QuantiMind

In Progress

2010-07-08T07:41:00.000-07:00

I have a post in progress that has required an unexpcted amount of time and research. Hence, you will find very many references, which took considerable time to find, retrieve, and read.

The subject is a causal link between major depression and antisocial personality, the latter of which, previous to DSM IV, had been referred to as sociopathy or psychopathy. Essentially, the severely depressed should display antisocial behaviors.

I hope to complete this post soon. I will complete it within the next week, if time allows.

No More Audio/Visual Versions

2010-06-06T08:45:00.000-07:00

I will no longer offer audio/visual versions of posts. It seems they aren't being used.

Get Past the Past

2010-06-06T08:38:00.000-07:00

There is an old drug that has fairly recently been shown to prevent the emotional consequences of memory recall via reconsolidation.

The drug is Propranolol, a beta blocker that prevents adrenergic stimulation. Marketed as Inderal, this medication has long been prescribed to control high blood pressure and anxiety.

Among the fascinating implications, Propranolol administration during the recall of painful memories may speed the habituation(healing) of past traumas, and help abolish chemical addiction.

Another Apology

2010-05-13T00:07:00.000-07:00

I apologize to readers for going nearly a month without a post. I've been unusually busy. I will try to post more often now.

Thank you for your patience.

Thoughts on Why Younger Men and Older Women Sometimes Mate

2010-05-12T20:03:00.000-07:00

audio/visual version
It is cliche to note that men are often attracted to younger women, and women to older men. The typical evolutionary explanation(page 9) is that men generally prefer younger women, because the latter are more fertile on average. Women usually prefer older men, because the men can command more resources on average, including experience, among other factors.

In recent years however, the phenomenon of the mutual attraction of younger men and older women is gaining attention. Older women, roughly referring to women aged 35 or older, are popularly referred to as "cougars," while the men who share a mutual attraction are referred to as "cubs."

While a few recent demographic trends may provide some insight into the higher frequency of this relationship pattern, there are some purer evolutionary explanations as well.

When it comes to why older women may sometimes choose younger men, the former may find fewer mating opportunities with preferred older men(page 6, last 2 paragraphs), and hence settle for younger. But, why would younger men find older women attractive?

Perhaps the reason is the same as that above for women sometimes dating younger men. It could be due to a lack of younger mate availabity. However, there may be an additional dimension to the attractiveness of older women to men, at least when the women look younger than their age. Perhaps these women send signals of genetically-determined longer fertility lives, and hence represent an optimal mating strategy even in absence of a scarcity of younger or same-aged women.

Of course, that last point is mere speculation, as I haven't found any research support for it yet. If any of you find some, please let me know.

Horrible Reporting

2010-04-16T15:14:00.000-07:00

audio/visual version
Here is a nice, quick post I can offer. It's in reference to a report that appeared last month in Science Daily. The report tries to make novelty out of a conclusion that deliberate and unconscious memory retrieval are facilitated by different pathways in the brain. Well, how could it be otherwise?

The report goes on to claim that the processes involved in unconsciously retrieving memories and likewise forgetting them are mysteries. This is simply untrue, except for purely neurophysiological mechanisms, though many of these are known too. To quote here:

Science still does not fully understand why our brain sometimes automatically supplies us with a memory that we have done nothing to deliberately call to mind, whereas why, on other occasions, we cannot remember things even though we make efforts to recall them.

There are several memory systems in the brain, but the two major ones are the explicit and implicit. The former is responsible for conscious, deliberate recall and the latter for unconscious recall. The explicit allows attempts to connect with previously stored predictive contexts for sought (net rewarding)memories. This is facilitated by the elicitation of incomplete predictive contexts, triggered consciously and unconscously. There are no memories without contexts, so explicit memories require these partial predictive contexts and then use associational methods, including those involving metacognition, to try to connect with the more complete contexts. The explicit system is involved to the degree that a context is new, so there is incomplete generalization. Thus, this process only works some of the time.

The implicit system involves well-learned habits that require little awareness. Examples include motor learning, but can occur with any type of behavior strongly generalized across predictive contexts.

Even considering the normally awful media reporting of scientific work, this example stands out. And this is worse for a publication that solely reports on science.

Posts in Progress

2010-04-12T11:21:00.000-07:00

I apologize for going nearly a week-and-a-half without a post, but I've been very busy and working on some posts that are taking longer than anticipated.

For example, I'm considering whether antisocial behavior(sociopathic) can result from extreme depression, and how to formalize such a relationship.

I am also considering cases in which general intelligence, defined as relatively high stimulus processing rates, can make for less intelligent decisions.

Another post in progress is one on the attractiveness of older women to younger men.

And, there is consideration of the reason bullying occurs among children.

So, please have patience as I try to put as much quality into my posts as possible.

Yes, maybe I'm spreading my attention too thin by simultaneously working on so many posts, but I've been shifting toward topics that I've incorrectly thought would take less time to complete.

Artificial Emotions

2010-04-02T06:17:00.000-07:00

audio/visual version
This article in New Scientist has me thinking about how to endow artificially intelligent machines with emotions. This shouldn't be a hard task.

Referring to a previous post on mood, as well as one on emotions, a computerized machine can be fitted with sensors to facilitate machine learning, with unconditioned and conditioned stimuli as incentives. Reward would be determined by the required rate intake of resources, and the net intake of resources deemed available. Resources can include energy, and even social approval. In the latter case, machines can detect facial features and be programmed to associate them with social signals, such as those revealed by facial expressions, for example. The sum of all available resources can be operationalized as mood.

