Exploring the Physics of Emotions: Is There a Fundamental Variable?

[dd129495]

So... this may not be the right forum... but I figured biology was pretty close.

While we have built a very strong correlation between let's say dopamine and happiness (not sure if that's right), I was wondering if anyone knows of research that looks at correlations between matter and emotions on a smaller scale. For example, one question would be if there is some "thing" that we could isolate within dopamine that we could associate with happiness rather than just associating the entire molecule itself. The next question could be how small could we go or what other factors have to come into play too for the emotion to exist. This would turn the process of analyzing emotion into more of a physics question rather than something that's more of a biological question. Admittedly the only way we can detect emotion directly (I think) is by asking someone how they feel (or watching the expressions of an animal maybe), so this would limit the experiments and require rough measurements (if I can even call them that). Also... well there are a decent number of problems I can think of off the top of my head...

Anyway I did check online but I was bogged down with new age and abstract biology, which is not really what I'm looking for.

By the way, dopamine is really more of an illustrative example because that is one of the few chemicals that I have been told is strongly associated with emotion.

Just seeing if anyone sort of just knew.

 

[Danger]

Welcome, David. I don't know whether or not this is in the right place. It's "iffy" to me, but I'm not in charge. I will report it to a Mentor and s/he might decide to move it.
I'm pretty sure that you can't isolate something within dopamine. Considering how many intricate brain chemicals there are that perform very specific tasks, I doubt that subdividing one would allow it to continue functioning. That would be like removing the engine from your car and expecting it to still get you to work on time.
As to basing emotion upon physics rather than chemistry, remember the words of the immortal Harlan Ellison: "Love Ain't Nothing But Sex Misspelled."

 

[Bandersnatch]

Hi David Diwik,

From your post I gather you don't quite understand what dopamine does. It's a neurotransmiter, you see. It's a molecule (one of many types) used by neurons to transmit information across the synapse.
Ultimately, emotions are just a kind of brain activity, which in turn is a pattern of neurons firing. There is nothing inherently connected with emotions in neurotransmitter molecules, just as there is nothing inherently connected with emotions in the electric potential of ions in a neuron that is firing. The connection lies merely in the fact that different brain areas use different molecules to communicate, and dopamine happens to be used for the risk-reward (among others) neural pathways in the brain.
In other words, the way dopamine is associated with the state of happiness, is that the areas of the brain whose activity, as seen through various brain scanning techniques, is causing you to think "I'm happy" use those neurotransmitters more than others.

For all we care, the "happiness" neurons in the brain could be just as well communicating via walkie-talkie, and in such a case one could say that walkie-talkie are responsible for happiness.

If you'd like to explore the topic in more detail, I strongly recommend these Stanford Uni lectures:
https://www.youtube.com/playlist?list=PL848F2368C90DDC3D
The specific lectures most relevant to your query are probably the "Introduction to neuroscience" and "Limbic system", although you may want to go through the whole list for a more thorough understanding (they're fun to watch too - Sapolsky is a great communicator). The former cover the basics of neural communication, the latter deals with the region of the brain most directly responsible for experiencing emotions.

 

[dd129495]

Hi David Diwik,

From your post I gather you don't quite understand what dopamine does. It's a neurotransmiter, you see. It's a molecule (one of many types) used by neurons to transmit information across the synapse.
Ultimately, emotions are just a kind of brain activity, which in turn is a pattern of neurons firing. There is nothing inherently connected with emotions in neurotransmitter molecules, just as there is nothing inherently connected with emotions in the electric potential of ions in a neuron that is firing. The connection lies merely in the fact that different brain areas use different molecules to communicate, and dopamine happens to be used for the risk-reward (among others) neural pathways in the brain.
In other words, the way dopamine is associated with the state of happiness, is that the areas of the brain whose activity, as seen through various brain scanning techniques, is causing you to think "I'm happy" use those neurotransmitters more than others.

For all we care, the "happiness" neurons in the brain could be just as well communicating via walkie-talkie, and in such a case one could say that walkie-talkie are responsible for happiness.

If you'd like to explore the topic in more detail, I strongly recommend these Stanford Uni lectures:
https://www.youtube.com/playlist?list=PL848F2368C90DDC3D
The specific lectures most relevant to your query are probably the "Introduction to neuroscience" and "Limbic system", although you may want to go through the whole list for a more thorough understanding (they're fun to watch too - Sapolsky is a great communicator). The former cover the basics of neural communication, the latter deals with the region of the brain most directly responsible for experiencing emotions.

