The Neuroscience of Consciousness: From Cells to Self

David F's picture

 Neural and Behavioral Sciences Senior Seminar

Bryn Mawr College, Spring 2010

The Neuroscience of Consciousness: From Cells to Self

The definition of consciousness and the role of neuroscience in explaining it are both highly contested issues, both on philosophical and empirical grounds. Some argue that we can generate a full picture of consciousness with a more detailed understanding of the brain, while others resist this notion. Even within the former school of thought, scientists diverge in their approaches, some identifying brain regions and others emphasizing connectivity. Which is the right perspective, and how does our answer to this question qualify the capacity of neuroscience as a whole? Do certain approaches allow us to be "less wrong" regarding the idea of consciousness? We will explore some recent empirical findings that shape the way we conceptualize the neuroscience of consciousness, critique their methodologies, and consider ways in which those findings can be applied in a clinical setting. 

Background readings:

Other materials:

 

David Fischer's final paper:

Guiding Plasticity: Another Route for the Neuroscience of Consciousness

 

Some relevant thoughts from last week:

Culture defines and makes people more sensitive to any deviations they may display from the societal norm, and this hypersensitivity can exacerbate the symptoms they display ... Labels, while separating people as being different, at the same time give them the recognition that they have a medical condition that is not a sign of weakness or something that can be changed on their own ... Bo-Rin Kim

Perhaps the categorization of people as depressed leads them to feel isolated and alone; but could it also influence them to seek treatment? ... sberman

Although this is a cavalier perspective on depression, if I could enjoy a European cruise for a few years paid for by my health insurance, I just might pretend to have depression ... we want everyone healthy and reenergized but to what extent can mental illnesses open the system to abuse? ... VGopinath

This desire to classify and treat illnesses and diseases is not unique to professionals in the medical field ... kenglander (see also vpina)

there would be no cohesive structure or unified mechanism of communication without a shared language system.  And there is no practical reason to abolish a system simply because some people do not have the ability to assimilate ... LMcCormick

It seems almost impossible to take life on a case-by-case basis, to change our culture to suit the needs of every individual person ... aliss

A new name for disabled people ... David Feingold

rather than focus all interventions on changing the disorder; these treatments instead change what is “normal”. Instead of bending patients to fit society these societies bend to fit their patients ... I am not quite sure how this methodology could be integrated with modern care ... dshanin

Our own culture engenders the negative attitude toward mental health illnesses because of its product-driven behavior ... meroberts

What Psychologists need, I think, is a way to contextualize illness without descending into complete relativism ... rdanfort

Could anything that was said in this hypothetical classroom actually stand up against the high powered and competitive culture that exists directly outside the classroom? ... EB Ver Hoeve

There has been a great deal of discussion regarding the Gender Identity Disorder and its place in future versions of the DSM, and I imagine that it could very well go the way of some of the other disorders that once described behavior that was considered abnormal but have since been phased out as culture has changed and as those behaviors have been recognized as not “disordered” ... Jeremy Posner

Is it feasible to imagine a culture in which the ends of "productivity" were defined on an individual basis? ... David F

We [could] create and recreate our culture to make everyone a meaningful contributor to it  ... Paul

we can philosophize and discuss and observe human behavior and differences all we want, but unless we have a solid understanding of the physical basis of whats going on in the brain we can never really be sure of whats going on in our head ... Sasha

I think it's worth considering how the brain may be responsible for influencing its own health ... Claire Ceriani

Might an understanding of the "physical basis" of consciousness help with thinking about "how the brain may be responsible for influencing its own health," about depression and mental "illness" generally, and about culture and cultural change? 

Discussion summary (Jeremy)

Follow-up on Last Week’s Discussion: can malingering lead to developing a real mental illness?  Is it the result of an evaluative bias on the part of people doing the diagnosis or is it perhaps the result of a cultural component of mental illness; a person with a diagnosis of a disorder is treated as though they were disordered and so begins to display the symptoms of that disorder. 

