对听感觉运动门控自上而下调节的动物模型和神经机制

对惊反射的前脉冲抑制是减少干扰影响、保护脑内信息加工的重要机制。它既是研究感觉运动门控的模型, 也是探究精神分裂症机制的模型。前脉冲抑制可被选择性注意和情绪等高级认知活动所调节。本论文工作围绕着恐惧条件化和知觉空间分离去掩蔽(空间选择性注意)对听觉前脉冲抑制多层次化的自上而下调节, 在大鼠行为模型、神经通路、神经电生理机制等几个层次上开展了系统性研究, 并引入了精神分裂症的神经发育模型, 证实早期社会隔离饲养对前脉冲抑制注意调节的破坏影响。本论文研究成果不仅对认识正常情况下脑在复杂刺激场景中的信息加工机制有重要意义, 以感觉运动门控认知调节功能缺失为基础的动物模型也将推动精神分裂症心理学和神经生物学机制的研究。     

Psychoticism and attentional flexibility

In three separate experiments, we tested the hypothesis that a systematic relationship between psychoticism (P) and visual selective attention is infrequently observed because the tasks typically used to test individual differences in efficiency of attentional mechanisms do not entail attentional flexibility. We manipulated the selection rule of the computerized divided visual attention (DIVA) task to be either (a) a predictable, or (b) a random manner, and a secondary task was added to check the quality of high P scorers’ performance in an interference condition; and we also introduced breaks between DIVA tasks to allow for cue utilization. Results revealed that low P scorers outperformed high P scorers in the regular selection rule alternation condition (cue utilization possible), whereas high P scorers performed better in random alternation condition – high P scorers also showed performance superiority in the dual task condition unless stimuli presentation was speeded up. Thus, P does not necessarily impair attentional performance; indeed, our data point to performance advantages of high P, especially attentional efficiency in tasks requiring small demands of attentional control.     

Selective attention and threat: quick orienting versus slow disengagement and two versions of the dot probe task

The dot probe task is often used to assess attentional bias in anxiety, but some aspects need clarification. First, the results, which are traditionally summarized in an attentional bias index, do not allow for distinguishing between different selective attention processes; orienting and disengagement. Second, different versions of the dot probe task have been used with unknown relative merits. Participants (N=133) completed two versions of the dot probe task: the detection task (i.e. is there a probe?) and the differentiation task (i.e. what sort of probe is it?). The analysis carried out allowed for a differentiation between orienting and disengagement. The main finding was that trait anxiety is related to disengagement difficulties and not to speed of orienting. Concerning the relative merits of the two dot probe task versions, the results suggest that the detection task may be superior to the differentiation task. Implications for past and future research are discussed.     

The role of attentional biases in PTSD: is it interference or facilitation?

Although attentional biases have been demonstrated in individuals with posttraumatic stress disorder (PTSD), the cognitive methodologies used have not allowed for disambiguation of two types of attentional biases. It remains unclear if PTSD involves difficulty disengaging attention from threatening stimuli (interference) or facilitated detection. To differentiate between attentional interference and facilitation, 57 male Vietnam-era veterans (30 High PTSD and 27 Low PTSD) completed a visual search task with a lexical decision component. High PTSD veterans who engaged in the interference task first showed increased interference to threat-relevant words relative to Low PTSD veterans. However, no evidence was found for facilitated detection of threatening stimuli in PTSD.     

Detection of emotional expressions in rapidly changing facial displays in high- and low-socially anxious women

Facial information and attention to facial displays are distributed over spatial as well as temporal domains. Thus far, research on selective attention to (dis)approving faces in the context of social anxiety has concentrated primarily on the spatial domain. Using a rapid serial visual presentation (RSVP) paradigm, the present study examined the temporal characteristics of visual attention for happy and angry faces in high- (n=16) and low-socially anxious individuals (n=17), to test whether also in the temporal domain socially anxious individuals are characterized by threat-confirming attentional biases. Results indicated that presenting angry faces as the first target (T1) did not aggravate the detection of the emotional expression of the second target (T2). Yet, participants generally showed superior detection of the emotional expression of T2, if T2 was an angry face. Casting doubt on the role of such attenuated attentional blink for angry faces in social anxiety, no evidence emerged to indicate that this effect was relatively strong in high-socially anxious individuals. Finally, the presentation of an angry face as T2 resulted in a relatively hampered identification of a happy-T1. Again, this "backward blink" was not especially pronounced in high-socially anxious individuals. The present anger superiority effects are consistent with evolutionary models stressing the importance of being especially vigilant for signals of dominance. Since the effects were not especially pronounced in high-anxious individuals, the present study adds to previous findings indicating that socially anxious individuals are not characterized by a bias in the (explicit) detection of emotional expressions [Philippot, P., & Douilliez, C. (2005). Social phobics do not misinterpret facial expression of emotion. Behaviour Research and Therapy, 43, 639-652].     

Processing efficiency in preschoolers’ memory span: Individual differences related to age and anxiety

In self-paced auditory memory span tasks, the microanalysis of response timing measures represents a developmentally sensitive measure, providing insights into the development of distinct processing rates during recall performance. The current study first examined the effects of age and trait anxiety on span accuracy (effectiveness) and response timing (efficiency) measures from word and digit span performance in a preschool sample (N = 76, mean age = 57 months, SD = 11). Children were reassessed 8 months later using the same two tasks plus a test of nonword memory span and a measure of articulation rate. The results at the second time point (T2) confirmed the effects of age on both processing effectiveness and efficiency. Trait anxiety was an additional negative predictor of span effectiveness (especially for digit span) and efficiency (in the case of word and nonword span). The findings are discussed in the context of factors contributing to early short-term memory development and attentional control theory.     

