Wark Barry, Lundstrom Brian Nils, Fairhall Adrienne
Graduate Program in Neurobiology and Behavior, University of Washington, United States.
Curr Opin Neurobiol. 2007 Aug;17(4):423-9. doi: 10.1016/j.conb.2007.07.001. Epub 2007 Aug 21.
Adaptation occurs in a variety of forms in all sensory systems, motivating the question: what is its purpose? A productive approach has been to hypothesize that adaptation helps neural systems to efficiently encode stimuli whose statistics vary in time. To encode efficiently, a neural system must change its coding strategy, or computation, as the distribution of stimuli changes. Information theoretic methods allow this efficient coding hypothesis to be tested quantitatively. Empirically, adaptive processes occur over a wide range of timescales. On short timescales, underlying mechanisms include the contribution of intrinsic nonlinearities. Over longer timescales, adaptation is often power-law-like, implying the coexistence of multiple timescales in a single adaptive process. Models demonstrate that this can result from mechanisms within a single neuron.
适应现象在所有感觉系统中以多种形式出现，这引发了一个问题：其目的是什么？一种有效的方法是假设适应有助于神经系统有效地编码统计特性随时间变化的刺激。为了进行有效编码，随着刺激分布的变化，神经系统必须改变其编码策略或计算方式。信息论方法使得这一有效编码假设能够得到定量检验。从经验上看，自适应过程发生在广泛的时间尺度上。在短时间尺度上，潜在机制包括内在非线性的作用。在较长时间尺度上，适应通常呈幂律形式，这意味着在单个自适应过程中存在多个时间尺度。模型表明，这可能是由单个神经元内的机制导致的。
