Differential effects of unilateral lesions on language production in children and adults.

We present the first direct comparison of language production in brain-injured children and adults, using age-corrected z scores for multiple lexical and grammatical measures. Spontaneous speech samples were elicited in a structured biographical interview from 38 children (5-8 years of age), 24 with congenital left-hemisphere damage (LHD) and 14 with congenital right-hemisphere damage (RHD), compared with 38 age- and gender-matched controls, 21 adults with unilateral injuries (14 LHD and 7 RHD), and 12 adult controls. Adults with LHD showed severe and contrasting profiles of impairment across all measures (including classic differences between fluent and nonfluent aphasia). Adults with RHD (and three nonaphasic adults with LHD) showed fluent but disinhibited and sometimes empty speech. None of these qualitative or quantitative deviations were observed in children with unilateral brain injury, who were in the normal range for their age on all measures. There were no significant differences between children with LHD and RHD on any measure. When LHD children were compared directly with LHD adults using age-corrected z scores, the children scored far better than their adult counterparts on structural measures. These results provide the first systematic confirmation of differential free-speech outcomes in children and adults and offer strong evidence for neural and behavioral plasticity following early brain damage.     

Context extinction following conditioning with delayed reward enhances subsequent instrumental responding

In Experiment 1, delayed reward generated low response rates relative to immediate reward delivered with the same frequency. Lister rats exposed to delayed reward subsequently responded at a higher rate in extinction if they received nonreinforced exposure to the conditioning context after instrumental training and prior to test, compared with animals that received home cage exposure. In Experiment 2, a signaled delay of reinforcement resulted in higher rates than an unsignaled delay. Nonreinforced exposure to the conditioning context elevated response rate for subjects in the unsignaled condition relative to a home cage group, but had no effect on response rates for subjects that had received the signaled delay. In Experiment 3, following an unsignaled reinforcement delay, groups receiving either no event or signaled food in the context responded faster in extinction than groups receiving no context exposure or unsignaled food.     

True intercorrelation among job components, time delay in rating, and rater intelligence as determinants of accuracy in performance ratings

Ninety subjects viewed one of three sets of videotapes which presented simulated work performances by five ratees. Subjects viewed videotapes where the true intercorrelation among the three job components was either high, moderate, or low. Half of the subjects completed ratings immediately after viewing all five ratees and again, 24 h later. The remaining subjects completed ratings only once, 24 h after viewing the videotapes. Rater intelligence was assessed via the Wesman Personnel Classification Test. Performance ratings for each ratee on each of the three job components were completed using a magnitude estimation scale. Subjects' ratings were compared to ratee true scores (based on objective worker output) to obtain four components of rater accuracy: elevation, differential elevation, stereotype accuracy, and differential accuracy as well as a measure of overall accuracy. Results indicated that subjects' ratings were more accurate with respect to overall accuracy and differential accuracy when the true intercorrelation among job components was high rather than low. Rater intelligence was significantly correlated with stereotype accuracy. In addition, rater intelligence was significantly related to overall accuracy, differential elevation, and elevation, but only when the true intercorrelation among job components was moderate or high. Also, there was a curvilinear component to the relationship between intelligence and both differential accuracy and stereotype accuracy such that the most intelligent raters tended to be less accurate than more moderately intelligent raters who were, in turn, more accurate than the least intelligent raters. Finally, subjects' immediate ratings were not more accurate than ratings provided by subjects who completed only delayed ratings. However, repeated measures analyses found that for subjects who completed both immediate and delayed ratings, delayed ratings were less accurate than immediate ratings with respect to overall accuracy, differential accuracy, and differential elevation.     

