177,018 research outputs found
Visuo-motor recalibration alters depth perception
No full textRelative depth from retinal disparities is overestimated at distances within the peripersonal space (where objects can be reached) and underestimated beyond the peripersonal space. This finding suggests that the extent of the peripersonal space may constrain the interpretation of retinal disparity. If this is the case then modifying the peripersonal space through visuo-motor recalibration should also modulate perceived depth from retinal disparities.
Participants performed a manual depth estimation task before and after visuo-motor recalibration. Visuo-motor recalibration was induced by displacing the visual feedback of the index finger in depth (15 cm). During the recalibration phase participants were required to repeatedly reach-to-point without haptic feedback to a vertical rod positioned at various distances within and beyond the peripersonal space. In the test phase, participants viewed a display composed of three vertical rods: one rod was positioned midway and in front of two flanking rods. Three depth separations were used between the central rod and the flanker rods, and this arrangement of rods was presented at three distances. Three-dimensional information was provided in a virtual environment by binocular disparities with consistent vergence and accommodation cues.
We found that visuo-motor recalibration strongly increased the estimates in the manual depth estimation task, coherently with the idea that the perceived depth is rescaled in accordance with an extended peripersonal space. Contrary to this result, the conflict between proprioceptive and visual cues in the recalibration phase should decrease perceived absolute distance. This would lead to an underestimation of the relative depth from retinal disparities. To test whether the effect we found in the manual depth estimation task is truly perceptual, participants also performed an open-loop reach-to-grasp task. Interestingly, in this motor task neither the grip aperture nor the final hand position were affected by recalibration revealing also a possible dissociation between reach-to-point and reach-to-grasp movements
Peace psychology in the Balkans: in times past, present and future
No full textThis chapter provides an overview of the contributions that Peace Psychologists have made to the understanding of confl ict and peace in the Balkan region. The recent history of physical violence in Balkan nations, such as Bosnia- Herzegovina, Croatia, Serbia, Macedonia and Romania, make this an important area of analysis given its potential to broaden our understanding of peace and confl ict processes world-wide. The analysis provided in this chapter is multi-directional in its consideration of past, present and future realities. Explanations for the history of confl ict in the region are identifi ed, the present realities of peace and confl ict explored and pathways to a more peaceful future proposed. The analysis is also multi-faceted considering both micro-level and macro-level factors relevant to the history and future of peace in the region. Micro-level factors, such as social norms, individual attitudes and relations to other ethnic groups, are shown to have complex interactions with macro-level factors, such as politics and economics, in predicting both peace and violence in the Balkan region. The analysis is relevant to academic disciplines as diverse as peace studies, politics and sociology, but remains fi rmly embedded within a peace psychological framework
Visuomotor adaptation changes the processing of binocular disparities and tactile discrimination.
No full textPerceptual judgments of relative depth from binocular disparity are systematically distorted in humans, despite in principle having
access to reliable 3D information. Interestingly, these distortions vanish at a natural grasping distance, as if perceived stereo depth is
contingent on a specific reference distance for depth-disparity scaling that corresponds to the length of our arm. Here we show that the
brain’s representation of the arm indeed powerfully modulates depth perception, and that this internal calibration can be quickly
updated. We used a classic visuomotor adaptation task in which subjects execute reaching movements with the visual feedback of their
reaching finger displaced farther in depth, as if they had a longer arm. After adaptation, 3D perception changed dramatically, and became
accurate at the “new” natural grasping distance, the updated disparity scaling reference distance.We further tested whether the rapid
adaptive changes were restricted to the visual modality or were characteristic of sensory systems in general. Remarkably, we found
an improvement in tactile discrimination consistent with a magnified internal image of the arm. This suggests that the brain
integrates sensory signals with information about arm length, and quickly adapts to an artificially updated body structure. These
adaptive processes are most likely a relic of the mechanisms needed to optimally correct for changes in size and shape of the body during ontogenesis
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Journalistic views on post-violent peacebuilding in Bosnia and Herzegovina
No full textIn this chapter we focus on the media portrayal content of a specific traumatic event and journalists’ discourse about it in Bosnia and Herzegovina (BIH). Despite the growing role and authority of journalists in shaping our understanding of collective pasts, the possible role of journalists as active agents in contributing to heightening tensions has been marginalized. Analyzing media texts can demonstrate how a “specific, limited truth” about the start of war in BIH is being selected, instrumentalized, and legitimized in the public awareness. Focus on journalists’ perceptions of war and positive post-violence offers an understanding of different views about the start of the war, and guilt. This is why the basic research questions here deal with how journalists in BIH represent the violent past. Specifically, how do they cover a specific traumatic event and what are their perceptions about possibilities of realizing positive post-violence? Research on post-conflict processes looks at the ways in which people attempt to recreate their social fabric in ways appropriated to the changes in their social environment. Thus, the larger question that we are interested in here is whether journalists, like storytellers, frame their stories according to their ethnical belonging and the cultural environment? Furthermore, what media conditions might make possible positive post-violence after violent conflict
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Letter from R. R. Zellick, Assistant Trust Officer, Anglo California National Bank of San Francisco, to Joseph R. Goodman, October 2, 1942
No full textLetter from R. R. Zellick, Assistant Trust Officer at The Anglo California National Bank of San Francisco, to Joseph R. Goodman, regarding property owned by Dave Tatsuno. Zellick mentions a dispute between current tenants and Tatsuno, and that Tatsuno has asked Goodman to help locate trustworthy tenants.Personal correspondence, organizational records, government documents, publications, and other papers created or collected by Joseph R. Goodman documenting the forced removal and incarceration of Japanese Americans during World War II, as well as organized resistance to incarceration. Included in the collection are records of the Japanese Young Men's Christian Association and the Japanese American Citizens' League in San Francisco, including papers of the Japanese YMCA's executive secretary Lincoln Kanai; Sakai family papers; Goodman's correspondence to and from Japanese American incarcerees, organizations opposing forced removal and incarceration of Japanese Americans, the War Relocation Authority, and others; publications, photographs, and ephemera from the Topaz Relocation Center, where Goodman taught high school; War Relocation Authority records and publications; and newspaper clippings, pamphlets, and reports about forced removal and incarceration created by various government, religious, and civic organizations, in California and nationwide
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