新颖寻求特质对药物成瘾易感性的影响及其机制

新颖寻求特质是个体对新颖刺激或潜在的奖赏线索表现出愉悦或兴奋的先天倾向, 并且这种先天倾向会导致个体为寻求潜在的奖赏进行频繁的探索性活动。众多研究表明, 新颖寻求水平高的个体药物成瘾易感性高。多巴胺、5-羟色胺、谷氨酸、γ-氨基丁酸、胆囊收缩素、成纤维细胞生长因子及皮质酮可能参与了新颖寻求特质影响药物成瘾易感性的过程。未来, 仍需对新颖寻求特质影响药物成瘾易感性的神经生物学机制进行深入研究。     

Motivational systems in adolescence: Possible implications for age differences in substance abuse and other risk-taking behaviors

Adolescence is an evolutionarily conserved developmental phase characterized by hormonal, physiological, neural and behavioral alterations evident widely across mammalian species. For instance, adolescent rats, like their human counterparts, exhibit elevations in peer-directed social interactions, risk-taking/novelty seeking and drug and alcohol use relative to adults, along with notable changes in motivational and reward-related brain regions. After reviewing these topics, the present paper discusses conditioned preference and aversion data showing adolescents to be more sensitive than adults to positive rewarding properties of various drugs and natural stimuli, while less sensitive to the aversive properties of these stimuli. Additional experiments designed to parse specific components of reward-related processing using natural rewards have yielded more mixed findings, with reports of accentuated positive hedonic sensitivity during adolescence contrasting with studies showing less positive hedonic affect and reduced incentive salience at this age. Implications of these findings for adolescent substance abuse will be discussed.     

小鼠新颖寻求特质对酒精的运动激活效应的影响

新颖寻求(或感觉寻求)特质与许多成瘾药物的易感性密切相关。例如, 高、低新颖寻求动物对可卡因、苯丙胺和吗啡等成瘾药物的奖赏、运动激活、强化效应的反应存在差异。长期饮用酒精也容易成瘾, 但尚未发现关于新颖寻求特质影响酒精成瘾的报道。本实验采用药物成瘾研究中常用的自发活动模型, 考察了高、低新颖寻求动物在酒精急性处理、慢性处理和激发过程中的行为表现。实验过程中首先采用两种新颖寻求模型, 即新颖环境中自发活动模型和新颖客体偏爱模型, 将昆明小鼠分别区分为高、低自发活动组和高、低新颖客体偏爱组, 连续10天给予酒精(2g/kg/d, i.p.)或等量盐水处理, 戒断2天后所有小鼠接受酒精(2g/kg)激发。实验结果表明, 新颖环境低自发活动小鼠比新颖环境高自发活动小鼠对酒精急性、慢性处理导致的运动激活效应更敏感; 在酒精激发期前者的自发活动水平也高于后者。本实验结果说明新颖环境中自发活动特质影响动物对酒精导致的运动激活效应的反应。     

How reward and emotional stimuli induce different reactions across the menstrual cycle

Despite widespread belief that moods are affected by the menstrual cycle, researchers on emotion and reward have not paid much attention to the menstrual cycle until recently. However, recent research has revealed different reactions to emotional stimuli and to rewarding stimuli across the different phases of the menstrual cycle. The current paper reviews the emerging literature on how ovarian hormone fluctuation during the menstrual cycle modulates reactions to emotional stimuli and to reward. Behavioral and neuroimaging studies in humans suggest that estrogen and progesterone have opposing influences. That is, it appears that estrogen enhances reactions to reward, but progesterone counters the facilitative effects of estrogen and decreases reactions to rewards. In contrast, reactions to emotionally arousing stimuli (particularly negative stimuli) appear to be decreased by estrogen but enhanced by progesterone. Potential factors that can modulate the effects of the ovarian hormones (e.g., an inverse quadratic function of hormones' effects; the structural changes of the hippocampus across the menstrual cycle) are also discussed.     

