The outer skin and other
external features of humans are deceptive. They show a solidity and continuity
that conceal the true nature of a human. If a person’s consciousness were visible, a human would take on the appearance of
an ever-changing entity, a being in a state of flux, one whose boundaries would
be shifting and indefinite, while perhaps remaining in a loosely-defined
general area. Consciousness lies at the heart of our study. It is also one of
the hardest of all terms to define, and any attempt to do so immediately runs
into the paradox discussed earlier in this book: Is it possible for the brain
to understand its own deepest functions, or does the complexity of the brain
preclude such an understanding? In short, is it even possible for us to discuss
consciousness coherently, much less grasp its quintessence?
Consciousness is the essential
phenomenon that makes a human different in degree from other animals. Humans
may not be alone in the possession of consciousness, but it is the advanced level of human consciousness
and the powers that derive from it that have given the human species at least
some level of control over this planet's surface. Human history may be thought
of as the way in which the experience of consciousness has affected the lives
and interactions of humans on this planet. It is the central thesis of this
book that humans do not understand their own consciousness fully. They are unaware
of all the variables that affect it, are unable to describe it clearly even as
they are experiencing it, and hence are unable to analyze completely the
situations in which they find themselves. In my view it is the incomplete
nature of human comprehension that is the chief factor driving the convoluted
history of our species. Obviously, therefore, a definition of consciousness is
crucial if we are to grasp this idea.
So what do we mean by the term consciousness? What is it? One way in which consciousness may be defined is the entire
set of a human’s thoughts, feelings, sensations, memories, perceptions, and
imaginings when they are awake (or in the dream world of sleep, which is a
simulacrum of waking consciousness). It is the sense of being a self, an I set aside from other selves. It is the awareness of being aware.
But in a sense, none of these
descriptions really gets to the heart of the matter. Consciousness feels like something. It is something
which is experienced. (We might well
ask, what does it mean to experience something?) Every human seems to
experience the phenomenon of consciousness in a completely subjective and
unique way, and yet, there is enough overlap in the experience of consciousness
between and among these humans that they understand something about what it's
like to be another human.
The sense of experience that
humans have at any given moment is sometimes referred to by the term mental state, how life seems at that moment. (And of course the
word seems is itself ambiguous.) As I have said, trying to understand the link
between the one and a third kilograms (or so) of gelatinous stuff in our skulls
and mental states is, in my mind, the supreme challenge to the human brain. It
is every bit as challenging as the human attempt to understand the quantum
world's counterintuitive operations. So, let's review the ideas of some of the
foremost students of this elusive phenomenon, the consciousness that defines who
and what we are.
Attempting a Definition of Consciousness
William James, in his classic
study, The Principles of Psychology
[1890], used the term the stream of
thought (which many express as the
stream of consciousness) to describe the actual experience of the self being
awake and aware. Here is how James described this stream:
How does it go on?
We notice immediately five important characters in the process, of which it
shall be the duty of the present chapter to treat in a general way:
1) Every thought tends to be part of a personal consciousness.
2) Within each personal consciousness thought is always changing.
3) Within each personal consciousness thought is sensibly continuous.
4) It always appears to deal with objects independent of itself.
5) It is interested in some parts of these objects to the exclusion of
others, and welcomes or rejects - chooses from among them, in a word - all the
while.1
It bears emphasis that if we
accept James' quite reasonable and empirically-verifiable criteria, then we
must conclude that every conscious human who has ever lived has had a unique internal life experience (however
similar their external circumstances to other people), and it is probable that
all humans who live in the future will also have a unique internal life
experience. (I would add that it may be possible in the future for the
consciousnesses of two or more separate humans to, temporarily, intersect so
completely that a group rather than individual identity might emerge.)
