Concurrent ratio schedules: Fixed vs. variable response requirements

Rats were trained on concurrent fixed-ratio variable-ratio or concurrent fixed-ratio mixed-ratio schedules of food reinforcement. The variable-ratio schedule was composed of an arithmetic sequence of 11 ratios that averaged 50; the mixed-ratio schedule consisted of equiprobable ratios of 1 and 99. Fixed-ratio values, varied over experimental conditions, included 25, 35, 50, 60, and 99. The proportion of responses and time allocated to the variable- or mixed-ratio schedule increased as the size of the fixed ratio increased. For most subjects, higher proportions of responses and time were maintained on the fixed-ratio schedule at fixed-ratio values of 25 and 35; higher proportions of responses and time were maintained on the variable- or mixed-ratio schedule at fixed-ratio values of 50 or higher. On concurrent variable-ratio fixed-ratio schedules, the tendency for responding to be maintained exclusively by one schedule was related to the difference in local reinforcement rates obtained from those schedules. Exclusive responding was approximated when the difference in local reinforcement rates obtained from those schedules was large; responding was more evenly distributed between the schedules as the difference in the rates at which reinforcement was obtained from each decreased.     

Choosing schedules of signaled appetitive events over schedules of unsignaled ones

Two experiments were completed allowing albino rats to choose between signaled and unsignaled reward conditions. These experiments examined the effects on preference of (1) response dependent versus response-independent reward and, (2) food pellets versus chocolate milk as the reward. All subjects preferred the signaled condition over the unsignaled condition, whether exposed to response-dependent, or to response-independent delivery of rewards. Preference was controlled most effectively by presenting both the signal itself and the correlated stimulus identifying the signaled condition. The signal presented alone (Extinction 3) controlled preference more effectively than did the stimulus correlated with the signaled condition (Extinction 2). The second experiment showed that the quality of the reinforcer (pellets and chocolate milk) did not affect preference for signaled reward since all subjects preferred the signaled condition at levels comparable to those observed in Experiment 1, with food pellets. These results, along with others, argue against species differences, response-dependency, and reinforcer quality as variables affecting the direction of preference.     

The double-alternative, double-start experimental apparatus: A new procedure for measuring preference

A new experimental chamber is described that permits rats to demonstrate behavioral preference for one of two conditions by running towards a goal chamber by one of two routes that are correlated with the different conditions. In a preliminary study, rats chose a route correlated with relatively lower shock, demonstrating the sensitivity of the apparatus. We also report evidence using this device that, of 10 rats tested, all preferred unsignaled rather than signaled, inescapable, unavoidable shock.     

Evaluations of pro-environmental behaviors by 7-month-old infants

Environmental morality is the foundation of a sustainable future, yet its ontogenetic origin remains unknown. In the present study, we asked whether 7-month-olds have a sense of ‘environmental morality’. Infants’ evaluations of two pro-environmental actions were assessed in both visual and reaching preferential tasks. In Experiment 1, the overt behavior of protecting (i.e., collecting artificial objects spread on a lawn) was compared with the action of harming the environment (i.e., by disregarding the objects). In Experiment 2, the covert behavior of protecting the environment (i.e., maintaining artificial objects inside a container) was compared with the action of harming the environment (i.e., littering the artificial objects on a lawn). The results showed infants’ reaching preference for the agent who performed overt pro-environmental actions (Experiment 1), and no preference for the agent who performed covert pro-environmental actions (Experiment 2). These findings reveal a rudimentary ecological sense and suggest that infants require different abilities to evaluate overt impact-oriented and covert intend-oriented pro-environmental behaviors.     

跨期决策中的维度差异偏好：眼动证据

在跨期决策研究领域,虽然基于维度的跨期模型得到了一些源自结果检验和过程检验的证据支持,但此类模型所假设的维度间差异比较的心理过程尚缺乏直接的过程证据。本研究通过两个眼动实验,系统考察了相关眼动指标对维度差异偏好的预测效应。结果发现,根据基于维度的权衡模型可有效拟合出个体在跨期决策中的维度差异偏好,并且反应时、眼跳注视熵和静态注视熵等指标均与维度差异偏好负相关,而基于维度的注意分配与维度差异判断正相关。这些研究发现支持了本研究所提出的跨期眼动模型的相关假设,证实了维度差异偏好与跨期决策的认知加工过程之间的联系,为基于维度的跨期模型提供了更直接的过程证据,并为今后跨期决策的眼动模型发展指明了新方向。     