Deafness and cultural adaptation:  Should the deaf be expected to learn to speak verbally despite how difficult this can be or should those who are not hearing impaired be expected to learn to sign despite the very limited number of times they will likely find it useful in everyday life?  It is probably true that those who are not deaf who do learn sign often do so more out of convenience (they regularly encounter the deaf) rather than out of a desire to adapt culturally to avoid disabling those with impaired hearing.  Should deaf parents provide a deaf child with a cochlear implant?  Is that a decision that should be left up to each family or should every child be given the option to hear?  Everyone agrees that it is not unreasonable that the curriculum at Gallaudet be taught in sign. 

More on the idea of disability: The argument over merging Asperger’s Syndrome into Autism and resistance to this change from those with the former.  The idea that they don’t want to be labeled as having a disability to the degree that is associated with Autism or that Asperger’s is associated with strength as well as with social difficulty and they want that aspect of the diagnosis preserved.

Paul’s proposal: that society is reworked so that people’s strength’s be celebrated while their weaknesses are not held against them.  Everyone is allowed to do what they do best and is rewarded for their talent, but without any judgment either of their relative skill in that area or of the worth of that skill so that there is no real perception of different ableness.  Class’s immediate reaction: economically unworkable.  Further reactions: struggle and challenge are part of the human condition, necessary to appreciate the better things in life, and necessary because people want to be challenged.  Would ignoring everyone’s weaknesses mean removing any opportunity or incentive for self improvement?  What if people don’t enjoy what they do well?  Should everyone just do what they enjoy then?  Even at their best most people will be overshadowed in skill by others, is that not still a kind of disability? 

Today’s Topic:  What is consciousness: In yoga the idea of being present, for example Paul is not present when he walks into the women’s bathroom out of habit.  Is this consciousness though, or focus and awareness, Paul is probably conscious of other things when he makes that mistake.  Is consciousness required to experience sensation?  Is life therefore a prerequisite for consciousness?  There seems to be a split here, some believe that something mechanical could never achieve consciousness, others that it’s simply a matter of having the ability to mirror the complexity and design of organic consciousness.  What about groups, can a society be conscious?  What is the best way to examine consciousness?  Using neural correlates or functional correlates?  Is it possible to understand exactly what consciousness is simply by examining the function of the brain?  Is consciousness somehow greater than the sum of the brain’s many functions?  There again seems to be some disagreement here. 

We finished with a discussion of the use of conscious and unconscious viewing of images to identify the active processes of consciousness in the brain.  The paper argued that one of the major components of identifying neural functions associated with consciousness is consistency and reproducibility.  The neural components of consciousness are consistent and reproduced each time a conscious process occurs within the brain.  One criticism of the study was that the neural activity observed could easily be the result of attention.  Finally back to computers and the idea that simple complexity and ability to process data is not sufficient to achieve consciousness.  The interactions of neurons and of the functions of various nuclei combine for form consciousness.  Paul proposes a working definition of consciousness as being able to discern separately the self and the non-self, which is a definition that has been used in psyche work in the past. 

 

Continuing discussion in forum below

Comments

Sasha's picture

Reflection

I really liked the New Scientist article David posted. It touched on some ideas that I don't think were really discussed last week- such as the roles of language and memory in self awareness. I also found the view on consciousness in animals interesting and think it adds a twist to our working definition of consciousness in class that: "all conscious beings are living". The article seems to indicate that animals are perhaps not truly conscious because they are not self aware or capable of self reflection in the same way humans are.
I would agree with our initial definition from last weeks class and say that my lab rats are conscious because they feel pain and pressure when we do surgery on them and they freak out whenever they see me, so they seem to know that a giant hand coming towards them is probably not good for them. However, I have no idea if at night after I put the rats away if they think back to themselves: "that giant hand is crazy. I don't like it here. I need to escape!" or even "How am I going to take over the world tonight?!" Considering none of our rats have yet to escape or even bitten me (and i don't think any of them have taken over the world) I would most likely agree with the idea that animals lack the ability to have an internal dialogue or self reflection. Does this mean they are not conscious? Is there a division between consciousness and self awareness? Can you be self aware and just ignore it or not care- is that being sociopathic? Are socopathic people conscious humans? What about animals like chimps that we teach language to. Does learning a language lead to self awareness?
 