Spiritual and religious concerns of the hospitalized adolescent

One of the tasks of adolescence is the development of a value system. The way in which these values are expressed in relationship to illness in adolescence, however, has not been studied. The authors conducted a social science survey to study the spiritual concerns of hospitalized adolescents. One hundred and fourteen hospitalized adolescents, ranging in age from 11 to 19, answered a Likert scale questionnaire on Spiritual and Religious Concerns (SRQ). Analysis of variance was performed to correlate responses with sex, race, religion, type of school, and severity of illness. A subgroup of hospitalized adolescents, those with more serious disease, experienced intensified spiritual and religious concerns. In response to the questionnaire, over 15% of the patients requested further help. Our findings suggest that training in adolescent health care and the provision of services to teenagers ought to include teaching in the area of spiritual and religious values of teenagers, with emphasis on the hospitalized adolescent.     

Computer-Presented Video Prompting for Teaching Microwave Oven Use to Three Adults with Developmental Disabilities

We evaluated the use of a video prompting procedure for teaching three adults with developmental disabilities to make popcorn using a microwave oven. Training, using a 10-step task analysis, was conducted in the kitchen of the participant’s vocational training program. During baseline, participants were instructed to make popcorn, but were given no further instructions or prompts. Video prompting consisted of first watching a video clip of a step being performed and then giving participants the opportunity to imitate that step. This prompting procedure was introduced in a delayed multiple-probe across subjects design. Following acquisition, video prompting was removed and maintenance in the absence of video prompting was assessed at 2, 6, and 10 weeks. Two of the three participants acquired the task when video prompting was introduced and performed at 80–100% correct during follow-up sessions. These data suggest that video prompting may be an effective instructional strategy for teaching daily living skills to adults with developmental disabilities.     

Voice acoustical measurement of the severity of major depression

A number of empirical studies have documented the relationship between quantifiable and objective acoustical measures of voice and speech, and clinical subjective ratings of severity of Major Depression. To further explore this relationship, speech samples were extracted from videotape recordings of structured interviews made during the administration of the 17-item Hamilton Depression Rating Scale (HDRS; ). Pilot data were obtained from seven subjects (five males, two females) from videotapes that have been used to train expert raters on the administration and scoring of the HDRS. Several speech samples were isolated for each subject and processed to obtain the acoustic measurements. Acoustic measures were selected on the basis that they were correlated with HDRS ratings of symptom severity as seen under ideal voice recording conditions in previous studies. Our findings corroborate earlier reports that speaking rate is well correlated (negatively) with HDRS scores, with a strong correlation and nearly significant trend seen for the measure of pitch variability. A moderate pairwise correlation between percent pause time and HDRS score was also revealed, although this relationship was not statistically significant. The results from this cross-sectional study further demonstrate the ability of voice and speech signal analyses to objectively track severity of depression. In the present case, it is suggested that this relationship is robust enough to be found despite the less than ideal recording conditions and equipment used during the original videotape recording. Voice acoustical analyses may provide a powerful compliment to the standard clinical interview for depression. Use of such measures increases the range of techniques that are available to explore the neurobiological substrates of Major Depression, its treatment, and the dynamic interplay of the systems that govern the motor, cognitive, and emotional aspects of speech production.     

"Frog, where are you?" Narratives in children with specific language impairment, early focal brain injury, and Williams syndrome

In this cross-population study, we use narratives as a context to investigate language development in children from 4 to 12 years of age from three experimental groups: children with early unilateral focal brain damage (FL; N=52); children with specific language impairment (SLI; N=44); children with Williams syndrome (WMS; N=36), and typically developing controls. We compare the developmental trajectories of these groups in the following domains: morphological errors, use of complex syntax, complexity of narrative structure, and types and frequency of evaluative devices. For the children with early unilateral brain damage, there is initial delay. However, by age 10, they are generally within the normal range of performance for all narrative measures. Interestingly, there are few, if any, side specific differences. Children with SLI, who have no frank neurological damage and show no cognitive impairment demonstrate significantly more delay on all morphosyntactic measures than the FL group. Quantitatively, on morphosyntactic measures, the SLI group clusters with those children with WMS who are moderately retarded. Together these data help us to understand the extent and nature of brain plasticity for language development and those aspects of language and discourse that are dissociable.