A Modeling Study of Potential Sources of Curvature in Human Reaching Movements

The authors of this article suggest that the slight but consistent posture-dependent curvature of the spatial paths in the kinematic transformation between intrinsic and extrinsic coordinates may result in a systematic curvature of movements initially planned as straight-line trajectories toward the target. A kinematic planning model is presented that takes into account the anisotropy of the intrinsic and extrinsic transformation and tends to avoid movements that require excessive joint rotations by introducing slight deviations from a straight-line trajectory. Preliminary simulations showed reasonably good agreement with experimental data, especially considering that the current model is strictly based on kinematics. A quantitative analysis showed that the strategy used in the model achieves a favorable compromise between straight-line movements and angular joint changes: By slightly increasing the spatial length of the movement (i.e., by introducing curvature), an individual can greatly reduce the total amount of joint rotation required to produce the movement.     

Reorienting with terrain slope and landmarks

Orientation (or reorientation) is the first step in navigation, because establishing a spatial frame of reference is essential for a sense of location and heading direction. Recent research on nonhuman animals has revealed that the vertical component of an environment provides an important source of spatial information, in both terrestrial and aquatic settings. Nonetheless, humans show large individual and sex differences in the ability to use terrain slope for reorientation. To understand why some participants—mainly women—exhibit a difficulty with slope, we tested reorientation in a richer environment than had been used previously, including both a tilted floor and a set of distinct objects that could be used as landmarks. This environment allowed for the use of two different strategies for solving the task, one based on directional cues (slope gradient) and one based on positional cues (landmarks). Overall, rather than using both cues, participants tended to focus on just one. Although men and women did not differ significantly in their encoding of or reliance on the two strategies, men showed greater confidence in solving the reorientation task. These facts suggest that one possible cause of the female difficulty with slope might be a generally lower spatial confidence during reorientation.     

Preface to Opicinus de Canistris: concluding lecture by C.G. Jung,Eranos, Ascona, 1943 and Further studies on Jung's Eranos seminar on Opicinus de Canistris

In 1943, Jung held a seminar at Eranos for a limited number of students dedicated to ‘solar myths’, which were exemplified specifically in the cartographic art of Opicinus de Canistris (c. 1296–1352). This seminar has stayed out of print until a few years ago. Notes taken during the seminar by one of Jung's students, Alwine von Keller (1878–1965), were discovered in the Eranos archives and published. Now, for the first time ever, the notes of another of his students, Rivkah Schärf Kluger, taken during the same seminar, are being published. This second series of notes are more extensive. They complete the first series by adding many features and so allow us to put together a more complete picture of Jung's seminar. James Hillman, who received these notes from William McGuire in 1976, firmly believed that they were important enough to be published. Now, seventy years after this seminar, thanks to the support of the Stiftung der Werke von C. G. Jung, the Eranos Foundation and the Journal of Analytical Psychology, these notes are finally being published.     

Consequence and Interpolation in ?ukasiewicz Logic

Building on Wójcicki??s work on infinite-valued ?ukasiewicz logic ?_??, we give a self-contained proof of the deductive interpolation theorem for ?_??. This paper aims at introducing the reader to the geometry of ?ukasiewicz logic.     

The ‘If’ in the ‘What If’

In this paper, I defend the view that any good account of the logical form of thought experiments should contain a conditional. Moreover, there are some reasons to think it should be a counterfactual conditional. First, I defend Williamson’s account of the logical form of thought experiments against a competing account offered by Ichikawa and Jarvis. The two accounts have a similar structure, but Williamson’s posits a counterfactual conditional where Ichikawa and Jarvis’ posits a strict conditional. Williamson’s motivation is related to the problem of deviant realizations, and Ichikawa and Jarvis propose to take care of this problem by enriching the content of the thought experiment in the way we enrich the content of a text of fiction. However, this sort of enrichment is also compatible with Williamson’s account. I then consider a different view, defended by Malmgren, on which a complex possibility claim exhausts our reasoning on typical thought experiments. I argue that this account, leaving out a conditional, fails to represent an important part of our reasoning with thought experiments. This is brought out by reflection on the relationship between thought experiments and similar actual cases and by reflection on the requirement, formulated by Malmgren herself, that our reasoning should have an adequate level of generality.

     

Songs as an aid for language acquisition

In previous research, Saffran and colleagues [Saffran, J. R., Aslin, R. N., & Newport, E. L. (1996). Statistical learning by 8-month-old infants. Science, 274, 1926-1928; Saffran, J. R., Newport, E. L., & Aslin, R. N. (1996). Word segmentation: The role of distributional cues. Journal of Memory and Language, 35, 606-621.] have shown that adults and infants can use the statistical properties of syllable sequences to extract words from continuous speech. They also showed that a similar learning mechanism operates with musical stimuli [Saffran, J. R., Johnson, R. E. K., Aslin, N., & Newport, E. L. (1999). Abstract Statistical learning of tone sequences by human infants and adults. Cognition, 70, 27-52.]. In this work we combined linguistic and musical information and we compared language learning based on speech sequences to language learning based on sung sequences. We hypothesized that, compared to speech sequences, a consistent mapping of linguistic and musical information would enhance learning. Results confirmed the hypothesis showing a strong learning facilitation of song compared to speech. Most importantly, the present results show that learning a new language, especially in the first learning phase wherein one needs to segment new words, may largely benefit of the motivational and structuring properties of music in song.     

An Elementary Proof of Chang's Completeness Theorem for the Infinite-valued Calculus of Lukasiewicz

The interpretation of propositions in Lukasiewicz's infinite-valued calculus as answers in Ulam's game with lies--the Boolean case corresponding to the traditional Twenty Questions game--gives added interest to the completeness theorem. The literature contains several different proofs, but they invariably require technical prerequisites from such areas as model-theory, algebraic geometry, or the theory of ordered groups. The aim of this paper is to provide a self-contained proof, only requiring the rudiments of algebra and convexity in finite-dimensional vector spaces.     

The process-observer in group therapy

This case study describes the inclusion of a nonverbal, trained process-observer into therapy groups for parents having severely disturbed family systems. The observer remained nonverbal during the sessions while taking notes to be used in writing a one-page clinical summary, which was mailed to each group member. The process-observer was included to improve the clients' initial involvement in dealing with personal problems and as a catalyst for group development. Among the important functions of the written summaries were: reduction of initial anxiety, focusing the group on important issues, enhancement of continuity across sessions, and promoting therapeutic work between sessions. The observer was also valuable in providing feedback to the therapists. Specific guidelines for the use of a process-observer are provided.     

Stress Management Counseling: From crisis to prevention

The importance of developing preventive stress management interventions in major societal institutions is emphasised, with particular attention given to the schools and employment settings. The unique role that counseling psychology can assume in promoting preventive stress management interventions is discussed. Review of major stress theories and examples of interventions are presented.