AGGRESSION AS POSITIVE REINFORCEMENT IN MICE UNDER VARIOUS RATIO‐ AND TIME‐BASED REINFORCEMENT SCHEDULES

There is evidence suggesting aggression may be a positive reinforcer in many species. However, only a few studies have examined the characteristics of aggression as a positive reinforcer in mice. Four types of reinforcement schedules were examined in the current experiment using male Swiss CFW albino mice in a resident—intruder model of aggression as a positive reinforcer. A nose poke response on an operant conditioning panel was reinforced under fixed‐ratio (FR 8), fixed‐interval (FI 5‐min), progressive ratio (PR 2), or differential reinforcement of low rate behavior reinforcement schedules (DRL 40‐s and DRL 80‐s). In the FR conditions, nose pokes were maintained by aggression and extinguished when the aggression contingency was removed. There were long postreinforcement pauses followed by bursts of responses with short interresponse times (IRTs). In the FI conditions, nose pokes were maintained by aggression, occurred more frequently as the interval elapsed, and extinguished when the contingency was removed. In the PR conditions, nose pokes were maintained by aggression, postreinforcement pauses increased as the ratio requirement increased, and responding was extinguished when the aggression contingency was removed. In the DRL conditions, the nose poke rate decreased, while the proportional distributions of IRTs and postreinforcement pauses shifted toward longer durations as the DRL interval increased. However, most responses occurred before the minimum IRT interval elapsed, suggesting weak temporal control of behavior. Overall, the findings suggest aggression can be a positive reinforcer for nose poke responses in mice on ratio‐ and time‐based reinforcement schedules.     

中小学生注意转换能力的发展研究

采用任务转换范式考察了108名中小学生的注意转换能力。反应—线索间距和线索—目标间距都分为200ms和2000ms两种水平。结果发现：（1）一般转换条件下,小5学生、初2学生和高2学生的定势选择速度相同,小5学生的定势选择正确性比初2学生和高2学生低;特定转换条件下,短时CTI下小5学生的定势转换速度比初2学生和高2学生慢,长时CTI下小5学生的定势转换速度比初2学生和高2学生快,初2学生的定势转换正确性比高2学生低;（2）一般转换条件下,任务定势重组在任务转换中作用不大,任务定势惯性在任务转换中起作用;特定转换条件下,任务定势重组和任务定势惯性在任务转换中的作用都不大。     

Parents' estimations of their own intelligence and that of their children: a comparison between English and Icelandic parents

In this study, 158 parents (79 fathers and 79 mothers) with a mean age of 38.3 yrs (SD = 8.2), estimated their own, and their children's, overall intelligence as well as their children's score on the 12 intelligence scales from the Wechsler's Intelligence Scale for Children (WISC-III). The sample included English (n = 122) and Icelandic parents (n = 36), and a comparison between them showed few differences except that Icelandic parents' estimates were lower than English parents' estimates. The results showed fathers estimated their own overall intelligence higher than mothers estimated theirs and sons were estimated higher than daughters on overall intelligence. Two factors (verbal, performance) of intelligence were identified through factor analysis of the ratings of the 12 WISC subscale score estimates. A hierarchical regression showed that these two factors explained most of the variance in the estimation of the child's overall intelligence; however, gender of child and parents' self-estimated own overall intelligence added incremental variance.     

Preferred Difficulty and Subjective Probability in Different Action Phases

Drawing on Gollwitzer's deliberative–implemental mindset distinction (P. M. Gollwitzer, 1990), it was predicted that people who are deliberating on different actions or goals would be more cautious or more realistic in their expectation of success in subsequent tasks than people who are going to implement a chosen action or goal. Participants were given a choice between different test-materials. They were interrupted before (deliberative) or immediately after decision-making (implemental). They then either had to choose between various levels of difficulty within one type of task (Experiment 1) or they had to predict their own future performance (Experiment 2). The results showed that deliberative participants preferred less difficult tasks and overestimated their probability of success less than implemental participants. In addition, deliberative participants referred more than implemental participants to their past performance when selecting levels of difficulty or predicting future performance; however, the two groups did not differ in actual performance. Taken together, the findings suggest that people are more realistic in a deliberative than in an implemental state of mind. The present studies extend prior research because for the first time they document mindset effects on peoples' estimates concerning their future performance in the achievement domain.     

