EXPERIMENTAL ANALYSIS OF THE LUMBAR SPINE KINEMATICS

Pain-provoking disorders of the lumbar spine affect most of adult population and nearly everyone suffers from some of them during their lifetime. A common symptom of diseases, injuries or inevitable changes in the area of lumbar spine is known as the Low Back Pain (LBP). A chronic form of the LBP, called the Low Back Pain syndrome, is mostly caused by degenerative changes of intervertebral discs of the lowest intervertebral joints. The work was focused on in vitro analysis of the porcine lumbar spine kinematics. Two last neighbouring intervertebral joints without active tissue, L4/5 and L5/6, were used. The total number of fifteen cadaveric samples of porcine lumbar spine was involved. A unique loading mechanism was designed and constructed for the purposes of this study. Samples were loaded by flexion/extension movement within the physiological range of motion of ± 5°, in a quasi-static mode. The recording and analysing of the lumbar spine kinematics was realized by the motion capture camera system (Qualisys AB, Göteborg, Sweden). The results showed that the so-called instantaneous axis of rotation (IAR), or the corresponding instantaneous centre of rotation (ICR), was an adequate objective parameter for the assessment of the lumbar spine kinematics. Its position was comparable across all samples and situated very close to the spinal canal. For the purposes of this work, an altered artificial disc of a ball-and-socket type (ProSpon, Ltd., Kladno, Czech Republic) was used to study the kinematics of two neighbouring joints after the disc replacement in the area of a caudally situated one. The results of this comparative analysis showed a significant influence of the artificial disc on the kinematics of both, caudally situated joint, where the disc was implanted, and the adjacent one

Modeling Accuracy and Variability of Motor Timing in Treated and Untreated Parkinson’s Disease and Healthy Controls

Parkinson’s disease (PD) is characterized by difficulty with the timing of movements. Data collected using the synchronization–continuation paradigm, an established motor timing paradigm, have produced varying results but with most studies finding impairment. Some of this inconsistency comes from variation in the medication state tested, in the inter-stimulus intervals (ISI) selected, and in changeable focus on either the synchronization (tapping in time with a tone) or continuation (maintaining the rhythm in the absence of the tone) phase. We sought to re-visit the paradigm by testing across four groups of participants: healthy controls, medication naïve de novo PD patients, and treated PD patients both “on” and “off” dopaminergic medication. Four finger tapping intervals (ISI) were used: 250, 500, 1000, and 2000 ms. Categorical predictors (group, ISI, and phase) were used to predict accuracy and variability using a linear mixed model. Accuracy was defined as the relative error of a tap, and variability as the deviation of the participant’s tap from group predicted relative error. Our primary finding is that the treated PD group (PD patients “on” and “off” dopaminergic therapy) showed a significantly different pattern of accuracy compared to the de novo group and the healthy controls at the 250-ms interval. At this interval, the treated PD patients performed “ahead” of the beat whilst the other groups performed “behind” the beat. We speculate that this “hastening” relates to the clinical phenomenon of motor festination. Across all groups, variability was smallest for both phases at the 500-ms interval, suggesting an innate preference for finger tapping within this range. Tapping variability for the two phases became increasingly divergent at the longer intervals, with worse performance in the continuation phase. The data suggest that patients with PD can be best discriminated from healthy controls on measures of motor timing accuracy, rather than variability

The Deep Structure of Lives

La psychologie a toujours traité le comportement et l’expérience comme étant enchâssés dans un flux temporel unidimensionnel, « le courant du comportement » dans lequel les événements et les actions occupent des intervalles de temps qui ne se chevauchent pas. Pourtant, une analyse phénoménologique révèle que la structure de nos vies est bien plus riche et intéressante. En utilisant la notion de « quasidécomposabilité » de Herbert Simon, je décris cette structure comme un assemblage d’épisodes quasi-indépendants se réalisant de façon concurrente, et de nature asynchrone. Il s’agit d’une « structure profonde» des vies contrairement à la conception courante qui conçoit les vies comme « plates ».Psychology has always treated behavior and experience as embedded in a unidimensional flow in time, the “stream of behavior”. This means that events and actions occupy non-overlapping time-intervals in this stream. Nevertheless a phenomenological analysis reveals that the structure of lives is richer and far more interesting. Using Herbert Simon’s notion of near-decomposability, I describe the structure of lives as a composite of nearly independent strands that run concurrently, and are asynchronous. This is a “deep structure” of lives in contrast to the current conception, which conceives of lives as “flat”

Internalization: A metaphor we can live without

Shepard has supposed that the mind is stocked with innate knowledge of the world and that this knowledge figures prominently in the way we see the world. According to him, this internal knowledge is the legacy of a process of internalization; a process of natural selection over the evolutionary history of the species. Shepard has developed his proposal most fully in his analysis of the relation between kinematic geometry and the shape of the motion path in apparent motion displays. We argue that Shepard has made a case for applying the principles of kinematic geometry to the perception of motion, but that he has not made the case for injecting these principles into the mind of the percipient. We offer a more modest interpretation of his important findings: that kinematic geometry may be a model of apparent motion. Inasmuch as our recommended interpretation does not lodge geometry in the mind of the percipient the motivation for positing internalization, a process that moves kinematic geometry into the mind, is obviated. In our conclusion we suggest that cognitive psychologists, in their embrace of internal mental universals and internalization may have been seduced by the siren call of metaphor. Theorists of perception face two fundamental questions

RESPIRATORY SOUNDS AS A SOURCE OF INFORMATION IN ASTHMA DIAGNOSIS

Around 300 million people all over the world at all age level suffer from asthma [1]. Patients with this disease have primarily difficult breathing with wheezing in respiratory sounds, cough and feeling of constricted chest. Therefore their physical activity is strongly limited [2]. Nowadays, there are several methods for asthma diagnosis, for example spirometry, measuring of peaks of expiratory velocity or measuring of bronchial reactivity. Although these methods are sufficiently reliable in most cases, they have also some imperfections, which are obvious especially by diagnosing of badly collaborating patients, e.g. small children aged up to three years. These infants can’t provide operations required for diagnosis, so results performed diagnosis are not reliable. For this reason, there is an idea of developing non invasive method of asthma diagnosis and other pulmonary diseases that would not need collaboration of patient [3]. One of the most probably working usable principles is comparison of air flow in airways of healthy and ill person. The difference of the air flow is caused by bronchial obstruction and constriction of airways of patient. There are other sounds and wheezing in the respiratory sounds detectable during breathing as a typical manifestation of the disease [4]. These phenomena can be detected by hearing of sound or by harmonic analysis

The Illusion Confusion

In "What the Nose Doesn't Know", I argue that there are no olfactory illusions. Central to the traditional notions of illusion and hallucination is a notion of object-failure—the failure of an experience to represent particular objects. Because there are no presented objects in the case of olfactory experience, I argue that the traditional ways of categorizing non-veridical experience do not apply to the olfactory case. In their place, I propose a novel notion of non-veridical experience for the olfactory case. In his (2011), Stevenson responds to my claim that there are no olfactory illusions. Although he agrees that it is natural—or at least commonplace—to think there are no olfactory illusions, he argues that there are and provides examples of them, many of which he suggests have analogues in the visual and auditory domains. In this paper, I examine the nature of the disagreement between us. I argue that Stevenson fails to argue against my conclusion that there are no olfactory illusions