Every reinforcer counts: reinforcer magnitude and local preference

Six pigeons were trained on concurrent variable-interval schedules. Sessions consisted of seven components, each lasting 10 reinforcers, with the conditions of reinforcement differing between components. The component sequence was randomly selected without replacement. In Experiment 1, the concurrent-schedule reinforcer ratios in components were all equal to 1.0, but across components reinforcer-magnitude ratios varied from 1:7 through 7:1. Three different overall reinforcer rates were arranged across conditions. In Experiment 2, the reinforcer-rate ratios varied across components from 27:1 to 1:27, and the reinforcer-magnitude ratios for each alternative were changed across conditions from 1:7 to 7:1. The results of Experiment 1 replicated the results for changing reinforcer-rate ratios across components reported by Davison and Baum (2000, 2002): Sensitivity to reinforcer-magnitude ratios increased with increasing numbers of reinforcers in components. Sensitivity to magnitude ratio, however, fell short of sensitivity to reinforcer-rate ratio. The degree of carryover from component to component depended on the reinforcer rate. Larger reinforcers produced larger and longer postreinforcer preference pulses than did smaller reinforcers. Similar results were found in Experiment 2, except that sensitivity to reinforcer magnitude was considerably higher and was greater for magnitudes that differed more from one another. Visit durations following reinforcers measured either as number of responses emitted or time spent responding before a changeover were longer following larger than following smaller reinforcers, and were longer following sequences of same reinforcers than following other sequences. The results add to the growing body of research that informs model building at local levels.     

Learning a pointing task with a kinematically redundant limb: Emerging synergies and patterns of final position variability

The study tested a hypothesis that practice of arm pointing movement can lead to a reorganization of the joint coordination reflected in the emergence of several synergies based on the same set of joints. In particular, involvement of the wrist may represent a choice by the central nervous system and not be driven by the typical “freezing-to-freeing” sequence. The effects of practice on the kinematic patterns and variability of a “fast and accurate” pointing movement using a pointer were studied. An obstacle was placed between the initial position and the target to encourage a curvilinear trajectory and larger wrist involvement. Practice led to a decrease in variability indices accompanied by an increase in movement speed of the endpoint and of the elbow and the shoulder, but not of the wrist joint. Five out of six subjects decreased the peak-to-peak amplitude of wrist motion. Before practice, the variability along the line connecting the endpoint to the shoulder (extent) was similar to that in the direction orthogonal to this line. After practice, variability was reduced along the extent, but not along the orthogonal direction perpendicular to this line. Prior to practice, indices of variability of the endpoint were lower than those of the marker placed over the wrist; after practice, the endpoint showed higher variability indices than the wrist. We interpret the data as consequences of the emergence of two synergies: (a) Pointing with a non-redundant set of the elbow and shoulder joints; and (b) keeping wrist position constant. The former synergy is based on a structural unit involving the elbow and the shoulder, while the latter is based on a structural unit that includes all the major arm joints.     

Robust nonorthogonal analyses revisited: An update based on trimmed means

Three approaches to the analysis of main and interaction effect hypotheses in nonorthogonal designs were compared in a 2×2 design for data that was neither normal in form nor equal in variance. The approaches involved either least squares or robust estimators of central tendency and variability and/or a test statistic that either pools or does not pool sources of variance. Specifically, we compared the ANOVA F test which used trimmed means and Winsorized variances, the Welch-James test with the usual least squares estimators for central tendency and variability and the Welch-James test using trimmed means and Winsorized variances. As hypothesized, we found that the latter approach provided excellent Type I error control, whereas the former two did not.Financial support for this research was provided by grants to the first author from the National Sciences and Engineering Research Council of Canada (#OGP0015855) and the Social Sciences and Humanities Research Council (#410-95-0006). The authors would like to express their appreciation to the Associate Editor as well as the reviewers who provided valuable comments on an earlier version of this paper.     

Parental Perceptions of Child Development Among Low-Income Mexican American Families

Parents' perceptions of child development are influenced by complex interactions among cultural, social, and economic factors. Insights into how parents from culturally diverse societies perceive the development of their children might explain why different cultural groups foster or value the development of different skills in their children. In this study, we explored the perceptions of child development among low income Mexican American parents. A series of ethnographic interviews were conducted with eight Mexican American families who had preschool children. Qualitative data analyses yielded three main themes that were important to these parents: family attitudes and values, changes, and adaptations. For these parents, the development of social attributes in children, that will enable them to function within their own cultural group, was as important as the development of cognitive or motor skills. Service providers, such as school and mental health personnel, should take into account cultural differences in parents' perceptions of the importance of various developmental milestones for their children when suggesting interventions typically used by parents in the dominant culture.     

