Analysis of methods to determine the latency of online movement adjustments

When studying online movement adjustments, one of the interesting parameters is their latency. We set out to compare three different methods of determining the latency: the threshold, confidence interval, and extrapolation methods. We simulated sets of movements with different movement times and amplitudes of movement adjustments, all with the same known latency. We applied the three different methods in order to determine when the position, velocity, and acceleration of the adjusted movements started to deviate from the values for unperturbed movements. We did so both for averaged data and for the data of individual trials. We evaluated the methods on the basis of their accuracy and precision, and according to whether the latency was influenced by the intensity of the movement adjustment. The extrapolation method applied to average acceleration data gave the most reliable estimates of latency, according to these criteria.     

Motor imagery in spinal cord injury patients: Moving makes the difference

Both real action control and execution and motor imagery abilities require knowledge of the spatial location of body parts, in other words efference copy information and feedbacks from the sensory system (Frith et al., 2000, Philos. Trans. R. Soc. Lond. B. Biol. Sci., 355, 1771). Spinal cord injuries induce severe motor disability, due to a damage of the descending motor pathways (Cramer et al., 2007, Exp. Brain. Res., 177, 233). Patients' motor imagery competences are variably reported as either normal or defective (Decety & Boisson, 1990, Eur. Arch. Psychiatry Clin. Neurosci., 240, 39; Lacourse et al., 1999, Behav. Brain Sci., 104, 73). We explored biomechanical constraint effects in Spinal Cord Injury (SCI) patients, as they are considered the most reliable indexes of motor imagery abilities (Parsons, 1987b, Cogn. Psychol., 19, 178). Sixteen spinal cord injuries patients and 16 neurologically unimpaired subjects have been administered with (1) the Hand Laterality Task (HLT), in which subjects were asked to judge the laterality of a rotated hand; and (2) the Mirror Letter Discrimination Task (MLD), in which subjects were asked to judge if a rotated character was in its correct upright position or mirror‐reversed form. Our patients did not present the effect of stimulus orientation, neither did they show any effect related to biomechanical constraints. Based on these data, the hypothesis is that SCI patients' performance may be ascribed to the use of a different strategy to solve the tasks, based on memory rather than on mental rotation.     

Disgust sensitivity predicts political ideology and policy attitudes in the Netherlands

Individual differences in disgust sensitivity have been linked to social attitudes and ideology, but the generalizability of this effect and the nature of the political issues implicated remain unclear. In two studies using large Dutch samples, we find that disgust sensitivity predicts political attitudes for issues in several domains related to physical/spiritual purity and pathogen risk. Sensitivity to disgust was significantly associated with attitudes for a general ‘physical and spiritual purity’ factor, as well as specific issue factors regarding sex and sexual minorities, immigration, and foreign outgroups. Additionally, disgust sensitivity was associated with greater likelihood of voting for the socially conservative “Freedom Party” (Partij Voor de Vrijheid). These results suggest that the tendency to experience disgust influences a specific subset of social and political attitudes across cultures. Copyright © 2014 John Wiley & Sons, Ltd.     

Is There a Cultural Barrier Between Historical Epistemology and Analytic Philosophy of Science?

One of the difficulties facing the philosopher of science today is the divide between historical epistemology and analytic philosophy of science. For over half a century these two traditions have followed independent and divergent paths. Historical epistemology, which originated in France in the early twentieth century, has recently been reformulated by a number of scholars such as Lorraine Daston, Ian Hacking, and Hans-Jörg Rheinberger. Elaborating novel historical methods, they seek to provide answers to major questions in the field. In the light of this situation, my article examines the cultural barrier that explains the uneasy relationship between the two traditions. This barrier hinges on a number of factors—institutional, political and social—that are bound up with the philosophical issues in question. By resorting both to historical study and logical analysis, the new historical epistemology incites us to move beyond a rather sterile antagonism.     

From Inverted Spectra to Colorless Qualia: A Wittgensteinian Critique

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Cognitive load of navigating without vision when guided by virtual sound versus spatial language

A vibrotactile N-back task was used to generate cognitive load while participants were guided along virtual paths without vision. As participants stepped in place, they moved along a virtual path of linear segments. Information was provided en route about the direction of the next turning point, by spatial language ("left," "right," or "straight") or virtual sound (i.e., the perceived azimuth of the sound indicated the target direction). The authors hypothesized that virtual sound, being processed at direct perceptual levels, would have lower load than even simple language commands, which require cognitive mediation. As predicted, whereas the guidance modes did not differ significantly in the no-load condition, participants showed shorter distance traveled and less time to complete a path when performing the N-back task while navigating with virtual sound as guidance. Virtual sound also produced better N-back performance than spatial language. By indicating the superiority of virtual sound for guidance when cognitive load is present, as is characteristic of everyday navigation, these results have implications for guidance systems for the visually impaired and others.     

Original thinking in preschool children: A validation of ideational fluency measures

This investigation examined the original thinking of preschool children (N=48). The instruments were lenient and stringent solution‐standard measures of original problem solving and two subsets of the Wechsler Preschool and Primary Scale of Intelligence. Scores for popular and original responses were computed for the lenient and stringent measures. Findings supported the construct validity of conceptualizations of original problem solving based on ideational fluency within the lenient measures, but not within stringent measures. Findings also indicated that the lenient measures are better predictors of real‐world original behavior than stringent measures, especially for young children. The need for development of more reliable and valid measures for assessing real‐world creative behavior is discussed.     

Knowledge About Hand Shaping and Knowledge About Objects

Our two experiments investigated associations between cognitive representations of objects and hand-shape categories. Hand configurations were partitioned according to prehensility and the size of the contacting surface, resulting in the classes: pinch, poke, palm, and clench. Experiment 1 elicited object names in response to configuration-name cues, provided ratings of the relevance of each configuration to a set of objects, and probed for the functions determining such relevance. Cueing with a configuration class elicited an associated object category with substantial intersubject agreement, and vice versa. Both the object categories and the functions associated with the four hand-configuration classes differed substantially, although the same object could be associated to some extent with multiple configurations, given variations in function. Experiment 2 elicited the names of hand-configuration classes in response to unfamiliar forms, which varied systematically in depth and the size of the projecting picture-plane surface. The modal response, response time, and degree of intersubject agreement were directly related to these variables. These structural variables, however, did not adequately predict shaping responses to real objects, as ascertained from Experiment 1. The results have implications for cognitive representation of motor categories and hand shaping in response to objects.