The philosopher Thomas Nagel
tackled consciousness in his famous article, "What Is It Like to Be a
Bat?" in 1974. It was his contention that there is something that it is
like to be when one is conscious, using
as his example the experience of bats, who navigate dark environments largely
by echolocation. This mode of perception is largely alien to humans, virtually
inconceivable. A human does not know what it would be like to be a bat. Nagel uses this example to argue
that experience is inherently subjective, and that it isn't really possible to know
the subjective experience of others, especially beings who are very different
from humans. Nagel states that while it is possible to describe mental events
in an "objective" way, this wouldn't give us a true idea about what
it is like to experience them if we had no first-hand
experience.2
So it can be argued that
consciousness is experienced in a uniquely internal and subjective way. But
what is it to be conscious? Stanislas
Dehaene, a researcher in the field of cognitive neuroscience, defines the key
element of consciousness to be what he calls conscious access. This, he says, is the ability to "see an
object and describe our perception to others". Dahaene then elaborates on
this idea. First, out of myriad possible sensory stimuli, consciousness can
focus on one specific stimulus. In fact, Dahaene maintains that we can really
only focus on one thought at a time, although that thought might be complex. Next,
attention given to one item means attention given to a previous item must be
dropped. When we make such a change of focus, to an item of which we had been preconscious, a whole host of mental
processes are now engaged, such as language. Dahaene then points out the
phenomenon of selective attention,
the product of the brain's ability to filter out various sensory stimuli and
memories. The action of this filtering process is one of which we are not
aware. Finally, he says that conscious access rests on vigilance, attention,
and wakefulness, but even these are not enough by themselves to enable us to
have such access.3
Max Velmans begins his survey
of consciousness by posing a series of questions,
what he calls the five chief problems involved in understanding it:
Problem 1. What
and where is consciousness?
Problem 2. How
are we to understand the causal relationships between consciousness and matter and, in particular, the causal
relationships between consciousness and the brain?
Problem 3. What
is the function of consciousness?
How, for example, does it relate to human information processing?
Problem 4. What
forms of matter are associated with
consciousness – in particular, what are the neural substrates of consciousness
in the human brain?
Problem 5. What are the appropriate ways to examine consciousness, to discover its nature?
Which features can we examine with first-person methods, which features require
third-person methods, and how do first- and third-person findings relate to
each other?
In terms of a definition,
Velmans keeps it simple and direct: consciousness rests on experience. If a
person is experiencing, they are conscious. If they're not experiencing
something, they're not. Expanding on this, he maintains that the presence or
absence of "phenomenal content" defines the presence of
consciousness.4 We will look at the concept of phenomena below.
What causes consciousness?
From where does it arise? John R. Searle, who specializes in the philosophy of
mind and language, is quite firm in his opinion that what he calls mental
phenomena arise from the physiology of the brain itself. He rejects the notion
of objective reality, arguing that "in general mental states have an
irreducibly subjective ontology". He also rejects the idea that the human
brain is capable of comprehending everything about the reality in which it is
immersed. Consciousness, he states, "is as much a part of the natural
biological order as any other biological features such as photosynthesis,
digestion, or mitosis."5
Mark Rowlands first considers
the nature of what is called phenomenal
consciousness. He points out that it is difficult to describe its content
in a non-circular way. He argues that the major attempts to define phenomenal
consciousness all have inherent limitations. For example, definitions often
focus chiefly on sensory perceptions, the limitations of which he points out:
There is often a tendency, particularly in the case of visual examples,
to place undue emphasis on perceptually basic, or near basic, experiences:
experiences of a patch of redness, and the like. But this, as Wittgenstein
would put it, might provide a diet of philosophically one-sided examples. Often,
the phenomenal character of an experience can depend on its significance for
the experiencer, and this, at least ostensibly, cannot be reduced to the
significance of a conglomeration of perceptually basic, or near basic,
properties.6
Rowlands examines the
contention that such experiences have a qualitative feel, that they possess qualia. [Broadly speaking, qualia
represent the sensory experience of phenomena.] He cites Nagel's argument, that
it is something to be like when one
experiences qualia, but he sees this argument as incomplete. He also examines
the argument that phenomenal consciousness is best approached by examining the
physical conditions in which it occurs. Rowlands says that even taken
collectively these approaches—analysis of sensory experience, focusing on
qualia, recreating specific physical states—are insufficient. After considering
various issues surrounding the concept of phenomenal consciousness, and other
attempts at a definition, Rowlands
arrives at the following position: consciousness possesses a dual structure. It
can "be both the directing of awareness and that upon which awareness is
directed". He argues that consciousness therefore has a "hybrid
character". It is "something of
which we are aware" in conscious experience, and it is "something with which we are aware".7
Gerald Edelman initially gives
us a rather conventional definition of consciousness, describing it as a kind
of awareness, and he adds to it the observation that consciousness "is
thus a process, not a thing", a process "not exhausting all aspects
of the objects with which it deals". It involves, he says, such things as
mental images, volition, decision-making, and intentionality. By this last word he means (as many others have
also said) that conscious thought is about
something, be it an object or something which has occurred. It has content.
