By K. Cole. Washington University in Saint Louis.
Beyond common applications discount slimex 10mg line, several specialized work environments have led to the development of haptic experts who routinely conduct high-resolution perception through tools order 15mg slimex otc. Geologists provide one example as they analyze sub-millimeter surface features using sharp-tipped probes (e. This kind of mechanical analysis is now being developed for automated sample measurement, for example, in unmanned NASA geological expeditions. A better understanding of the active strategies and mechanical filtering employed in the model vibrissa sensory system may provide not only a better understanding of fundamental principles of neural representation, but also insight into important aspects of human perception. Jason Ritt for collaboration on development of many of the ideas presented here, and Cheryl Cheney for assistance in preparation of the manuscript. The description of a cortical field composed of discrete cytoarchitectonic units, Brain Res 17 (2), 205-42, 1970. Adaptation and coding of stimulus parameters, Somatos- ens Res 1 (2), 95-117, 1983. Hyvarinen, Cortical neuronal mecha- nisms in flutter-vibration studied in unanesthetized monkeys. Neuronal periodicity and frequency discrimination, J Neurophysiol 32 (3), 452-484, 1969. A continuum mechan- ics model of skin predicting mechanoreceptor responses to bars, edges, and gratings, J Neurophysiol 46 (6), 1204-25, 1981. Fluctuations in Cortical Excitability B Timing-Based Plasticity of Intracortical Connections C. Concluding Observations Concerning Temporal Plasticity Rules Acknowledgments References I. SUMMARY We outline a systematic approach to investigating the role of modular map-like cortical organization in the processing of sensory information. We survey current evidence concerning the functional significance of cortical maps and modules, argu- ing that the topographic framework of primary sensory cortex renders the encoding and storage of sensory information efficient, fast, and reliable. Neuronal populations in sensory cortex exhibit fluctuations in excitability, charac- terized by bursts of spikes synchronized across barrel cortex. By comparing the plasticity induced by sensory inputs delivered during bursts compared to those delivered between bursts, we discovered that the strength of co-activity between columns in the barrel cortex can be modified by sensory input patterns during discrete, intermittent intervals time-locked to bursts. These spatial and temporal rules provide a context for understanding the barrel cortex in an awake exploring rat.
It is important to know that at 45° of abduction generic slimex 15mg mastercard, the test primarily evaluates the medial glenohumeral ligament and the subscapularis tendon generic slimex 10mg without a prescription. At or above 90° of abduction, the stabilizing effect of the sub- Buckup, Clinical Tests for the Musculoskeletal System © 2004 Thieme All rights reserved. Apprehension Test (Supine) Procedure: The patient is supine with the arm abducted, externally rotated, and flexed at the elbow. Buckup, Clinical Tests for the Musculoskeletal System © 2004 Thieme All rights reserved. Rowe Test Procedure: The patient stands and bends forward slightly with the arm relaxed. Assessment: This position allows the examiner to perform a slight anterior-inferior translation and evaluate the stability of the shoulder. Leffert Test Procedure and assessment: The Leffert test can be used to quantify a drawer phenomenon. Assessment: Significant anterior or posterior mobility of the humeral head suggests instability. The affected shoulder is held in 80°–120° of abduction, 0°–20° of flexion, and 0°–30° of external rotation as loosely and without pain as possible. The examiner immobilizes the scapula with the left hand (with the index and middle fingers on the scapular spine and the thumb on the cora- coid). Assessment: The relative motion between the immobilized scapula and the anteriorly displaced humerus is a measure of anterior instability and can be classified in degrees. Buckup, Clinical Tests for the Musculoskeletal System © 2004 Thieme All rights reserved. By pressing the abducted, horizontally flexed, and internally rotated arm posteriorly, the examiner attempts to provoke posterior subluxation of the humeral head. Assessment: Suf• cient laxity in the capsular ligaments will allow posterior subluxation or even dislocation of the humeral head with associated pain. Maintaining the axial pressure on the humeral head increasingly abducts and retracts the arm.
