Using a variation of the classical conditioning paradigm with electrical stimulation of neural tissue in behaving primates, Robert Doty (1965, 1969) was able to deduce the ‘sensational’ coding operations of the sensory maps of the neocortex by converting a classical conditioning task into an operant task (also see: Bartlett, Doty et al. 2005; Bartlett and Doty 1980; Doty et al. 1980). Monkeys were trained to depress or release a lever for reward, to signal the detection of electricity delivered to the neocortex. For sensory maps such as area V1, for example, if a monkey was trained to detect electricity delivered to one site and then the electrode was moved to another location within the map (whether ipsilateral or contralateral), the detection response was transferred immediately, much like what happens when a monkey is trained to detect a visual stimulus in one part of the visual field: it can afterwards generalize the response to any location within the visual field immediately (Schiller and Tehovnik 2015). But if the electrode is moved to extrastriate area V4, for example, the detection response acquired by stimulation of V1 is not transferred to V4. New training is required to associate the percept generated by electrical stimulation of V4 and the motor response to obtain a reward. This suggests that the percepts generated by neocortical stimulation are bound per map (Bartlett, Doty et al. 2005). This result concurs with the work of Penfield and colleagues who found that common sensations—i.e., qualitatively similar phosphenes—were evoked from a cortical topographic map (Penfield 1975; Penfield and Rasmussen 1952). Hence, individual maps of the neocortex define sensation or conscious experience, and this sensation depends on the connectivity between the neurons of a map for the immediate transfer of information.

Most significantly, when the forgoing experiment was done in the hippocampal formation, there was never any transfer of the detection response between the different stimulation sites (Knight 1964). This suggests that the hippocampal fibres transmit information independently to and from the neocortex, which is what one would want of a hippocampal pathway mediating the consolidation and retrieval of information vis-à-vis the neocortex (Corkin 2002; Rolls 2004; Penfield and Roberts 1967; Schwarzlose, Kanwisher et al. 2005; Scoville and Milner 1957; Squire et al. 2001). The neocortex contains information that is highly distributed and this information must be recomposed to drive behavior volitionally or a conscious state volitionally, e.g., thinking about biology and consciousness (Corkin 2002; Hebb 1949; Ibayashi et al. 2018; Kimura 1993; Ojemann 1991; Penfield 1975; Sacks 2012; Sereno et al. 2022; Squire et al. 2001; Vanderwolf 2007). The stream of consciousness, as introduced by James (1890), depends on recomposing (or unifying) the cortical information so that the outputs make sense. Schizophrenia is a condition whereby the outputs make no sense.

Summary:

(1) Individual maps of the neocortex define sensation or conscious experience, and this sensation depends on the connectivity between the neurons of a map.

(2) Pathways transmitting information to and from the neocortex to consolidate and retrieve information are composed of neurons that are independent, so that information is stored flexibly throughout the neocortex.

(3) Neocortical information must be recomposed correctly for one not to be diagnosed as a schizophrenic.