Consciousness is not only awareness but awareness of its own functions or
awareness of the fact that it is having perceptions. He makes a distinction
between what he calls primary
consciousness, which chiefly deals with mental imagery, and higher-order consciousness, "which
in humans is also able to embody a model of the personal (what we shall call
direct awareness) and also of the past and future."8
Edelman expands on his
examination of consciousness with a list of what he calls constraints. The
first is an assertion that a "global theory of brain function" and
consciousness must rest on "a materialist metaphysics and on an
epistemology of qualified realism". (By qualified realism, Edelman means
that our perception of reality is indirect.) The second constraint is the
contention that a model of consciousness must rest on an overarching theory of
brain function. Edelman calls his global brain theory the theory of neuronal group selection. By this Edelman means a theory
of consciousness that is strictly biological. In his words, "The theory
should stay close to the structure, development, and evolution of the nervous
system as it relates to the rest of the phenotype". The third constraint
is the contention that consciousness can only form in "a species having the
appropriate brain structure at a certain stage of brain development". And
the fourth constraint is the contention that a carefully constructed model of
brain function should be explanatory.
It should allow us to say that if certain carefully defined conditions exist,
then consciousness will emerge in an animal's brain.9
Edelman surveys a number of
conventional, dictionary-based definitions of consciousness, and then plunges
into the tasks that must be accomplished by what he calls an extended theory of
consciousness. Among these are accounting for consciousness as an evolutionary
product, accounting for the varieties of consciousness, explaining how primary
consciousness leads to higher order consciousness, explaining the subjective
character of consciousness, the ability of consciousness to account for objects
outside of itself, and many others. It is by following these rigorous and
extensive criteria that he hopes to point the way to a comprehensive
definition.10
Antti
Revonsuo focuses first on the concept of phenomenal consciousness, or as he
puts it, "the study of the world-for-me, or, more generally, worlds-for-someone: the subjective
psychological realities within which all of us live our lives." The
foremost feature of phenomenal consciousness, in Revonsuo's view, is presence. As he puts it, "For a
sensation to be present-for-me it
must manifest itself directly before my mind, somewhere within my perceptual
space." Presence, he says, is both spatial and temporal, and is something
which happens to one in the immediate present. Then Revonsuo elaborates.
Consciously-experienced events have a location,
they are occurring within a person's subjective experience and most of them
have an identifiable source. They possess duration,
but here he is careful to note that the experience itself has duration, not
necessarily the stimulus causing it. Experiences also have intensity.
Of
particular note to Revonsuo is the next feature of experience: its quality. Experiences are of a certain kind, such as the perception of one color as opposed to another, or
of one kind of physical sensation as opposed to another. "Qualities are
thus the 'stuff' that experiences are made of." He adds:
The sensory-perceptual world we normally
enjoy involves immensely complex, ever-changing dynamic combinations of
qualities. The qualities are carefully organized to make up shapes and forms,
surfaces and objects, melodies and words, aromas and caresses: the entire
world-for-me.11
Revonsuo
then moves to a discussion of qualia, pointing to them as the basis of
phenomenal consciousness. But he adds an important note: we don't experience
qualia, these irreducibly basic phenomena, simply as a mass of sensations and
perceptions. These phenomena are organized by the brain in such a way that
"they are instinctively taken as meaningful, familiar objects".12
It is because qualia appear to
present themselves in patterns that evoke meaning that it would be a good idea,
at this juncture, to talk about the idea of representation
in consciousness. Different researchers use the term to mean somewhat different
things. What do we mean, in general, when we say the mind represents something? In the realm of pure thought, such as when we
imagine or visualize objects, the objects we see in our imagination are mental
representations of those objects, not the objects themselves. The use of
language is a form of representation, inasmuch as words represent objects or
ideas. Mathematical expressions represent ideas specific to that realm.
Memories, especially those based on association,
are a form of representation. In the view of some researchers there is a representing world and the represented world. [Broadly speaking,
the represented world is the exterior world we perceive and the representing
world is the way that world is interpreted in our consciousness.] As one
specialist puts it, "The representation is an element within the
representing world, and it reflects, stands for, or signifies some aspect of
the represented world". 13
There is strong debate among
philosophers about this doctrine, with many rejecting it outright. The great
weakness of the representational view, in the eyes of many, is that it cannot
adequately account for our awareness of bodily sensations. One can make a
coherent argument for representation, or intentionality [again, the idea that
perceptions have content] in such areas as visual stimuli. It is more
difficult, even impossible, say critics, in such areas as painful or
pleasurable physical experiences. There are representationalist philosophers
who have attempted to integrate bodily sensations into representational schemes,
but these efforts have not been universally convincing.