Something old,something new: a developmental transition from familiarity to novelty preferences with hidden objects

Novelty seeking is viewed as adaptive, and novelty preferences in infancy predict cognitive performance into adulthood. Yet 7‐month‐olds prefer familiar stimuli to novel ones when searching for hidden objects, in contrast to their strong novelty preferences with visible objects ( Shinskey & Munakata, 2005 ). According to a graded representations perspective on object knowledge, infants gradually develop stronger object representations through experience, such that representations of familiar objects can be better maintained, supporting greater search than with novel objects. Object representations should strengthen with further development to allow older infants to shift from familiarity to novelty preferences with hidden objects. The current study tested this prediction by presenting 24 11‐month‐olds with novel and familiar objects that were sometimes visible and sometimes hidden. Unlike 7‐month‐olds, 11‐month‐olds showed novelty preferences with both visible and hidden objects. This developmental shift from familiarity to novelty preference with hidden objects parallels one that infants show months earlier with perceptible stimuli, but the two transitions may reflect different underlying mechanisms. The current findings suggest both change and continuity in the adaptive development of object representations and associated cognitive processes.     

奖惩线索条件下内外倾个体的自主唤醒和行为反应

将停止信号任务和金钱激励延迟任务相结合,使用16导生理记录仪记录被试的生理指标,探讨内外倾者在动机凸显情景下的生理唤醒特点以及反应调节能力。结果发现,隐含奖励和惩罚线索呈现之后,内外倾者的心率增快,内倾者的皮肤电活动显著增强。在停止信号任务中的优势反应阶段,内外倾者表现为对奖励凸显线索刺激的反应时缩短;而在非优势反应阶段,和外倾者相比较,内倾者的抑制反应错误率增高。表明内外倾者在奖惩线索条件下表现出不同的生理唤醒特点和行为反应。     

The relationship between reward and probability: Evidence that exploration may be intrinsically rewarding

ABSTRACT

The probability of an event occurring and the reward associated with the event can both modulate behaviour. Response times are decreased to stimuli that are either more rewarding or more likely. These two factors can be combined to give an Expected Value (EV) associated with the event (i.e., probability of the event x reward magnitude). In four experiments we investigate the effect of reward and probability on both saccadic and manual responses. When tested separately we find evidence for both a reward and probability effect across response types. When manipulations of reward magnitude and probability of the event were combined, the probability modulations dominated and these data were not well accounted for by the EV. However, a post-hoc model that included an additional intrinsic reward associated with responding provided an excellent account for the data. We argue that reward consists of both an explicit and intrinsic component. In our task, the saccadic and manual responses are linked to the information provided by the targets and the goals of the task, and successful completion of these is in itself rewarding. As a result, targets associated with a higher probability of being presented have a higher intrinsic reward.     

The happy spotlight: positive mood and selective attention to rewarding information

Positive mood states are thought to sensitize individuals to rewards in their environment, presumably in the service of approach-related decision making and behavior. From a selective attention standpoint, such mood-related effects should be associated with selective attention biases favoring rewarding stimuli. No prior results along these lines have been reported. Therefore, the authors conducted a systematic program of research designed to document such relations. Study 1 found that daily positive mood states were associated with attention to reward words in a spatial probe task. Studies 2-5 replicated this association in the context of mood manipulations. The latter studies also show that the effect generalizes across different mood manipulation procedures, is specific to positive mood states, and is particularly apparent in relation to rewarding (vs. non-rewarding) positive stimuli. The results extend our knowledge of mood-cognition relations and have important implications for understanding the social cognitive consequences of positive mood states.     

Reward history but not search history explains value-driven attentional capture

In past years, an extensive amount of research has focused on how past experiences guide future attention. Humans automatically attend to stimuli previously associated with reward and stimuli that have been experienced during visual search, even when it is disadvantageous in present situations. Recently, the relationship between “reward history” and “search history” has been discussed critically. We review results from research on value-driven attentional capture (VDAC) with a focus on these two experience-based attentional selection processes and their distinction. To clarify inconsistencies, we examined VDAC within a design that allows a direct comparison with other mechanisms of attentional selection. Eighty-four healthy adults were trained to incidentally associate colors with reward (10 cents, 2 cents) or with no reward. In a subsequent visual search task, distraction by reward-associated and unrewarded stimuli was contrasted. In the training phase, reward signals facilitated performance. When these value-signaling stimuli appeared as distractors in the test phase, they continuously shaped attentional selection, despite their task irrelevance. Our findings clearly cannot be attributed to a history of target search. We conclude that once an association is established, value signals guide attention automatically in new situations, which can be beneficial or not, depending on the congruency with current goals.     