Effects of attentional-focus instructions on movement kinematics

BackgroundRecent research has shown that internal (body-related) attention-focus instructions disrupt motor learning and performance, whereas paying attention to the environmental effects of movements (external focus) leads to better performance than an internal focus [see, for reviews, Wulf, G. (2007). Attentional focus and motor learning: a review of 10 years of research. E-Journal Bewegung und Training, 1, 4–14.; Wulf, G., &; Prinz, W. (2001). Directing attention to movement effects enhances learning: a review. Psychonomic Bulletin &; Review, 8, 648–660.]. However, Beilock's studies [Beilock, S. L., Bertenthal, B. I., McCoy, A. M., &; Carr, T. H. (2004). Haste does not always make waste: expertise, direction of attention, and speed versus accuracy in performing sensorimotor skills. Psychonomic Bulletin &; Review, 11, 373–379.] suggest that an internal focus is detrimental in experts but not in novices. Because detrimental effects of consciously attending to movements have generally been measured by performance scores such as accuracy scores or reaction times, it remains unclear how internal and external attentional-focus instructions influence movement kinematics when learning a new skill. To fill this gap, the present study investigated attentional-focus effects on a biomechanical level.MethodsA video of an expert juggler demonstrating a two-ball juggling task was presented to juggling novices. Experimental groups were given either body-related (internal group) or ball-related (external group) verbal instructions or no attention-guiding instructions (control group). In the retention phase without attention-guiding instructions, the body-movement and ball-flight aspects of performance focused on in the verbal instruction were subjected to biomechanical analyses.Results and ConclusionsJuggling performance improved equally in all three groups. However, internally vs. externally instructed acquisition phases had differential effects on the kinematics of the upper body as well as ball trajectories when performing the juggling task. Remarkably, ball trajectories in the control group who received no specific attentional cueing were similar to those in the externally instructed group. This suggests that task-relevant information is picked up independently of instructions, and that external instructions provide redundant information. Internal instructions for object-related tasks, however, may confront novice learners with the need to process additional information. As a result, task difficulty might be unnecessarily enhanced in an observational learning setting.     

Studies on time: a proposal on how to get out of circularity

The analysis of time is vitiated very often by circularity: several disciplines, such as psychology, linguistics, and neurosciences, analyze time by using concepts or terms which already contain in themselves, or are based, on the experience and notion of time (as when, for example, time is defined as “duration”, or when our ability to estimate durations is explained by resorting to the notion of an internal clock). Some detailed examples of circularity in the analysis of time are given here and examined. A way out of circularity is then given: it is represented by the proposal of attentional semantics (AS) of considering words and their meanings in terms of the aim they serve, and the means and processes developed and implemented in order to achieve that aim. According to AS, the main aim of words is that of indicating to, and eliciting in, the listener or reader a specific conscious experience: namely, the conscious experience referred to by their meanings. Words achieve their main aim by conveying the condensed instructions on the attentional operations one has to perform if one wants to consciously experience what is expressed through and by them. By describing the conscious experiences elicited by words in terms of the attentional operations that are responsible for the production of such conscious experiences, AS offers an a-linguistic counterpart to language, and therefore an effective way out of circularity. Following in footsteps of Mach (Contributions to the analysis of the sensations, 1890), but slightly revising his hypothesis, AS defines time-sensation as the perception of the effort made, or alternatively the nervous energy expended, by the organ of attention when performing a “temporal activity” (for instance, estimating duration), that is, when one’s own attention is focused in a continuous and incremental way on the conscious product of the (“non-temporal”) activity performed by means of another portion of one’s attention.

自我概念在父母情感关爱与儿童发展间的完全中介效应

运用问卷法,对北京612名中小学生及其父母分别进行了儿童孤独退缩行为、自我概念及父母情感关爱行为测试,运用LISEREL软件对数据的分析结果表明:父母情感关爱行为通过儿童自我概念的完全中介作用,对儿童的孤独退缩行为起到明显的抑制作用;在父母情感关爱行为和儿童学业成就之间,儿童的学业自我概念也起到了明显的完全中介效果.从而支持了儿童自我概念在父母情感关爱与儿童发展间的完全中介地位.     

单侧化准备电位的含义和应用

单侧化准备电位（Lateralized readiness potential, LRP）是指在随意运动中,反应效应器方位所对应的对侧大脑皮层出现的准备电位。LRP分析的关键是确定启动时间点。LRP可以揭示刺激-反应不同阶段的认知加工时间特性。可以从反应准备的抽象性或具体性以及大脑控制运动输出的“中枢”机制或“外周”机制这两个思路去验证LRP。LRP在阈下知觉和内隐学习、运动准备和反应执行、西蒙效应等方面的认知心理学研究以及新兴的脑-机界面工程心理学研究得到了广泛的应用,但LRP的应用存在着某些限制因素,如：脑电干扰、测量的低信噪比和其本身对反应效应器的要求等