A ratio scale for social distance

Choosing a larger–later reward over a smaller–sooner reward may be thought of as altruism toward one's future self. A question that arises in this connection is: What is the relation between delay and social discounting? To begin to answer this question, social and delay discount functions need to be comparable. Delay is ordinarily measured on a ratio scale (time), which allows for meaningful division and addition. Social distance is ordinarily measured on an ordinal scale (rank order of social closeness). To convert social distance to a ratio scale we use a psychophysical distance function obtained via magnitude estimation (Stevens, 1956). The distance functions obtained are well described by a power function (median exponent = 1.9); we show how they may be used to rescale ordinal to ratio social discount functions.     

Developing access to number magnitude: a study of the SNARC effect in 7- to 9-year-olds

The SNARC (spatial-numerical association of response codes) effect refers to the finding that small numbers facilitate left responses, whereas larger numbers facilitate right responses. The development of this spatial association was studied in 7-, 8-, and 9-year-olds, as well as in adults, using a task where number magnitude was essential to perform the task and another task where number magnitude was irrelevant. When number magnitude was essential, a SNARC effect was found in all age groups. But when number magnitude was irrelevant, a SNARC effect was found only in 9-year-olds and adults. These results are taken to suggest that (a) 7-year-olds represent number magnitudes in a way similar to that of adults and that (b) when perceiving Arabic numerals, children have developed automatic access to magnitude information by around 9 years of age.     

物质奖励对内在动机的侵蚀效应

物质奖励制度在现实生活中无处不在, 但物质奖励能够激发人们的工作热情吗？依据认知评价理论, 奖励具有信息和控制两种因素, 前者有助于内在动机的维持, 后者则会损害内在动机, 即有侵蚀效应。这种侵蚀效应已经为众多研究所证明。对此效应的深入研究发现, 在不同情形下, 侵蚀效应的大小受到奖励条件设置、竞争情形、个体的归因倾向、反馈信息、自主选择空间等因素的影响。近年来神经学研究则进一步观察到侵蚀效应的神经表征与机制。     

Resurgence and alternative‐reinforcer magnitude

Resurgence is defined as an increase in the frequency of a previously reinforced target response when an alternative source of reinforcement is suspended. Despite an extensive body of research examining factors that affect resurgence, the effects of alternative‐reinforcer magnitude have not been examined. Thus, the present experiments aimed to fill this gap in the literature. In Experiment 1, rats pressed levers for single‐pellet reinforcers during Phase 1. In Phase 2, target‐lever pressing was extinguished, and alternative‐lever pressing produced either five‐pellet, one‐pellet, or no alternative reinforcement. In Phase 3, alternative reinforcement was suspended to test for resurgence. Five‐pellet alternative reinforcement produced faster elimination and greater resurgence of target‐lever pressing than one‐pellet alternative reinforcement. In Experiment 2, effects of decreasing alternative‐reinforcer magnitude on resurgence were examined. Rats pressed levers and pulled chains for six‐pellet reinforcers during Phases 1 and 2, respectively. In Phase 3, alternative reinforcement was decreased to three pellets for one group, one pellet for a second group, and suspended altogether for a third group. Shifting from six‐pellet to one‐pellet alternative reinforcement produced as much resurgence as suspending alternative reinforcement altogether, while shifting from six pellets to three pellets did not produce resurgence. These results suggest that alternative‐reinforcer magnitude has effects on elimination and resurgence of target behavior that are similar to those of alternative‐reinforcer rate. Thus, both suppression of target behavior during alternative reinforcement and resurgence when conditions of alternative reinforcement are altered may be related to variables that affect the value of the alternative‐reinforcement source.     

How does reward compete with goal-directed and stimulus-driven shifts of attention?

In order to behave adaptively, attention can be directed in space either voluntarily (i.e. endogenously) according to strategic goals, or involuntarily (i.e. exogenously) through reflexive capture by salient or novel events. The emotional or motivational values of stimuli can also influence attentional orienting. However, little is known about how reward-related effects compete or interact with endogenous and exogenous attention mechanisms. Here we designed a visual search paradigm in which goal-driven and stimulus-driven shifts of attention were manipulated by classic spatial cueing procedures, while an irrelevant, but previously rewarded stimulus also appeared as a distractor and hence competed with both types of spatial attention during search. Our results demonstrated that stimuli previously associated with a high monetary reward received higher attentional priority in the subsequent visual search task, even though these stimuli and reward were no longer task-relevant, mitigating the attentional orienting induced by both endogenous and exogenous cues.     

