A Historical Survey of Police Suicide in Queensland,Australia, 1843–1992

Police suicide research has yielded inconsistent results. An opportunity presented to survey Queensland police suicides in a historical context and add to the existing literature; the study describes changes in police suicide over time, the associated characteristics, and opportunities for intervention. Suicides were examined from the origins of police in Queensland in 1843 up to 1992. Suicide rates were higher earlier, around 60 per 100,000, declining to around 20 per 100,000 recently. The recent rate is lower than most other police studies but the same as the general community (employed). Most suicides were associated with psychological and physical ill health, alcohol abuse, and domestic problems, in keeping with general community surveys. However, occupational problems were more evident than is generally the case. The proximity in time of disciplinary events and suicides was striking. Future studies should explore the interactions between these factors.     

A Study of Blocking and Overshadowing in Filial Imprinting

The occurrence of blocking and overshadowing in filial imprinting was investigated in junglefowl chicks (Gallus gallus spadiceus). When subjects were exposed to a novel object in the presence of a familiar one, imprinting on the novel object was impaired in one of two experimental groups (Experiment 1). When subjects were exposed to two objects from the beginning, imprinting on each object was impaired (Experiment 2). These results suggest that phenomena resembling blocking and overshadowing in conditioning may occur in imprinting. The fact that overshadowing was much more prevalent and convincing than blocking is discussed by referring to processes involved in the formation of internal representations. It is suggested that processes connecting these representations to the executive system of filial behaviour may follow the rules of associative learning.     

Auditory physiology and behavior in RB/1bg, RB/3bg, and their F1 hybrid mice (Mus musculus): influence of genetics, age, and acoustic variables on audiogenic seizure thresholds and cochlear functions

In the early 1950s, Frings and Frings began a process of selection for audiogenic seizure susceptibility and resistance in albino mice. The present study was conducted to examine behavioral and cochlear functions in the inbred descendants of these mice. The cochlear action potential (AP) thresholds of the susceptible RB/1bg inbred mice were abnormally high, and the resistant inbred RB/3bg mice had normal AP audiograms. The F1 hybrid showed heterosis for its cochlear function. Only the RB/1bg was susceptible to audiogenic seizures on the first acoustic exposure. Thresholds for the successive components of their audiogenic seizures were determined in response to narrow bands of noise. These paralleled the AP thresholds of RB/1bg mice (r = .89). This RB/1bg mouse showed little age-related cochlear loss, which probably accounts for its robust sensitivity to audiogenic seizures over most of its lifespan. Earlier studies had demonstrated that the susceptible RB line had a robust AP, but little or no cochlear microphonic (CM). The susceptible RB/1bg had well-defined AP and CM responses at low frequencies. The nonsusceptible RB/3bg mice were more resistant to acoustic priming than another mouse (CBA/J) strain with a similar audiometric profile.     

Modification of verbal behavior in speech deficient children

Operant conditioning techniques were applied to the verbal behavior of three speech deficient children. Subjects A and B having no intelligible speech and Subject C having very little. Using candy and a puppet with a 13-yr-old boy (A), it was possible to condition vocalization rate. Using social reinforcement with a 6-yr-old boy (B), it was possible to extinguish animal-like sounds, to condition vocalization rate, and to shape a small vocabulary of syllables, but not to gain discriminative control over word emission. Using varied reinforcers, e.g., candy, praise, repetitions other own responses, and hand clapping with a 13-yr-old girl (C), it was possible to condition rate of verbalization, to establish appropriate mimicking, and to establish naming of five pictures. The results were consistent with the findings of Salzinger et al. (1965) and with those of Kerr et al. (1965).     

Monaural studies eliciting an hemispheric asymmetry; a bibliography: II

Since 1979, 32 behavioral studies using monaural stimulation elicited an hemispheric asymmetry confirming the findings of 74 investigations published between 1967 and 1979, which were compiled by Henry, 1979. 13 psychophysiological studies also using monaural stimulation have been added; they reach the same conclusion.