On the common stimulus condition and explanation of the Müller‐Lyer,Poggendorff and Zöllner illusions: The basis for a class of geometrical illusions

Although the Müller‐Lyer, Poggendorff and Zöllner figures and the illusions with which they are associated– those of length, misalignment and non‐parallelism, respectively – are quite different, all three are attributable to the same basic effect, that of the difference in the apparent length of equal lines forming acute and obtuse angles. The role of this basic affect, reported originally by Müller‐Lyer but overlooked by him and others as a possible cause of the three illusions, is identified and discussed. It is suggested that the demonstration of a basic stimulus condition (acute and obtuse angles) and its associated illusion (difference in apparent length) generating a class of “higher order” geometric illusions has implications not only for a closer understanding of the three illusions under consideration but for other classes of illusory phenomena that might also share a common basis.     

On the mean and variance of response times under the diffusion model with an application to parameter estimation

We give closed form expressions for the mean and variance of RTs for Ratcliff’s diffusion model [Ratcliff, R. (1978). A theory of memory retrieval. Psychological Review, 85, 59-108] under the simplifying assumption that there is no variability across trials in the parameters. These expressions are more general than those currently available. As an application, we demonstrate their use in a method-of-moments estimation procedure that addresses some of the weaknesses of the EZ method [Wagenmakers, E.-J., van der Maas, H. L. J., & Grasman, R. P. P. P. (2007). An EZ-diffusion model for response time and accuracy. Psychonomic Bulletin & Review, 14, 3-22], and illustrate this with lexical decision data. We discuss further possible applications.     

Associative learning versus fear habituation as predictors of long-term extinction retention

Violation of unconditioned stimulus (US) expectancy during extinction training may enhance associative learning and result in improved long-term extinction retention compared to within-session habituation. This experiment examines variation in US expectancy (i.e., expectancy violation) as a predictor of long-term extinction retention. It also examines within-session habituation of fear-potentiated startle (electromyography, EMG) and fear of conditioned stimuli (CS) throughout extinction training as predictors of extinction retention. Participants (n?=?63) underwent fear conditioning, extinction and retention and provided continuous ratings of US expectancy and EMG, as well as CS fear ratings before and after each phase. Variation in US expectancy throughout extinction and habituation of EMG and fear was entered into a regression as predictors of retention and reinstatement of levels of expectancy and fear. Greater variation in US expectancy throughout extinction training was significantly predictive of enhanced extinction performance measured at retention test, although not after reinstatement test. Slope of EMG and CS fear during extinction did not predict retention of extinction. Within-session habituation of EMG and self-reported fear is not sufficient for long-term retention of extinction learning, and models emphasizing expectation violation may result in enhanced outcomes.     

Using Retrieval Cues to Attenuate Return of Fear in Individuals With Public Speaking Anxiety

Even after successful exposure, relapse is not uncommon. Based on the retrieval model of fear extinction (e.g., Vervliet, Craske, & Hermans, 2013), return of fear can occur after exposure due to an elapse of time (spontaneous recovery) or change in context (contextual renewal). The use of external salient stimuli presented throughout extinction (i.e., retrieval cues [RCs]) has been suggested as a potential solution to this problem (Bouton, 2002). The current study examined whether RCs attenuated return of fear in individuals with public speaking anxiety. Sixty-five participants completed a brief exposure while presented with two RC stimuli aimed at a variety of senses (visual, tactile, olfactory, and auditory). Later, half the participants were tested for return of fear in a context different from the exposure context, and the other half in the same context. Half of each context group were presented with the same cues as in exposure, while the other half were not. Return of fear due to an elapse of time, change in context, and effects of RCs were evaluated on subjective, behavioral, and physiological measures of anxiety. Although contextual renewal was not observed, results supported effects of RCs in reducing spontaneous recovery on behavioral and physiological measures of anxiety. There was also evidence that participants who were reminded of feeling anxious during exposure by the RCs benefited more from using them at follow-up, whereas those who perceived the cues as comforting (safety signals) benefited less. Clinical implications of the findings are discussed.     