I appreciate both of your responses (thanks). I will look at that lecture, but what I gather is that you would have to focus on the transmitter, the sender, and the receptor if you were trying to analyze emotion (not just the transmitter... aka dopamine.. sort of). I suppose what I really want (and excuse my leaning towards aesthetics) is one or two variables where different degrees of such would be associated with the full spectrum of emotion. Admittedly there seem to be complex reactions behind different emotions, but it would be pleasing if all of these reactions focused a central variable (will explain). For example there are many ways to wire a light to a switch, but at the end of the day the key is that you have to connect the metal from one side to the other. Similarly there are many complicated ways for emotions to manifest with chemicals (is my assumption), but there is one (or two etc.) underlying variable that is really the key to creating and differentiating between the emotions themselves. This is whimsy, uneducated (hence I will look at the lectures etc.), and idealistic, but I should at least explain what I was thinking (even if nothing comes from it). Thanks again for reading and responding to my post (to both of you).

Diwik

 

[dd129495]

Actually, I still want to believe that idea... but I should look into things first at least

 

[madness]

Emotion is obviously not contained within a molecule. Chemicals like dopamine act as reward signals, which are related to emotional states. I found this theory interesting - http://www.ncbi.nlm.nih.gov/pubmed/24126130. It says that emotion is related to the brains perception of the body's internal state, and specifically that it is related to a predictive model in the brain of the body's internal states.

 

[DiracPool]

Admittedly there seem to be complex reactions behind different emotions, but it would be pleasing if all of these reactions focused a central variable (will explain). For example there are many ways to wire a light to a switch, but at the end of the day the key is that you have to connect the metal from one side to the other. Similarly there are many complicated ways for emotions to manifest with chemicals (is my assumption), but there is one (or two etc.) underlying variable that is really the key to creating and differentiating between the emotions themselves.

I think Bandersnatch (and madness) gave a correct response to your query. To reinforce that argument, dopamine is just a molecule, there's nothing inherent about its structure that makes it special, it's where it functions within the forebrain that makes it special. You're looking for the magic bullet of happiness, but emotion is a very complex process involving many (actually every) brain region and can't be reduced to a single molecule. That said, can we look for a Kernal of happiness and sadness? I think we can, in the reciprocal action of reward and punishment mechanisms, each of which has a specified neuroanatomical geography associated with it with their participatory transmitters. But it isn't the transmitters per se that are important, it's how they function in the network. The reciprocal action works as a go no-go network, with the meso-limbic medial forebrain bundle pathway driving the "go" while portions of the amygdala and periaquaductal grey drive the "no-go." Why this is significant is that these mammalian subcortical networks can be traced back phylogentically to more primitive approach-withdrawal stimulus-response networks in lower vertebrates and even invertebrate species, and the neurochemistry appears to be conserved. In mammals, for instance, the "go" or reward network related to dopamine innervates the main motoric pathways of the striatum/basal ganglia and fronto-cortical motor pathways. Activation of the punishment areas inhibit activation of this pathway and frequently result in "freezing" responses under chemical inhibition or intracranial stimulation. So there's your "central variable" as you phrased it, how it manifests on a more global level as happiness and sadness is a more involved issue.

 

[Pythagorean]

If you want to know more about neural correlates of emotion, it's best to think in terms of brain structures and the activity within those structures. For example, fear is often associated with activity in the amygdala, which is a functionally and anatomically distinct brain structure in the temporal lobes.

http://www.annualreviews.org/doi/abs/10.1146/annurev.ne.15.030192.002033?journalCode=neuro
http://www.ncbi.nlm.nih.gov/pubmed/12724154
http://www.nature.com/nature/journal/v509/n7501/full/nature13258.html
http://www.nature.com/neuro/journal/v16/n3/full/nn.3323.html

It's true that some molecules will be more associated with certain feelings than others... but the moloecules are a very small part of the whole phenomena and often have other functions associated with them

 

[Evo]

To add to your reading list, this article on depression may help to simply answer why there is no simple answer.

It’s often said that depression results from a chemical imbalance, but that figure of speech doesn’t capture how complex the disease is. Research suggests that depression doesn’t spring from simply having too much or too little of certain brain chemicals. Rather, depression has many possible causes, including faulty mood regulation by the brain, genetic vulnerability, stressful life events, medications, and medical problems. It’s believed that several of these forces interact to bring on depression.

To be sure, chemicals are involved in this process, but it is not a simple matter of one chemical being too low and another too high. Rather, many chemicals are involved, working both inside and outside nerve cells.

