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。     

冲动还是习惯?成瘾不同阶段中冲动性的性质与机制

冲动性是一种缺乏充分思考、不顾后果的冒险行为或行为倾向, 它既表现在人格特质中, 也会表现为各类环境中的行为。成瘾者具有典型的冲动性特征, 但成瘾者的冲动性是如何影响和促进成瘾行为的发生、发展, 目前还并不明朗。从成瘾形成的不同阶段, 也许可以对此有更进一步的了解。在药物使用的开始阶段, 冲动性人格特质作为动机原因, 促进成瘾物质的首次使用; 接着操作性条件学习导致用药者进入“目标-导向”阶段, 呈现出选择冲动性。第三阶段, 经典条件学习又使相关线索和药物效应不断匹配, 形成条件反射性药物使用行为。成瘾者进入习惯性用药阶段, 表现出显著的停止冲动性。     

Impulsivity and Behavior-Dependent Life Events Mediate the Relationship of Reward Sensitivity and Depression,but Not Hypomania,Among at-Risk Adolescents

Both reward sensitivity and impulsivity are related to the development and course of bipolar spectrum disorders (BSDs) and have been implicated in other disorders and negative functional outcomes such as substance abuse, obesity, suicidal behaviors, and risk-taking. Furthermore, according to the transactional component of the Behavioral Approach System (BAS)/reward hypersensitivity theory of BSDs, people with reward hypersensitivity should experience more BAS-relevant events, and thus, are more vulnerable to mood symptoms and episodes via stress generation. Impulsivity may exacerbate stress generation in individuals at risk for BSDs based on exhibiting reward hypersensitivity. The current study examined whether impulsivity explained the generation of stress and subsequent mood symptoms beyond what is explained by reward sensitivity alone. Participants were 131 Moderate BAS and 216 High BAS sensitivity adolescents (M = 18.43 years, SD = 1.40), who completed baseline measures of reward sensitivity and impulsivity, as well as follow-up measures of life events and mood symptoms. Results from linear regression analyses indicated that higher baseline impulsivity predicted behavior-dependent, but not behavior-independent, life events. Furthermore, path analyses suggested that the effect of BAS group on depression symptoms at next follow-up was partly explained via the indirect effect of impulsivity and negative behavior-dependent life events. We did not find these effects for behavior-independent or positive-dependent events or for prediction of hypomanic symptoms. The findings suggest that impulsivity may account for stress generation of negative events that precede depression.     

Infant-adult vocal interaction dynamics depend on infant vocal type,child-directedness of adult speech,and timeframe

This study explored the temporal contingencies between infant and adult vocalizations as a function of the type of infant vocalization, whether adult caregivers’ vocalizations were infant-directed or other-directed, and the timescale of analysis. We analyzed excerpts taken from day-long home audio recordings that were collected from nineteen 12- to 13-month-old American infants and their caregivers using the LENA system. Three 5-minute sections having high child vocalization rates were identified within each recording and coded by trained researchers. Infant and adult vocalizations were sequenced and defined as contingent if they occurred within 1 s, 2 s, or 5 s of each other. When using 1 s or 2 s definitions of temporal adjacency, infant vocalizations generally predicted subsequent infant-directed adult vocalizations. A reflexive vocalization (i.e. a cry or a laugh) was the strongest predictor. Likewise, within 1–2 s timeframes, infant-directed adult speech generally predicted infant vocalizations with reflexive vocalizations being particularly predictive. Infant vocalizations predicted fewer subsequent other-directed adult vocalizations and were less likely following other-directed adult vocalizations when considering up to 5 s lags. This suggests an understudied communicative role for infants of non-infant-directed adult speech. These results demonstrate the importance of timescale in studying infant-adult interactions, support the communicative significance of reflexive infant vocalizations and other-directed adult speech in addition to more commonly studied vocalization types, and highlight the challenges of determining direction(s) of influence when using only two-event sequences.     

