Behavioral variability and frequency-dependent selection.

In Experiment 1, two conditions were compared: (a) a variability schedule in which food reinforcement was delivered for the fourth peck in a sequence that differed from the preceding N four-peck sequences, with the value of N continuously adjusted to maintain reinforcement probability approximately constant; and (b) a control condition in which the variability constraint was dropped but reinforcement probability remained constant. Pigeons responded approximately randomly under the variability schedule but showed strong stereotyped behavior under the control condition. Experiments 2 and 3 tested the idea that variability is the outcome of a type of frequency-dependent selection, namely differential reinforcement of infrequent behavior patterns. The results showed that pigeons alternate when frequency-dependent selection is applied to single pecks because alternation is an easy-to-learn stable pattern that satisfies the frequency-dependent condition. Nevertheless, 2 of 4 pigeons showed random behavior when frequency-dependent selection was applied to two pecks, even though double alternation is a permissible and stable stereotype under these conditions. It appears that random behavior results when pigeons are unable to acquire the stable stereotyped behavior under a given frequency-dependent schedule.     

Immediate reinforcement in delayed reward learning in pigeons

Pigeons were trained on simultaneous red-green discrimination procedures with delayed reward and sequences of stimuli during the delay. In Experiment 1, three stimuli appeared during the 60-second intervals between the correct responses and reward, and the incorrect responses and nonreward. The stimulus that immediately followed a correct response also preceded nonreward, and the stimulus that followed an incorrect response preceded reward. These stimuli were 10 or .33 second in duration for different groups. Stimuli during the remainder of the delay interval differed following correct and incorrect responses. Group 10 initially persisted in the nonrewarded choice, but shifted to a preponderance of rewarded responses after further training. Group .33 rapidly acquired the correct response. Similar results were obtained in Experiment 2 where delay intervals consisted of opposite sequences of two stimuli of equal duration and total delays were 6, 20, or 60 seconds. Early in training, generalization of differential conditioned-reinforcing properties from the conditions preceding reward and nonreward to postchoice conditions had a greater effect relative to backchaining than it did later. It was concluded that delayed-reward learning is best analyzed in terms of the conditioned-reinforcing value of the patterns of cues that follow immediately after rewarded and nonrewarded responses.     

朱熹《大学章句》道德教育理论的当代启示

朱熹对《大学》研究有很大贡献,《大学章句》道德教育理论在道德教育的理论基础、道德教育目的、道德教育过程、道德教育规范、道德教育方法等逻辑要素方面有丰富的内容,《大学章句》展示的中国古代道德教育模式为当代公民道德建设尤其是大学生思想政治教育提供了文化滋养。     

Seasonal eating patterns in Norway: a non-clinical population study

Seasonal deviations in normal eating habits have been associated with seasonal affective disorder (SAD) and bulimia nervosa (BN). Two studies on seasonal variation in eating habits are reported in this paper. In Study 1, seasonal patterns of eating disturbances were measured cross-sectionally in 6313 participants using an eating disturbance scale (EDS-5) and a modified version of the Seasonal Pattern Assessment Questionnaire (SPAQ). Eating disturbance scores were predicted by seasonal sensitivity scores from the SPAQ, gender, age, and light. Study 2 used a longitudinal design in which 908 participants were given the EDS-5 every month from November 1993 to January 1995. Scores on the EDS-5 fluctuated with the season of the year, with higher EDS-5 scores in winter and lower in summer. The results suggest that seasonal fluctuations affect only a subset of the total population.     

Gaze tracking patterns on different types of traffic risk in early-stage Alzheimer’s disease

Many fatal accidents are caused by the driver’s inability, upon the occurrence of sudden events, to detect hazards in time, an ability that is based on the driver’s eye movement patterns, the detection of involved persons, events, objects, as well as the length of time spent on noticing same. This study intends to compare risk perception and decision-making in high-risk traffic situations between individuals with AD and controls by exploring gaze tracking and hazard detection patterns. The study included 16 individuals with early-stage AD and 26 controls. During the experiment, participants underwent several vision and cognitive tests and watched twelve videos of high-risk traffic situations while their eye movement patterns were being recorded by the eye tracking device, in order to understand how cognitive abilities affect eye movement patterns during high-risk traffic situations. The results revealed poorer cognitive abilities and diminished risk perception in individuals with AD compared with the controls and thus an inability to predict potential accidents. In terms of high-risk traffic situations involving pedestrians, traffic violations by others and view-blocking events, a significant difference in gaze patterns was found between individuals with AD and healthy seniors. The contribution of this study is in elaborating the effect of different traffic event type and specific cognitive abilities on traffic risk-detection in individuals with AD. The results of this study may aid in the formulation of driver licensing policies and the design of traffic scenarios; they also elucidate the driving behaviors of individuals with AD.     

Mood—Creativity Relationship in Groups: The Role of Equality in Idea Contribution in Temporal Mood Effects

As people working in groups might fare better in solving complex problems than those working alone (e.g., Laughlin, Hatch, Silver, & Boh, Journal of Personality and Social Psychology, 90 , 2006 and 644), organizations have increasingly assigned creative projects to groups. Group members contribute their collective efforts over time until the creative project has come to fruition. Although mood is identified as an important antecedent to creativity, little is known about the temporal pattern of how group mood enhances or inhibits group creativity, as well as the underpinning group process that explains the mood—creativity link in groups. We set out to address these questions by taking a within-group approach to study the temporal trends of how group mood precedes group creativity and to examine idea contribution equality (ICE) as a mediating group process. We conducted a three-wave longitudinal study among student workgroups tasked to complete a creativity project over a 1-month span. Evidence showed that positive mood is positively associated with concurrent ICE and negative mood is negatively associated with lagged ICE. Furthermore, a mediation model showed that negative mood eventually hampered expert-rated group creative performance by reducing ICE over time. These findings add new knowledge to the temporal mood—creativity relation within the group context.