LMcCormick's picture

Consciousness and Intelligence

One thing that struck me as odd during our conversation last week was the idea that consciousness is a matter of complexity of neural connections as well as reproducibility.  Although this seems to make sense initially, it seems oddly reminiscent of how we determine intellect and learning.  We say that learning is the process of forming strong synaptic connections (long term potentiation); thus, it logically follows that a more intelligent person will have more complex and strongly formed synapses (assuming that you agree that learning is a key component of intelligence).  This seems like a flaw in the theory; are we really saying that consciousness is equated with intelligence?  Perhaps to some degree this is true – a human is more intelligent than a fly and most people would agree that the human is more conscious as well (although we don’t really know this).  However, I would argue that consciousness in human adults is not correlated with intellect, and I feel that it is dangerous to draw a connection between consciousness and intellect in this way.  The phi value (info & connections) seems to be missing a key component – I’m just not sure what.

            Bo-Rin’s comment about the possibility that there are more than “two clear cut categories of consciousness and unconsciousness” made me think about a discussion I recently had with some of my friends.  Sometimes when I am just waking up, I see something that doesn’t exist (like a person) within the context of the “real world” (what actually exists around me).  I’m not sure if this is a common phenomenon (my friends seemed to think I was weird, so maybe not), but it made me wonder what state of consciousness this would be classified under.  I am consciousness when it occurs – as I experience the “real world” around me – but my brain simultaneously conjures a false image.  If consciousness involves experiencing "real" sensations from the surrounding world, then am I really conscious when this occurs?

 

mrobbins's picture

  The enigmatic nature of

 

The enigmatic nature of consciousness is hard to make peace with. Any way we define it I don’t completely agree with. I believe that we are something outside of our experiences and actions. That something is consciousness. This further supports that behavioe can exist outside of internal identity of self. Getting down to nitty gritty nature of something is extremely hard! If we break down the parts of the whole why does it show completion? If a whole is made of its parts then shouldn’t the parts contain pieces of the whole? Consciousness doesn’t seem to work this way. Our brains map our our existences without completely providing an “I” or and “you.” It is true that you can approach consciousness in terms of being an assembly of neurons, and that one unity can be made up of many unities. But I remain unsatisfied with how we can find the person beneath such a network when you can have a network without the person.

Perhaps consciousness is an undiscovered synchrony rather than an integration of parts. The integration of parts may explain our behavior, our survival, and our species, etc. I like to think of consciousness as a symphony. Each instrument must follow a sheet of notes. Playing all the instruments together gives you plain noise.  But the way in which these instruments synchronize with one another is wholly unique unto a single song. Each single piece of complex music can then be seen as a conscious identity and composed personalities similar and dissimilar to other types of music.  Furthermore, maybe being able to come in and out of consciousness is just a pause in a greater rhythm of who we are.

 

Paul Grobstein's picture

From consciousness to imaging and anxiety

Some thoughts from this week's discussion relevant to our next conversations on imaging and anxiety
I am really intrigued by this potential ability/ evolutionary advantage of being able to turn on and off our own consciousness ... EB Ver Hoeve
What does our brain do to make us go from one state to the other? Is there a physical difference between an unconscious and conscious brain (I’m sure there is—I just don’t know exactly what the difference is)? ... Bo-Rin Kim
"it is not as easy as putting someone in an fMRI and providing them with a consciousness-relevant task to create an image of the neural map of consciousness.  That does not mean, however, that such a map does not exist" ... Jeremy Posner
Without the knowledge of unconsciousness, it seems hard to acknowledge one's own consciousness ... aliss
I was sort of skeptical of the topic of consciousness in general- at least approaching it from a scientific side ... After some thought, however, I think that is very useful to understand consciousness in cases of extreme head injury  .... sberman
and, perhaps, depression, and anxiety, and ... ?  Its interesting, perhaps significant, that a group of NBS seniors would be so skeptical about "consciouness" as a part of brain/behavior  ... PG

EB Ver Hoeve's picture

To Rationalize our irrationality ...