Self representational schemes seem to rest on the idea that not
only do we experience phenomena in a subjective way, but we are aware of our
own awareness. We have the experience and we are aware that is the self that is experiencing whatever
phenomenal input is causing our subjective awareness, that it is the self that
is being represented.14 This particular viewpoint (which I am
greatly over-simplifying for the sake of brevity) is also disputed by various
philosophers.
Some researchers prefer to
emphasize different kinds or varieties of consciousness. These varieties are
known as higher-order theories of
consciousness. For example, the philosopher Ned Block differentiates
between phenomenal consciousness and access
consciousness. In a 1995 paper he explained the distinction:
Phenomenal consciousness is experience; the phenomenally conscious
aspect of a state is what it is like to be in that state. The mark of
access-consciousness, by contrast, is availability for use in reasoning and
rationally guiding speech and action.
Block argues that it is
possible to have phenomenal consciousness without having access consciousness.
We might be aware of a sound, for example, and not associate it with a
particular source doing a specific thing. When we identify that source, we are
in access mode.15
Antonio Damasio points out
that consciousness supports the actions the human animal needs to take in order
to survive. Such actions include the acquisition of energy for the body and
defense against physical threats. The images that consciousness provides us
facilitate these actions by giving us options
and letting us imagine outcomes. Advanced consciousness is therefore an
evolutionary advantage humans have over other living things. As he puts it,
The pathbreaking novelty provided by consciousness was the possibility
of connecting the inner sanctum of life regulation with the processing of
images. Put in other words, it was the possibility of bringing the system of
life regulation—which is housed in the depths of the brain in regions such as
the brain stem and hypothalamus—to bear on the processing of the images which
represent the things and events which exist inside and outside the organism.16
Damasio then turns to the
issues that surround a definition of consciousness. Here he makes crucially
important points about the term mind,
which is often used interchangeably with the term consciousness. Consciousness
is only one part of the mind, the part that "pertains to the knowing of
any object or action attributed to a self". We can have mind without the
experience of consciousness.17
Paul Nunez maintains that
consciousness is what he calls a fundamental entity, something that can only be
described by circular definitions. He offers an unconventional interpretation
of the term. He puts it this way:
"To me, consciousness seems more analogous to fundamental physical
properties like charge and energy...Given this argument, I posit that any
serious study of consciousness must adopt a conceptual framework that allows
for the possibility that consciousness is a fundamental property of the
universe."18
Needless to say, such a
position is open to very wide interpretation, and it is also one which many scientists
and philosophers would contest vigorously.
There are researchers who
argue that humans do not actually possess conscious thought at all. Philosopher
Peter Carruthers says that we cannot explain the sources of our thought, and our
interpretations of the thoughts of others are affected by unconscious influences
we cannot really know.
I believe that the whole
idea of conscious thought is an error. I came to this conclusion by following
out the implications of the two of the main theories of consciousness... Now,
whichever view you adopt, it turns out that thoughts such as decisions and
judgments should not be considered to be conscious. They are not accessible in
working memory, nor are we directly aware of them. We merely have what I call
“the illusion of immediacy”—the false impression that we know our thoughts
directly.
Carruthers maintains that we are required to try to guess the
motivations of others, and we generally do so by assuming that others know
their own mind, when in fact they face the same illusion of immediacy as we. He
maintains that the unconscious and what we call the conscious "are not
separate spheres; they operate in tandem." Consciousness, he argues,
"is not direct awareness of our inner world of thoughts and judgments but
a highly inferential process." 19
Finally, other researchers speculate that quantum mechanics
can give us insights into consciousness, citing the strange fact that quantum
events seem to vary depending on whether they are observed or not. Some
philosophers wonder if inanimate objects or individual particles possess
consciousness (panpsychism). And there are ideas, such as those espoused by
Daniel Dennett, that consciousness is an illusion, and if it goes too far to
say that it doesn't really exist, it can at least be said it doesn't exist in
the way we think it does.
The Hard Problem of Consciousness
Philosopher David Chalmers has
written extensively on consciousness, and is most notably associated with the
idea of "the hard problem of consciousness". Here is his definition
of the term:
The hard problem...is the question of how physical processes in the brain
give rise to subjective experience. This puzzle involves the inner aspect of
thought and perception: the way things feel for the subject. When we see, for
example, we experience visual sensations, such as that of vivid blue. Or think
of the ineffable sound of a distant oboe, the agony of an intense pain, the
sparkle of happiness or the meditative quality of a moment lost in thought. All
are part of what I am calling consciousness. It
is these phenomena that pose the real mystery of the mind.