新颖性寻求对创造性行为表现的影响：语义网络的中介作用

研究采用物品多用途任务、中文复合远距离联想任务和汉语双字词词对相关性判断任务,考察新颖性寻求特质水平对创造性表现的影响,探明语义网络在其中的作用。结果发现：（1）高新颖性寻求个体在物品多用途任务中有更高的新颖性得分,而在中文复合远距离联想任务中与低新颖性寻求个体表现一致;（2）在低相关词对判断时,高新颖性寻求个体反应时更短;（3）低相关词对判断反应时在新颖性寻求对创造性行为表现的影响中起部分中介作用。本研究结果预示着,新颖性寻求特质有利于个体建构形成能快速激活远距离信息的语义网络,进而促进其创造性行为表现。     

Deepened extinction following compound stimulus presentation: noradrenergic modulation

Behavioral extinction is an active form of new learning involving the prediction of nonreward where reward has previously been present. The expression of extinction learning can be disrupted by the presentation of reward itself or reward-predictive stimuli (reinstatement) as well as the passage of time (spontaneous recovery) or contextual changes (renewal). The following experiments replicated the demonstration that presenting multiple previously rewarded stimuli in compound during extinction enhances extinction learning. To explore the pharmacological basis for this we next examined the effects of pharmacological treatments that either facilitated or blocked noradrenergic activity to test the hypothesis that increased noradrenergic activity at the time of extinction training would improve, whereas blockade of noradrenergic activity would impair the extinction of appetitive stimulus-reward memories. Different groups of rats were trained in a discriminative stimulus paradigm to lever-press for food reward. Once stable responding was achieved, responding was extinguished for 2 d. Prior to a third extinction session, rats received systemic administration of either saline, yohimbine (α2 antagonist), atomoxetine (norepinephrine reuptake inhibitor), or propranolol (β-receptor antagonist). Spontaneous recovery of responding to the stimuli was tested 4 wk later. Our results indicate that increasing noradrenergic activity during extinction augments extinction learning resulting in less recovery of responding at test. These results have important implications for models of relapse to drug seeking and the development of extinction-based therapies.     

气质的遗传因素:基因多态性研究

气质是婴儿出生以后最早表现出来的一种人格特征,而人格特征的形成具有一定的生物学基础。气质作为人格特征的组成单元,与人格特征享有共同的生物过程。因此,与成年人人格特征相关的基因也有可能影响儿童气质。本文在成年人的人格特征研究的基础上,针对早期儿童发展的特点,讨论了可能影响早期儿童气质的候选基因。研究成人的人格特征与基因的相关性不能排除环境因素的影响,本文强调了对早期儿童气质与基因多态性之间的关系进行直接研究的重要性。     

Interaction of the Dopaminergic System With Mechanisms of Associative Learning and Cognition:Implications for Drug Abuse

The possible role of mechanisms of associative learning in drug abuse and addiction is considered with respect to psychomotor stimulant drugs such as cocaine and amphetamine. Although the initial sites of the reinforcing effects of these drugs are associated with the mesolimbic dopamine projection to the nucleus accumbens, other important neuromodulatory influences are identified. These include the amygdala, which appears to mediate the associative processes by which environmental stimuli come to control drug-seeking behavior. Possible parallel mechanisms by which stimulant drugs enhance effects of aversive as well as rewarding stimuli are discussed. The importance of attribution and context in determining relative rewarding and aversive effects is pointed out. These attributional and contextual factors may be a function of cortical regions that may themselves be impaired by chronic drug abuse, leading to further dysexecutive control over cognition and behavior.     

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。     

Motivation and Personality: A Neuropsychological Perspective

Personality is strongly influenced by motivation systems that organise responses to rewards and punishments and that drive approach and avoidance behavior. Neuropsychological research has identified: (a) two avoidance systems, one related to pure active avoidance and escape, and one to passive avoidance and behavioral inhibition produced by goal‐conflict; and (b) two approach systems, one related to the actions of reward seeking and one to experience and behavior related to pleasure on receiving reward. These systems mediate fluid moment‐by‐moment reactions to changing stimuli, with relatively stable person‐specific sensitivities to these stimuli manifested in personality traits. We review what is known about these motivational traits, integrating the theory‐driven approach based on animal learning paradigms with the empirical tradition of the Big Five personality model.     

