# Neuroscience heads



## The_African (Oct 9, 2010)

Is it even theoretically possible for a being to be conscious, to have the capacity for thought and sensory awareness, without feeling any emotions. Are there any known humans who have some unusual medical condition that prevents them from experiencing any kind of emotion? Is it possible for a nervous system to function without neurotransmitters?


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## AngryReader (Oct 12, 2010)

Disclaimer: I am a student of neuroscience, I don’t have a degree (yet).

*Rephrased: Is it theoretically possible for a nervous system to function without neurotransmitters?*
  Yes.  

  Some neurons don’t have chemical synapses that use neurotransmitters. These neurons use gap junctions. It might be theoretically possible for an organism to evolve, or be engineered, to have only gap junctions. There are reasons chemical synapses evolved to be the primary means of neuronal signaling. Chemical synapses allow for more complex electrical interactions in neurons than gap junctions could ever allow for. An organism that only used gap junctions might not be able to have complex behaviors.

  If your question wasn’t hypothetical, the answer would be no. An organism with a nervous system that couldn’t use its neurotransmitters would die effectively instantly (sarin gas). Also, keep in mind that neurotransmitters are a very diverse group of molecules. Some are simple organic molecules that have only three atoms, others are proteins hundreds of amino acids long, with thousands or tens of thousands of atoms.

*Is it even theoretically possible for a being to be conscious, to have the capacity for thought and sensory awareness, without feeling any emotions.*
  No.

  There are not any comprehensive theories of neural systems or their properties: thought, awareness, and emotion. There is no direct theoretical base from which to answer your question. Evolutionary psychology explores the relationship between psychological construct and their relationship to organisms. I’m of the opinion that this field is largely philosophical, and not scientific, but that doesn’t mean that one cannot make educated guesses about organisms and the psychological traits they posses. I would not expect to see an organism evolve that lacked emotion. Emotion is the critical component to avoiding or seeking certain behaviors.

*Are there any known humans who have some unusual medical condition that prevents them from experiencing any kind of emotion?*
  Yes.

  Emotion is a difficult concept to define philosophically, and impossible to define empirically, and therefore scientifically, at this point in time. Although there are many who would disagree with that statement. Nevertheless, there are a lot of case studies and clinical research into physiological and psychiatric conditions that affect apparent emotional deficits, both complete and partial.

  Damage to certain brain regions can cause emotional deficits for specific emotions, such as fear or pleasure. There is no single structure in the brain that causes emotion. I’m unaware of an injury that could cause a person the total loss of emotion. There are psychiatric conditions which result in blunted affect, such as some forms of schizophrenia. Anti-psychotic medication can also cause blunted affect.


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## mosaix (Oct 12, 2010)

Good post. Thanks, AngryReader. 

P.S. Welcome to the Chrons.


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## The_African (Oct 16, 2010)

Thank you, Angry Reader.

Is it possible that pleasure and stress are the only 2 emotions that actually exist? I know that there are people with a medical condition (not congenital analgesia, I forgot what it's called) who sense injury but they don't have our stressful reaction it, this is hard to understand because we associatate the objects of our emotions with our emotions. Is it possible that the pleasure we get from sexual sensation, eating food, giving to charity etc. is the exact same emotion but we feel that there are different kinds of pleasure/stress because these feelings are triggered or accompanied (the way adrenaline is part of anger but it can also be apart of joy) by different sensations?

How is it that medium levels of serotonin increase well-being but high levels are linked with depression or oxytocin plays a role in affection and empathy but it also plays a role in envy?


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## Nik (Oct 16, 2010)

We seem to have Multiple brain areas, some of them apparently semi-autonomous. Raise the level of a chemical throughout, and paradoxical things may happen. Stimulate one area of brain eg with Transcranial Magnetic Stimulation, and remarkable things may happen to outlook and senses, suggesting how changes to complex equilibrium(s) within brain may work...


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## J-WO (Oct 17, 2010)

AngryReader said:


> *Is it even theoretically possible for a being to be conscious, to have the capacity for thought and sensory awareness, without feeling any emotions.*
> No.
> 
> *   *   *
> ...



I'd be the first to admit I'm as thick as fudge, but I just can't see how these two answers don't contradict one another.


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## AngryReader (Oct 19, 2010)

J-WO said:


> I'd be the first to admit I'm as thick as fudge, but I just can't see how these two answers don't contradict one another.



I see your point. I answered the first question from the perspective of a species, and the second from the perspective of a member in a species. 

Would I expect to see a species without something I would call emotion in a survey of the universe? No. 

Would I see members of species without something I would call emotion? Yes, and we do see this in humans.

Perhaps I answered the first question from an unintended perspective, but addressing a biological possibility of an emotionless species seemed to be what was being asked to me.


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## Dozmonic (Oct 19, 2010)

Consciousness is a fascinating subject. With the limited work I did on artificial intelligence it was fascinating to see order arise from chaos with neural networks and the like. But they all have something in common - they rely on input and feedback. The thing about consciousness is that the input comes from within, which keeps my head spinning ;-)


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## AngryReader (Oct 19, 2010)

On Pleasure and Fear

  I’m not sure if by stress you mean stress or fear. I wouldn’t consider stress an emotion, in any definition. There are three brain regions I’m aware of that are associated with emotion: the amygdala (fear), the basal ganglia (pleasure), and the medial prefrontal cortex (pleasure). The pleasure pathway for the medial prefrontal cortex isn’t directly related with the basal ganglia, but both structures employ dopamine, among other neurotransmitters. From this I would say that pleasure and fear are two basic emotions. Possibly the only emotions, with all others derived from pleasure or fear. However, I would be quick to point out that that pleasure is associated with two different brain regions, that apparently aren’t directly related functional. This oddity leaves some questions for defining emotion in terms of brain structures. As for lack of fear and pleasure, many psychologists teach sociopathic behavior is the result of insensitivity to fear and pleasure. Although sociopaths may appear to have insensitivity to fear or pleasure, I’m skeptical of a causal relation. 

