The Transition from Automatic to Controlled Processing.
The transition from automatic (unconscious) to controlled (conscious) processing is described in terms of a neural network model of classical conditioning ([Schmajuk et al., 1996]). In the framework of the network, an environmental stimulus is processed in controlled or conscious mode when Novelty and attention to the stimulus are large, and in automatic or unconscious mode otherwise. In the model, indirect dopamine (DA) agonists, such as amphetamine or nicotine, enhance the DA representation of Novelty, thereby increasing attention and engaging conscious processing of environmental stimuli. By contrast, DA receptor antagonists, such as haloperidol, reduce the DA representation of Novelty, thereby decreasing attention, and engaging unconscious processing of the stimuli.