 

Ok, so when Paul walks “mindlessly” to the spot where the Men’s bathroom used to be, he is not conscious of his actions. He is alive and he is behaving, but he is not present/aware of his behavior. As Paul said, “we don't need "consciousness" for most of our behavior”. I am really intrigued by this potential ability/ evolutionary advantage of being able to turn on and off our own consciousness. I think about driving a car and how I often find that I am not actually thinking about HOW to drive the car… Instead, I find myself just driving. I don’t need to be focused on the actual work that goes into driving a car. My brain has made it so that I don’t have to consciously think about driving and instead has allowed me to expend my conscious energy on other things/problems that could exist on the road. Is the ability to turn consciousness on and off an evolutionary brain adaptation? It kind of seems possible… We have the ability to be conscious which allows us to think and act at a higher level/power. It allows us to act on things greater than our natural instincts.

 

My other thought of the week is that although I do agree with Jermey that, the study of the nervous system and its interactions within the body will explain almost all human behavior, I believe that there will come a point where we won’t be able to rationalize why we are irrational. Paul, maybe you would argue that the central pattern generators begin to explain how output behavior can be generated without input, but I think that at some greater level, we are simply not capable of rationalizing our irrationality.

 

Paul Grobstein's picture

rationalizing irrationality

"In an indeterminate universe, there is not only the possibility of alternative futures but a role for me and other people in expanding the array of possible futures by our own thoughts and actions.  I like the idea that people might matter in that way and like still more the idea that the task of humans (myself included) is not to figure out what we are ignorant of but instead to create what has yet to be tried out by an evolving universe of which we are a part." ... On beyond an algorithmic universe

See also

Bo-Rin Kim's picture

Professor Grobstein’s

Professor Grobstein’s question of why we switch between conscious and unconscious states led me to think about what the difference is between being conscious and unconscious. What does our brain do to make us go from one state to the other? Is there a physical difference between an unconscious and conscious brain (I’m sure there is—I just don’t know exactly what the difference is)? Moreover, while dwelling on this issue, I realized that consciousness isn’t split into two clear-cut categories of conscious and unconscious. There are also several altered states of consciousness under which things such as sleep and hypnosis fall under. Do all these different conscious states have different neural bases as well? I think these questions are interesting because knowing the neural differences between conscious, unconscious/altered states may help us to see what neural correlates are unique to consciousness.

However, as mentioned by Bobby, knowing all these different neural mechanism does not solve the mystery of consciousness. In his post, Bobby drew a parallel to computers and said that in order to understand the relationship between Windows and computer chips, you need to understand the different aspects of coding that occurs between the two. Likewise, in order to understand consciousness, we need to understand not only the neural correlates, but the coding that occurs between the brain and consciousness. Similar to how electric (and whatever else) signals in computer chips give rise to a visual, interactive computer program, how do neurons/chemicals/electric signals give rise to consciousness in the brain? The question of how a sense of being arises from physical matter is where I think the real mystery of consciousness lies.
 

Paul Grobstein's picture

Consciousness: a conceptual problem needing a practical approach

Thanks all.  Interesting conversation both last Monday night and in followups here.  I'm inclined to agree with Jeremy that "everything that is necessary to understand human behavior (in a sense) is available to us through the study of the nervous system and its interactions within the body,"  that "All of the components of consciousness are simple processes," and that "if a mechanical consciousness is created it will be the result of replicating the structure of a working consciousness."  Like Bobby, I'm less sure that "continued development of imaging technologies" will make that possible.  I can see all parts of a functioning engine and still have no idea of how it works.  The latter depends as well on, among other things, knowing what function the engine serves in the larger context of which it is a part.