  Damage to the amygdala can lead to an apparent lack of fear. I’m perversely amused by a study done on people with amygdala damage. One group was comprised of people with amygdala damage, another with damage to the hippocampus (memory for events). The subjects were shown a blue box, and then shocked. After a number of times the researchers presented the blue box, and asked the subject some questions about it. People with hippocampal damage answered they were afraid of the blue box and didn’t like it. They didn’t know that the blue box meant they were going to get shocked, they just didn’t like it. The group with amygdala damage had no feelings one way or another about the box. They did say that they knew there were about to get shocked, an event for which they apparently had no feelings on way or the other. Shocked, not getting shocked, all the same to people with amygdala damage.



The_African said:


> How is it that medium levels of serotonin increase well-being but high levels are linked with depression or oxytocin plays a role in affection and empathy but it also plays a role in envy?


  Side Point:

  The usual problem with psychology is definitions and measurements. What is well-being? Can you point out well-being in nature? If you can’t observe it, you can’t measure it. Not empirically at least. 

  Short Answer:

  How is it that a neurotransmitter can be related to two seeming unrelated, or even mutually exclusive behaviors or emotions or functions? It’s the patterns of neuron firing, not the neurotransmitters, that are responsible for behavior. Neurons for mutually exclusive functions might use the same neurotransmitter, neurons for highly related might use the same neurotransmitter, you can’t automatically draw any conclusions on the functionality of a brain regions because it contains neurons that use one type of neurotransmitter. 


  The rest of my post is a longer  explanation of what neurotransmitters are, and what their ‘linking’ to certain behaviors means. You’re focusing a lot on the relationship between neurotransmitters and behavior. I think that this relationship is less than what you think it is. There was a lot of talk in the 90’s of neurotransmitters and chemical imbalances and what not. It gave people the impression there are clouds of chemicals roaming the expanse of neurons that somehow cause behavior. Too much or too little of a concentration caused abnormal functioning. That’s not how it works.

  A neuron releases one type of neurotransmitter only, and responds to one type of neurotransmitter (basically). A class of neurons might respond to dopamine, but release GABA. Another class might respond to dopamine, and release dopamine. In a given brain region there are neurons that release and respond to many different types of neurotransmitters. Some neurotransmitters are used by neurons throughout the brain, like dopamine and serotonin. That doesn’t mean that if brain region A and brain region B both have neurons that use dopamine that those brain regions are functionally related.  

  When a neuron fires, it releases neurotransmitters onto a target cell or cells, namely onto neurons. The target cell ‘translates’ the neurotransmitters into a voltage change. If there is enough of a change in voltage in a given period of time the target neuron will then fire as well, releasing neurotransmitters onto its target cells. This can go on and on in long chains or big loops called circuits. 

  The space between the neurons is a tiny compared to the size of the neurons, like one building in all of a city or even one building in all of a state or province. Neurotransmitters are made, released, and recycled in this space the area right around it. Still, it is not an enclosed space, and as neurons fire, some neurotransmitter escape the recycling method and float around for awhile in the space between brain cells. Only the neurotransmitters released from one neuron directly onto another have sufficient concentration to allow the target neuron to fire. The neurotransmitters floating around in between cells can’t do that.

  Popular press picks up stories about dopamine and schizophrenia or parkinson’s and send them out. These stories only serve to further the misconception of how a nervous system works. People start to think that excess dopamine causes schizophernia, or that a lack of dopamine causes parkinson’s. You can establish a correlation between the extracellular concentration of a neurotransmitter and some other variable.  You can establish a correlation between the lack or excess of production or recycling or release of a neurotransmitter and the symptoms of a disease. Unfortunately, that doesn’t tell you if the diseases is cause by this, or if the problem with neurotransmitters is another symptom or consequence of a disease. All you know is there is a correlation, you don’t know anything about the functional relationship between the variables.

  We don’t really know how the brain works to produce behavior. Neurotransmitters are an important aspect in how and when a neuron fires, but they are a piece of the puzzle, not the whole picture. But it is clear that it is computation of the neurons that drives behavior, not the messengers between them.


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## J-WO (Oct 20, 2010)

I'm increasingly of the opinion that the popular press should just leave the brain well alone for the next thirty years or so until we're in a position to make any solid statements about these things.

Then again, it could just be all this serotonin I keep producing!

(Nice post by the way, Angry. Fascinating stuff.)


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## The Procrastinator (Oct 20, 2010)

Yes, very interesting! Maybe philosophers should do so as well as the popular press, J-wo. "What is the Mind", cue tennis ball, bunk, bonk, bunk, bonk, ball floats up to ceiling where no one can reach it but everyone keeps talking about what it looks like from their perspective and saying the other one is wrong. But then I spose getting philosophers to stop talking is a bit of an ask... 

Angry R, if you ever get the urge to post anything about your studies, go right ahead.


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