Correlation between performance and quantity/variability of leg exploration in a contingency learning task during infancy

Quantity and quality of motor exploration are proposed to be fundamental for infant motor development. However, it is still not clear what types of motor exploration contribute to learning. To determine whether changes in quantity of leg movement and/or variability of leg acceleration are related to performance in a contingency learning task, twenty 6–8-month-old infants with typical development participated in a contingency learning task. During this task, a robot provided reinforcement when the infant’s right leg peak acceleration was above an individualized threshold. The correlation coefficient between the infant’s performance and the change in quantity of right leg movement, linear variability, and nonlinear variability of right leg movement acceleration from baseline were calculated. Simple linear regression and multiple linear regression were calculated to explain the contribution of each variable to the performance individually and collectively. We found significant correlation between the performance and the change in quantity of right leg movement (r = 0.86, p < 0.001), linear variability (r = 0.71, p < 0.001), and nonlinear variability (r = 0.62, p = 0.004) of right leg movement acceleration, respectively. However, multiple linear regression showed that only quantity and linear variability of leg movements were significant predicting factors for the performance ratio (p < 0.001, adjusted R² = 0.94). These results indicated that the quantity of exploration and variable exploratory strategies could be critical for the motor learning process during infancy.     

效率源自公平——关于效率与公平关系的层次分析

如果我们超越纯经济学的狭隘眼界而从整个社会的宏观角度来进行考察,那么公平与效率不但不是对立的,而且可以说效率源自公平。具体表现为:生产效率源自分配公平;市场效率源自交换公平;社会效率源自矫正公平;生态效率源自代际公平。     

Characterizing positive and negative ‘voicers’ in elite sport teams: The role of the Five Factor Model and narcissism in players’ frequency and passing on of voice

ObjectiveThis study examined the role of the Five Factor Model and grandiose narcissism in players’ positive (i.e., constructive voice, supportive voice) and negative voice (i.e., defensive voice, destructive voice) in elite sport teams.MethodPlayers from six field hockey and seven korfball teams from the two highest national levels were assessed for four weeks. Using social network analyses, players’ personality was related to their self-reported voice frequency, their voice frequency as perceived by all teammates (other-ratings), and the extent to which they pass on voice.ResultsExtraversion was positively related to players’ frequency of positive and negative voice. Other traits such as conscientiousness and emotional stability were only related to, respectively, positive or negative types of voice. Not all personalities (e.g., extraversion) were consistent in how they assess their own voice versus how others perceive this. Interestingly, traits such as extraversion, emotional stability and the agentic facet of narcissism were found to predict the passing on of voice.ConclusionThis study explored the importance of personality for (a) players’ frequency of a differentiated set of positive and negative voice and (b) the extent to which they function as ‘gates’ that more covertly pass on voice. Further, the results provide perspective on how specific personalities view their voice behavior versus how their teammates perceive their voice behavior. In this way, this study is a first step in identifying players who have the potential to endanger or strengthen a team in a clear or subtle, yet influential way.     

Beyond the molar-molecular distinction: we need multiscaled analyses.

Dinsmoor's (2001) adherence to molecular analyses may require him to assert that molar and molecular principles are mutually exclusive, but to instead analyze the phenomena of avoidance as inherently multiscaled is to follow a well-established practice in the natural sciences. Besides the issue of scale, two-factor theory, which Dinsmoor advocates, has little to say about some important and longstanding results in experiments that qualify as avoidance.     

Tau and Kappa effects in physical space: the case of audition

The organization of spatio-temporal information in an auditory memory task was studied in two experiments. Stimuli consisted of four different configurations of eight sequentially presented beeps. In two configurations, the stimuli were space-time congruent, with (constant or variable) inter-stimulus distances corresponding to (constant or variable) inter-stimulus time intervals. In the other two configurations, the stimuli were space-time incongruent, with (constant or variable) inter-stimulus distances not corresponding to (variable or constant) inter-stimulus time intervals. After a learning phase consisting of 20 presentations of the target configuration, participants reproduced the spatial (Experiment 1) or temporal (Experiment 2) characteristics of the target 60 times in succession without re-examining the target configuration. Accuracy (with respect to the target) and variability (between responses) were found to evolve independently. In the incongruent space-time conditions, effects of variable inter-stimulus time intervals or distances on the reproduction of, respectively, constant distances (Tau effect) or constant time intervals (Kappa effect) were observed, while the reverse was not the case. Thus, dimensional interference occurred when the dimension to be ignored was variable. The results are discussed in the light of the distinction between properties of the stabilized mental image and the process of stabilization.     

The Influence of Bloomfield's Linguistics on Skinner

Bloomfield''s “Linguistics as a Science” (1930/1970), Language (1933/1961), and “Language or Ideas?” (1936a/1970), and Skinner''s Verbal Behavior (1957) and Science and Human Behavior (1953) were analyzed in regard to their respective perspectives on science and scientific method, the verbal episode, meaning, and subject matter. Similarities between the two authors were found. In particular both asserted that (a) the study of language must be carried out through the methods of science; (b) the main function of language is to produce practical effects on the world through the mediation of a listener; and (c) a physicalist conception of meaning. Their differences concern the subject matter of their disciplines and their use of different models for the analysis of behavior. Bloomfield''s linguistics and Skinner''s functional analysis of verbal behavior are complementary approaches to language.