Chalmers
speaks of what another researcher has called "the explanatory gap".
Chalmers asserts that even if we had a thorough understanding of the neural
correlates of consciousness, which is to say the places in the brain that are
electrically active during conscious experience, we would still be at a loss to
explain what it's like to be aware of our awareness. "Remarkably,
subjective experience seems to emerge from a physical process. But we have no
idea how or why this is."20
The
response to Chalmers has, unsurprisingly, been varied. Some have even gone so
far as to assert the hard problem is beyond solution. Adopting a position
sometimes known as mysterianism, they contend that our brains are capable of
knowing the hard problem exists, but lack the cognitive abilities to understand
it.21
One
researcher believes that concentrating on the hard problem distracts us from
more pressing issues:
But there is an alternative, which I
like to call the real problem: how to account for the various properties of
consciousness in terms of biological mechanisms; without pretending it doesn’t
exist (easy problem) and without worrying too much about explaining its
existence in the first place (hard problem)...In the same way, tackling the
real problem of consciousness depends on distinguishing different aspects of
consciousness, and mapping their phenomenological properties (subjective
first-person descriptions of what conscious experiences are like) onto
underlying biological mechanisms (objective third-person descriptions).
But
this researcher is not only talking about mapping the regions of the brain's
activity. There is, he says, a more important consideration. He contends that a
good model of the conscious brain might be Hermann von Helmholtz's concept of
the brain as prediction machine.
According to this hypothesis, the brain combines sensory signals (the meaning
of which is not always apparent) with expectations and beliefs about the nature
of the world. This process makes consciousness a sort of elaborate guess. When
there is input that seems to violate these expectations, it's not always
perceived as such. Finding out how the brain handles perception is therefore
crucial to our understanding of consciousness, more so perhaps than trying to
understand why consciousness exists in the first place.22
The "Easy" Problems of Consciousness
Chalmers has also discussed
what he believes to be the "easy" problems of consciousness, by which
he means mental phenomena that can be explained by straightforward scientific
means, mental phenomena that have clearly identified mechanisms. Chalmers
includes within this definition the following, in his words:
the ability to
discriminate, categorize, and react to environmental stimuli;
the integration of
information by a cognitive system;
the reportability of
mental states;
the ability of a
system to access its own internal states;
the focus of
attention;
the deliberate control
of behavior;
the difference between wakefulness and sleep.23
Chalmers' concept has been
challenged by several other consciousness researchers, among them philosopher
E. J. Lowe. Lowe argues that the terms Chalmers uses are themselves ambiguous
and more applicable to insentient objects than to human beings. Moreover, Lowe
contends that the experience of qualia and human cognition are deeply,
intimately interrelated.24
The Search for the Neural Correlates of Consciousness
Since the advent of brain
scans capable of detecting activity in certain parts of the brain during particular states of conscious awareness,
there has been a major effort made to locate the neural correlates of
consciousness (NCC), those brain regions which seem to generate consciousness
itself. But several researchers make a crucial point about this subject, which
I summarize like this: Simply because some
region of the brain "lights up" on brain scans when a person is
feeling a particular emotion or sensation, it does not "explain" what
it is like to experience the
phenomenon. It merely indicates that that region of the brain is involved in the phenomenon.
And yet these regions bear
examination. Perhaps the most crucially important study of this matter was
published by Francis Crick and Christof Koch in 1990. In a paper entitled
"Towards a neurobiological theory of consciousness", Crick and Koch
laid out a cogent argument that the key to understanding the workings of
consciousness is an understanding of what happens at the neural level. To
illustrate this they focused on visual perception. After examining the
mechanisms that underlie it, they came to the following conclusion:
Why, then, is consciousness so mysterious? A striking feature of our
visual awareness (and of consciousness in general) is that it is very rich in
information, even if much of it is retained for only a rather brief time. Not
only can the system switch rapidly from one object to another, but in addition
it can handle a very large amount of information in a coherent way at a single
moment. We believe it is mainly these two abilities, combined with the very
transient memory systems involved, that has made it appear so strange. We have
no experience (apart from the very limited view provided by our own
introspection) of machines having complex, rapidly changing and highly parallel
activity of this type. When we can both construct such machines and understand
their detailed behavior, much of the mystery of consciousness may disappear.25
Koch and another respected
expert in the study of consciousness, Florian Mormann, came to the following
conclusion after another extensive examination of the issues surrounding NCCs.
