Drug postulate of Eysenck in the rat

The present work is an attempt to investigate the Drug Postulate of Eysenck in the animal field. The Ss were 36 male Wistar rats. The extraversion measure used was animal ambulation in a low-frightening open-field. d-Amphetamine, reserpine and saline were administered before the extinction of a lever-press FR 25 schedule for food. The results show that reserpine produces a decrement in the resistance to extinction (RExt), while d-amphetamine produces a biphasic effect, increasing the RExt in high-ambulatory (extravert) rats and leaving the RExt of low-ambulatory (introvert) rats unaffected. Therefore, reserpine acted as a depressant drug, d-amphetamine as a stimulant drug and ambulation as extraversion.     

Personality,amphetamine and intracranial self-stimulation in rats

The relationship between open-field ambulation and intracranial self-stimulation (ICSS) at the lateral hypothalamic area was studied in rats. A treatment with i.p. saline of d-amphetamine was also applied to the animals prior to ICSS tests. High-ambulatory rats (comparable to human extraverts) showed an equally higher susceptibility to ICSS reward than low-ambulatory rats (comparable to human introverts) with both saline and amphetamine. These findings were interpreted comsidering the ICSS as a strong stimulation which would tend to produce ‘unconditioned inhibition’ much earlier in low-ambulatory rats than high-ambulatory rats thus leading to a better conditioning among the high-ambulatory Ss.     

The use of extreme groups to test for the presence of a relationship

Experimenters in psychology frequently investigate the relationship between two variables by selecting extreme groups on the first measure and comparing their mean scores on the second. This paper considers the efficacy of this procedure from the criterion of the power of the statistical tests. Optimal cutting points for the extreme groups are defined, and the power of the difference approach is compared to that of significance tests for the productmoment correlation coefficient.     

Neophobia in spontaneous hypertensive (SHR) and normotensive control (WKY) rats

Latency of approaching a novel object (white-colored cube) placed in an unfamiliar open field, duration of object exploration, ambulation, rearing, grooming, and defecation were investigated in spontaneous hypertensive rats (SHR), their genetic normotensive controls (WKY), and standard Laboratory rats of Wistar origin (Tif:RAIf). The parameters measured were taken as indices of fear due to novelty (neophobia). Remarkable differences in behavior of all three strains were observed. By comparison to RAIf and WKY rats, SHR showed decreased neophobia as reflected in the significantly shorter latency of approaching the object and enhanced ambulation and rearing activity in the open field. By comparison to RAIf rats SHR also showed reduced grooming and defecation. WKY rats distinguished themselves from both SHR and RAIf by almost total absence of all responses in this test situation. This behavioral suppression was antagonized by 7.5 mg/kg ip of chlordiazepoxide. The results of this study further support the notion that, by comparison to standard laboratory rats, both SHR and WKY rats show possible genetically determined, altered behaviors which are diametrically opposite to each other.     

Evoked potential augmenting-reducing and personality differences

Normal volunteers (N = 120) were screened on the evoked potential (EP) measure of augmenting/reducing introduced by Buchsbaum and Silverman (1968). Extreme augmenters were compared with extreme reducers on the Zuckerman Sensation-seeking Scales, the Eysenck Personality Questionnaire, the Myers-Briggs Type Indicator, Raven's Advanced Progressive Matrices (RAPM) and a measure of pain sensitivity. Reducers are more extraverted and more sensation-seeking than augmenters; they are also less sensitive to pain and they have higher scores on the RAPM test. The fact that individuals selected for contrasting EP response patterns differ on these psychological variables supports the idea that there is a neurophysiological basis for individual differences in personality, pain perception and intelligence.     

Gender differences in pressure pain threshold in a repeated measures assessment

The objective of this study was to evaluate gender differences in the pain threshold, considering the type of pressure point, its location and the repetition of the assessment. The pressure pain threshold was evaluated in 30 healthy volunteers (12 men and 18 women) in three assessment sessions separated by 15 min and 7 days, respectively. Each assessment session was in turn composed of two trials in each of which 24 different pressure points (symmetrically located), representing the 18 tender points for the diagnosis of fibromyalgia and six control points, were assessed. Gender differences were found in the pain threshold for all of the points and the measures taken, women showing a lower pain threshold in comparison to men and being these differences more pronounced for control points than for tender points, the former reaching statistical significance in all cases. The analysis of the influence of repeated measures on gender differences in the pain threshold showed a distinct pattern of recuperation in men than in women, although only one difference in pain threshold was significant. The utility of the tender point concept to study gender differences in pain threshold and the mechanisms that may explain different patterns of recuperation between genders are discussed.     

