Preference for shock signals as a function of the temporal accuracy of the signals

Three groups of rats were exposed to pairs of three different contingencies on two sides of a shuttlebox. One signaled contingency provided 10-min danger and safety cues plus an additional 10-sec cue immediately preceeding shock (P-S), another signaled contingency provided 10-min danger and safety cues but random 10-sec cues with respect to shock (R-S), and an unsignaled contingency provided no safety period, but only a 20-min danger period during which shock could occur (NS). Signaled P-S and R-S contingencies were preferred in a choice test to the unsignaled NS contingency, and P-S was preferred to R-S. Independent tests of the fear-eliciting properties of the cues made in an off-baseline test of suppression of ongoing exploration indicated more freezing (fear) to the 10-sec cue in rats experiencing the P-S contingency. The results were interpreted as indicating a preference for cues providing more precise information about the temporal location of shock even when those cues were fear-eliciting.     

Finger tapping: effects of trials and sessions

18 normal, self-reported dextral subjects (9 men, 9 women) were assessed with a Halstead Manual Finger Tapping device, with 10 trials per hand for 10 consecutive wk. The test-retest reliability of the 10-trial average between the 10 sessions averaged .94 for men and .86 for women, for both preferred and nonpreferred hands. There were no statistically significant effects of increases in performance over sessions or effects of fatigue over trials for either sex or hand. There were, however, significant increases over trials for men for both preferred and nonpreferred hands.     

Altering the proportion of components in a mixed fixed-ratio schedule

Pigeons were trained under a schedule consisting of a number of fixed-ratio 100 components followed by a single fixed-ratio 10 component. The proportion of fixed-ratio 100 to fixed-ratio 10 components was varied according to several ascending and descending series within the range of 99:1 to 1:1. When this proportion was reduced to about 20:1 and below, the pause following each fixed-ratio 100 gradually decreased in length. Primes, a burst of responses at the start of the fixed-ratio 100 component, increased in frequency, and then decreased when the proportion became extremely low. Also, when the relative frequency of fixed-ratio 10 components was very high, primes were seldom observed in the first fixed-ratio 100 component following a fixed-ratio 10 component, but were distributed evenly throughout the remaining fixed-ratio 100 components.     

A Longitudinal Factor Model For Studying Change In Ability Structure

Models of the Longitudinal Factor Analysis type were designed to describe the development of ability structure between the ages 10 and 13. The parameters of the models were estimated by the LISREL program (Jöreskog & van Thillo, 1973). The sample comprised 375 girls and 353 boys who were tested at age 10 and retested at age 13 with six ability tests and two achievement tests. The results indicate that verbal, inductive, and spatial abilities can be described as developing fairly independently of each other between the ages 10 and 13. At age 13, but not at age 10, two subfactors of the inductive factor could be differentiated. The unique variances show a marked decrease between age 10 and age 13. Consequently the factors, and the relationships between factors, explain more of the variance of the response variates at age 13 than at age 10.     

Experience level influences the effect of attentional focus on sprint performance

Two experiments evaluated the influence of attentional focus on 10-meter sprint time and start kinetics in a group of collegiate soccer players and highly experienced sprinters. In Experiment 1, the collegiate soccer players were asked to perform 10-meter sprints under an external focus condition, an internal focus condition and a control condition. For the 10-meter sprint time, the results showed that both the external focus and control conditions resulted in significantly faster sprint times than the internal focus condition. There were no significant differences observed between the external focus and control conditions. There were also no significant differences observed across any of the conditions for a select set of kinetic variables. In Experiment 2, the highly experienced sprinters performed the same 10-meter sprint task using the same instructional conditions as in Experiment 1. For the 10-meter sprint time and kinetic variables, there were no significant differences observed across any of the conditions. These results provide new evidence that experience level mediates the influence of attentional focus on sprint performance.     