Regions that affect mood

Increasingly sophisticated forms of brain imaging — such as positron emission tomography (PET), single-photon emission computed tomography (SPECT), and functional magnetic resonance imaging (fMRI) — permit a much closer look at the working brain than was possible in the past. An fMRI scan, for example, can track changes that take place when a region of the brain responds during various tasks. A PET or SPECT scan can map the brain by measuring the distribution and density of neurotransmitter receptors in certain areas.

Use of this technology has led to a better understanding of which brain regions regulate mood and how other functions, such as memory, may be affected by depression. Areas that play a significant role in depression are the amygdala, the thalamus, and the hippocampus (see Figure 1).

Research shows that the hippocampus is smaller in some depressed people. For example, in one fMRI study published in The Journal of Neuroscience, investigators studied 24 women who had a history of depression. On average, the hippocampus was 9% to 13% smaller in depressed women compared with those who were not depressed. The more bouts of depression a woman had, the smaller the hippocampus. Stress, which plays a role in depression, may be a key factor here, since experts believe stress can suppress the production of new neurons (nerve cells) in the hippocampus.

http://www.health.harvard.edu/newsweek/what-causes-depression.htm

 

[Ygggdrasil]

one question would be if there is some "thing" that we could isolate within dopamine that we could associate with happiness rather than just associating the entire molecule itself.

From a chemistry point of view, it is possible to figure out which parts of the dopamine molecule are most important for its function (in this case, binding to and activating dopamine receptors in neurons). The best way to do this is to determine the structure of the molecule bound to its target (e.g. through x-ray crystallography). Such a structural information gives very direct insight into which parts of the molecule are interacting with what parts of the receptor. However, these structural experiments are often very difficult to perform (especially for membrane-embeded proteins), so most drug discovery efforts will instead synthesize many analogs of the molecule and test the effects of each of these analogs. If your analog modifies an important moiety of the molecule, it will likely show very reduced activity in your biological assay, whereas modifications that do not affect the activity of your molecule likely modify parts of the molecule that are unimportant for its function. Together, these studies lead one to define a pharmacophore, an abstract model of the minimal features a molecule needs to bind to a specific target. This type of trial-and-error testing can be made more rigorous through quantitative structure-activity relationship models.

These types of experiments are great for examining drug-receptor interactions at the molecular scale, but determining how these interactions lead to further downstream effects involves many more experiments. So, even if you can define exactly how dopamine interacts with dopamine receptors, that's still a long ways away from understanding how activation of dopamine receptors affects the neural circuitry of the brain to produce emotion.

 

[dd129495]

Thank-you for such detailed posts. I think I have a lot to look at (really thanks). I do understand that you can't just look at the dopamine, but have to look at the system of receptors etc. as a whole, and now I have a lot of information to think about this in more detail. Really appreciate the posts. I hope this wasn't too much trouble.

By the way, I also get it that it's probably way difficult to find a "central variable" in sort of physicsish detail (such that your looking at electrons and what not) that is fundamental to varying emotions (if there even is one). But, in general we don't want to memorize reactions between one molecule and another as they relate to emotions; it's much more appealing to have one law that explains why the reactions lead to the emotion in question (something that could even predict new emotions outside of our typical spectrum because we haven't needed them). However, this was pretty much covered (as impractical at the least) and I'm pretty sure I understand the contention.

I will definitely look at the links.

Diwik

 

[RabbitWho]

There are some free psychology courses on the internet about Emotion. There's a great Dacher Keltener one from Berkeley (on itunes)and another great and very well-made one from June Gruber from Yale (on youtube). June Gruber also interviews the big names in emotion research.

These courses go right from what is known about... let's say the gui.. right from the gui (facial expressions) all the way down to machine code (hormones, neuro-transmitters) and hardware (brain structures) .

Paul Eckman has his own youtube channel too, but that's all about the ghost in the machine (cognitive level of emotion) as well as facial expressions, which I gather you are not interested in. But it's all connected.. you know holding a pencil in your mouth makes you slightly happier? That's what I mean, your emotions affect your facial expressions and vice versa.

 

[Danger]

By the way, I also get it that it's probably way difficult to find a "central variable" in sort of physicsish detail (such that your looking at electrons and what not) that is fundamental to varying emotions (if there even is one).

I wouldn't call it a "central variable", but I know an awful lot of people who swear up and down that the changing atmospheric conditions in advance of a Chinook (or whatever it's called in your area; Santa Ana in the US, I think) changes their state of mind. I know that most, if not all, "room air ionizers" are a joke, but the anecdotal evidence for wind-related ionization and barometric changes goes back centuries. There might be something to it.