I also agree with Vadilson and others that "Consciousness is a difficult topic to pin down."  My guess is it will turn out in the long run that the difficulty is a consequence of using the same term in a variety of different ways (cf Sara on conscious, subconscious, and unconscious and Alison on "presence in the moment and attention," and "simply being awake and alert ... and responding to one's surroundings."  My own inclination is that we need to focus a bit more on particular things that we want to account for and let the definition of consciousness evolve from that rather than arguing about what is or is not "conscious."   Yes, I think plants don't have it.  Whether societies do or don't is an interesting question but one that ought to wait until we have a clearer sense of what we want to account for in cases where we're surer of what we're exploring.

The upshot, for me, is to be inclined to focus for the moment on humans and on the pretty straightforward observations that human behavior can occur without any internal awareness of one's self and one's behavior or with such an awareness.  If we take the latter as an operational definition of "consciousness," some interesting things follow from it.  Among them is that consciousness (in this sense) is neither dependent on language (contra David) nor simply a function of neuronal number/complexity (see Megan).   We can have awareness without language and, given a nervous system of (at any given time) constant neuronal number/complexity, we can switch between unconscious and conscious function.

Two other interesting things that follow from this line of approach are a recognition that we don't need "consciousness" for most of our behavior and that we can be "conscious" without behaving in the sense of reacting to the world around us (thinking and dreaming both involve an active awareness of self).  And from that comes what I think is an important question that may help get a better handle on the context within which consciousness needs to be explored. 

Consciousness is not synomous, for humans, with either being alive or behaving.  We can do both without it.  It seems to be an additional capability, one we have in addition to being able to live and behave.  It is in this context that I think we can ask some further questions about consciousness that might be productive: what is the function of consciousness?  what does it make it possible to do that we can't do without it?   why do we switch between conscious and unconscious states?  what aspects of human behavior/experience wouldn't exist if we we're conscious?

I'm intrigued by the notion that neither pain nor disability (among other things) would exist without consciousness.  And by the idea, connecting to our earlier discussions, that depression as a human phenomenon and the contagion of mental illness diagnoses might not exist either.  Perhaps if we better understood what's involved in these sorts of phenomena (as well as a number of more positive versions of them), we might better understand the function consciousness serves in the larger context of the nervous system and human behavior/experience, and that in turn might give us a way to better interpret observations on the nervous system itself, and suggest new ones that should be made.       

Consciousness is a conceptual (and semantic) problem, but is is also a practical one (as per vgopinath), and one we have all kinds of experiences with in our day to day lives.   Perhaps more attention to its down to earth and practical manifestations would contribute significantly to clarifying the conceptual and semantic issues (cf The role of story in mental illness)?

Jeremy Posner's picture

The Building Blocks of Consciousness

 Consciousness really is a nebulous concept, particularly if it needs to be operationalized.  I actually appreciate the definition that Paul provided at the end of class a lot, that consciousness is defined by an awareness of a separate self and non-self.  The test for this definition of consciousness is also pretty neatly designed; the test subject is placed in front of a mirror repeatedly so as to develop recognition of its own appearance and a dot is then drawn on its face.  The idea being that a conscious animal will look to touch its own face when viewing the mirror, because it understands that the image it sees is its reflection but not actually its self.  Of course as neat as this definition is and as easy as its operationalization is having a definition of what “consciousness” in a behavior sense doesn’t do much to explain how it functions neurologically.  I personally suspect that everything that is necessary to understand human behavior (in a sense) is available to us through the study of the nervous system and its interactions within the body. 

Of course it is not as easy as putting someone in an fMRI and providing them with a consciousness-relevant task to create an image of the neural map of consciousness.  That does not mean, however, that such a map does not exist, and I feel similarly about creating consciousness mechanically.  All of the components of consciousness are simple processes, though the sum of those simple processes may be incredibly and (currently) incomprehensibly complex.  Eventually understanding those processes is simply a matter of time and continued development of imaging techniques.  I am very curious as to whether the base components of consciousness will be identified.  I imagine that if a mechanical consciousness is created it will be the result of replicating the structure of a working consciousness; and in order to create an original consciousness mechanically it would be necessary to understand what the fundamental building blocks of a consciousness are and what details are alterable.  The ethics of editing components of a consciousness will be an interesting topic I’m sure.                

vpina's picture

Open mindedness

As David has already put in great thank you for the participation in Monday’s class. Consciousness is a difficult topic to pin down and even in David and my research to find articles for the discussion, we found ourselves looking at articles for self-consciousness and elephants.  At this point we had to really specify what we would be talking about for class. In class we really came along in our personal definition of what consciousness could be and we also came to a lot of road blocks with the idea that in certain people there might be many wholes in one whole (remember Paul’s comment). 

