toddler-preschool years after the initial developmental delays.     

AUDITORY PITCH AS A PERCEPTUAL ANALOGUE TO ODOR QUALITY

Abstract— Experiments in cross-modal matching suggest that smells can be arranged by odor qualify along the color dimensions of hue and lightness. Here we report that subjects readily adjust the loudness-equalized pitch of on auditory tone to match a stimulus odor. The results allow odors to be arranged in sequence by their pitch-equivalents. The tone matches appear to be based on perceptual feature of olfaction other than stimulus intensity or pleasantness. The results suggest that features of odor quality may be more accessible and structured than previously acknowledged.     

A COMPARISON BETWEEN TWO PLACEMENT PROGRAMS FOR HARD-CORE UNEMPLOYED PERSONS

An exploratory placement class was conducted to teach vocational rehabilitation clients techniques of securing jobs. The results of this attempt were compared to a similar program conducted through another agency. The differences between the two programs suggest techniques that could increase the employment potential of vocational rehabilitation clients.     

Reaction time to the start and end of weak signals in noise

Summary A theoretical extension of Zwislocki's theory of temporal summation in hearing predicts that the growth of auditory sensation is faster than its decay. Hence the reaction time to the start of a tone ought to be faster than that to its end. Two experiments which investigated this hypothesis are described. Both experiments measured the reaction times of subjects to the start and end of an imperfectly detectable 1000-Hz tone embedded in continuous noise. All three subjects in Experiment I and three of four subjects in Experiment II revealed reaction-time differences in the expected direction; that is to say, the reaction time to the start of the tone was faster than that to its end. One subject in Experiment II did not show this difference, however, and this subject's anomalous behaviour is seen as a qualification to the general nature of the theory.This research was supported by a grant to R.J. Irwin from the Golden Kiwi Scientific Research Distribution Committee and from the University of Auckland     

Item response theory in personality assessment: a demonstration using the MMPI-2 depression scale

Item response theory (IRT) analyses have, over the past 3 decades, added much to our understanding of the relationships among and characteristics of test items, as revealed in examinees response patterns. Assessment instruments used outside the educational context have only infrequently been analyzed using IRT, however. This study demonstrates the relevance of IRT to personality data through analyses of Scale 2 (the Depression Scale) on the revised Minnesota Multiphasic Personality Inventory (MMPI-2). A rich set of hypotheses regarding the items on this scale, including contrasts among the Harris-Lingoes and Wiener-Harmon subscales and differences in the items measurement characteristics for men and women, are investigated through the IRT analyses.