Progress of Researches on Brain Mechanism Underlying Regulatory Effect of Acupuncture Intervention on Visual Plasticity of Amblyopia / 针刺研究

Acupuncture therapy has a positive effect in the treatment of amblyopia. This article summarizes findings of the research on brain mechanisms underlying the regulatory effect of acupuncture on visual plasticity of amblyopia. In a multi-system and multi-level viewpoints, we elaborated brain mechanism underlying the regulatory effect of acupuncture on visual plasticity in amblyopia from the perspective of ultrastructure, plasticity, electrical activities, neural coding and visual microcirculation of the neurons of the visual cortex, and the targeting points from the visual center to the effector organ.

What we see is how we are: New paradigms in visual research

As most sensory modalities, the visual system needs to deal with very fast changes in the environment. Instead of processing all sensory stimuli, the brain is able to construct a perceptual experience by combining selected sensory input with an ongoing internal activity. Thus, the study of visual perception needs to be approached by examining not only the physical properties of stimuli, but also the brain's ongoing dynamical states onto which these perturbations are imposed. At least three different models account for this internal dynamics. One model is based on cardinal cells where the activity of few cells by itself constitutes the neuronal correlate of perception, while a second model is based on a population coding that states that the neuronal correlate of perception requires distributed activity throughout many areas of the brain. A third proposition, known as the temporal correlation hypothesis states that the distributed neuronal populations that correlate with perception, are also defined by synchronization of the activity on a millisecond time scale. This would serve to encode contextual information by defining relations between the features of visual objects. If temporal properties of neural activity are important to establish the neural mechanisms of perception, then the study of appropriate dynamical stimuli should be instrumental to determine how these systems operate. The use of natural stimuli and natural behaviors such as free viewing, which features fast changes of internal brain states as seen by motor markers, is proposed as a new experimental paradigm to study visual perception.

El proyecto comuutacional conexionista en el análisis teórico de la actividad / Cociente the commptational-connectionist project in the theoreticcal analysis of conscious activity

Consciousness, that experienced flow of subjective states, is one of the mysteries, and perhaps, the fundamental challenge of science until now. It is also a field of exploration specially active and fruitful, a field that has passed over the frontier of XIX and XX centuries, and recently arrived again with a strong impetus in the XXI century. However, there is a great controversy about the plausibility of a theoretical, analytical and formal (v.g.: computational) explanation of the phenomena that we associate with consciousness. Is it possible to establish a reductionist explanation of consciousness? Or in other words, is it possible to make a description of the conscious phenomena expressed in terms of functional and/or causal relationships? In this article I give some relevant elements to sketch the sufficiency of explanation of the connectionist computational paradigm, and how we could elucidate the formal principles embedded in the study of consciousness. The purpose of the present article is to suggest that the plausibility of the connectionist paradigm is supported by the following issues: (1) the level of fine-grained detail with which we define the representation and computability of conscious states, (2) the methodological and conceptual advances of brain sciences, and (3) the difference that we assume between the notions of simulation, modelling and computational representation of consciousness. With these ideas in mind, through the manuscript I will show a basic framework to understand why connectionism can be a plausible candidate to think about a formal theory of consciousness. Finally, in the light of the previous statements, I will point out some important issues to discuss the plausibility of a computational theory of consciousness.

La actividad conciente, ese devenir que experimentamos como una serie de estados de subjetividad, es uno de los misterios, y quizás el desafío fundamental de la ciencia contemporánea. Es también un campo de exploración especialmente activo y fructífero que sobrevivió la transición entre los siglos XIX y XX, y nuevamente ha tomado un fuerte impulso ahora en el XXI. Existe, sin embargo, una gran controversia sobre la plausibilidad de una explicación teórica, analítica y formal (v.g.: computacional) de los fenómenos que asociamos a la actividad conciente. ¿Es factible formular una explicación reduccionista de la actividad conciente, es decir, una descripción del fenómeno expresada en términos de relaciones funcionales y/o causales? Los párrafos del presente ensayo escudriñan algunos elementos relevantes a fin de establecer la suficiencia explicativa que tiene el paradigma computacional conexionista para dilucidar los principios formales imbricados en el estudio de la actividad conciente. El propósito que subyace la elaboración siguiente es sugerir que la viabilidad del conexionismo y del proyecto computacional depende de los siguientes aspectos: (1) El grado de refinamiento con el que se defina la representación y la computabilidad de los estados concientes, (2) Los avances metodológicos y conceptuales de las ciencias del cerebro, y (3) La distinción que se haga entre simulación, modelamiento y representación computacional de la actividad conciente. Con estas ideas en mente, a través del capítulo mostraré un esquema conceptual básico para entender por qué el paradigma conexionista puede ser un candidato plausible para pensar una teoría formal de la actividad conciente. Finalmente, a la luz de los planteamientos presentados, señalaré algunos aspectos importantes para establecer la viabilidad de una teoría computacional de la actividad conciente.

Research development in informatics entropy of neural coding / 国际生物医学工程杂志

With the development of brain research, study of neural coding has attracted more attention. Neural coding by informatics entropy is a very important aspect in the research field. This paper presents an overview of typical entropy coding methods of neuronal spike train including binary string method, direct method, asymptotically unbiased estimator method, inter-spike interval and mutual information method. Related principles and application are reviwed.

Status and advance of electronic retina / 医疗卫生装备

This paper summarizes the core issues, realization scheme and key technologies of electronic retina with its status and advance reviewed. On the basis of the relationship between the information processing in visual cortex and retinal nerve coding, the prospect of electronic retina is predicted, and thus our futural orientation is determined.