Hypothesis generation, sparse categories, and the positive test strategy

We consider the situation in which a learner must induce the rule that explains an observed set of data but the hypothesis space of possible rules is not explicitly enumerated or identified. The first part of the article demonstrates that as long as hypotheses are sparse (i.e., index less than half of the possible entities in the domain) then a positive test strategy is near optimal. The second part of this article then demonstrates that a preference for sparse hypotheses (a sparsity bias) emerges as a natural consequence of the family resemblance principle; that is, it arises from the requirement that good rules index entities that are more similar to one another than they are to entities that do not satisfy the rule.     

Social cognitive predictors of Mexican American college students' academic and life satisfaction

In this study, we used Lent's (2004) social cognitive model of well being to examine the academic and life satisfaction of 457 Mexican American college students attending a Hispanic-Serving Institution. Using structural equation modeling, results indicated that the model provided a good fit to the data. Specifically, we found positive relations from positive affect to enculturation, acculturation, college self-efficacy, academic satisfaction, and life satisfaction; from enculturation to college self-efficacy; from acculturation to college self-efficacy and college outcome expectations; from college self-efficacy to college outcome expectations, academic goal progress, academic satisfaction, and life satisfaction; from college outcome expectations to academic satisfaction; from academic goal progress to academic and life satisfaction; and from academic satisfaction to life satisfaction. Findings indicated the model was invariant across gender groups, and overall, 38% and 14% of the variance in academic satisfaction and life satisfaction, respectively, were explained by the predictor variables. Implications for research and practice are discussed.     

Inhibitory processes, working memory, phonological awareness, naming speed, and early arithmetic achievement

This study identified the cognitive processes that underlie the individual differences in early mathematical performance in elementary school children. Taking into account the Baddeley framework multicomponent model, the inhibitory processes, working memory, phonological awareness, and naming speed are considered to be related to early math learning. To examine this relationship, we compared the performance of a total of 424 typically developing middle-class children, aged between 4 and 7 years in a battery of cognitive and early numeric tests: The Utrecht Early Numeracy Test, the Rapid Automatized Naming Test, Spanish version of the Stroop task, the Numeracy Interference Test, Digit Span test, and Phonological Knowledge Test. The mean age of the participants was 72.21 months (sd = 14.8), and 48.6% were male and 51.4% were female. The results demonstrated that children performing worst on central executive, phonological processing, and inhibitory processes showed lower results in early mathematical tasks measured by The Utrecht Early Numeracy Test. Results supported the notion that the executive system is an important predictor of children's mathematical performance.     

Persons with acquired brain injury and multiple disabilities access stimulation independently through microswitch-based technology

The possibility of enabling two adults with acquired brain injury and profound multiple disabilities to use microswitch-based technology to attain preferred environmental stimuli on their own was assessed. Each of the participants was provided with two microswitches that could be activated by right and left head-turning or head-bending responses. The microswitches were introduced sequentially according to a multiple probe design across microswitches (responses) and allowed access to different sets of auditory or visual stimuli. Eventually, the two microswitches were made available simultaneously. Sessions lasted 5 min. Each participant learned to use the two microswitches successfully and maintained consistent levels of responding when they were simultaneously available. During this phase, both participants showed large within-session variations in their right and left response frequencies, with one of them showing an overall prevalence of the left-side response. The importance of assistive technology within programs for persons with acquired brain injury and multiple disabilities is discussed.     

Effects of acute,subchronic and intermittent MDMA (‘ECSTASY’) administration on agonistic interactions between male mice

Recent studies suggest that acute administration of 3,4‐methylenedioxymethamphetamine (MDMA), an amphetamine derivative popularly known as “ecstasy,” produces an antiaggressive effect in male mice. However, there is no evidence with respect to the development of tolerance or sensitization after its subchronic or intermittent administration. In this study, we examined the action of low to moderate doses of MDMA (1.25, 2.5 and 5 mg/kg, i.p), administered acutely, subchronically (for 7 days) or intermittently, on agonistic behavior elicited by isolation in male mice. Individually housed mice were exposed to anosmic “standard opponents” 30 minutes after the drug administration, and the encounters were videotaped and evaluated using an ethologically based analysis. Acute treatment with MDMA provoked a significant reduction of aggressive behaviors, without altering immobility. However, this action was only selective at 1.25 mg/kg. With the intermediate (2.5 mg/kg) and the highest doses (5 mg/kg) of the drug, it was observed a significant decrease of offensive behaviors, accompanied by an increase of exploration from a distance, avoidance/flee and defense/submission behaviors. This ethopharmacological profile could indicate the existence of an anxiogenic‐like effect of MDMA. The overall picture of the effects of MDMA was very similar in the acutely, intermittently and daily treated animals. No tolerance or sensitization to the actions of the drug was developed after its repeated or intermittent administration.     

