|Slow Waves, Consciousness and the Geon||Memory|
Slow oscillations (0.5 - 1 Hz) have been shown to cause the loss of consciousness in slow wave sleep, general anesthesia (Lewis et al., 2012) and certain types of epilepsy (Englot et al., 2010). Recently, mounting evidence has suggested that the resting state networks play a key role in consciousness (Vanhaudenhuyse et al., 2010; Heine et al., 2012; Danielson et al., 2011).
The resting state networks consist of four networks: default mode network (DMN), cingulo-opercular network, fronto-parietal network, and cerebellar network. The brain areas in these networks are not connected by direct synaptic contacts due to their long distances. Yet, they are functionally connected as revealed by the functional magnetic resonance imaging (fMRI). The functional connectivity measures the degree of synchronized neural activity between different brain regions (Coutanche and Thompson-Schill, 2013).
The resting state networks oscillate synchronously at very low frequency, 0.02 - 0.1 Hz (Biswal et al., 1995; Achard et al., 2006; Broyd et al., 2011). It is likely that the DOWN state of the slow oscillations may disrupt the global synchronization of the resting state networks, thereby resulting in the loss of consciousness.
At a more fundamental level, consciousness may arise from the formation of a gravitational geon. According to the Geon Hypothesis, the major role of the resting state activity is to produce a gravitational geon which is composed of only gravitational waves held together in a confined region by their mutual attraction. Once a basic conscious geon is formed, it can bind several pieces of information to produce a unified conscious percept. The information is encoded in the gravitational waves which normally propagate at the speed of light. Therefore, in the absence of a geon, the sensory information will leave the brain almost instantly without being perceived. This explains why during the slow wave sleep or under general anesthesia, the subject cannot experience any sensory stimuli, although the sensory areas (e.g., auditory cortex) still function as normal (Issa and Wang, 2008; Hudetz, 2012).
Author: Frank Lee
[A detailed and updated version is available in the book, The Origin of Consciousness.]