These are excerpts and elaborations from my book "The Nature of Consciousness"
The Solipsistic Brain The US neurophysiologist
Walter Freeman discovered that the neural activity due to sensory stimuli
disappears in the cortex and in lieu of it an apparently unrelated pattern
appears, as if the brain created its own version of what happens in the world.
Most of the sensory input is basically wasted. Freeman came to believe that
"a form of epistemological solipsism isolates brains from the world". Each brain creates its own world, which is
internally consistent and complete. Contrary to a popular paradigm, perception
does not consist of information reception, processing, storage, and recall.
Perception is the creation of meaning, a very "subjective" process. How do
"solipsistic" brains communicate? Brains communicate, basically, by
"unlearning": unlearning is a process by which a brain must give up
its beliefs and learn new ones through "socially cooperative"
actions. Freeman believes that brains
have evolved primarily as organs of social cooperation, and originally they
started communicating for sexual reproduction. He retraces the story of
socialization, from the early formation of pair bonds and tribal groups and
identifies music, dance, and sexually based rituals as the means by which
meanings in the brains were shared. Since awareness follows
brain activity by about half a second, Freeman believes that awareness is the
perception of the brain's working, and not the other way around. Brain-machine Interfaces Once understood how parts of
the brain work and send commands to the body, it was not difficult to connect
brains to machines so that the brain's activity directed the machine's
movement. The first electrical implant
in an ear was the work of French surgeons
André Djourno and Charles Eyriès in 1957. Building upon their
work, in 1961 William House invented
the “cochlear implant”, an electronic implant that sends signals from the ear
directly to the auditory nerve (as opposed to hearing aids that simply amplify
the sound in the ear). Spanish-born neuroscientist
José Delgado published the first paper on implanting electrodes into human
brains: “Permanent Implantation of Multi-lead Electrodes in the Brain“ (1952).
In 1965 he famously managed to control a bull via a remote device, injecting
fear at will into the beast’s brain. He then published his dystopian vision in
the book “Physical Control of the Mind - Toward a Psychocivilized Society” (1969). In 1969 he implanted devices in the
brain of a monkey and then sent signals in response to the brain's activity,
thus creating the first bidirectional brain-machine-brain interface. In 2000 William Dobelle developed in Portugal an
implanted vision system that allows blind people to see outlines of the scene.
His patients Jens Naumann and Cheri Robertson became “bionic” celebrities as
Dobelle continued to refine his artificial vision system. In 2002 John Chapin debuted his
"roborats", rats whose brains were fed electrical signals via a
remote computer to guide their movements. As for getting data out of
the brain into a machine (output neuroprosthetics) in 1998 Philip Kennedy developed a brain implant that could capture the “will”
of a paralyzed man (Johnny Ray ) to move an arm. In 2005 Cathy Hutchinson, a
paralyzed woman, received a brain implant from
John Donoghue’s team that allowed her to operate a robotic arm. In 2004 Theodore Berger demonstrated a hippocampal
prosthesis that can provide the long-term-memory function lost by a damaged
hippocampus. And in 2012 Sam Deadwyler’s brain implant managed to even improve the long-term memory of monkeys. Two-way transmission was
just a matter of combining the two technologies. In 2013 the Brazilian-born
neurophysiologist Miguel Nicolelis made two rats communicate (and they were
located in two different countries) by capturing the “thoughts” of one rat’s
brain and sending them to the other rat’s brain over the Internet and an
electrode. In 2013 Rajesh Rao and Andrea Stocco devised a way to send a brain
signal from Rao’s brain to Stocco’s hand over the Internet, i.e. Rao made
Stocco’s hand move, probably the first time that a human was capable of
controlling the body part of another human. In 2014, thanks to Silvestro
Micera’s team, an amputee, Dennis Aabo, received an
artificial hand capable of sending electrical signals to the nervous
system so as to create the touch sensation. When in 2002 the
Brazilian-born neurophysiologist Miguel Nicolelis made a monkey's brain control a
robot's arm, the monkey's brain was extended in three directions: it expanded
the distance at which that brain could operate (because the robot was
physically outside the monkey's body), it increased the strength of the force
it could generate (because the robot was stronger than the monkey's body), and
it reduced the time for a thought to translate into a movement (because the
robot reacted faster than the body itself). In 2008 the team made the monkey
control a remote robot (in fact, located in another continent) and control it
to cause bipedal locomotion. This further extended the distance, the strength
and the speed of which the monkey's brain was capable. Finally, they
implemented a bidirectional brain-machine-brain interface within the same
individual brain. Nicolelis grounds his experiments into a
theory of the brain that views the neural group (a population of interconnected
neurons) as the elementary unit of thought rather than the single neuron. A
stimulus has an effect on a neural group: a population of "tuned" neurons
is the unit that detects, stores and responds to information. This is a view
that he contrasts with the reductionist approach to dig deeper and deeper into
smaller and smaller constituents to explain the functioning of the whole. The
individual neuron may participate in more than one neural group, and its
spiking may have different "meanings" in the various groups. And,
viceversa, a particular outcome may be generated by a variety of different
neural activities. For example, there are multiple ways that a brain can encode
a memory. Neurons can interact even
with distant neurons because the substance enveloping them is highly conductive
of electrical signals. This facilitates the creation of countless feedforward
and feedback connections, and not only among neighboring neurons. Nicolelis therefore is lukewarm
concerning the idea that the cortex is divided into functionally specialized
areas. This broad connectionist
view also implies that the brain's working cannot be reduced to a computational
algorithm: the human brain is noncomputable. Nicolelis also emphasizes that the brain
is not a passive tool waiting to react to stimuli from the environment but an
active information-seeker. And there is vast consensus among biologists that
this is true for all forms of life. Nicolelis believes that this active process
generates a "brain's point of view" about what is going on in the
world and in the body. This nonstop process de facto provides a live simulation
of the world, and therefore a set of expectations that in turn determine what
the brain seeks for and what the brain will "understand". Hence the
brain is three machines in one: a tool to maintain homeostasis in the body
(basically, to keep us alive); a simulator to continuously update a model of
the world; and an agent to continuously seek information in the environment. Another interesting finding
came from the analysis of brain activity, a finding first presented by Atsushi
Iriki ("Coding of modified body
schema during tool use by macaque postcentral neurons", 1996). Brains seem
to incorporate the tools that the body is using not only in their model of the
world but in their very model of the body itself. Tools are represented by the
brain as seamless extensions of the body. These "extensions"
contributing to one's sense of self would then include clothes, kitchenware,
bicycles, cars, digital devices... and even family, friends and acquaintances. (One could also interview
these findings the other way around: perhaps it is not that tools are
represented as limbs or organs by the brain but that limbs and organs are
represented by the brain just like tools: from the viewpoint of a brain they
are all "tools" that help the brain survive, explore the environment,
manipulate the environment, fuel itself and reproduce). Nicolelis envisions a brain-centered
future in which one's brain would do everything simply by thinking, without
having to rely on body movements and not even on language; in which machines
will obey orders received wirelessly from the brain of the master; in which
people will be able to communicate remotely with each other without any need to
pick up a phone or type an email; in which people will be able to experience
the surface of a distant planet while comfortably sitting in a living room's
armchair; and in which one would be able to access the thoughts of their dead
forefathers and relive vividly their most intimate experiences. Back to the beginning of the chapter "Inside The Brain" | Back to the index of all chapters |