Learning through observation: The effects of peer modeling on acquisition and generalization in autistic children

The purpose of this study was to systematically determine whether lowfunctioning autistic children [MA of approximately half of their CA or less] could learn through observation by the use of a peer modeling procedure. Since modeling is less structured than traditional one-on-one procedures, it was also thought that modeling might facilitate subsequent generalization of tasks learned through observation. Four autistic children were taught two receptive labeling tasks. One task was taught by a traditional trial and error procedure, while the other task was taught by a modeling procedure wherein the models were other autistic children. Results indicated that all four children learned through observation of their peer model. Additionally, generalization and maintenance of correct responding were superior when the children learned through observation rather than by trial and error. These results are discussed in terms of the modeling literature, generalization issues, and implications for designing teaching settings for autistic children.This research was supported by USPHS Research Grants MH 28231 and MH 29210 from the National Institute of Mental Health. The authors would like to acknowledge Paul Lizotte for his assistance.     

State and trait differences in depressive self-perceptions.

A number of investigators have interpreted a tendency for depressed people to recall more negative than positive self-referent adjectives as evidence for a depressive self-schema made up of predominantly negative characterological information. We sought to confirm this account by eliciting the subjective self-perceptions of the depressed. Depressed patients and controls were required to rate whether or not a series of positive and negative adjectives applied to them during the previous week, at any time, and generally. The depressed distinguished clearly between these questions and, although describing themselves currently in largely negative terms, described their general state as equally composed of positive and negative elements.     

Contextual factors in vigilance testing of children with ADHD

The effect of contextual factors on continuous performance testing was examined by administering a vigilance task to 51 children with ADHD under conditions of examiner presence and absence at different times (i.e., beginning and middle) of an assessment battery. The results showed that the ability to differentiate target stimuli from distractors (d-prime) was related to examiner presence vs. absence, and that response bias (beta), a measure of the subject's carefulness in responding to stimuli, was associated with the time of task administration. The decline in d-prime under conditions of examiner absence was shown to be related more to level of aggression as opposed to level of inattention. Children with ADHD having relatively high levels of aggression demonstrated a significant decline in d-prime scores under conditions of examiner absence, but those with relatively low levels of aggression did not. The results demonstrated the importance of contextual factors on vigilance task performance and suggested a differential impact of contextual variables on children who are inattentive vs. aggressive.     

The effects of marital disharmony on prepubertal children

The study investigated the association between marital disharmony and childhood behavior problems in a sample of families drawn from a general population. Eighty-three families where the marital relationship had previously been rated as disharmonious were matched with an equivalent number of families where the marriage was rated harmonious. Mothers, fathers, and children were interviewed, using a semistructured interview format. Children living in disharmonious homes had significantly more problems than children from harmonious homes, and control for confounding variables, such as the mothers' mental health, did not alter this relationship. The main effects found were in antisocial symptomatology. Gender differences and differences according to the accounts of different respondents were found. One possible interpretation is that mothers perceived their sons as more affected by marital disharmony, while evidence from children suggested that boys and girls were equally affected.     

Informational masking and auditory attention

Informational masking is broadly defined as a degradation of auditory detection or discrimination of a signal embedded ina context of other similar sounds; it is not related to energetic masking caused by physical interactions between signal and masker. In this paper, we report a systematic release from informational masking of a target tone in anine-tone rapid auditory sequence as the target is increasingly isolated in frequency or intensity from the remaieining sequence components. Improved target-tone frequency difference limens as isolation increases are interpreted as a reflection of increasingly focused auditory attention. The change from diffuse to highly focused attention is gradual over the frequency and intensity ranges examined, with each 1-dB increment in target intensity relative to the remaining components producing performance improvements equivalent to those produced by a 2% increase in frequency isolation. The results are modeled as bands of attention in the frequency and intensity domains. For attention directed by frequency isolation, there is a strong correspondence with auditory filters predicted by the power spectrum model of masking. These data also support the existence of an attention band of intensity, with a bandwidth of about 5–7 dB at the moderate levels used in this experiment.     

Modification of preschool children's bathroom behaviors by contigent teacher attention

In response to teacher requests for assistance in dealing with bathroom behavior problems, repeated measures of the frequency of paper towel litter, unflushed toilets, dirty sinks, and running water faucets were used to evaluate the effectiveness of contingent teacher praise for appropriate bathroom use by preschool children. Contingent praise for appropriate bathroom behaviors resulted in markedly decreased frequencies of the four target behaviors. Findings suggest that teacher monitoring and contingent social reinforcement can be used to maintain a clean environment in school toilet facilities. The importance of employing natural reinforcers in school settings is discussed.     

The Impact of Segmental Trunk Support on Posture and Reaching While Sitting in Healthy Adults

The authors investigated postural and arm control in seated reaches while providing trunk support at midribs and pelvic levels in adults. Kinematics and electromyography of the arm and ipsiliateral and contralateral paraspinal muscles were examined before and during reaching. Kinematics remained constant across conditions, but changes were observed in neuromuscular control. With midribs support, the ipsilateral cervical muscle showed either increased anticipatory activity or earlier compensatory muscle responses, suggesting its major role in head stabilization. The baseline activity of bilateral lumbar muscles was enhanced with midribs support, whereas with pelvic support, the activation frequency of paraspinal muscles increased during reaching. The results suggest that segmental trunk support in healthy adults modulates ipsilateral or contralateral paraspinal activity while overall kinematic outputs remain invariant.