It was their opinion that a feedback system from the frontal lobe to the
sensory cortices reaches a sort of critical mass, upon which activity is
distributed to a wide number of brain regions, creating what they call
"the global workspace model of consciousness". They further concluded
while there can be "complex behavior without conscious sensation", consciousness
itself rests on this feedback system.26
A very thorough examination of
the brain substrate that is involved in the generation of consciousness has
identified what its author refers to as the
consciousness system. Within this system are interacting networks of brain
structures and neurotransmitters, all working in concert, frequently in
parallel to each other, and exerting their influences in varying degrees at
varying times. The overall tasks of the system are alertness, attention, and
awareness. The consciousness system
has both cortical and subcortical structures. The cortical structures involved
include the association cortices (frontal and parietal), the anterior cingulate
region, medial frontal cortex, the precuneus, the posterior cingulate region, and
the retrosplenial cortex. [The retrosplenial cortex is involved in various
cognitive functions, such as navigation, imagination, and episodic memory. It
has major connections to the hippocampal regions.] The subcortical structures
include the upper brainstem, thalamus, hypothalamus, and basal forebrain. The
basal ganglia, cerebellum, claustrum, and amygdala may also be involved. At
least seven different neurotransmitters appear to play a role as well.27 [It
should be noted here that the term association cortex is sometimes rendered as
the association areas, and refers to
most of the cerebral surface. These areas process and coordinate information
coming from the sensory cortices.]
The author makes a crucial
observation about the role of the association cortices:
It is the collective activity
of widespread areas of the bilateral association cortex that determines the level
of consciousness. Taken as a whole, the higher-order association cortex
interacts with subcortical arousal systems to exert powerful control over the
overall level of arousal, attention, and awareness.28
The author of this study
emphasizes that the neurophysiology of consciousness is just as important as
the neuroanatomical networks involved in it, and that this physiology is much
less well understood. Many hypotheses about neurophysiology have been proposed,
such as that of Koch and Mormann above. I hope an examination of specific areas
of conscious experience and other aspects of mind will yield clues to this.
Consciousness as an Emergent Phenomenon
In a significant study
released in 2011, physicist and expert in complex networks Danielle Bassett and
psychologist and neuroscientist Michael Gazzaniga argued that, "The
brain...can be understood as a complex system or network, in which mental
states emerge from the interaction between multiple physical and functional
levels." They first note the ability of complex network theory to describe
connections within a system, and how the system's growth can be shaped by
external factors. This theory, they contend, is "particularly applicable
to the study of the human brain", which they describe as a complex system
with many subcomponents interacting across both time and space. They contend
that the constraints on the brain's anatomy constrain its physiology, while
noting that the degree of a brain region's neuronal connectivity does not
necessarily tell us about that region's specific function. (Interestingly, they
explain that the cortex possesses multipotentiality,
noting that in people blind from a young age structures devoted to vision can
develop into structures devoted to hearing.)29
Most
significantly, the authors point out that the brain's components are organized
in different scales of size, and act at different rates of speed. They refer to
this as multiscale organization. For
example, the highest frequency of gamma waves (those in excess of 30 hertz)
appear to be necessary in higher cognitive processes, while lower frequencies
of gamma, beta, delta, or theta waves affect other functions. [These brainwaves
are the electrical pulses produced by groups of neurons.] It is this multiscale
organization that allows the brain to be "more than the sum of the
system’s parts at any particular level or across levels" as they put it.
Consciousness itself may be the product of this organization, a genuine
emergent phenomenon.30 There appears to be a constant interaction
between the brain and what the authors call mind, the contents of the physical
brain. It is this interaction that appears to shape who and what we are.
Summary
So, after weighing these
various opinions, and considering the evidence presented in the previous
chapters of this volume, along with my own hypotheses, I take the following
positions:
A. Consciousness arises solely
from the anatomy and physiology of the brain. When an animal brain becomes
sufficiently large in absolute terms, sufficiently large in relation to the
animal's size and composed chiefly of cortical tissue (in other words, when a
brain possesses a high degree of encephalization), and, most crucially, when an
animal brain has a connectome of sufficient density and interconnectivity,
consciousness will arise. In the human animal, absolute brain size, degree of
encephalization, and connectome complexity have allowed that animal to have the
highest degree of conscious awareness of any member of the animal kingdom. It
is probable that the capacity for conscious experience grew throughout our
genus's evolutionary development. Consciousness is therefore one of the emergent phenomena brought about by
organic evolution, a phenomenon which is more than the sum of its component
elements, and its possession gives humans distinct survival and reproductive
advantages.