BEHAVIOUR OF RATS UNDER THE INFLUENCE OF ETHYL ALCOHOL IN AN OPEN-FIELD SITUATION

In a standardized open-field test, ambulation, defecation, time of non-locomotor activity, time spent motionless, preening, and rearing were recorded. Inter-observer differences were small. Test repetition caused significant behavioural changes. Different rats were used for each of five doses of alcohol (0.5–2 mg/g). The lowest dose (0.75 mg/g) affecting behaviour significantly increased time motionless, decreased non-locomotor activity, and depressed preening. Ambulation was the last sensitive measure of behaviour. The results suggest that arousal mechanisms are particularly sensitive to alcohol. The procedure seems useful for studies of effects of small doses of alcohol.     

Chronic sweet intake lowers pain thresholds without changing brain mu- or delta-opiate receptors

Sprague-Dawley rats drank sweetened (3% dextrose + 0.144% saccharin, w/v) or unflavored water for 18 days and subsequent pain reactivity was assessed using a hot plate. Compared to the rats that consumed unflavored water, the rats that consumed sweet water responded more quickly on the hot plate indicating that their threshold for pain was lowered. Another group of rats given identical exposure to the fluids had their brains prepared for measuring opiate receptor binding using the delta-receptor ligand [3H]D-Ala-D-Leu-enkephalin ([3H]DADLE) and the mu-receptor selective ligand [3H]Tyr-D-Ala-Gly-MePhe-Gly-ol ([ 3H]DAGO). Binding of these opiates to mu- and delta-receptors in the cerebral cortex, striatum, hippocampus, hypothalamus, brain stem, and remaining brain regions was the same for the rats that drank sweet fluids and those that drank unflavored water. These findings suggest that drinking sweet fluids lowers pain thresholds but does not alter mu- and delta-receptors.     

The effects of Δ9 THC on cutaneous sensitivity and its relation to personality

Pain threshold/tolerance and vibration perception were studied in a sample of female frequent and infrequent cannabis users. Interactions with personality characteristics were examined using the EPI. Performance on all measures was investigated after oral administration of either 10mgΔ⁹ THC or 20 mg Δ⁹ THC. Results indicated that while the 10mg dosage produced no consistent changes in cutaneous sensory response, the 20 mg dosage was followed by lowering of the vibration threshold. Frequent and infrequent cannabis users differed in their response to the pain stimulus (pain tolerance scores were higher among infrequent users). They also differed with respect to the personality measure (frequent users had lower E, N and L scores). The findings provide experimental support for cannabis users' reports of enhanced sensory awareness consequent to drug intake. The results also show that frequent and infrequent cannabis users differ in pain response and personality characteristics.     

Correlative effects of psychogenetic selection: A study of the roman high and low avoidance strains of rats

A sample of 86 rats of the RHA and RLA strains, selectively bred in Rome for speed of acquisition of conditioned avoidance responses (CAR), was given the open-field test of emotionality, and re-tested for conditioning in their new environment. Both sexes were included in a balanced-order design. The standardized open-field test and a conventional shuttle-box with buzzer as the conditioned stimulus and shock as the unconditioned stimulus were used. The results show that the Roman strains do not differ in respect of open-field defecation. While the RHA strain was confirmed as superior in measures of CAR formation, it was also found to be significantly more active both in the open-field (ambulation) and in inter-trial activity during conditioning. No effects attributable either to order of test administration or the previous history of the subjects were detected, and those due to their sex merely confirmed previous findings. These results are contrasted with the findings for the Maudsley strains of reactive and non-reactive rats which differ significantly in respect of emotional elimination as a result of a similar selection procedure, but which also display a similar difference in CAR acquisition and in mature body weight.     

