Figure 4.

A schematic illustrating the difference between the ecology and mechanisms of learning. For simplification, the speech system (central white box) is as the aspect of the system that maps acoustic inputs to categories. In most models, learning mechanisms are presumed to operate within this system (even as they may get information from other systems). The ecology of the learning system includes properties of the environment such as the distribution of cues, or the availability of signals such as visual cues. It can include factors that are internal to the child such as the lexicon, knowledge of the reading system, or speech production (many of which are discussed later).