EMG biofeedback: the effects of CRF, FR, VR, FI, and VI schedules of reinforcement on the acquisition and extinction of increases in forearm muscle tension.

Biofeedback was used to increase forearm-muscle tension. Feedback was delivered under continuous reinforcement (CRF), variable interval (VI), fixed interval (FI), variable ratio (VR), and fixed ratio (FR) schedules of reinforcement when college students increased their muscle tension (electromyograph, EMG) above a high threshold. There were three daily sessions of feedback, and Session 3 was immediately followed by a session without feedback (extinction). The CRF schedule resulted in the highest EMG, closely followed by the FR and VR schedules, and the lowest EMG scores were produced by the FI and VI schedules. Similarly, the CRF schedule resulted in the greatest amount of time-above-threshold and the VI and FI schedules produced the lowest time-above-threshold. The highest response rates were generated by the FR schedule, followed by the VR schedule. The CRF schedule produced relatively low response rates, comparable to the rates under the VI and FI schedules. Some of the data are consistent with the partial-reinforcement-extinction effect. The present data suggest that different schedules of feedback should be considered in muscle-strengthening-contexts such as during the rehabilitation of muscles following brain damage or peripheral nervous-system injury.

Aspects of psychiatric admissions of migrants to hospitals in Perth, Western Australia.

OBJECTIVE: Recent Australian Government initiatives have emphasised problems with service provision to the ethnic mentally ill. This study aims to address the paucity of contemporary data describing the disposition of the ethnic mentally ill in hospital settings. METHOD: Patterns of admissions for psychiatric disorders to all hospitals in Perth, Western Australia, for the 3 years from 1990 to 1992, of migrants and the Australian born were compared using data from the Western Australian Mental Health Information System. RESULTS: The overall rates for European migrants showed a 'normalisation' towards those of the Australian-born. There were high rates for the schizophrenic spectrum disorders in Polish and Yugoslavian (old terminology) migrants. There were low admission rates for South-East Asian migrants, predominantly those from Vietnam and Malaysia. Rates for alcoholism were low in Italian and all Asian migrants. There were high rates of organic psychosis, especially in those older than 75 years, among the Italian and Dutch migrants. The relative risk of a first admission in the 3 years being an involuntary admission to a mental hospital was almost twice that of the Australian-born for migrants from Poland, Yugoslavia, Malaysia and Vietnam. CONCLUSIONS: The results imply the possibility of significant untreated and/or undiagnosed psychiatric morbidity in the South-East Asian-born. They also indicate a need for further exploration of the unexpectedly high levels of psychiatric morbidity among some ethnic elderly groups, specifically the Dutch- and Italian-born. The findings demonstrate the persistence of high rates of presentation for psychotic disorders among Eastern European-born populations, many years post migration.

Validation of an Italian translation of the 30-item General Health Questionnaire for use in Australia.

A validity study of an Italian translation of the GHQ-30 was conducted on a sample of 96 Italian-born subjects in the community in Perth, Western Australia, using the shortened version of the Present State Examination as the gold standard for a "case" of non-psychotic psychiatric morbidity. The 96 subjects were a subsample of a study of 1109 subjects seen in a community survey, in which 45.8% had a score above 4 on the GHQ-30. It was found that 5/6 was the most appropriate cut-off point. At this level the sensitivity was 81.2%, the specificity 79.7%, the positive predictive value 66.7%, the negative predictive value 89.5% and the overall misclassification rate 19.8%. Adjusting the results to truly reflect the lower case-prevalence rate in the community, using a method suggested by Goldberg, the corresponding values were 57.7%, 92.6%, 66.7%, 89.5% and 14.6%. It was concluded that this version of the GHQ-30 is suitable for use in the Italian-born, in the community and in general practice in Australia, using a cut-off point of 5/6.