B. There is no separation of
"mind" and "body". Mind, being an emergent property of a
sufficiently sophisticated brain, is an aspect
of body. However, the terms consciousness
and mind are not synonymous.
Consciousness is only a part of the mind. Other features of the mind can act
without being consciously experienced.
C. While consciousness arises
out of the anatomy and physiology of the brain, it cannot be understood simply by an analysis of the
physical factors which underlie it and by which it is generated. Consciousness
can only truly be apprehended by the experience of phenomena or qualia and the
ways by which we access such phenomena
or qualia. The perception of sensory information is imbued with various degrees
of association and meaning. Inanimate objects often carry a variety of such
meanings and associations, and other animals, particularly humans, often carry
far more such meanings and associations. Moreover, since all regions of the
brain are interconnected, intellectual, emotional, and basic survival functions
interact with each other on a constant, reciprocal basis. Our responses to the
world and our picture of ourselves are the product of this extremely complex
interaction.
D. All definitions of
consciousness are, to varying degrees, circular. The term awareness is an
example of this principle. (To be aware is to be conscious. To be conscious is
to be aware.) Again, consciousness must be experienced to be understood. Consciousness
is not a thing, it is a process, a manifestation of the mind's
hypotheses about itself and the "outer" world. And as is the case
with the fundamental forces which underlie all physical reality, consciousness
is best understood by what it does rather
than what it is. It is the emergent
brain property that permits a human to understand that they are a distinct
physical entity, one set apart from other physical entities. It gives a human a
sense of being a self (whether we accept the ultimate reality of that term or
not). A self has a life story or narrative, and this narrative is based on a
set of memories particular to the person who has them. A self has a
characteristic way of perceiving reality, one which has been shaped by certain
genetic predispositions, emotional reactions, and reactions to those reactions.
Consciousness allows for the imagination of various scenarios, courses of
action, personal expressions, and images involving the self. Consciousness
allows a human to think about their own thoughts, to engage in reflexive and
recursive thought. It is the awareness that one is aware. It incorporates
within itself the entire sum of a human's sensory perceptions when awake, the
ways the brain filters those perceptions at any given moment, the focus of a
human's attention, the subconscious influences at work at any given moment, and
the mixture of intellect and emotion by which a human interprets their
experience. There appear to be different levels of consciousness, such as the
distinction between the basic experience of qualia and the interpretation of those qualia.
E. Every human's conscious
awareness is unique and individual. No two humans experience conscious
awareness in identical ways. We must assume that no two humans in the past have
ever had identical states of consciousness. And although we cannot assume that
in the future no two humans will ever have identical conscious states, we must
consider it unlikely. Therefore, we must assume that every human being who has
ever lived has experienced the world in their own particular way. We must also assume, in my view, that they
did not fully understand this experience. Nonetheless, humans have enough
similarity of conscious experience that they can, to a limited degree,
understand the experience of others. This understanding is by its very nature
incomplete, and it is easy for a human to believe that they understand more
about others than they really do. Humans sometimes say that they are of
"one mind" with another or with a group of others. I submit that the
concept of "one mind" is an illusion. Humans are forced to make
assessments of other humans, but these assessments are often based on
guesswork, and are never more than approximations.
F. Consciousness does not give
a human a direct understanding of reality. It gives them a mediated version of
it, one which is specific to our species. No human perceives "the thing in
itself", nor has any human in the past ever done so. It is unlikely that
any human in the future will ever do so, either. What humans perceive are representations of reality, a reality
that is often filtered through a distinct sense of self. The processes which
form consciousness do so in a synergistic fashion. But the processes themselves
are flawed or incomplete. Perception can actually be misperception. Memory is
not a fully reliable or complete record of a human's experience. What we think
is understanding can actually be misunderstanding. Sensations may not be
interpreted completely. Subconscious influences can affect judgment.
Conflicting emotions can prevent complete focus on a given situation. The
intellect may be lacking in key information. In short, consciousness has given
humans immense powers and capabilities, but it has also made these same humans
deeply fallible. Intelligence, and consciousness in general, did not evolve to
give humans complete understanding of their situation. They evolved to help
humans survive long enough to reproduce their genes. It is unlikely in the
extreme that humans have the ability to consciously understand everything about
the reality in which they live.
