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951.
DEMAND EQUATIONS FOR QUALITATIVELY DIFFERENT FOODS UNDER FIXED‐RATIO SCHEDULES: A COMPARISON OF THREE DATA CONVERSIONS
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T. Mary Foster Catherine E. Sumpter William Temple Amanda Flevill Alan Poling 《Journal of the experimental analysis of behavior》2009,92(3):305-326
Concurrent schedules were used to establish 6 hens' preferences for three foods. The resulting biases suggested wheat was preferred over honey‐puffed and puffed wheat, and puffed wheat was the least preferred food. The hens then responded under fixed‐ratio schedules for each food in 40‐min (excluding reinforcer time) sessions, with the response requirement doubling each session until no reinforcers were received. At the smaller ratios, the less preferred the food, the faster the hens' overall response rates (mainly as a result of shorter postreinforcement pauses) and the more reinforcers they received. The relations between the logarithms of the number of reinforcers obtained (consumption) and the response ratio (price) were well fitted by curvilinear demand functions. Wheat produced the smallest initial consumption (ln L), followed by honey‐puffed and puffed wheat, respectively. The response requirement at which the demand functions predicted maximal responding (Pmax) were larger for wheat than for the other foods. Normalizing consumption and price, as suggested by Hursh and Winger (1995), moved the data for the three foods towards a single demand function; however, the Pmax values were generally largest for puffed wheat. The results of normalization, as suggested by Hursh and Silberberg (2008), depended on the k value used. The parameter k is related to the range of the data, and the same k value needs to be used for all data sets that are compared. A k value of 8.0 gave significantly higher essential values (smaller α values) for puffed wheat as compared to honey‐puffed wheat and wheat, and the Pmax values, in normalized standard price units, were largest for puffed wheat. Normalizing demand by converting the puffed and honey‐puffed wheat reinforcers to wheat equivalents (by applying the bias parameter from the concurrent‐schedules procedure) maintained separate demand functions for the foods. Those for wheat had the smallest rates of change in elasticity (a) and, in contrast to the other analyses, the largest Pmax values. Normalizing demand in terms of concurrent‐schedule preference appears to have some advantages and to merit further investigation. 相似文献
952.
S. Alexander Haslam Jolanda Jetten Tom Postmes Catherine Haslam 《Psychologie appliquee》2009,58(1):1-23
The social environment comprising communities, families, neighbourhoods, work teams, and various other forms of social group is not simply an external feature of the world that provides a context for individual behaviour. Instead these groups impact on the psychology of individuals through their capacity to be internalised as part of a person's social identity. If groups provide individuals with a sense of meaning, purpose, and belonging (i.e. a positive sense of social identity) they tend to have positive psychological consequences. The impact of these identity processes on health and well-being is explored in the contributions to this special issue. In this editorial, we discuss these contributions in light of five central themes that have emerged from research to date. These themes address the relationship between social identity and (a) symptom appraisal and response, (b) health-related norms and behaviour, (c) social support, (d) coping, and (e) clinical outcomes. The special issue as a whole points to the capacity for a social identity approach to enrich academic understanding in these areas and to play a key role in shaping health-related policy and practice. 相似文献
953.
Coordination of task choice and performance in multitask environments likely involves attentional processes. Subjects completed
the Attention Network Test (ANT) and a voluntary task-switching procedure. Task choice, but not task performance, was correlated
with the executive score from the ANT, with higher switch probabilities for subjects with more efficient executive control
networks. Task performance was correlated with the alerting score, with larger response time switch costs for subjects with
larger alerting scores. The dissociation of task choice and task performance measures in terms of the pattern of correlations
with attentional networks suggests that these two measures may reflect different cognitive processes engaged in voluntary
task switching. 相似文献
954.
This study addresses two issues associated with the relationship between martial arts training and aggressiveness. The first is a replication of two recent findings, that for students trained traditionally, length of training varies inversely with aggressiveness, whereas for students trained in a “modern” style, length of training and aggressiveness are related directly. Second, we examine two competing explanations for the findings above. One is the training hypothesis, which holds that elements present in traditional approaches to martial arts but absent in modern approaches act to reduce aggression levels of students. These may include meditation, philosophy, emphasis on the kata (the forms of combat), etc. The alternate hypothesis, selection, holds instead that these findings are artifactual, a result of differential mortality in a setting characterized by high drop-out rates. Two categories of students were interviewed: “movers,” students who had trained in more than one school, and “quitters,” students who had terminated their training, for any reason. These students were compared with “stayers” from an earlier study. Our results are consistent with the opposite effects of traditional and modern martial arts training on aggressiveness. Further, the data generally support the training hypothesis as against selection. 相似文献
955.
Catherine Haslam Tegan Cruwys Melissa Xue‐Ling Chang Bethany Eckley Heather Buckingham Elizabeth Channon 《Journal of community & applied social psychology》2020,30(4):381-387
The present research examined the mechanisms through which community groups improve well‐being in adults (N = 156) experiencing socio‐economic disadvantage. Analysis showed that joining a group improved outcomes by enhancing people's group identification and wider sense of belonging to multiple groups and that this effect was stronger for more socio‐economically disadvantaged participants. 相似文献
956.
