Page 108 - Artificial Intelligence in the Age of Neural Networks and Brain Computing

96 CHAPTER 5 From Synapses to Ephapsis

Freeman and Vitiello propose that the physical nature of SBS carrier wave is a
dipole wave in which the 3D-rotational (electric) axis is spontaneously broken.
They believe that cortical boson condensate, or its wave packet, may explain the rapid
course of perception: how neocortex can respond to the impact of photons from a face
in a crowd on a handful of retinal neurons mixed among many impulses elicited by
light from the crowd. Phase transition of order from disorder emerges suddenly: the
neural vapor as it were condenses into neural droplets, the first step in recognition
within a few tens of milliseconds, which is insufficient for classical models.
Boson condensate enables an orderly description of the phase transition that in-
cludes all levels of macroscopic, mesoscopic, and microscopic organization of the ce-
rebral patterns that mediate the integration of animal with its environment. Dendritic
trees may interact by ephapsis of the ionic currents from their neighbors densely
packed in neuropil. No one knows how ephaptic transmission works, but the candidate
mechanism may include coupling through water dipoles, because both the intracel-
lular and extracellular compartments are weak ionic solutions, comprised of more
than 80% water, with high electrical conductivity on either side of the lipid layers.
This is in good agreement with Carver Mead’s observation in Collective Electrody-
namics that electric dipoles coupling is million time stronger than coupling of mag-
netic dipoles. Nambu-Goldstone (NG) theorem predicts that the quanta have zero
mass and thus they can span the whole system volume without inertia.
According to Freeman, cognitivists assign the starting point for analysis to the
sensory receptors in the skin. Bundles of axons serve as channels to carry the infor-
mation to the brainstem and eventually information converges in thalamus where it
is already subdivided and classified by the receptors in respect to its features such as
color, motion, or tonal modulation. These researchers view thalamus as acting like a
postmaster to deliver the bits of information to destinations that have already been
assigned by the sensory receptors. They think that stimulus salience selects the in-
formation for transmission to cortex. Pulses represent primitive elements of sensa-
tion, or features. The primary cortex combines these representations of features
into representations of objects and transmits them into adjacent association areas;
a combination of lines and colors might make up a face, a set of phonemes might
form a sentence, and a sequence of joint angles might represent a gesture after a
“binding” process is executed. The problem is that so far cognitivists have not
been able to show where that happens or in what way perception differs from sensa-
tion or where the information in perception changes into information for action.
Freeman assigns the starting point to the limbic system, not the sensory recep-
tors. Hippocampus is a part of surface of each cerebral hemisphere, only buried
deep inside the medial temporal lobe. It is more like the hub of spider web than
the memory bank or CPU of a computer. Entorhinal cortex, which interacts with
so many other parts of the brain, is the main source of input and output from hippo-
campus and it, rather than thalamus, performs multisensory convergence, followed
by spatial localization of events and temporal sequencing of them into hippocampus,
which cooperates with other areas to form multisensory perceptions and coordinates
learning, remembering, and recall. Perception starts with attention and expectations