Fig. 17.

In the START model framework, ART category learning circuits and Spectral Timing circuits can both inhibit the orienting system: When a good enough match occurs between a feature pattern at level F ₁ and the top-down expectation from the category level F ₂, inhibition can occur of the orienting system A, thereby preventing a memory search. If inhibition from the cognitive-emotional sensory-drive (S − D) resonance that is supported by hippocampal adaptive timing also inhibits A, then the orienting system again cannot fire until the adaptively timed signal is removed. The former mechanism clarifies how hippocampal novelty potentials fade away as thalamo-cortical and cortico-cortical category learning consolidates. The latter mechanism clarifies how orienting responses are inhibited during expected disconfirmations