Steven J. Howard Caylee J. Cook Lizl Everts Edward Melhuish Gaia Scerif Shane Norris Rhian Twine Kathleen Kahn Catherine E. Draper 《Developmental science》2020,23(1)
The widely and internationally replicated socioeconomic status (SES) gradient of executive function (EF) implies that intervention approaches may do well to extrapolate conditions and practices from contexts that generate better child outcomes (in this case, higher SES circumstances) and translate these to contexts with comparatively poorer outcomes (often low‐SES populations). Yet, can the reverse also be true? Using data from equivalent assessments of 1,092 pre‐schoolers’ EFs in South Africa and Australia, we evaluated: the SES gradient of EF within each sample; and whether this SES gradient extended cross‐culturally. The oft‐found EF‐SES gradients were replicated in both samples. However, contrary to the inferences of EF‐SES associations found nationally, the most highly disadvantaged South African subsample outperformed middle‐ and high‐SES Australian pre‐schoolers on two of three EFs. This suggests the possibility of EF‐protective and ‐promotive practices within low‐ and middle‐income countries that may aid understandings of the nature and promotion of EFs. 相似文献
957.
Karen J. Mathewson Daphne Maurer Catherine J. Mondloch Saroj Saigal Ryan J. Van Lieshout Louis A. Schmidt 《Developmental science》2020,23(2)
Being born at extremely low birth weight (ELBW; ≤1,000 g) is associated with enduring visual impairments. We tested for long‐term, higher order visual processing problems in the oldest known prospectively followed cohort of ELBW survivors. Configural processing (spacing among features of an object) was examined in 62 adults born at ELBW (Mage = 31.9 years) and 82 adults born at normal birth weight (NBW; ≥2,500 g: Mage = 32.5 years). Pairs of human faces, monkey faces, or houses were presented in a delayed match‐to‐sample task, where non‐matching stimuli differed only in the spacing of their features. Discrimination accuracy for each stimulus type was compared between birth weight groups, adjusting for neurosensory impairment, visual acuity, binocular fusion ability, IQ, and sex. Both groups were better able to discriminate human faces than monkey faces (p < .001). However, the ELBW group discriminated between human faces (p < .001), between monkey faces (p < .001), and to some degree, between houses (p < .06), more poorly than NBW control participants, suggesting a general deficit in perceptual processing. Human face discrimination was related to performance IQ (PIQ) across groups, but especially among ELBW survivors. Coding (a PIQ subtest) also predicted human face discrimination in ELBW survivors, consistent with previously reported links between visuo‐perceptive difficulties and regional slowing of cortical activity in individuals born preterm. Correlations with Coding suggested ELBW survivors may have used a feature‐matching approach to processing human faces. Future studies could examine brain‐based anatomical and functional evidence for altered face processing, as well as the social and memory consequences of face‐processing deficits in ELBW survivors. 相似文献
958.
Catherine Z. Elgin 《Erkenntnis》2000,52(2):175-183
To understand a term or other symbol, I argue that it is generally neither necessary nor sufficient to assign it a unique determinate reference. Independent of and prior to investigation, it is frequently indeterminate not only whether a sentence is true, but also what its truth conditions are. Nelson Goodman's discussions of likeness of meaning are deployed to explain how this can be so. 相似文献
959.
Solomon Daniel Battistich Victor Watson Marilyn Schaps Eric Lewis Catherine 《Social Psychology of Education》2000,4(1):3-51
A comprehensive elementary school program, the Child Development Project, was conducted in two schools in each of six school districts over a three-year period. Two additional schools in each district served as a comparison group. The program attempts to create a 'caring community of learners' in school and classroom through classroom, schoolwide, and parent involvement components. The classroom component includes student collaboration, a literature-based approach to reading, and a student-centered approach to classroom management. Classroom observation, student questionnaire, teacher questionnaire, and test data were collected in a baseline year and in each of the three years of program implementation. Results showed positive student results in the five program schools that made significant progress in implementation. Schools that progressed in implementation showed gains – relative to their comparison schools – in students' personal, social, and ethical attitudes, values, and motives. Significant effects on academic achievement were found only in two schools with a performance-based assessment and a highly consistent local reform mandate. Modeling analyses indicated that student sense of community was an important mediating variable for almost all dependent variables – indicating that the program produced positive effects to the degree that it was successful in establishing a caring community in the school. 相似文献
960.
Catherine Gosselin Denis Larocque Frank Vitaro Claude Gagnon 《International journal of psychology》2000,35(1):46-59
The goal of this study was to identify protective and risk factors linked to substance use during adolescence. A sample of 1000 subjects participated in a four‐wave data collection. Results showed that precocious substance use is likely to be persistent. Moreover, school inadaptation, lack of parental supervision and positive self‐perception in relationships with peers have been identified as risk factors predictive of cigarette, alcohol and drug use. Protective factors were associated with high moral qualities and negative reaction to mother's use of cigarettes and alcohol. Findings are discussed in terms of developmental trajectories which might lead to substance use and abuse through adult life. 相似文献