The CNN video was also one that was very intriguing because it sheds new light in the ability to communicate to people that were diagnosed to be brain dead yet they seem to understand us and respond. Many would argue that if this is possible than those people are conscious and thus our definition of being brain dead has changed since a person that is “brain-dead” surely can not be conscious. Everyday the world of science is learning new things and contradicting or correcting itself, it is because of this that we keep an open mind to all new things.    

meroberts's picture

Quantifying a yet-to-be defined concept

In class I was struck by the idea that consciousness could be represented by the amount of information, and the way in which this information is integrated/linked together, that an entity can contain. The concept of quantifying consciousness initially seemed ludicrous to me. The Scientific American article even explained that "fi" is incredibly hard to compute, even for "simple" organisms. This makes absolute sense since it's impossible to quantify information processed by the brain. Everyday human brains are constantly barraged by images, both consciously and sub/unconsciously. These images, and the connections made from or between them, are supposed to determine "fi". But how can we begin to quantify consciousness if we don't even have a definition shared by a majority of scholars?

What good is a number if we don't know what it represents? Will this number eventually be used to discriminate between organisms with and without consciousness to create a consciousness hierarchy? We already do that anyway even though we don't have definitive proof that some organisms lack consciousness. Let's take the example from class about plants. Plants are alive and plant behavior can change in response to stimuli, as noted in Alie's post. Does this imply that plants would have a nonzero "fi"? I think so, but still plants are believed to lack consciousness. Is it really because plants can talk about themselves? I don't think I believe that the ability to produce/comprehend language entails, or guarantees, that an organism is conscious. People can certainly talk and be less than conscious, as in the case of Freudian slips. And what about animals that have their own systems of communication within their "societies". If a bird chirps to attract the attention of a mate, is that bird conscious of itself and it's role in the universe? Or is a bird chirp an innate behavior completely devoid of consciousness? I think before we attempt to quantify consciousness, we have to come to a more widely-accepted definition, or understanding, of consciousness. Otherwise there would be no reason to quantify it and no purpose for the information.

rdanfort's picture

Great job last night! Have a post:

 Consciousness is such a great and terrible discussion.  As a phenomena, consciousness is captivating, the source of awareness of all other phenomena, and at the same time so poorly understood or even defined.  We are not only unable to find it, we are unsure of what exactly we are looking for.

 

It is in this way that prominent researchers can propose that consciousness is simultaneously a product of the brain and that consciousness is not a product of neuronal firings.  The contention is not necessarily dualistic in nature, but generally one rooted in the nature of logical equivalence.  These thinkers argue that the activities of a neuron or neurons do not, in any conceivable way, correspond to the qualia of perception, thought, and emotion, and that some contiguous or higher-level system must fill that conceptual gap.  Among them is Nicholas Humphrey, who advocates pursuit of a "functional correlate of consciousness" in an essay that Jeremy and I have assigned as reading for next week's class.  (You had better read it!)

Nicholas essentially argues that what really matters in pursuit of consciousness is not the neuronal activity, but the "processes" carried out by said activity.  Brain-computer analogies are cliche and riddled with holes, but I think that one fits here: we cannot understand Windows from looking at the transistors on a processor, even if we perfectly understand all of them.  What produces Windows activity, and what allows us to examine and understand Windows, are the levels of code between the computing experience and the computer chip.  In this sense, a neural correlate of consciousness may give us clues, regions of interest, and other information, but it will not give us a causative role or deepen our understanding of what happens when we experience being conscious.

