Impairments in tactile search following superior parietal damage

The superior parietal cortex is critical for the control of visually guided actions. Research suggests that visual stimuli relevant to actions are preferentially processed when they are in peripersonal space. One recent study demonstrated that visually guided movements towards the body were more impaired in a patient with damage to superior parietal cortex. Whereas past studies have explored disordered movement in optic ataxic patients, there has been less exploration of space perception in terms of search capacity in this population. In addition, there is some debate concerning the relationship between deficits of visuomotor control and impaired attention/perception in optic ataxia. Given that the dorsal stream has been implicated in the spatial processing of stimuli in peripersonal space, and damage to this region is known to cause optic ataxia, we felt that further investigation was warranted. We examined tactile search behavior in the fronto-parallel and radial planes in a patient with right superior parietal damage and optic ataxia. We used a pegboard with removable cylindrical pegs that allowed for the reorganization of targets between trials. To better characterize three-dimensional search behavior, we included both horizontal and vertical search conditions. Results showed that the patient spent more time searching, was more accurate and revisited more targets in right versus left space. Interestingly, the patient spent the majority of her time specifically searching the lower right quadrant of the stimulus array. Further analysis revealed lower target detection rates along the outer borders of the pegboard on all sides. The search pattern observed here is unusual considering that all targets were within arm's reach. The present experiment demonstrates that damage to superior parietal cortex impairs tactile search and biases exploration towards lower right peripersonal space.     

脑动静脉畸形手术前后血流灌注的TCD研究

对脑AVM患者手术前后进行TCD检查以及激光多普勒监测,以探讨脑AVM患者血流动力学指标与手术后局部脑皮层血流量指标变化的相关性,从而为预测正常灌注压突破综合征提供依据。结果显示AVM患者高流量组与低流量组之间手术后rCBF值存在显著差异(P0.05),并且不同流量AVM供血动脉的血流动力学指标差异性于手术后消失。因此,通过对AVM患者手术前后TCD监测,有助于为预测术后局部脑皮层血流量变化提供依据。     

Detection and discrimination of optical flow components

Observers viewed animation sequences consisting of random dots, some of which moved coherently in a given direction (signal dots) and the rest of which moved randomly (noise dots). Using forced-choice procedures, detectability of weak signals within noise was measured for translation, rotation, and expansion/contraction. Sensitivity to all motion types was approximately equal, with practiced observers reliably detecting coherent motion at signal levels as low as 4%. Observers were able to identify the motion structure presented on a given trial at signal levels corresponding to the detection threshold, implying that the neural signals supporting detection are labeled for motion type. Results are discussed in the context of hierarchical analysis of optic flow in which all motion types are registered as patterns of activity among neurons comprising a single mechanism.     

Flow: Beyond Fluidity and Rigidity

The term flow refers to a particular type of experience characterized by feelings of fusion with an on-going activity, effortlessness and fluidity. This article concerns the results of an empirical investigation and phenomenological analysis of this type of experience. The analysis yields a distinction between three phenomenological structures, identified as arising in different combinations within concrete experiences of flow. These results are discussed in relation to the theories of Alfred Schutz and Erving Goffman regarding the organization of experience in everyday life, and in relation to the theory of Otto Friedrich Bollnow regarding moods in everyday life. The results of the analysis are also discussed in relation to different uses of the flow concept in a variety of contexts found in recent theoretical contributions. These differences of usage and approach are explained in the light of the results of the phenomenological analysis, which distinguishes qualitatively different varients within the phenomenon termed flow experience. In conclusion, the need to adopt a broader concept of experience in sociological analysis is emphasized, as well as the need for further empirical studies of the contextual frames of different variants of flow experiences.     

Ethnographic Interview

For an occupational therapist unfamiliar with a culturally diverse treatment population, ethnographic interview is described as an appropriate method for assessing client group needs. This study describes the use of ethnographic interview as a tool which was culturally sensitive to the occupational behaviors of American Indians and Alaska Natives of the Northwest involved in drug and alcohol treatment. Results of the interviews helped the researcher identify sociocultural factors in the acquisition and maintenance of maladaptive behaviors. Recurring themes of the extended family network, the strength and complexity of social norms and codes, and the pervasiveness of alcohol use among this population are described in review of the literature and results of the interviews. Results of the Tennessee Self-concept Scale revealed an overall measure of self-esteem significantly lower than that of the normed population, and enerally supported rehabilitation issues originally identified by the f iterature and expanded on in the interviews. Implications for treatment discuss acceptance of the therapist by members of the culture, the concept of nonmterference, the role of purposeful activity, cultural identification and assimilation, and the use of group work.     

