Some effects of response-independent shocks after unsignaled avoidance conditioning in rats

After extended unsignaled avoidance training, the majority of rats continued frequent responding during long periods when only response-independent shocks were presented. Most responses were shock elicited, i.e., followed immediately after shock. Response rates were directly related to both the frequency and the intensity of response-independent shocks. Responding continued to approximately the same extent, whether shocks were presented at fixed or variable intervals. Few responses were directed toward a second lever in the test chamber, even when the lever previously associated with avoidance was removed. When avoidance was scheduled on the second lever, the rats learned to avoid by operating it. Meanwhile, responding on the first lever became infrequent. Subsequently, when only response-independent shocks were presented, almost all responses occurred upon the lever initially associated with avoidance. Responding that was elicited by response-independent shocks was suppressed by response-dependent (punishment)_shocks of the same intensity. When punishment was withdrawn, recovery of responding occurred. An explanation of the results based upon shock-elicited behaviors is preferred to one stressing unextinguished avoidance responding.     

Personal social networks as a focus for primary prevention of child mistreatment

This article explores the nature and functions of social networks as support systems, and the relationship between social networks and early child rearing. The rationale and operational design of a primary prevention program which seeks to strengthen the social networks of parents of very young children are presented. It is concluded that personal social networks are important not only in mediating general life stress, but also support parental child-rearing responsibilities and, therefore, can serve as primary preventives of child abuse.     

Measuring Associative Strength: Category-Item Associations and Their Activation from Memory

Three measures of the strength of association between a category and members of the category were investigated: (a) a naming measure, in which the participants (93 undergraduates) were asked to list the members of a category and the listing order was assumed to reflect associative strength; (b) a latency measure, which assessed the latency to correctly identify specific items as members or nonmembers of a given category; and (c) a facilitation measure, in which the spontaneous activation of an item upon presentation of a category label as a prime was assessed by considering the extent to which the prime facilitated recognition of an initially degraded (visually obscured) item. The three measures correlated substantially, thus validating the naming and latency measures as reasonable approximations of the likelihood that a given item will receive activation in memory when the category is presented. Many of the constructs of interest to survey researchers can be viewed similarly as associations in memory, and the naming and latency measures can be fruitfully used in surveys; research attesting to the utility of namingand latency data is reviewed.     

Equipment malfunctions and attribution of causality

The purpose of this study was to test whether individuals would be more likely to attribute the cause for the malfunction of a new piece of equipment as a manufacturing problem in the equipment or as an inability on their part to properly work with the equipment. The subjects were 600 residents of Florida, selected by a stratified random sample and interviewed in a statewide telephone survey. Subjects were more likely to attribute the cause to themselves rather than the machine. Overall, 71% attributed the cause to themselves, while only 24% said the machine was at fault. There was also an interaction effect in terms of income, with middle-income users more likely to blame the machine and upper-income users more likely to blame themselves. Further, there was also a significant relationship between attribution of cause and age, with older respondents being more likely to attribute cause to themselves. These results imply that attribution may differ when the potential object of attribution is a machine rather than another person.     

Locomotor analysis of the taiep rat

Locomotor activity (tremor, ataxia, immobility, epilepsy, and paralysis) in the taiep rat, which suffers from a myelin deficient disorder, has not been previously documented. This study used walking track analysis of footprints to analyze locomotor activity in the taiep rat in comparison to normal, age-matched controls. The results confirmed differences between normal and taiep rats in terms of stride length, step length, and stride width. In addition, we found significant interactions between age and condition for stride and step length. The results suggest that locomotor analysis is a sensitive indicator of myelin deficiency. The results are discussed in terms of the underlying myelin deficiency and possible treatment regimens.     

Sleep quality, sleep propensity and academic performance

We examined associations between measures of sleep propensity on the Epworth Sleepiness Scale, sleep quality on the Pittsburgh Sleep Quality Index and academic performance by GPA and grades in introductory psychology for 414 students. In the total sample, neither sleep propensity nor sleep quality correlated with GPA or introductory psychology grades. However, among students carrying a full course load, those reporting poor sleep quality performed less well on academic measures than those reporting a better quality of sleep. Further research is needed to assess the moderating influence of overall demands of daytime functioning on the association between sleep quality and academic performance.     

Two-component arterial blood pressure conditional response in rat

The objective of these experiments was to quantify the pattern of change in arterial blood pressure (BP) during a discriminative aversive classical conditioning paradigm in rat using a new “high resolution” computer analysis. Sprague-Dawley rats (n=5) were restrained in a soft, conical cloth pouch and conditioned using a 6 sec. pulsed tone (CS+) followed by a 0.5 sec. tail shock; a steady tone, never followed by shock, served as a CS-. BP peaked at 16.4±6.5 mm Hg (mean±SD) above control at 1.5±0.1 sec. after onset of CS+. This “first component” (“C₁”) also occurred during CS- (12.1±3.8 mm Hg), although the magnitudes of the two were significantly (p<0.05) different. Another group of rats (n=8) was treated identically except the tones were 15 seconds long. The conditional BP response consisted of two components. C₁ was reminiscent of that seen using the short tone: for CS+ a peak of 13.6±5.6 mm Hg at 1.5 sec. or, for CS-, of 10.0±4.3 at 1.3 sec. (p<0.05). In CS+ trials BP peaked again (“C₂,” 7.4±2.5 mm Hg) at 8.3±1.2 sec. There was no statistically significant C₂ for CS- trials, clearly demonstrating discrimination between tones. The unconditional BP response in both groups consisted of two large, closely spaced peaks in BP. Respiration was recorded in 3 additional rats. After shock delivery these subjects often showed a sudden shift between (1) a regular respiratory pattern with moderate chest excursion and (2) apneic episodes interspersed with single, deep breaths. This latter pattern was associated with large, low frequency fluctuations in BP. Continued development of the rat conditioning paradigm is especially warranted because of the ability to record sympathetic nerve activity in intact, awake subjects and the large number of readily available genetic strains, which model human pathological states.