The Psychological Record - Two experiments using rats show the effects of introducing response-reinforcer contiguity on a modified recycling conjunctive fixed-time 30 s fixed-ratio 1 schedule of... 相似文献
In two experiments, rats were trained initially on a recycling conjunctive schedule in which a food pellet was delivered after 30 s provided at least one response had occurred; otherwise the next cycle began immediately. This produced low rate responding characterized by either a pause-respond-pause pattern or else a pause-respond pattern. The schedule then was changed so that half of the intervals ended with the presentation of a brief stimulus instead of food. Patterning after food was little affected, whereas patterning after the brief stimulus varied across rats. Generally, a short pause after the brief stimulus was followed by an initial increase in responding that led to either a fairly constant rate, or else to a decrease in rate throughout the interval. In later conditions, when the incidence of response-food and response- stimulus contiguity were manipulated separately, only the former increased response rate; this was so even when the brief stimulus was paired with food in some conditions. Rate increases were accompanied by changes in patterning across all intervals. These results do not support a simple conditioned reinforcement interpretation of the control acquired by a brief stimulus on a second-order schedule with fixed-interval components. Rather, they suggest that a number of interrelated variables combine to maintain responding. These variables include response-reinforcer contiguity, the temporal location of the response dependency, and the contingency between the brief stimulus and the reinforcer.
This paper describes a set of computer programs that allow students to participate as subjects in well-known experiments selected from the current literature on memory and cognition. The experiments address five major areas: levels of processing, encoding specificity, semantic memory, sentence-picture verification, and constructive processes in prose comprehension. 相似文献
Conjunction faces are formed from feature sets learned across different faces. In previous studies, false alarms (“old” responses)
to conjunctions have been very high, approaching hits to old faces; this is surprising, because, perceptually, upright faces
are processed configurally, with strong integration of parts into the whole. We test the idea that the atypical reliance on
unrelated parts could be due to using unnatural line drawings as stimuli, and to forming conjunctions across external features
(e.g., hair) and internal features (e.g., eyes, mouth). We used realistic face stimuli and conjunctions made entirely from
internal features. Results were, as expected, consistent with configural processing for upright faces (hits to old faces much
greater than FA to conjunctions) and not for inverted faces (hits to old = FA to conjunctions). 相似文献
In this study, the authors assessed the relationship between adolescent tobacco smoking and measures of inner control, deviant behavior, and associating with deviant peers, which are indicators of problem behavior. African American (N = 333) and Puerto Rican (N = 329) early adolescents completed questionnaires in their classrooms in 1990 at Time 1 (T1) and were individually interviewed thereafter when they were late adolescents in 1995 at Time 2 (T2) and as young adults in 2000 at Time 3 (T3). The authors used ordinary least squares regression analysis to assess the comparative association of adolescent smoking patterns at T1 and T2 and the young adult outcomes at T3; they controlled for demographic variables, level of the outcome measure at T2, and marijuana use at T2. The analyses suggested that experimental tobacco smokers demonstrated more problem behaviors than did nonsmokers, and late and continuous smokers demonstrated more problem behaviors as young adults than did experimental smokers and nonusers. These findings may provide a useful guide to a next step that involves translational research. 相似文献
For over a decade, prenatal screening for cystic fibrosis (CF) has been considered a model for the integration of genetic testing into routine medical practice. Data from pilot studies and public policy discourse have led to recommendations by some professional organizations that CF screening should be offered or made available to pregnant women and their partners, and to couples planning a pregnancy. It is crucial that genetic counselors gain thorough understanding of the complexities of CF and the implications of positive test results, so that they may serve as a reliable, educated referral base and resource for health care providers and their patients. While not all pregnant women will be referred for genetic counseling prior to CF carrier testing, genetic counselors often will be asked to counsel clients after they have a positive test result, or who are found to be at increased risk. Genetic counselors can play an important role in providing accurate and current information as well as support for patients informed decisions. These recommendations were created by a multicenter working group of genetic counselors with expertise in CF and are based on personal clinical experience, review of pertinent English language medical articles, and reports of expert committees. The recommendations should not be construed as dictating an exclusive course of management, nor does the use of such recommendations guarantee a particular outcome. These recommendations do not displace a health care providers professional judgment based on the clinical circumstances of a particular client. 相似文献
What happens to everyday social interactions when other-race recognition fails? Here, we provide the first formal investigation of this question. We gave East Asian international students (N = 89) a questionnaire concerning their experiences of the other-race effect (ORE) in Australia, and a laboratory test of their objective other-race face recognition deficit using the Cambridge Face Memory Test (CFMT). As a ‘perpetrator’ of the ORE, participants reported that their problems telling apart Caucasian people contributed significantly to difficulties socializing with them. Moreover, the severity of this problem correlated with their ORE on the CFMT. As a ‘victim’ of the ORE, participants reported that Caucasians' problems telling them apart also contributed to difficulties socializing. Further, 81% of participants had been confused with other Asians by a Caucasian authority figure (e.g., university tutor, workplace boss), resulting in varying levels of upset/difficulty. When compared to previously established contributors to international students' high rates of social isolation, ORE-related problems were perceived as equally important as the language barrier and only moderately less important than cultural differences. We conclude that the real-world impact of the ORE extends beyond previously identified specialized settings (eyewitness testimony, security), to common everyday situations experienced by all humans. 相似文献