Matching locations is not just matching sensory representations

People make systematic errors when matching locations of an unseen index finger with the index finger of the other hand, or with a visual target. In this study, we present two experiments that test the consistency of such matching errors across different combinations of matching methods. In the first experiment, subjects had to move their unseen index fingers to visually presented targets. We examined the consistency between matching errors for the two hands and for different postures (hand above a board or below it). We found very little consistency: The matching error depends on the posture and differs between the hands. In the second experiment, we designed sets of tasks that involved the same matching configurations. For example, we compared matching errors when moving with the unseen index finger to a visual target, with errors when moving a visual target to the unseen index finger. We found that matching errors are not invertible. Furthermore, moving both index fingers to the same visual target results in a different mismatch between the hands than directly matching the two index fingers. We conclude that the errors that we make when matching locations cannot only arise from systematic mismatches between sensory representations of the positions of the fingers and of visually perceived space. We discuss how these results can be interpreted in terms of sensory transformations that depend on the movement that needs to be made

Speciale Somalia

La rivista, dedicata ai temi dell'istruzione, del sistema educativo e della lingua in Somalia, contiene i seguenti contributi: M. Pavanello, Premessa; C. Sampietro, Cooperazione tra l'Italia e la Somalia: dati e riflessioni; P. Malesani, L'Università Nazionale della Somalia; A. Amato, L'insegnamento della lingua italiana veicolare in Somalia. Aspetti teorici e operativi; F. Romano, Appunti sul sistema educativo somalo; G. Bonani, Problemi dell'istruzione secondaria superiore in Somalia e ruolo della cooperazione; B. Panza, La lingua somala; B. Tedeschini Lalli, Prospettive della lingua somala.Majalladu waxay ka hadlaysaa mawaadiic ku saabsan waxbarasho, gaar ahaan habka waxbarashada iyo Af-soomaaliga. Dadka wax ka qoray iyo mawaadiicdoodu waa kuwan: M. Pavanello, Premessa; C. Sampietro, Cooperazione tra l'Italia e la Somalia: dati e riflessioni; P. Malesani, L'Università Nazionale della Somalia; A. Amato, L'insegnamento della lingua italiana veicolare in Somalia. Aspetti teorici e operativi; F. Romano, Appunti sul sistema educativo somalo; G. Bonani, Problemi dell'istruzione secondaria superiore in Somalia e ruolo della cooperazione; B. Panza, La lingua somala; B. Tedeschini Lalli, Prospettive della lingua somala.The journal, dedicated to the themes of education, educational system and language in Somalia, includes the following articles: M. Pavanello, Premessa; C. Sampietro, Cooperazione tra l'Italia e la Somalia: dati e riflessioni; P. Malesani, L'Università Nazionale della Somalia; A. Amato, L'insegnamento della lingua italiana veicolare in Somalia. Aspetti teorici e operativi; F. Romano, Appunti sul sistema educativo somalo; G. Bonani, Problemi dell'istruzione secondaria superiore in Somalia e ruolo della cooperazione; B. Panza, La lingua somala; B. Tedeschini Lalli, Prospettive della lingua somala

Framework for planning of long-term reconstruction and recovery - Draft

Guidelines for macroeconomics reconstruction prepared by the International Monetary Fund.Qoraal tilmaamaya habkii loo raaci lahaa dibudhiska dhaqaalaha, waxaana soo diyaariyay hay'adda IMF (miisaaniyadda lacageed ee caalamiga).Linee guida per la ricostruzione economica preparato dal Fondo Monetario Internazionale

Misjudgment of direction contributes to curvature in movements towards haptically defined targets

The trajectories of arm movements toward visually defined targets are curved, even if participants try to move in a straight line. A factor contributing to this curvature may be that participants systematically misjudge the direction to the target, and try to achieve a straight path by always moving in the perceived direction of the target. If so, the relation between perception of direction and initial movement direction should not only be present for movements toward visually defined targets, but also when making movements toward haptically defined targets. To test whether this is so, we compared errors in the initial movement direction when moving as straight as possible toward haptically defined targets with errors in a pointer setting task toward the same targets. We found a modest correlation between perception of direction and initial movement direction for movements toward haptically defined targets. The amount of correlation depended on the geometry of the task. © 2013 American Psychological Association

Proprioceptive Biases in Different Experimental Designs

Systematic biases have been found when matching proprioceptive and visual locations. In this study we investigated whether such visuo-haptic biases depend on the indicator that subjects use and on whether targets are presented on a board (2D) or in free space (3D). Subjects had to move their unseen hand to visually presented targets. They indicated the perceived target position either with their index finger or with a hand-held device, and either on a surface or in free space. We found no differences between the magnitudes of the biases or the directions of the biases. Thus, the results of studies on visuo-haptic biasesis not merely dependent on the used experimental designs and can be generalized