Figure 12.

Model’s trajectory through semantic space during the bank trial. This plot illustrates the effect of controlled retrieval on the model’s internal representations. We first presented each word to the model in turn, allowed it to settle and recorded activity of the hub layer. Multidimensional scaling was used to plot the relationships between these states in a two-dimensional space (words used in the current trial are highlighted). We then recorded the activity of the hub units as the model completed the dominant and subordinate versions of the bank trial with and without controlled retrieval (CR). The lines plot the trajectory taken by the model through the semantic space as it settled. Without controlled retrieval, settling is determined solely by the identity of the probe, resulting in similar paths on dominant and subordinate trials, both of which end near the canonical representation of bank. Under controlled retrieval, settling is constrained by both probe and target. As a consequence, the model is deflected into areas of the semantic space somewhere between bank and either cashier or tree.