摘要:
Auxiliary signals which are proportional to the tracking error between the process and identifier outputs are introduced into the s eries-p arallel (SP) identifier [1-2]. The coefficients of these auxiliary signals are updated at each computational cycle. The asymptotic hyperstability of the resulting SP identifier with variable relaxation gains is proved theoretically and demonstrated experimentally. Computational considerations for implementing SP identifiers are noted and the on-line computational requirements of the two SP identifiers are then compared.
摘要:
Cuneothalamic relay (CTR) neurons display heterogeneity in terms of response properties and morphological characteristics. Subsystems have been proposed in which speed of conduction and afferent synaptic strength serve as distinguishing features. The relevance of these 2 parameters to other commonly measured characteristics of CTR cells was examined. Response properties of 63 CTR cells to electrical stimulation of the ipsilateral superficial radial nerve were studied using extracellular single-cell recording methods in chloralose-anesthetized cats. The stimulus was varied in amplitude and frequency. Conduction speed was inferred from antidromic latency to stimulating of the medial lemniscus just caudal to the thalamus, and from orthodromic first spike latency to superficial radial nerve stimulation. Afferent synaptic strength was estimated by determining maximum frequency following ability (FMAX). Other properties measured include number of spikes per discharge, threshold for electrical activation at the superficial radial nerve, depth of cell within the tissue, and a latency-intensity relation. Antidromic conduction time from the medial lemniscus had a significant inverse correlation only with cell depth. Orthodromic 1st spike latency was correlated (inversely) only with FMAX. The shape of the latency-intensity function was significantly linked to FMAX. Cells appeared to fall into 3 subsets tentatively identified with subsets proposed elsewhere on the basis of responses to natural stimulation.