Comparing the Effects of Loving-Kindness Meditation (LKM), Music and LKM Plus Music on Psychological Well-Being

Loving-kindness meditation (LKM), a meditative practice directing caring feelings toward self and others, is a popular, evidence-base approach to increasing well-being. Music listening is also a popular form of emotion regulation used to enhance well-being. This interdisciplinary study evaluated a novel intervention called Convergence—combining LKM with accompanying classical guitar music—and its effects on adults’ well-being, mindfulness, compassion and self-compassion outcomes. Convergence was compared to active control groups LKM-only and Music-only regarding their relative effectiveness in improving these outcomes. Participants (N?=?78; aged 18 to 69?years; 90% females; recruited from the general public) were assigned to either the Convergence, LKM-only, or Music-only condition. Each condition received a 2-hour workshop, involving psychoeducation, three prerecorded meditations, and group enquiry and discussion. Participants were assessed at pre-program, post-program, and 4-week follow-up. Findings revealed that Convergence, LKM-only and Music-only were equally effective interventions, producing improvements in dependent variables with small effect sizes. There was no additive effect of the components when delivered together as Convergence. Significant correlations were found between the amount of home practice, and mindfulness and self-compassion at follow-up. LKM, music listening and Convergence all provide brief, evidence-based alternatives for improving well-being. Practical and theoretical implications are provided, as well as recommendations for future research.     

颞叶皮层在灵长类不变性知觉和原型表征中的重要作用

如果要走出人工智能在感知觉领域的困境．就必须认识到人类特有的受生物现实约束的认知特点。综合分析各种证据表明,知觉和客体识别的本质不是分析千差万别的局部特征,而是提取环境中的大范围不变量（早期为拓扑特性检测）,形成并存贮一定原型表征;颞叶皮层在灵长类这种不变性知觉和原型表征中具有重要作用。     

Flow at Work: Evidence for an Upward Spiral of Personal and Organizational Resources*

The present 2-wave study among 258 secondary school teachers investigates the relationship between personal and organizational resources on the one hand, and work-related flow on the other hand. On the basis of Hobfoll’s (1988) conservation of resources theory, Bandura’ social cognitive theory (1997; 2001), and Fredrickson’s (1998) “broaden-and-build” theory of positive emotions, we formulated two hypotheses: (1) personal resources (i.e., self-efficacy beliefs) and organizational resources (including social support climate and clear goals) facilitate work-related flow (work absorption, work enjoyment, and intrinsic work motivation); and (2) work-related flow has a positive influence on personal and organizational resources. The results of a series of structural equation modeling analyses offer clear support for both hypotheses. The theoretical and practical implications of these findings are discussed. *This research was supported by a grant from the Bancaixa Foundation (#11232.01/1) and the Spanish Ministry of Science & Technology (CICYT #SEC2000-1031).     

A neural model of how the brain computes heading from optic flow in realistic scenes

Visually-based navigation is a key competence during spatial cognition. Animals avoid obstacles and approach goals in novel cluttered environments using optic flow to compute heading with respect to the environment. Most navigation models try either explain data, or to demonstrate navigational competence in real-world environments without regard to behavioral and neural substrates. The current article develops a model that does both. The ViSTARS neural model describes interactions among neurons in the primate magnocellular pathway, including V1, MT⁺, and MSTd. Model outputs are quantitatively similar to human heading data in response to complex natural scenes. The model estimates heading to within 1.5° in random dot or photo-realistically rendered scenes, and within 3° in video streams from driving in real-world environments. Simulated rotations of less than 1°/s do not affect heading estimates, but faster simulated rotation rates do, as in humans. The model is part of a larger navigational system that identifies and tracks objects while navigating in cluttered environments.