Mapping Open-Field Behavior in Rats: Applicability Across Sexes

Open-field behavior of female and male Sprague-Dawley rats was plotted on a map using scores derived from a principal-component analysis. As reference points on the map, three treatment conditions were used: electric shock, extensive stroking, and additional trials after habituation to the field. Five measures were used: ambulation, penetration into the inner square, rearing, defecation, and urination. The behaviors in each treatment condition clearly cohered with each other on the map, regardless of sex difference in raw scores. This coherence shows that the nature of the emotional behavior caused by the present treatments is similar across sexes, indicating, to some degree, the applicability of the map across the sexes. The additional experiment (concerning the estrus effect on the open-field behavior) suggests that the estrus effect is not large enough to compromise the validity of the map, which was constructed on the basis of the data without control of the estrus effect.     

The stability of depressive symptoms in college students: An empirical demonstration of regression to the mean

In a recent paper, Vredenburg, Flett, and Krames (1993) hypothesized that the apparent instability of depressive symptom scores in college students may be due, in part, to the phenomenon known as statistical regression to the mean. This statistical principle was demonstrated in the current study. A sample of 183 university students completed the Beck Depression Inventory (BDI) at two timepoints separated by a 3-month interval. Consistent with past results, analyses revealed substantial changes in symptom scores over time with decrements being evident among many subjects with elevated symptom scores at Time 1. Examination of the amount of change over time in BDI scores indicated a pattern of findings that approximated the regression to the mean phenomenon. Statistical tests confirmed that regression to the mean accounted for a significant amount of the change in symptom scores over time. The implications of these findings are discussed in terms of the nature of depressive symptoms in students and the inappropriateness of assigning subjects to depressed or nondepressed groups on the basis of elevated scores on a self-report measure.     

Sex-dependent habituation to novelty in rats

Male and female rats were familiarized with one-half of an exploration box for 30 or 60 minutes. When later tested, females showed higher preferences for the other novel half than males. Females also showed higher levels of rearing and ambulation. No sex differences were evident for grooming, freezing or defecation. The results were interpreted as females having habituated to the forced-exposure novelty of the familiar half of the apparatus more rapidly than males when the familiarization period was relatively short. With a longer period, males would have had more time to reach a similar level of habituation to that attained by females familiarized for 30 minutes. Relationships between novelty preferences and both rearing and ambulation as indices of exploration were also discussed in the light of significant correlations for males only.     

Sex-dependent habituation to novelty in rats

Male and female rats were familiarized with one-half of an exploration box for 30 or 60 minutes. When later tested, females showed higher preferences for the other novel half than males. Females also showed higher levels of rearing and ambulation. No sex differences were evident for grooming, freezing or defecation. The results were interpreted as females having habituated to the forced-exposure novelty of the familiar half of the apparatus more rapidly than males when the familiarization period was relatively short. With a longer period, males would have had more time to reach a similar level of habituation to that attained by females familiarized for 30 minutes. Relationships between novelty preferences and both rearing and ambulation as indices of exploration were also discussed in the light of significant correlations for males only.     

Two Types of Strain Differences in Open-Field Behavior in Rats and their Mapping

Open-field behavior of three treatments for three strains of rats (SD, Long-Evans, Fischer-344) was plotted on a map by component scores that were derived from principal component analysis. The treatments consisted of electric shock, extensive stroking, or testing after habituation to the field. Five measures were used: ambulation, penetration into the inner square, rearing, defecation, and urination. There was a clear strain difference on the basis of a raw open-field test score. This was termed a raw-score strain difference. A treatment-effect strain difference, however, which is obtained by comparing treatment and control conditions, was not clear. Thus, the behavior of each treatment condition cohered clearly with each other on the map, regardless of raw-score strain differences. This indicates that the nature of emotional behavior caused by the present treatments is very similar among strains despite the clear raw-score strain difference.     

Subject emotionality and subsequent pylorus ligation-induced or restraint-induced gastric ulcer

Rats were tested for “emotionality” in a standardized open-field procedure for four consecutive days. In one experiment, open-field testing was followed by a 24-hour period of starvation and by a 10-hour period of pyloric occlusion. In a second study, open-field testing was followed by 12 hours of starvation and by three hours of supine restraint-cold (4–6° C). “High-emotional” and “low-emotional” animals differed significantly in terms of glandular ulcers (both experiments) and gastric secretion (Experiment 1). Low-emotional animals had less gastric damage and secreted a smaller volume of less concentrated gastric acid. Discriminant analysis indicated that the behavioral measures of open-field defecation and open-field ambulation were the best discriminators of high and low emotionality. Multiple regression analysis also suggested that open-field defecation and ambulation were good predictors of gastric glandular ulceration induced by either pyloric ligation or stress due to supine restraint-cold.     

