海洛因戒断者对金钱奖赏的反馈加工异常：来自ERP的证据

本研究采用金钱奖赏延迟任务考察了海洛因戒断者对金钱奖赏和损失的预期和反馈加工及其电生理机制。结果发现,预期阶段两组被试由不同线索诱发的P3波幅不存在显著差异。在金钱奖赏加工的反馈阶段,海洛因戒断组由金钱收益条件诱发的RewP波幅显著小于对照组由金钱收益条件诱发的RewP波幅,而在无收益无损失条件下两组被试诱发的RewP波幅不存在显著差异。此外,海洛因戒断组由金钱收益条件诱发的P3波幅与无收益无损失条件诱发的P3波幅不存在显著差异,而对照组由金钱收益条件诱发的P3波幅显著大于其由无收益无损失条件诱发的P3波幅。在金钱损失加工的反馈阶段,由金钱损失和无收益无损失条件诱发的RewP波幅在两组被试之间不存在显著差异,且两组被试由金钱损失条件诱发的P3波幅均显著大于其由无收益无损失条件诱发的P3波幅。以上结果说明海洛因戒断者对金钱奖赏的反馈加工存在异常,具体表现为其对金钱奖赏的敏感性降低或对金钱奖赏的趋近动机减弱。     

异种器官移植技术中的伦理问题面面观

目前,有关异种器官移植技术的伦理问题讨论的既有文献大多集中于该技术试验阶段。从受体、供体及社会的维度,讨论异种器官移植技术的试验及临床应用阶段可能引发的伦理问题,这些问题包括：受体的人格同一性危机,生理不相容引发医疗安全问题;供体动物的道德权利问题,生物安全问题;异种器官利用的公平可及问题,技术的滥用问题,受体的“污名化”问题。对上述伦理问题进行深入的伦理讨论和辨析,为异种器官移植技术的研究提供科学合理的方向,也将有助于该技术成熟后,合伦理的推广应用。

     

Building blocks of self-control: increased tolerance for delay with bundled rewards

Impulsive choice can be defined as temporary preference for a smaller-sooner reward (SS) over a larger-later reward (LL). Hyperbolic discounting implies that impulsive choices will occur less when organisms choose between a series of SSs versus LLs all at once than when they choose between single SS versus LL pairs. Eight rats were exposed to two conditions of an intertemporal choice paradigm using sucrose solution as reward. In both conditions, the LL was 150 microl delayed by 3 s, while the SS was an immediate reward that ranged from 25-150 microl across sessions. Preference for the LL was greater when the chosen reward was automatically delivered three times in succession (bundled) than when it was chosen singly and delivered after each choice. For each of the 8 rats, the estimated SS amount that produced indifference was higher in the bundled condition than in the single condition. Because bundling in humans may be based on the perception that one's current choice is predictive of future choices, the data presented here may demonstrate an important building block of self-control.     

药物成瘾者决策缺陷的特征、机制及干预

药物成瘾者存在决策缺陷, 并表现出冲动性、风险寻求、奖赏失调、躯体内感信号缺失等特征。神经影像学研究表明药物滥用导致成瘾者背外侧前额皮层、前扣带回、眶额叶皮层、腹内侧前额皮层、杏仁核、脑岛等脑区受损, 这些损伤是引发其决策缺陷的主要原因。认知训练有利于提高个体的决策能力, 如目标管理训练和正念冥想等可以增强个体工作记忆、促进自我觉察和以目标为导向的行为; 而非侵入性脑刺激则可以直接改变与成瘾者决策相关脑区的激活状态, 从而提升与决策相关的认知功能。总体而言, 未来认知训练和非侵入性脑刺激在成瘾干预方面仍有广阔的拓展空间。     

Influence of social context on the relationship between guilt and prosocial behaviour

While some previous researchers have found that guilt encourages prosocial behaviour towards a victim at the expense of other people, others have found the opposite, that is, people allocate resources at the expense of themselves. The present research used a hypothetical scenario method to determine which of these patterns would be replicated in the collectivistic context of Japanese society. In addition, we separated the cause of feelings of guilt into having caused harm and being at fault, and examined in more detail the effect of guilt on prosocial behaviour. Our results show that, in line with the second set of previous researchers, participants who were induced to feel guilt for having caused harm were more likely to allocate their resources to their victim at the expense of themselves than were individuals in the no‐harm condition. This suggests that differences in social context influence the effect of guilt on prosocial behaviour in different ways.     