The role of the magnocellular and parvocellular pathways in the attentional blink

The attentional blink refers to the transient impairment in perceiving the 2nd of two targets presented in close temporal proximity in a rapid serial visual presentation (RSVP) stream. The purpose of this study was to examine the effect on human attentional-blink performance of disrupting the function of the magnocellular pathway--a major visual-processing pathway specialized in temporal segregation. The study was motivated by recent theories that relate the attentional blink to the limited temporal resolution of attentional responses, and by a number of poorly understood empirical findings, including the effects on the attentional blink of luminance adaptation and distraction. The attentional blink was assessed for stimuli on a red background (Experiment 1), stimuli on an equiluminant background (Experiment 2), and following flicker or motion adaptation (Experiment 3), three psychophysical manipulations known to disrupt magnocellular function. Contrary to our expectations, the attentional blink was not affected by these manipulations, suggesting no specific relationship between the attentional blink and magnocellular and/or parvocellular processing.     

Does attention impair temporal discrimination? Examining non-attentional accounts

Recently, Yeshurun and Levy (Psychol Sci 14:225-231, 2003) have provided evidence for the notion that visual attention impairs the temporal resolution of the visual system. Specifically, the detection of a temporal gap within a visual stimulus was impaired when a cue directed attention towards the spatial location of the stimulus. As this negative cueing effect is important to constrain theories about visual attention, we further investigated this novel effect and assessed whether it truly reflects an attentional effect. Experiment 1 examines whether the negative cueing effect is due to local temporal interference, and Experiments 2 and 3 investigate whether it reflects a luminance confound. The complete pattern of results argues against these alternatives and thus further strengthens the conclusion of Yeshurun and Levy (Psychol Sci 14: 225-231, 2003).     

PTSD青少年对威胁图片注意偏向的时程特点及习惯化倾向

探讨创伤后应激障碍(post-traumatic stress disorder,PTSD)青少年(n=20)与创伤控制组(n=20)对威胁图片注意偏向的时间进程特点以及习惯化倾向.在线索提示任务中,图片的呈现时间为100ms、500ms和1250ms.研究表明:(1)在时间进程上,当图片呈现100ms时,创伤控制组对地震图存在注意警觉;当呈现时间为500ms时,两组被试对负性图和地震图存在注意回避;当呈现时间为1250ms时,PTSD组对负性图仍存在注意回避、对地震图的注意偏向消失,创伤控制组对负性图和地震图的注意偏向均消失.(2)在习惯化倾向上,当第六次呈现威胁图片时,PTSD组对负性图和地震图的注意偏向消失,而创伤控制组对负性图和地震图的注意回避仍未消失.     

On emotional innumeracy: Predicted and actual affective responses to grand-scale tragedies

The present research demonstrates that people overestimate the intensity of their emotional responses to grand-scale tragedies. Participants predicted that they would feel significantly worse if thousands of people were killed in a disaster than if only a few people were killed, and yet they exhibited an “emotional flatline,” feeling equally sad regardless of the number of people killed. This unforeseeable emotional flatline was demonstrated in response to deaths stemming from human violence and natural disasters, both close to home and far away (including hurricanes in the United States, a forest fire in Spain, and the Iraq War). Participants’ actual emotional responses were calibrated with fatalities only when abstract death tolls were translated into concrete images. We argue that affective forecasts and emotional experiences may arise from separate systems, leading to reliable forecasting errors, as well as influencing subsequent judgments.     

Personality traits of the behavioural approach and inhibition systems: associations with processing of emotional stimuli

This study examined the relationships of the traits associated with Gray's behavioural approach system (BAS) and behavioural inhibition system (BIS) with cognitive processing of emotional information. Initially, participants completed questionnaires covering trait impulsivity and anxiety, and BAS and BIS sensitivities. They were then tested individually. After completing a questionnaire of current positive and negative moods, they completed three tasks measuring processing of pleasant, unpleasant and neutral information. Consistent with Gray’s theory, the results showed that impulsivity and BAS sensitivity were associated with the processing of pleasant information, while anxiety and BIS sensitivity were associated with the processing of unpleasant information. These findings imply that Gray’s BAS–BIS theory can be extended to cognitive processing of emotional information.