Temporal summation of pain from radiant stimulation

Latency thresholds of pricking pain, using radiant thermal stimulation, were obtained. Ten Ss were tested for 10 sessions, and, in each session, single latency determinations were made at each of 10 stimulus intensities. Each intensity was administered to a different spot along the volar surface of S’s nonpreferred forearm. Thus, 10 latency thresholds were obtained from each S at. each intensity and each spot. Initial skin temperature was controlled so that a threshold determination was made when skin temperature measured 33.5° ± 0.5° C. Analysis of variance of the log₁₀ t (seconds) values revealed a highly significant linearity of regression of log t on log intensity, thus confirming the hypothesized inverse and exponential relationship between latency and intensity. The parameters (slope and x-intercept) of the curve were discussed. The x-intercept may be interpreted as an index of an aversive threshold and could be used as a possible measure of the physiological component of pain.     

Autokinetic movement as a function of symbolic meaning of target shape.

The autokinetic movement responses of 10 American, 10 Chinese, and 10 Iranian students to religious symbols and control stimuli were measured. The hypothesis of differential direction response as a function of the target shapes was supported. Iranian students did show a pattern of responding significantly different from the American and Chinese.     

短式知觉压力量表(PSS-10)在中国大学生中的信效度

考察短式知觉压力量表(PSS-10)在中国大学生中的效度和信度。用PSS-10、一般健康问卷(GHQ-12)、生活取向测验修订版(LOT-R)、一般自我效能量表(GSES)以及Connor-Davidson心理韧性量表(CD-RISC)对1762名大学生进行调查。PSS-10的条目质量良好; 经探索与验证后,量表的潜在结构为稳定的两个因子,与实测数据拟良好; PSS-10的效标关联效度较好。总量表、无助感和自我效能信念的内部一致性系数达到了测量学要求; 两周后其重测信度大于0.6; 它们的问卷辨识系数均大于0.9。短式知觉压力量表在中国大学生中具有良好的信效度,能够作为有效测量大学生领悟或感受到压力的程度。     

Infantile handling and the extinction of responses acquired under food reward

A comparison was made of the runway behaviour of rats which had been handled from Days 1-21 and their non-handled litter mates. The training began on Day 70 after the animals were habituated to a restricted food schedule for 10 days. The subjects were given six trials each day in the runway and were rewarded with a 0.045 g. Noyes pellet. After 10 days of rewarded training trials, subjects were given 6 extinction trials a day for 10 days. Results showed that handled rats ran faster than non-handled rats during acquisition and during the first 3 days of extinction. The extinction data suggested that the relationship between emotionality and effects of frustrative non-reward should be re-evaluated.     

A comparison of mothers' and fathers' speech to their 3-year-old sons

The language patterns of 10 mothers and 10 fathers with their firstborn 3-year-old sons were compared. Ten-minute mother-son and father-son conversations were recorded independently in the home during a free-play session with standard play mterials. The findings of this study indicate that although mothers and fathers used a similar number of utterances in conversing with their sons over a 10-minute period, their patterns of speech were different on a number of quantitative measures including MLU, MLU of five longest utterances, percent of imperatives, and percent of questions. In general, fathers' communication was viewed as more controlling and involving the child less, while mothers' communication was viewed as more child-centered and involving the child more.     

Cross-system concordance of personality disorder diagnoses of DSM-IV and diagnostic criteria for research of ICD-10

The aim in this study was to examine the cross-system concordance between the personality disorders (PDs) of DSM-IV and Diagnostic Criteria for Research of ICD-10 Classification of Mental and Behavioral Disorders, 10th rev. (ICD-10) PD diagnoses were made by a structured interview in a clinical psychiatric sample of 138 individuals. Both categorical and dimensional scores for each PD were established. The frequency of patients with a PD diagnosis on either classification who were also positive on the other varied from 26% for the schizoid PDs to 88% for the histrionic PDs. The chance-corrected agreement (Cohen's kappa) ranged from .37 to .94. The dimensional correlation (Pearson's r) between pairs of PD criteria sets was in the range of .79 to .98. In conclusion, when analyzed categorically, some of the PDs of DSM-IV and ICD-10-DCR were only moderately concordant. The reasons appear to be different criteria formulations and arbitrary thresholds for diagnoses. In contrast to categorical diagnoses, dimensional agreement was high, implicating similar trait-concept definitions. The least concordant pair of PD was antisocial (DSM-IV)-dissocial (ICD-10).     