Adaptation to continuous perturbation of balance: progressive reduction of postural muscle activity with invariant or increasing oscillations of the center of mass depending on perturbation frequency and vision conditions

We investigated the adaptation of balancing behavior during a continuous, predictable perturbation of stance consisting of 3-min backward and forward horizontal sinusoidal oscillations of the support base. Two visual conditions (eyes-open, EO; eyes-closed, EC) and two oscillation frequencies (LF, 0.2 Hz; HF, 0.6 Hz) were used. Center of Mass (CoM) and Center of Pressure (CoP) oscillations and EMG of Soleus (Sol) and Tibialis Anterior (TA) were recorded. The time course of each variable was estimated through an exponential model. An adaptation index allowed comparison of the degree of adaptation of different variables. Muscle activity pattern was initially prominent under the more challenging conditions (HF, EC and EO; LF, EC) and diminished progressively to reach a steady state. At HF, the behavior of CoM and CoP was almost invariant. The time-constant of EMG adaptation was shorter for TA than for Sol. With EC, the adaptation index showed a larger decay in the TA than Sol activity at the end of the balancing trial, pointing to a different role of the two muscles in the adaptation process. At LF, CoM and CoP oscillations increased during the balancing trial to match the platform translations. This occurred regardless of the different EMG patterns under EO and EC. Contrary to CoM and CoP, the adaptation of the muscle activities had a similar time-course at both HF and LF, in spite of the two frequencies implying a different number of oscillation cycles. During adaptation, under critical balancing conditions (HF), postural muscle activity is tuned to that sufficient for keeping CoM within narrow limits. On the contrary, at LF, when vision permits, a similar decreasing pattern of muscle activity parallels a progressive increase in CoM oscillation amplitude, and the adaptive balancing behavior shifts from the initially reactive behavior to one of passive riding the platform. Adaptive balance control would rely on on-line computation of risk of falling and sensory inflow, while minimizing balance challenge and muscle effort. The results from this study contribute to the understanding of plasticity of the balance control mechanisms under posture-challenging conditions.     

Leadership and Regressive Small Group Processes: A Case Study

The psychoanalytic literature of regressive group and intergroup processes is reviewed briefly and selectively to derive principles of effective, working group leadership. These principles are applied to a case study of the leadership provided by Terje Larsen to the unique work group of Palestinians, Israelis, and Norwegians who produced the 1993 Oslo Peace Accords.     

Achievement and self-concept of students with learning disabilities

The internal/external frame of reference (I/E) model by Marsh (Am Educ Res J 23:129–149, 1986) assumes that, besides social comparisons with their classmates, students engage in intraindividual, dimensional comparisons, comparing their own achievement in one subject with their achievement in other subjects. These dimensional comparison processes are assumed to result in negative paths from achievement in one subject (e.g., math) to self-concept in another (e.g., the verbal domain). In a study with N = 270 students, we investigated the generalizability of the I/E model to students with learning disabilities. Analyses showed positive correlations between math and German achievement and positive effects of achievement in both subjects on the corresponding domain-specific self-concept. Verbal and math self-concepts were almost uncorrelated. Moreover, there were negative effects of achievement in one domain on self-concept in the other. Our results therefore indicate that the I/E model can be generalized to students with learning disabilities.     

语篇情绪理解及其认知神经机制

在心理语言学领域,情绪信息加工是语篇理解的重要方面,得到了广泛关注。目前的研究表明,读者在语篇阅读中可以在线地、自动地推测出语篇情绪信息,追踪情绪信息的变化,并对其进行更新。语篇理解相关的模型及一些事件相关电位(ERP)的实证研究表明语篇情绪理解至少包括两个重要的加工过程:一是对语篇情绪信息的实时监控,二是对当前情绪信息的评估与更新。相关的功能磁共振(f MRI)的研究表明语篇情绪理解除了需要经典的情绪加工网络,还需要多个脑区网络的参与,如,语篇理解网络、心理理论(To M)网络。未来研究还需更加深入地、更加细致地探讨语篇情绪理解的认知神经机制及其可能的影响因素,研究成果也可以为情感计算领域提供一定的借鉴。     

数字空间联结的工作记忆机制

大量研究证实数字空间联结是一种稳定存在的表征形式。而关于数字空间联结的机制目前仍存在较大争论,本文在系统整理了大量有关长时记忆"心理数字线"难以解释的研究后,分析总结了工作记忆在数字空间联结中的重要作用。基于多个研究任务分析了工作记忆不同成分,即中央执行、语音环路和视空模板等,在数字空间联结中的重要作用,并系统介绍了对数字空间联结的工作记忆序列位置的解释。总之,数字空间联结的工作记忆机制仍有较多需要解决的问题,具有进一步探索的广泛空间。