数量空间表征的特点:跨视听通道下的SNARC效应

从跨通道的角度入手,采用大小比较任务,对视听单通道及跨通道下数量空间表征的特点及表征过程中的相互影响进行探讨。结果发现,视觉通道和听觉通道均存在SNARC效应;在跨通道任务下,无论启动通道是视觉还是听觉通道,都表现出,当启动通道的数量大小信息与主通道的数量大小一致或无关时,主通道的SNARC效应没有显著变化;但当启动通道的数量大小信息与主通道不一致时,主通道的SNARC效应受到显著影响,表现为降低或消失。这进一步证明了SNARC效应受情境影响的特点,并发现在进行跨通道数量空间表征时,听觉通道的数量信息对视觉通道下的数量空间表征的影响大于视觉通道的数量信息对听觉通道下的数量空间表征的影响。     

Sensitivity to reward and risky driving,risky decision making,and risky health behaviour: A literature review

Young driver road safety has persisted as a global problem for decades, despite copious and diverse intervention. Recently the influence in reward sensitivity, which refers to the individual’s personal sensitivity to rewards, has received attention in health-related research, including more generally through decision making in risky circumstances, and in risky driving behaviour specifically. As such, a literature review and synthesis of the literature regarding reward sensitivity in relation to risky driving, risky decision making, and risky health behaviour, with a focus on literature in which adolescents and young adults feature, is timely. Thirty-one papers were identified, and the literature revealed that young drivers with greater reward sensitivity engage in more risky driving behaviours including speeding, crashes and traffic violations; and that individuals with greater reward sensitivity engage in more risky decision making and other risky health-related behaviours (such as drinking and drug use). Adolescents and young adults exhibit heightened sensitivity to rewards in the presence of peers, which has considerable implications for young driver road safety as research consistently demonstrates that carrying peer passengers places all vehicle occupants at greater risk of being involved in a road crash. Consideration of the influence of reward sensitivity in young driver road safety, and other adolescent/young adult health-related safety, appears to be a promising avenue of intervention, with gain-framed messages more likely to be accepted by young drivers with greater reward sensitivity. Future research in jurisdictions other than Australia and Europe will increase our understanding of the influence of reward sensitivity, and exploration of the differential impacts of reward-responsiveness and fun-seeking specifically are warranted.     

不同药物相关线索反应下感觉-运动脑区的激活及作用

药物相关线索反应不仅表现在心理渴求, 也表现在强迫性用药行为上。相关线索下, 除包括奖赏环路在内的边缘系统被激活外, 感觉-运动脑区也被激活, 引发自动化动作图式的表达, 这对相关线索反应及复吸行为具有特殊的意义。是否所有相关线索都会激活感觉-运动脑区, 目前, 还不清楚, 而这对临床治疗具有重要意义。本研究采用磁共振扫描, 生理测试等方法探索了不同类型相关线索下, 海洛因成瘾戒断者的大脑激活状况, 试图了解他们在不同线索刺激下的大脑反应。采用组内实验设计, 测量29名海洛因成瘾者相关线索反应下的血氧水平。结果发现, 相比对照线索, 所有药物相关线索, 包括药物、用药工具、用药动作线索都更多激活扣带回、海马、舌回、梭回等与奖赏机制相关的脑区; 而不同类型的药物相关线索之间的比较则显示, 用药工具和用药动作线索更多激活了双侧颞中回、双侧顶下小叶、左侧顶上小叶和右侧额下回等感觉-运动脑区。用药动作线索比单纯药物和用药工具线索, 激活了更为广泛的动作脑区。由此, 我们认为药物相关线索导致成瘾者大脑中奖赏和感觉-动作两套系统被激活, 包含用药工具、用药动作在内的相关线索会激活更多的感觉-运动脑区。