It is this idea that drove me to venture that societies and computer networks may be conscious in class discussion.  We know of some basic properties of the individual consciousness - planning, perception, sensation, etc. - and it may be argued that these carry over to societies in certain carefully-worded respects.  While similarities in behavior do not necessarily indicate similarities in mechanism, the view of consciousness as a product of "operations" and "processes" does suggest that such an equivalence is possible.  It can at least be said that the processes producing a single consciousness are present in each and every constituent of a society.  The discussion of "complexity" also informed my ideas, although I think it does refer to a more specific and more broadly-distributed conception of consciousness.

I think that it's important not to take this line of inquiry to mean that current research on consciousness is hopeless or misguided.  Without an understanding of biological brain activity at the lowest level, we are far less equipped to investigate the aggregate effects of neurons and how they may produce consciousness.  Rather, I think it is true that there are additional (and, potentially, much more difficult) tasks awaiting researchers as our sense of the nervous system improves. 

 

sberman's picture

subconsciousness and purpose of research

Since last class, I've been thinking a lot about the difference between our conscious, subconscious, and unconscious components. When I hear the word subconscious, my mind immediately jumps to a behavior that is not under direct cognitive control (and is not completely present) but still is based on an experience (which is different than unconsciousness, such as when a person is under anesthesia). For example, if you are jealous that someone received a promotion over you, and then treat them coldly without a focused intention to do so, I would consider that subconscious behavior. But how is that different than unconscious behavior in a person who is wholly conscious? Is Professor Grobstein's lack of attentional focus that led him to the women's bathroom a subconscious behavior? Or would it only be a subconscious behavior if he was angry about the building plans being changed and this anger somehow (albeit, unintentionally) manifested itself in his behavior? According to the study in Science, consciousness is marked by neural reproducibility, whereas subconsciousness is marked by variability in neural patterns. Maybe I'm just getting bogged down in semantics, but I think there is indeed a distinction between subconscious and unconscious behaviors -- though I'm not sure if there is a difference in brain patterns or not between subconscious processing (seeing a yellow spot though a house is present) and the minimal/lack of processing in unconscious behaviors.

Initially, I was sort of skeptical of the topic of consciousness in general- at least approaching it from a scientific side. Consciousness is a hugely abstract concept that is difficult/impossible to describe so that there are not exceptions. For example, if we describe conscious beings as alive beings, does this mean that plants are conscious? Or if we describe conscious beings as highly integrated, connected beings, are computers conscious? After some thought, however, I think that is very useful to understand consciousness in cases of extreme head injury, so we can determine whether patients are indeed able to process their surroundings but not able to interact. I hope that consciousness research focuses more on neural, scientific representations that can be used in cases of VS and MCS patients to provide better, more tailored treatments.

aliss's picture

Our discussion of

Our discussion of consciousness yesterday really got me thinking about the nature of consciousness.  We wouldn't even be having this conversation if not for the fact that we were conscious.  We can tell that our dogs and cats are conscious, we're pretty sure that our fish are conscious (goldfish have a memory of 5 seconds, right?), but are plants conscious?  Is a computer conscious?  My immediate answer would be "no."  But then, what is consciousness?  We described two types of consciousness yesterday.
The first type of consciousness we discussed is presence in the moment and attention.  I think this type of consciousness can be related to (but not equated to) theory of mind.  Theory of mind is something that human beings develop as toddlers - the idea that other people have consciousness that is separate from one's own, and that other people are intelligent.  Higher primates have also been shown to have theory of mind (a hallmark of which is the ability to recognize oneself in a mirror and not think another person is staring back).  Theory of mind in humans seems to develop alongside language and the knowledge of mortality.  These could be coincidences, but I don't believe they are.  As David mentioned, language is an integral part of consciousness.  If you don't have the words to describe your state or your existence, how can you conceive of the fact that you exist?  Recognition of mortality is akin to recognizing the possibility of unconsciousness.  Without the knowledge of unconsciousness, it seems hard to acknowledge one's own consciousness.
Then, we also discussed the other type of consciousness: simply being awake and alert rather than asleep, and responding to one's surroundings.  In this case, the line of consciousness seems harder to define.  Plants react to their surroundings - the grow towards light and grow more when they are exposed to classical music.  Are they awake as opposed to asleep?  That is harder to say.  However, I think that the response to one's surroundings is an important aspect of consciousness that we didn't discuss in class.  In this line of thinking, plants and individual cells are conscious.  I don't believe that plants have the same experience as a human being might have.  However, defining consciousness might require expanding our definitions of what is conscious.