A cross-cultural comparison of where drivers choose to look when viewing driving scenes

A substantial proportion of road accidents occur as a result of drivers having poor or insufficient visual search strategies. However, the majority of research into drivers visual search comes from high income Western countries where roads are relatively safe, with less being known about the visual search of drivers from non-western, low and middle income countries with much higher crash rates. This is despite the fact that cross-cultural studies have shown differences in visual search outside of driving between Western and Eastern individuals. The current study aimed to see whether these differences were present in driving by asking UK and Malaysian drivers to select where they would look when viewing images of roads from the perspective of a driver. Results showed that all drivers selected a similar number of focal objects, however there was a difference in the type of background information drivers chose to attend to, with Malaysian drivers selecting more task irrelevant information at the expense of task relevant information. Results suggest that there are cultural differences in what drivers choose to attend to which may contribute to the increased crash rate amongst drivers from low and middle income countries.     

When leader–member exchange differentiation improves work group functioning: The combined roles of differentiation bases and reward interdependence

Drawing on social hierarchy theory, we develop a contingency model of leader–member exchange (LMX) differentiation in which LMX differentiation is positively and negatively related to group cooperation and group social undermining, respectively, when it is based on the group members’ performance, but the relations are reversed (i.e., negative and positive, respectively) when it stems from a leader's personal liking of the members. In addition, we propose that the moderating effects of the performance and personal liking bases of LMX differentiation are magnified by the levels of reward interdependence. Specifically, under a high (vs. low) level of reward interdependence, LMX differentiation based on performance more strongly relates to high group cooperation and low group social undermining, whereas LMX differentiation with a personal liking basis is more likely to decrease group cooperation and increase group social undermining. Group cooperation and social undermining are then hypothesized to convey the three‐way interactive effects of LMX differentiation, its two bases, and reward interdependence on subsequent group performance. Analyses of data from 328 sales groups of a large retailer support the core part of our contingency model of LMX differentiation.     

社会动机理论视角下自闭症谱系障碍者的社交缺陷

社交缺陷是自闭症谱系障碍的核心症状。以往研究更多从社会认知的角度指出该症状是心理理论损伤所致, 但自闭症谱系障碍个体在获得心理理论之前已表现出社会动机不足的特质, 且部分能通过心理理论测试的个体依旧表现出社会动机不足的特点。社会动机理论指出社会动机是促进人类进化、激发和维持个体社会性活动的重要内部动力, 自闭症谱系障碍者的社交缺陷是由于社会动机不足所致。该理论从行为表现、神经科学和生物学三个方面对自闭症谱系障碍者的社交缺陷进行解释。未来应进一步完善自闭症谱系障碍个体社会动机的神经机制研究, 明确社会动机理论在自闭症谱系障碍群体中的适用范围, 探究社会动机理论在评估诊断和临床康复中的应用价值。     

Relationships Among Sleep Disturbance,Reward System Functioning,Anhedonia, and Depressive Symptoms

Recent models propose reward system dysfunction as a key mediator of the relationship between sleep and depression and anhedonia. This study explored interrelationships among sleep disturbance, depressive symptoms, anhedonia, and reward responsiveness. Two-hundred and sixty undergraduate students completed questionnaires and a daily diary paradigm assessing sleep, reward responsiveness, depression, anhedonia, and positive affect over 1 week. Baseline sleep disturbance was associated with depressive symptoms, anhedonia, and reward responsiveness. Daily diary sleep parameters showed differential associations with anticipatory versus consummatory reward responsiveness and positive affect. Poorer sleep quality, shorter sleep duration, and longer awakening after sleep onset predicted blunted anticipatory and consummatory reward responsiveness, while increased sleep onset latency and lower sleep efficiency predicted only decreased consummatory reward responsiveness. All sleep indices, except sleep onset latency, were associated with positive affect. Findings demonstrate unique associations between disparate sleep disturbance and reward responsiveness elements, highlighting new treatment mechanisms for anhedonia and depression.     

Taken out of context? Cross-level effects of between-person self-efficacy and difficulty on the within-person relationship of self-efficacy with resource allocation and performance

Research examining the within-person relationship among self-efficacy, resource allocation, and performance has been decidedly mixed, with positive, null, and even negative relationships being observed. In the present research, we propose that relationship of within-person changes in self-efficacy with subsequent changes in resource allocation and performance depends upon one’s typical level of self-efficacy; that is, increases and decreases in self-efficacy have different implications for individuals that are generally highly efficacious than for individuals who are typically less efficacious. Moreover, we propose that these relationships further depend upon the difficulty of goal being pursued. Support for these arguments is found across two studies. These results provide support for self-efficacy’s non-monotonic relationship with resource allocation, including our proposition that the nature of this non-monotonic relationship differs as a function of difficulty. These results also help further illuminate when and for whom self-efficacy is likely to increase or decrease resource allocation and performance.