Reward expectancy promotes generalized increases in attentional bias for rewarding stimuli

Expectations of drug availability increase the magnitude of attentional biases for drug-related cues. However, it is unknown whether these effects are outcome specific, or whether expectation of a specific reinforcer produces a general enhancement of attentional bias for other types of rewarding cues. In the present study, 31 social drinkers completed an eye-tracking task in which attentional bias for alcohol- and chocolate-related cues was assessed while the expectation of receiving alcohol and chocolate was manipulated on a trial-by-trial basis. Participants showed attentional bias for alcohol and chocolate cues (relative to neutral cues) overall. Importantly, these attentional biases for reward cues were magnified when participants expected to receive alcohol and chocolate, but effects were not outcome specific: The expectation of receiving either alcohol or chocolate increased attentional bias for both alcohol and chocolate cues. Results suggest that anticipation of reward produces a general rather than an outcome-specific enhancement of attentional bias for reward-related stimuli.     

Reward expectation influences audiovisual spatial integration

In order to determine the spatial location of an object that is simultaneously seen and heard, the brain assigns higher weights to the sensory inputs that provide the most reliable information. For example, in the well-known ventriloquism effect, the perceived location of a sound is shifted toward the location of a concurrent but spatially misaligned visual stimulus. This perceptual illusion can be explained by the usually much higher spatial resolution of the visual system as compared to the auditory system. Recently, it has been demonstrated that this cross-modal binding process is not fully automatic, but can be modulated by emotional learning. Here we tested whether cross-modal binding is similarly affected by motivational factors, as exemplified by reward expectancy. Participants received a monetary reward for precise and accurate localization of brief auditory stimuli. Auditory stimuli were accompanied by task-irrelevant, spatially misaligned visual stimuli. Thus, the participants’ motivational goal of maximizing their reward was put in conflict with the spatial bias of auditory localization induced by the ventriloquist situation. Crucially, the amounts of expected reward differed between the two hemifields. As compared to the hemifield associated with a low reward, the ventriloquism effect was reduced in the high-reward hemifield. This finding suggests that reward expectations modulate cross-modal binding processes, possibly mediated via cognitive control mechanisms. The motivational significance of the stimulus material, thus, constitutes an important factor that needs to be considered in the study of top-down influences on multisensory integration.     

焦虑情绪对奖赏学习的影响

焦虑是在我们日常生活中占据重要地位的一种情绪, 对人类的决策行为能够产生显著影响。探讨决策研究的重要领域--奖赏学习, 可以帮助我们更深入地认识焦虑情绪在决策过程中扮演的角色。过往研究者较少关注焦虑对奖赏学习的潜在影响, 而且已有研究在实验技术和任务范式方面存在一定的局限性。考虑到奖赏学习概念的复杂性, 为了全面地考察个体焦虑水平与奖赏学习的关系, 本文作者建议设置不同类型的奖赏学习情境, 例如概率学习、联结学习、逆向学习和社会学习等。在上述各类不同任务中, 个体焦虑水平对奖赏学习能力的影响模式可能并不一致, 有待研究者们进行深入探讨。     

Adult temperament and childbearing over the life course

Emerging evidence suggests that temperament may predict childbearing. We examined the association between four temperament traits (novelty seeking, harm avoidance, reward dependence and persistence of the Temperament and Character Inventory) and childbearing over the life course in the population‐based Cardiovascular Risk in Young Finns study (n = 1535; 985 women, 550 men). Temperament was assessed when the participants were aged 20–35 and fertility history from adolescence to adulthood was reported by the participants at age 30–45. Discrete‐time survival analysis modelling indicated that high childbearing probability was predicted by low novelty seeking (standardized OR = 0.92; 95% confidence interval 0.88–0.97), low harm avoidance (OR = 0.90; 0.85–0.95), high reward dependence (OR = 1.09; 1.03–1.15) and low persistence (OR = 0.91; 0.87–0.96) with no sex differences or quadratic effects. These associations grew stronger with increase in numbers of children. The findings were substantially the same in a completely prospective analysis. Adjusting for education did not influence the associations. Despite its negative association with overall childbearing, high novelty seeking increased the probability of having children in participants who were not living with a partner (OR = 1.29; 1.12–1.49). These data provide novel evidence for the role of temperament in influencing childbearing, and suggest possible weak natural selection of temperament traits in contemporary humans. Copyright © 2009 John Wiley & Sons, Ltd.