Bo-Rin Kim's picture

I think this is a really

I think this is a really important distinction that you made here, and it notes that we need to be clear in which aspect of consciousness we are talking about when we use the term. I also think it's interesting to note that among the two types of consciousness that you described, one (theory of mind) cannot exist without the other (being awake). I mean, there are times when I am dreaming and I am kind of aware of who I am, but for the most part, when we are sleeping we aren't really aware of our surroundings or who we are (definitely not to the same level as we are when are awake). So could it be that there are different levels of conciousness and humans have just acquired the highest level? Just a question that popped into my head as I read this post....

VGopinath's picture

Significance of Former Consciousness

     One question David brought up in class yesterday that I have been thinking about is the number of neurons we can replace with electrical chips and still consider the person to be conscious.  Even if these new chips do not have the same plasticity as a neuron and just connect the two nerves/areas of the brain the replaced neuron connected, I would consider the person to be conscious.  Personally, it's difficult for me to consider determining that a human being, especially someone talking, walking, reading and doing arithmetic, lacks consciousness.  Yet those are all skills a computer has.  Perhaps an aspect of consciousness that I had initially not considered is whether or not that entity ever had agreed-upon consciousness and if we, as society, are "giving" or "revoking" consciousness in making a decision.

     A person who is inarguably conscious and sustains serious trauma to the head may no longer fit into our definitions of consciousness but because the person was conscious, when basic capabilities are left, we don't want to take their consciousness from them.  Synergy and connections between information are critical to consciousness but, as we discussed yesterday, split brain patients are considered to be conscious yet they do not have a corpus callosum to connect the hemispheres of their brain.  They lack the connectivity we deemed crucial.  Similarly, a computer in which we can input information but no new information can be stored would not be considered nearing consciousness.  This computer does not have the ability to retain new information and respond to its environment in a long-term fashion.  A person who has anterograde amnesia and can no longer form new memories nor remember reactions and details about the environment is similar to that computer.  Yet that person has a history and was undoubtedly conscious.  Therefore, because we can't conclusively and decisively determine what consciousness is, we don't want to inadvertently define it by revoking consciousness for people who sustain certain injuries.  Society has difficulty giving consciousness to a machine or something that we haven't already agreed is a conscious entity and we also have difficulty revoking consciousness from an entity society has agreed is conscious.  When we are arguing about consciousness, I believe that most of us are subconsciously trying to maintain the status quo and prevent other animals/ machines from being conscious while preserving it in humans, even babies (who lack language and an internal dialogue) and individuals with brian injury.   

David F's picture

Language as an integral part of consciousness

Thanks to everyone for your participation in today's discussion. I learned a lot about the neuroscience of consciousness through hearing your ideas.

It struck me as interesting that consciousness may be "more than the sum of its parts," that investigating neurons, or even sets of neurons, has not -- and perhaps can not -- be sufficient to explain the phenomenon of consciousness. But then what does it consist in? There are several answers to this question, but I think we might have hinted at some of them in class, such as language. Below is an article that suggests that consciousness is an inherently language-based phenomenon. This is an interesting possibility that many take seriously, and which may offer another perspective to those interested in the consciousness problem.

http://www.newscientist.com/article/mg14119104.400-all-in-the-mind-inner-voices-distant-memories--understanding-the-human-mind-is-easy-once-you-realise-that-consciousness-is-a-trick-of-memory-and-selfawareness-an-illusion-of-language.html?full=true#

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