Human operant performance: Sensitivity and pseudosensitivity to contingencies

Undergraduates' button presses occasionally produced points exchangeable for money. Left and right buttons were initially correlated with multiple random-ratio (RR) and random-interval (RI) components, respectively. During interruptions of the multiple schedule, students filled out sentence-completion guess sheets describing the schedules, and points were contingent upon the accuracy of guesses. To test for sensitivity to schedule contingencies, schedule components were repeatedly reversed between the two buttons. Pressing rates were consistently higher in ratio than in interval components even when feedback for guesses was discontinued, demonstrating sensitivity to the difference between ratio and interval contingencies. The question was whether this sensitivity was based directly on the contingencies or whether it was rule-governed. For two students, when multiple RR RI schedules were changed to multiple RI RI schedules, rates became low in both components of the multiple RI RI schedule; however, subsequent prevention of point deliveries for the first few responses in any component produced high rates in that component. For a third student, response rates became higher in the RI component that provided the lower rate of reinforcement. In each case, performance was inconsistent with typical effects of the respective schedules with nonhuman organisms; it was therefore plausible to conclude that the apparently contingency-governed performances were instead rule-governed.     

Choice As A Function Of Reinforcement Ratios In Delayed Matching-to-sample

Pigeons were studied in two experiments using a delayed matching-to-sample task. In Experiment 1, 4 subjects were exposed to a task in which the proportion of reinforcement associated with matching and nonmatching, and the overall proportion of reinforcement associated with selecting each choice, regardless of the sample stimulus, were varied. Choice was sensitive to both proportions. A least squares regression analysis showed that Wixted's (1989) proportions of reinforcement model closely fit the data from Experiment 1; however, the model failed to make accurate qualitative predictions for some test conditions. In Experiment 2, 4 subjects were exposed to a delayed matching-to-sample task in which the retention intervals and the reduction in delay to reinforcement signaled by the onset of the sample stimulus were independently varied. When the retention interval was short and when the delay-reduction value of the sample stimulus was high, the sample exerted greater control over choice; the control by the overall proportion of reinforcements for selecting each choice stimulus was correspondingly low. Conversely, when the retention interval was long and the delay-reduction value of the sample stimulus was low, the sample exerted relatively less control over choice; control by the overall proportion of reinforcements obtained for selecting each choice stimulus was correspondingly high. A signal detection analysis found that sensitivity to reinforcement varied directly with retention interval. Data were also consistent with misallocation models. No evidence was found to suggest that pigeons ignore the rate at which selecting individual choice stimuli is reinforced, as has been reported in studies with human subjects.     

Statistical inference based on latent ability estimates

The quality of approximations to first and second order moments (e.g., statistics like means, variances, regression coefficients) based on latent ability estimates is being discussed. The ability estimates are obtained using either the Rasch, or the two-parameter logistic model. Straightforward use of such statistics to make inferences with respect to true latent ability is not recommended, unless we account for the fact that the basic quantities are estimates. In this paper true score theory is used to account for the latter; the counterpart of observed/true score being estimated/true latent ability. It is shown that statistics based on the true score theory are virtually unbiased if the number of items presented to each examinee is larger than fifteen. Three types of estimators are compared: maximum likelihood, weighted maximum likelihood, and Bayes modal. Furthermore, the (dis)advantages of the true score method and direct modeling of latent ability is discussed.     

仪表数量与信号间隔时距对监视作业效绩的影响

用信号察觉反应时与信号误报率作指标 ,对监视作业中监视仪表数量与信号间隔时距对监视作业效绩的影响问题进行研究。结果表明 ,监视作业的效绩会随仪表增多和信号间隔时距增大而呈下降趋势。当监视仪表达到 8个时 ,监视作业的效绩会因负荷过重而明显下降。信号出现间隔时距增长时 ,会因警戒水平下降使监视仪表作业的效绩明显降低。     

Response suppression by visual stimuli paired with postsession d-amphetamine injections in the pigeon

Responding of pigeons, maintained under a fixed-interval 3-minute schedule of food presentation, was decreased on days that the color of the lights illuminating the food magazine was changed and d-amphetamine (1.0 mg/kg, i.m.) was injected after the session. Responding was not decreased by keylight color changes paired with postsession d-amphetamine or by postsession injections of saline. Administration of pentobarbital (3.0 to 5.6 mg/kg), but not d-amphetamine (.3 to 3.0 mg/kg), before the session increased rates of responding suppressed by drug-paired magazine lights. Responding maintained under a fixed-ratio 30-response schedule was not decreased when differently colored magazine lights were paired with a low (.3 mg/kg) postsession dose of d-amphetamine; with high (3.0 mg/kg) postsession doses, however, responding was completely suppressed after two pairings. The effects of pairing magazine stimuli with an intermediate (1.0 mg/kg) postsession dose of d-amphetamine depended upon the magnitude of prior postsession doses. After being paired with a low dose, stimuli paired with 1.0 mg/kg did not suppress responding. After being paired with a high dose, stimuli paired with 1.0 mg/kg completely suppressed responding. The suppression of food-maintained responding by stimuli paired with postsession drug administration depends upon both behavioral and pharmacological variables.