Behavioral profile of L–741,741, a selective D4 dopamine receptor antagonist,in social encounters between male mice

Although the role of dopamine D1–D2–D3 receptors in the modulation of aggression has been extensively documented, there is not information with respect to the implication of D4 receptor. The aim of this study was to examine the acute effects of L–741,741 (0.75, 1.5 and 3 mg/kg, i.p), a selective D4 receptor antagonist, on social encounters between male mice using an ethopharmacological approach. Ten min of diadic interactions were staged between a singly housed and an anosmic mouse in a neutral area. These encounters were videotaped and the accumulated time allocated by subjects to ten broad behavioral categories was estimated. Besides other behaviors, the aggressive and motor behaviors were evaluated 30 min after injection using an ethologically based analysis. L–741,741 did not affect significantly offensive behaviors (threat and attack), as compared with the control group. Likewise, motor and anxiety‐related behaviors (such as social investigation, avoidance/flee or defense submission) were not altered after drug administration. These results suggest that dopamine D4 receptor is not involved in the modulation of aggressive behavior. Aggr. Behav. 29:552–557, 2003. © 2003 Wiley‐Liss, Inc.     

An ethopharmacological assessment of agmatine's effects on agonistic encounters between male mice

The endogenous polyamine agmatine may be a new central neurotransmitter. Agmatine‐like immunoreactivity has been described in numerous brain regions (such as the hypothalamus and amygdala), long thought involved in the control of aggression. Consequently, the present study examined agmatine's (2.5–80 mg/kg, ip) effects on behavior directed by isolated male mice to anosmic partners in a neutral area. The videotaped encounters were analysed in terms of 10 broad behavioral categories. Agmatine did not appear to be involved in the modulation of aggression or anxiety in this test. Aggr. Behav. 31:000000, 2005. © 2005 Wiley‐Liss, Inc.     

Stimulus Control with Computer Assisted Learning

Computer Assisted Learning (CAL) has been shown to be an efficient learning-teaching procedure. Although there is an extensive educational software tradition using CAL approaches, few of them have demonstrated a better student performance than standard drill and practice methods. The purpose of this study was (a) to evaluate the effectiveness of the Let's Play With... software program, and (b) to evaluate the effectiveness of a prompt (i.e. a blinking object) used in the program. The educational software Let's Play With... was designed to teach basic concepts involving shapes and body positions to preschool students. The software structure follows a behavioral design and uses a stimulus control procedure. The study was carried out with 64 preschool students in the Cadiz (Spain) School District. Statistically significant differences were found between the experimental group and a control group.     

Women abuse: beliefs and attitudes in university students

Beliefs and attitudes positives toward domestic violence are one of the risks factors for his occurrence. Among his most studied predictors are gender, gender role attitudes or educational level. In this paper, domestic violence beliefs and attitudes are analysed in 1395 university students. "Inventory of Thoughts Distorted on the Woman and the Violence" (Echeburúa and Fernández-Montalvo, 1997) and "Inventory of Social Desirability" by Crowne and Marlowe (Form C, Reynolds, 1982) were administrated. Boys and students without specific formation about this subject show more positive beliefs and attitudes toward domestic violence. Though social desirability introduces some limitations, these results suggest the importance of incorporating matters on this subject in the curriculum of university students in general and, especially, in future professional that will work with these groups.     

Quality service in supermarkets: a proposal of measurement

This assignment has the aim of going deeply into the study of service quality perception in supermarkets. The research tries to find the criterion used when rating the services received in a supermarket and also to elaborate an instrument to measure the service quality in this context. From the review of the existing bibliography, four theoretical factors and a thirteen items scale have been composed. These four factors are: price, product, service and image and fresh product. In order to check the psychometrical properties of the questionnaire we carried out a computer assisted telephone interviewing (CATI) with a sample of 300 interviews. The results obtained allow us to show a scale with a factorial structure of 4 dimensions that throws up optimal indexes of reliability and validity. At the same time we conclude that the variable called establishment global rate is an important variable in the perceptive structure of the consumers.