对学前儿童语言学习能力诊断量表的效度评价

以所编制的量表为工具 ,对采集的数据进行效度分析 ,结果表明各分测验与全量表有较好的相关 ,说明量表的内容效度是比较高的。使用因素分析的方法 ,将全部变量作系统分类 ,研究量表的结构 ,绝大部分分测验在所得的四个因素上的共通性都大于 0 .70 ;保留下的分测验与所属因素的相关系数在0 .5 3 -0 .84之间 ,它们在各个因素上有较高的负荷量 ,说明量表有较好的结构效度。从效度分析的结果看 ,本量表的测量结果应该是准确的。另外 ,还根据因素分析结果指示的方向 ,调整了分测验 ,调整后的量表结构不但与假设的量表结构十分吻合 ,而且更条理化。     

Career maturity aspects of the Kuder Occupational Interest Survey

The Kuder Occupational Interest Survey (1979) (KOIS) is used in counseling services as an aid in career counseling, but the KOIS does not have a measure of career maturity. The purpose of this study was to determine if selected scores from the KOIS could be indicative of client career maturity. The data for each subject included three scores from the KOIS and one measure of career maturity. The three scores from the KOIS included the highest Occupation score, the highest College Major score, and either the Father score for male subjects or the Mother score for female subjects. Career maturity was assessed with the Career Maturity Inventory Attitude Scale (1973) (CMI). The three scores from the KOIS were correlated with the score from the CMI to determine the relationship between the KOIS and career maturity. t tests were used to test for significant differences between men and women on the four measures. Significant correlations were found between the KOIS scores and career maturity, supporting the statements in the KOIS manual regarding the relationship between high KOIS scores and maturity. There was no significant difference between females and males on the CMI, Occupation, or College Major scores, but females scored significantly higher on the Mother scale than males did on the Father scale. Implications for career counseling were discussed.     

Improved matrix reasoning is limited to training on tasks with a visuospatial component

Recent studies (e.g.,  and ) have provided evidence that scores on tests of fluid intelligence can be improved by having participants complete a four week training program using the dual n-back task. The dual n-back task is a working memory task that presents auditory and visual stimuli simultaneously. The primary goal of our study was to determine whether a visuospatial component is required in the training program for participants to experience gains in tests of fluid intelligence. We had participants complete variations of the dual n-back task or a short-term memory task as training. Participants were assessed with four tests of fluid intelligence and four cognitive tests. We were successful in corroborating Jaeggi et al.'s results, however, improvements in scores were observed on only two out of four tests of fluid intelligence for participants who completed the dual n-back task, the visual n-back task, or a short-term memory task training program. Our results raise the issue of whether the tests measure the construct of fluid intelligence exclusively, or whether they may be sensitive to other factors. The findings are discussed in terms of implications for conceptualizing and assessing fluid intelligence.     

SOCIAL CONFORMITY AND PSYCHOLOGICAL DIFFERENTIATION12

This study examined the role of socialization experiences in the development of psychological differentiation. In each of three countries (Holland, Italy, Mexico) two villages were selected as presenting a contrasting picture with regard to degree of emphasis on conformity to family, religious and political authority. It was hypothesized that within the pair of villages in each country children from the village which stressed social conformity would tend to be more field dependent and show other signs of less developed differentiation than children from the village in which social conformity was less emphasized. In each of the six villages approximately 100 children (boys and girls, aged 9–11 and 13–15) were studied. Differentiation was assessed by a battery of tests of field-dependence-independence and the figure-drawing test. In every comparison of mean test scores between pairs of villages, in each of the three countries, children from the village in which social conformity was stressed obtained scores reflecting less differentiated functioning. Village differences were significant for every measure of differentiation in all three countries. Addition alanalyses of the data from the tests of differentiation and other tests used yielded results essentially consistent with findings from previous studies.