PDP experimenters train them with thousands of example inputs with correction feedback. But connectionist models are claimed to be able to explain actual brain processes. One possibility is that the brain tutors its own neural networks through a bootstrapping process. Cognition could involve development of easily acquired tutoring processes of limited efficiency and effectiveness which in turn tutor later and cognitively more effective and efficient processes. The development of reading may provide such an example.
Children pass through several stages in learning to read English.
The limited vocabulary of logographically recognizable words could provide the examples needed to train the phonological neuronal network. This relationship could occur between the phonological and orthographic neuronal networks with the phonological decoding of written words functioning not only to identify them but also to tutor the development of hidden units in the orthographic network. While this analogy is misleading, it is true that the PDP account of learning requires a kind of conditional reinforcement in the form of adjustment of hidden units by back-propagation. But it could be important to our understanding of the role of PDP models in. A. Nature 331.