Behavioral consequences of song learning: Discrimination of song types by male white-crowned sparrows

The functional significance of learned population differences in male song in the white-crowned sparrow was explored in natural populations using playback tests. Laboratory results have shown that learning of the population-specific song seems to take place in early life and is strongly dependent upon the nature of the auditory experience at that time. However, the varied results of recent studies make it difficult to reach a confident conclusion about the ecological functions of song learning. The present research took advantage of naturally occurring variation in the differences between songs of adjacent populations to determine a function relating degree of difference in song to intensity of territorial singing elicited. Applying a typological evaluation of syllable structure to the four segments of the song allowed a crude quantitative ranking of the differences between local songs and playback stimuli. These results, together with those of other studies, suggest a unimodal aggressive response function of males to songs of other males. A maximum response to songs slightly different from the local song environment suggests that male exclusion based upon acquired song components may contribute to the maintenance of discrete and stable song dialects.     

Food anticipation and lever-directed activities in rats

Three experiments are described which elaborate some of the conditions under which rats will contact and manipulate a periodically presented retractable lever. Experiment 1 demonstrated that (i) initial manipulative oral and manual contact with the lever was facilitated if the rat had previous experience of food delivery in the experimental chamber; (ii) persistence in contacting the lever on successive presentations was a function of whether food continued to be presented in the experimental environment; and (iii) food satiation significantly reduced the tendency of the rat to contact the lever even though an expectancy of food had previously been established under conditions of food deprivation. Experiment 2 suggested that the tendency to approach and contact the lever was in part a function of the local moment-to-moment conditional probability of food delivery. Experiment 3 found that the probability of contacting the lever was higher during presentation of an auditory CS signaling a high rate of food delivery than during stimuli signaling no food at all. These results are interpreted as suggesting that the food-signaling aspects of an appetitive CS and that CS's ability to generate signal-directed behaviors are experimentall separable properties.     

Messianic hopes and the crisis of relativism: A common process in pastoral counseling

This essay explores the dynamics underlying the search for a Messiah in psychotherapy. It argues that the disenchantment with one's Messiah emerges primarily from the confrontation with multiple messiahs, and hence, the personal crisis of relativism. The nature of this personal crisis is investigated through the developmental scheme of William Perry. Suggestions are made as to how pastoral counselors can help those struggling with the problem of relativism.The Southeastern Illinois Center for Pastoral Counseling is located at 100 South Church Street, Carmi, Illinois, 62821.     

The validity of Mobley's (1977) model of employee turnover

Unlike earlier tests of an oversimplified version of this model, the validity of W. Mobley's (1977, Journal of Applied Psychology, 62, 237-240) original turnover model was fully investigated. Constructs that were neglected in prior studies were assessed and previously examined constructs were operationalized with more reliable measures. Measures of all constructs in Mobley's model were obtained from a survey of 192 hospital employees. Turnover data were collected a year following survey administration. Following the theoretical causal ordering of Mobley's constructs, each construct was regressed on all causally prior constructs. In general, each construct was accurately predicted by the linear combination of predictors representing its causal determinants. In the majority of instances, the best predictor of a model construct was the construct's immediate causal antecedent. Further, an alternative model was evaluated and compared with Mobley's model using path analysis.     

DETERMINANTS OF R AND D COMPENSATION STRATEGIES IN THE HIGH TECH INDUSTRY

This study indicates that sales volume, stage in the product life cycle, profitability and turnover are all important predictors of the method and magnitude of financial rewards provided by high tech firms to R and D employees. The most favorable situational factors for R and D incentive compensation are a low sales volume high tech company, operating in the growth stage of the product life cycle, with high turnover rates, and capable of linking profitability to incentive rewards such as bonuses.     

Developmental influences on speech-motor equivalence: some implications for articulatory disordered children

The peak amplitude of EMG activity was measured from the orbicularis oris superior (OOS), orbicularis oris inferior (OOI) and masseter muscles for 3 normal 4-yr.-old children and compared to past data gathered on a group of articulatory disordered children, normal children, and adults. The 4-yr.-olds evidenced greater average peak EMG activity than the other groups, suggesting that speech-sound production becomes more efficient with maturation. Also, levels of variability obtained for the younger children were considerably smaller than for the normal speakers across the three muscles, showing that motor equivalence changes with age whereby the flexibility in the control of articulators increases. The coefficient of variation for the OOI muscle for the disordered children, however, was similar to that for the 4-yr.-olds, while the corresponding data for the other two muscles paralleled those for normal ones. These findings were interpreted as reflecting a delay in the development of speech-motor equivalence that affects certain muscles while sparing others.     

Polydipsia's contribution to temporal discrimination of rats on a fixed interval schedule

This experiment concerned the contribution of polydipsia on the temporal discrimination of rats during a fixed-interval 60-sec. schedule. In this study, the timing accuracy of 12 rats which had access to water during training was compared to that of 12 rats which had no water during training. The rats were trained for 25 sessions on an FI 60-sec. schedule. In early sessions before polydipsia was fully developed, no differences existed between the timing accuracy of the water group and no-water group. As the amount of water drunk by the water group increased as the number of sessions increased, a parallel increase was noted in the timing accuracy of the water group. In the final sessions, a significant difference was found between the timing accuracy of rats in the water group and that of those in the no-water group. It was concluded that polydipsia facilitated the development of the temporal discrimination which is characteristic of a fixed-interval 60-sec. schedule.