Let’s start by taking a look at a classic computational model of visual word recognition – the interactive activation (IA) model introduced by McClelland and Rumelhart in 1981. To load the model choose Load model from the main menu:

select the file titled ia.eNm. After a few seconds you will see the architecture of the model displayed on the right-hand side of the screen:

The IA model is sometimes referred to as a simple model, but this is misleading. It’s true that the architecture of the model is simple – it consists of just three layers, corresponding to letter features, letters and words. Furthermore, this is a localist model, and so each node within the model corresponds to a meaningful entity (i.e., a feature, letter or word). Nevertheless, the model can give rise to complex behaviour. This complexity arises from the nonlinearity of the model’s activation equation and the feedback within and between layers.

Next: Running a trial