Low body temperature,time dilation,and long-trace conditioned flavor aversion in rats

Conditioned flavor aversion was examined in Wistar-derived albino rats that were immersed in cold water for 0, 2.5, 5, or 10 min immediately following 10-min exposure to a.1% saccharin solution and given an intraperitoneal (i.p.) injection of 0.15 M lithium chloride (LiCl) either 90, 135, 180, or 225 min later. Cold water immersion for 2.5, 5, and 10 min led to body temperature decreases of approximately 4.5, 7, and 10 degrees C, respectively. Rats whose body temperatures were not reduced (0 min immersion) showed no saccharin aversion when the LiCl was delayed 90 min. Rats whose body temperatures were reduced 4.5, 7, and 10 degrees C displayed conditioned aversions at LiCl delays up to 135, 180, and 225 min, respectively. These results were interpreted in terms of a cold-induced slowing of a biochemical clock that may uniquely govern specific timing processes involved in associative learning over long delays, such as long-trace conditioned flavor aversion, learned safety, and certain types of learning that involve an extensive time lapse (e.g., extinction of fear).     

Massed vs. spaced exposure sessions in the treatment of agoraphobia

The differential effects of massed and spaced sessions of exposure in vivo were investigated with 11 agoraphobics in a crossover design. Clients were randomly assigned to one of the following two groups: (a) 10 daily sessions followed by 10 weekly sessions, or (b) 10 once-weekly sessions followed by 10 daily sessions. The results indicated that both massed and spaced sessions of exposure in vivo effected changes in avoidance behavior and subjective anxiety of agoraphobics, massed practice being superior especially with respect to avoidance. It was suggested that the superiority of massed practice is due to the lack of opportunity to engage in avoidance or escape during short inter-session intervals. The relationship between subjective anxiety and avoidance were considered and the differences between clinical and statistical significance were discussed.     

Synthetic variable-interval schedules of reinforcement

Three pigeons pecked for food on a synthetic variable-interval schedule of reinforcement that had two independent parts: a variable-interval schedule that arranged a distribution of interreinforcement intervals, and a device that randomly assigned each reinforcement to one of 10 classes of interresponse times. The frequencies of reinforcement for the 10 classes of interresponse times were systematically varied, while the overall frequency of reinforcement was held within a comparatively narrow range. The 10 classes extended either from 0.1 to 0.6 sec in 0.05-sec intervals, or from 1.0 to 6.0 sec in 0.5-sec intervals. In the former case, some control by reinforcement was obtained, but it was weak and no simple relationships were discernible. In the latter case, the relative frequency of an interresponse time was a generally increasing function of its relative frequency of reinforcement, and two simple controlling relationships were found. First, the function relating interresponse times per opportunity to reinforcements per opportunity was, over a restricted range, approximately linear with a slope of unity. Second, when all 10 classes of interresponse times were reinforced equally often, the relative frequency of an interresponse time approximately equalled the relative reciprocal of its length.     

DETERIORATION OF MENTAL AND MOTOR FUNCTIONS IN HYPERBARIC AIR

The effects of hyperbaric air on manual dexterity and arithmetic calculation capacity were studied in 15 subjects at ambient pressures of 4, 7, 10, and 13 ata at rest, and at 4, 7, and 10 ata during exercise (300 kpm/min). A significant reduction of the performance in both tests was observed at 10 and 13 ata at rest. During exercise in manual dexterity the reduction was significant at 4, 7 and 10 ata and in arithmetic calculation capacity at 7 and 10 ata. At 13 ata (at rest) a number of marked behavioural symptoms were observed, including changes in mood, impairment of consciousness, disturbance of perception, and deterioration of motor functions. These changes were readily reversible as soon as the pressure was lowered.     