行为可见增加利他偏好及其社会规范机制

在不同社会偏好类型中,研究者较为关注利他偏好及其信号功能。本研究探究在独裁者游戏中,决策者的利他偏好如何受到分配方案对接受者可见性的影响。实验1采用行为实验结合计算建模的方法,发现无论在选择或评分条件下,相比于行为不可见,当分配者的行为能够为接受者所见时,分配者都表现出更大程度的利他偏好。此外,相比于评分条件,在选择时人们更加在意分配效率。实验2仅使用选择条件,并操纵社会规范,发现行为可见增加利他偏好的作用依赖于利他的社会规范,当存在非利他社会规范时,行为可见的影响减小。本研究结果表明,在利他社会规范下,当行为对接受者可见时,人们将表现出更多利他偏好。     

Analysis of four measures of positional bias within a multiple stimulus without replacement preference assessment

Positional bias is a pattern of responding to a specific location that can be influenced by response effort and/or prior learning history. Prior research on positional bias within stimulus preference assessments have focused primarily on its use in paired stimulus assessments due to the complex nature of the multiple stimulus without replacement (MSWO) preference assessment. The present study is a secondary data analysis that utilized four different methods to measure side and center bias in a MSWO preference assessment for 19 young children with autism spectrum disorder. Participants displayed varying degrees of biased responding but collectively engaged in minimal biased responding. This study includes an analysis of the four methodologies, discussion of general patterns of responding, and general recommendations for the application of these methodologies in future research.     

Evaluating the efficacy of pictorial preference assessments with children who engage in food selectivity

Preference assessments are used in practice with individuals who engage in food refusal and selectivity to identify foods that a child will readily consume before assessment and treatment. Traditional edible preference assessments may be challenging for children who engage in food refusal or selectivity as the child may not consume foods, but rather engage in inappropriate mealtime behavior simply due to the presence of food. Alternative modality preference assessments, such as pictorial, may offer benefits compared to traditional preference assessment formats (e.g., stimulus preference assessment and paired-stimulus preference assessment). The use of pictures may reduce any evocative effects of the presence of food and result in choice-making without inappropriate mealtime behavior. Experiment 1 assessed the correspondence between the hierarchies yielded from pictorial preference assessments (with and without access) to a standard edible preference assessment. Experiment 2 evaluated the accuracy of each preference assessment by presenting foods identified as preferred and non-preferred to determine if the child would accept them. Results suggested that pictorial preference assessments with access corresponded the most with the traditional edible preference assessment. Also, for one individual, the traditional preference assessment did not accurately identify foods that the participant would consume, while the pictorial preference assessment without access yielded a hierarchy.     

An examination of stimulus technology level and preference displacement during multiple stimulus without replacement preference assessments

Researchers have observed that preference for edible items may displace preference for leisure items when items from the stimulus classes are assessed together within multiple stimulus without replacement (MSWO) preference assessments. The current study extends previous research by examining patterns of preference and displacement when assessing preference for high-tech and low-tech leisure items. We conducted three separate MSWO preference assessments; one assessing low-tech items, another assessing high-tech items, and a combined assessment (using the top four high- and low-tech items from the previous assessments) to test for displacement. Preference for high-tech items fully or partially displaced preference for low-tech items in five of eight participants. We then conducted concurrent and single operant reinforcer assessments using the highly preferred high-tech and low-tech items. Reinforcer assessment results demonstrated similar levels of responding for the highest preferred high-tech and low-tech items, indicating that combining high- and low-tech items within preference assessments may influence the validity of results.     

中学生时间洞察力特质与健康行为选择内隐偏好：未来情景性思维的作用

本研究采用经典内隐联想测验任务,研究了现在享乐、现在宿命和未来三种时间洞察力特质中学生的健康行为选择内隐偏好以及未来情景性思维在时间洞察力类型与健康行为选择内隐偏好中的调节作用。结果发现：未来特质中学生的健康行为选择内隐偏好高于现在享乐和现在宿命特质中学生;未来情景性思维水平在中学生时间洞察力类型与健康行为选择内隐偏好的关系中起调节作用,即未来情景性思维显著提高现在享乐和未来特质中学生的健康行为选择内隐偏好,而对现在宿命特质的作用不显著。本研究的发现表明未来时间洞察力特质是中学生选择健康行为的积极因素;未来情景性思维能促进现在享乐和未来时间洞察力特质中学生的健康行为选择内隐偏好。