Signal, Noise, Performance, and Age
Signal, Noise, Performance, and Age
复制标题
信号、噪声、性能和寿命
作者：
A. Welford
十年前，对影响表现的中枢机制的年龄变化的研究20年来，似乎可以用四个主要标题来总结：感知和行动的减慢、注意力的任何转移对短期记忆的破坏增加、在长期记忆中寻找材料的困难，以及应对某些类型的复杂性的困难。根据最近的发现，这四个标题下的理论被重新审视，这些发现表明，老年人大脑中的信噪比较低，但同时有一种自发的倾向，即采取优化表现的策略。这种方法直接导致了在歧视和一些选择反应任务中花费更长的时间，并间接地解释了至少部分老年人更倾向于监测自己的反应。提出了一个将同样的方法应用于记忆的模型。在这个模型中，短时记忆和长时记忆的表现都很差，这是由于未能将项目从初级记忆转移到二级记忆，以及长期记忆中建立的痕迹的薄弱。该模型提出了一些尚未回答的问题，即信号和响应之间的复杂关系是如何处理的。
Ten years ago, it seemed reasonable to summarize two decades of research on the age changes in central mechanisms affecting performance under four main headings: slowing of perception and action, increased disruption of short-term memory by any shift of attention, difficulty in searching material in long-term memory, and difficulty in coping with certain kinds of complexity. Theories under these four headings are reexamined in light of recent findings which imply that older people have a reduced signal-to-noise ratio in the brain but at the same time a spontaneous tendency to adopt strategies which optimize performance. This approach accounts directly for longer times taken in discrimination and some choice reaction tasks, and indirectly for at least some of the greater tendency of older people to monitor their responses. A model is proposed which applies the same approach to memory. In terms of this model, poor performances in both short- and long-term memory are due to failure to transfer items from primary to secondary memory and to the weakness of traces established in long-term memory. The model raises some as yet unanswered questions about the precise manner in which complex relationships between signals and responses are handled.