The validity of psychomotor vigilance tasks of less than 10-minute duration

The 10-min psychomotor vigilance task (PVT) has often been used to assess the impact of sleep loss on performance. Due to time constraints, however, regular testing may not be practical in field studies. The aim of the present study was to examine the suitability of tests shorter than 10 min. in duration. Changes in performance across a night of sustained wakefulness were compared during a standard 10-min PVT, the first 5 min of the PVT, and the first 2 min of the PVT. Four performance metrics were assessed: (1) mean reaction time (RT), (2) fastest 10% of RT, (3) lapse percentage, and (4) slowest 10% of RT. Performance during the 10-min PVT significantly deteriorated with increasing wakefulness for all metrics. Performance during the first 5 min and the first 2 min of the PVT deteriorated in a manner similar to that observed for the whole 10-min task, with all metrics except lapse percentage displaying significant impairment across the night. However, the shorter the task sampling time, the less sensitive the test is to sleepiness. Nevertheless, the 5-min PVT may provide a viable alternative to the 10-min PVT for some performance metrics.     

The validity of psychomotor vigilance tasks of less than 10-minute duration.

The 10-min psychomotor vigilance task (PVT) has often been used to assess the impact of sleep loss on performance. Due to time constraints, however, regular testing may not be practical in field studies. The aim of the present study was to examine the suitability of tests shorter than 10 min. in duration. Changes in performance across a night of sustained wakefulness were compared during a standard 10-min PVT, the first 5 min of the PVT, and the first 2 min of the PVT. Four performance metrics were assessed: (1) mean reaction time (RT), (2) fastest 10% of RT, (3) lapse percentage, and (4) slowest 10% of RT. Performance during the 10-min PVT significantly deteriorated with increasing wakefulness for all metrics. Performance during the first 5 min and the first 2 min of the PVT deteriorated in a manner similar to that observed for the whole 10-min task, with all metrics except lapse percentage displaying significant impairment across the night. However, the shorter the task sampling time, the less sensitive the test is to sleepiness. Nevertheless, the 5-min PVT may provide a viable alternative to the 10-min PVT for some performance metrics.     

Factor structure and interpretation of the K10

The Kessler 10 Psychological Distress Scale (K10) is a brief 10-item questionnaire designed to measure the level of distress and severity associated with psychological symptoms in population surveys. It is being used widely, including in the World Health Organization World Mental Health Survey, and as a clinical outcome measure, although little information is available about the structure of the measure. The factorial composition of the K10 was examined in a prospective community survey and cross-validated in a separate large community survey. The K10 was found to consist of 4 factors and a 2-factor second-order factor structure. This was stable across the 2 waves of the prospective study and the Australian National Survey of Mental Health and Well-Being. The 4 factors, labeled Nervous, Negative Affect, Fatigue, and Agitation, were consistent with the original scales from which the items were taken. The 2 second-order factors represent Depression and Anxiety.     

Evidence of a detrimental effect of extrinsic incentives on breaking a mental set

College students were either rewarded ($1.50) or not for solving a series of 10 water-jar problems. The first 9 of these were designed to establish a set for a relatively complicated, three-jar solution (B ? A ? 2C). The 10th problem was a set breaker which required that subjects discover a simple (A-C) solution. The mental activities needed to produce a solution to the two types of problems (Problems 1 to 9 and Problem 10) were, therefore, different and one interest was in seeing whether reward would be detrimental for performance on both types of problems. It was not. Poorer reward group performance was obtained only on Problem 10. This result was not due to between-group differences in mathematical ability, and explanations in terms of differences in time taken to check answers or concern over quality of performance were considered and discounted. Measures of intrinsic interest (subject evaluations of the task and a measure of willingness to volunteer for future research) failed to support the belief that interest differences account for performance differences.