Personal Observations
The brain, the core of the nervous system, combines incoming sensory
data with the emotional/intellectual memory of the past self and its reaction
to similar input. Our responses to the world and our picture of ourselves are the product
of this extremely complex interaction. There is a continuous synergetic relationship
between the “outer” world of experience and the “inner” world of consciousness.
This picture of ourselves and
the responses to the world formed by the human nervous system are (in most
humans) consistent enough, predictable enough, and stable enough to allow for
interaction with other humans and with the physical environment in which all of
these humans live. It is sufficient to allow humans to make assessments about
themselves relative to those humans and the environment. It provides a human with
the means to navigate the ordinary, everyday world. It does not, however,
provide a human with the automatic ability to cope with the most difficult or
challenging or novel situations.
The fundamental reason
consciousness began to evolve, in my view, is that certain information received
by an animal is more crucial than
other information. Certain information takes priority, and the ability of a nervous
system to sort out signals, assess them,
and attend to the most crucial ones is very much the key to survival. In a
sense, I think consciousness is yet another manifestation of natural selection.
(We will examine the possible origins of consciousness in the next chapter.)
An individual consciousness,
the product of the brain's evolution, is shaped by the world, but it in turn
shapes the world. Since the world is enormous in relation to it, this may not
seem possible. But the individual brain decides what reality is, even though
the person possessing that brain may not be fully aware that such a decision is
being made. It is by the individual response
to the world that consciousness shapes that world. In a sense, the world is
what I say it is in the universe of myself. When we are awake we and the world
are influencing each other, and humans are constantly interpreting their
experience. What we are doing by this process, in my view, is creating a
continuous metaphor, a picture of reality suited to the capacities of our
brains.
I have stated that
consciousness is best understood by what it does
rather than what it is. And what it
does, within the limits of genetic inheritance and inherent human physical
capabilities, is make the human animal almost infinitely malleable in its
behavior, if not at the individual than at the collective level. The collective
action of consciousnesses working in concert can shape the world decisively,
but never in the exact way
anticipated. Human consciousness appears to be very good at organization (in
general), but very poor at the understanding of long-term consequences (again,
in general). Human consciousness, as stated in the conclusions, is inherently
incapable of understanding everything in the environment around it. Nor is
human consciousness able to perceive or understand all the variables at work in
a given situation. These variables are simply too multitudinous, too diverse,
too varied in their origins, and too complex and subtle in their interactions.
It is unlikely (but not impossible) that any human will ever possess complete
understanding of the nature and operation of these variables.
Human consciousness makes
possible a capacity often called reflexivity, which fundamentally means self-awareness. It is
the realization that one is part of the reality one is observing, and that the
act of observing can itself alter this reality. Human consciousness allows for self-assessment, a trait unique to
humans. Humans can evaluate their thoughts, current situation, and actions.
They can think about their own thinking. Humans are capable of describing (in
part) their internal experience and conveying this (however imperfectly) to
other conscious humans. They are capable of compartmentalization,
the ability to separate patterns of thought and the associated content these
patterns create from other patterns and content.
Finally, every human who has
ever survived infancy has lived in the river of consciousness, a place
saturated with sensory perceptions, one in which vague, ill-defined pictures
are "seen" and pieces of conversation and music are
"heard". It is a place of both reaction and initiative, continuously
changing, a place where long-forgotten memories can spontaneously be revived,
along with the attendant emotions surrounding them. It is (for the vast
majority) a place where language is processed and used. It holds tastes, preferences,
knowledge, intellect. It is a place not only where we feel but try to
understand what and why we are
feeling. It is the place where the hidden or non-conscious parts of the mind
act to shape us. It is the place in which the human senses the existence of a
unique being—themself. And it is the place in which interaction with other
conscious minds and with the world in which everyone exists takes place. When
two conscious humans interact, it is as if two rivers have briefly flowed into
each other, however incompletely. These confluences, over the course of a
lifetime, give human consciousness characteristics that are virtually
impossible to fully assess. The quest to understand consciousness and all the
factors that shape it is, in one sense, a search for that which has driven the
human story forward, a story that has unfolded in often puzzling or unexpected
ways. Consciousness can be a place of mundane, ordinary experience, or a place
of exaltation, or a place of torment, or a place of serenity, or a place of
madness. But however it is being experienced, it is for us the entire universe.
It is everything we are or ever will be.
So now we turn to the possible origins of this elusive, seemingly indefinable
phenomenon, reassured perhaps that we can know how it may have come to be
without really being able to define it.
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