Figure 2.

The connectivity of brain centers involved in the processing of olfactory information and sites that have been proposed to be the neural correlates of attentional selection and conscious processing. Three potential sites of attentional selection and two potential sites of conscious processing can be combined to six models (A–F). Conscious processing of olfactory information could occur in the orbitofrontal cortex with attentional selection occurring prior to conscious processing either in the piriform cortex (A), or the olfactory bulb (B), or the mediodorsal nucleus of the thalamus (C). Alternatively, conscious processing could occur in the piriform cortex with attentional selection occurring in the same structure (D), or prior to conscious processing in the olfactory bulb (E), or after conscious processing in the mediodorsal nucleus of the thalamus.