An inexpensive electro-fistular swivel for negative feedback control of self-stimulation

A swivel was developed for concurrent intraorganismic fluid injection and intracranial electrical stimulation of the unrestrained rat. Effects of various intragastric injections on bar-pressing maintained by electrical stimulation of the hypothalamus were studied. In some subjects, intragastric injections of either water or milk decreased the rate of responding. This decrease resulted from pauses in responding rather than from decreases in the local rates of responding. The decrement in responding occurred at a lower gastric volume during milk injection than during water injection. In other subjects, however, neither water, milk, nor 32% sucrose injections affected the rate of self-stimulation.     

Source variability and recall of auditory material 1

Recall of auditory narrative material was measured under three conditions of presentation. These were a single source condition with material from one speaker, a four source fixed sequence condition with material from four speakers in a fixed sequence of 3-sec. lengths, and a four source random condition with material from four speakers in a random sequence of 3-sec. lengths. Recall was better for the single source condition than for the four source conditions. No significant difference was found between the fixed and random sequential presentations. Results are discussed in terms of the attentional behaviors involved in the tasks.     

Preemployment screening procedures: How human resource managers perceive them

A survey of Human Resource practitioners' perceptions of pre-employment screening procedures was conducted. The results indicated differences between tests in terms of perceived accuracy and offensiveness, as well as other attributes. Regression analyses suggested that beliefs about validity, the number of other companies using these procedures, perceived offensiveness of the test, and ease in passing the test were important factors in the willingness to use a particular test. Conversely, perceptions regarding the discriminatory impact of the test and the cost of using the test generally were not related to willingness to use the test. Limitations of this study, which was primarily exploratory, are noted.     

Differences in Student Perceptions of Secondary Vocational Education: Implications for Multicultural Career Counseling

Comparative analysis of 204 African-American and White students' perceptions toward secondary vocational education revealed that students formed perceptions toward these programs from a multidimensional perspective. Generally, African-American female students held positive perceptions whereas African-American male students held negative perceptions toward vocational education programs.     

Potentiation of the pressor response to stress by tolbutamide in dogs

Tolbutamide has previously been shown to amplify the pressor effects of “exogenous” catecholamines in conscious dogs, possibly due to sensitization of the α₁-adrenoreceptor-mediated vasoconstriction. The objective of this study was to examine if tolbutamide also amplifies the pressor effects of “endogenous” catecholamines released during psychological stress (classical Pavlovian aversive conditioning). Experiments were conducted in β-adrenoreceptor-blocked (propranolol, 1 mg/kg, i.v.) conscious dogs (n=4) trained in classical aversive conditioning. Conditioning was accomplished by following a tone (CS+) with a 1/2 second shock; another tone (CS-) was not followed by any shock and served as control. With saline pretreatment, aversive conditioning (i.e., CS+) increased mean arterial pressure (MAP) only by approximately 4.7% when compared to CS-, whereas with tolbutamide (45 mg/kg, i.v.) pretreatment, the increase in MAP induced by CS+ beyond what was induced by the CS- (approximately 6.2%) was significantly (p<0.05) larger than that with saline pretreatment. In isolated canine femoral arterial segments (n=4), the vasoconstrictor effect of phenylephrine (an α₁-agonist) at 5×10^?6M (which was the EC₅₀ value) was amplified by 2×10^?2M of tolbutamide from 54.0±2.0% to 66.9±2.1%. In conclusion, tolbutamide amplifies the pressor effects of “endogenous” catecholamines in conscious dogs, possibly by sensitization of the α₁-adrenoreceptor-mediated vasoconstriction. This mechanism of action is novel and has not been reported with other agents.     

Ingroup Versus Outgroup Perceptions of the Characteristics of High-Risk Youth: Negative Stereotyping1

Adolescents tend to categorize themselves and their peers into discrete ingroups and outgroups. A comparison of ingroup versus outgroup perceptions of the characteristics of high-risk youth was investigated. Based on current stereotype research, we examined the perspective that outgroup members would hold a more extreme stereotype of high-risk youth compared to the perceptions of ingroup members. A total of 955 7th- and 10th-grade southern California adolescents completed a questionnaire regarding the characteristics of their own peer group and a high-risk group. Support was obtained for an extremity of judgement effect. Outgroup youth perceived that their high-risk peers engaged in fewer school and nonschool low-risk activities, more high-risk activities, and greater drug use than did ingroup members. Outgroup members also held perceptions of high-risk youth as less likely to hold a white-collar job than did the ingroup members. The perceptions that adolescents have of these groups may play major roles in their own social behavior. The implications of these results for future tobacco use prevention programs are considered.     

Contributors to the Appraisal of Major Life Changes: Gender, Perceived Controllability, Sensation Seeking, Strain, and Social Support

This study investigated relationships between the appraisal of life events and gender, locus of control, social support, strain, and sensation seeking. In group sessions, undergraduate males and females completed self-report measures assessing life events appraisals and self-report measures for the above individual differences. Analyses supported the notion that a range of these variables, previously shown to serve as moderators of life stress, are significantly related to the appraisals of life events. Moreover, in addition to the gender differences obtained for the perception of life events, gender was found to influence several associations between the individual differences and life events appraisal.