The machine is then capable of attaching values to various stimuli and now emotions can be added. Anger, for example, can be programmed as an unexpected subjective loss. But could machines feel?

I think emotional feelings in human beings serve as signals to the working memory in the prefrontal cortex, allowing for metacognitive differentiation. That is, with regard to our thinking about our emotional reactions, it helps to be able to distinguish each emotional response from others. Hence, there is no reason to think such differentiation cannot be programmed into artificial intellgence systems.

Free Will Absolution?

2010-03-28T11:22:00.000-07:00

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This book review has spurred me to offer a brief follow up to a previous post on free will.

I agree with the review author Holly Anderson, who dismisses the idea that "emergence," or the consideration that brain functioning as a whole is more than the sum of its parts, by pointing out that any process governed by the brain is deterministic. However, focus of this post is on the issue of whether this means people shouldn't be held responsible for their actions.

The answer, in my opinion, is that in a pure abstract moral sense they can't be, but we have to assign responsibility to those who engage in externally damaging behavior anyway, for practical reasons. We have to protect society.

By the way, it is interesting to me that the question of whether a lack free will cancels moral responsibility is only considered with respect to negative behavior, at least in my experience.

Suicide is Adaptive(Evolutionarily)

2010-03-26T14:02:00.000-07:00

audio/visual version
Update: This post is not meant to advocate suicide. It only speaks to evoluationary motives.

Suicide is often a natural behavior. This is because it may help to pass genes.

This seeming paradox is resolved when you consider the implications of inclusive fitness, or more specifically with regard to kinship selection. This refers to the fact that close relatives have a high number of genes in common, the hence the passing on of shared genes sometimes benefits from sacrifices at the expense of one or more relatives, even leading to death. Particularly, individuals with low access to resources needed to pass genes directly, relative to family members, become a drag on the resources of others in the family.

This idea was perhaps first put forth by Denys deCatanzaro, but the logic first appealed to me years before I found this paper and related research.

This is not to say that all cases of suicide are related to kinship selection, but does suggest the existence of a sort of "mental program" that is activated by low moods, relative to family members. Other causes for suicide include the metacognitive avoidance of psychical and or physical pain, the influence of psychoactive drugs, and more purely neurological causes.

6 Days and No Longer Counting

2010-03-21T23:28:00.000-07:00

I apologize for my lack of posts over the last six days. Everyday, I've been busier than anticipated, always thinking that finishing one or more posts I've been working on was coming the very next day or night. Hence, I didn't post a message revealing any intention to take a break from posting.

Unfortunately, my posts sometimes take hours to complete, given the research requirements. Sometimes searching for and/or actually obtaining relevant papers create unanticipated delays, apart from unexpected changes in my general schedule.

I will try to post more frequently whatever my schedule, but let you know when I'm not certain about the length of a delay. Thank you for sticking with me.

Depressed Parents Play Favorites

2010-03-21T23:19:00.000-07:00

audio/visual version
The model of behavioral investment as determined by mood that I previously presented has an interesting implication for the way parents treat their children. That is, depressed parents are more likely to succumb to favoritism. Specifically, as mood decreases, parental investment shifts toward children deemed more reproductively fit(1).

Parental investment involves the amount of time, energy, and other resources offered each child by their parents(2), and reproductive fitness(3) can be revealed in signals related to physical attractiveness(cuteness, etc), physical fitness, intelligence, emotional robustness, susceptibility to illness, ability to make friends, and even resemblance to one or both parents, among other cues. There is even evidence that birth weight is moderated by a mother's stress levels(lower mood), with higher stress associated with lower weights.

This is part of a larger phenomenon(first link above) in which depressed parents often unconsciously develop high quantity, low parental investment reproductive strategies in environments peceived as hostile to higher per-child investment strategies.

1. D. Beaulieu, D. Bugental (July 2008) Contingent parental investment: an evolutionary framework for understanding early interaction between mothers and children.
Evolution and Human Behavior, Volume 29, Issue 4, Pages 249-255

2. Trivers, R.L. (1972). Parental investment and sexual selection. In B. Campbell (Ed.), Sexual selection and the descent of man, 1871-1971 (pp. 136-179). Chicago, IL: Aldine.

3. Hamilton, W.D. 1964. The genetical evolution of social behavior. Journal of Theoretical Biology 7:1-52

No Allergies or Immunity to Learning

2010-03-15T01:25:00.000-07:00

audio/visual version
This post can be considered an extension of my last one on learned tolerance to addictive substances.

Like reactions to addictive substances, allergic and immune responses are influenced by external environments and mental states. Both can be learned and forgotten, depending on the contexts. I lump them together here, because they are actually both functions of the immune system.

Both types of responses can be triggered by external environments and mental states that are similar to those in which allergens(former) or pathogens(for example, latter) were previously encountered. Likewise, learned responses can fail to occur in environments and or mental states that are subjectively dissimilar. So, when it comes to the acquisition and extinction(unlearning) of allergies and specific immune responses, all of the principles of learning apply.

One implication is that exposure treatments, involving the gradual presentation of contexts(stimuli) previously experienced with an allergen or pathogen, sans those threats, should sometimes diminish learned allergic and immune responses. This is similar to systematic desensitization treatments used to treat phobias and more general anxiety disorders. Perhaps this approach can also apply to treatment for some cases of autoimmune disorders.

So, this is just another example of how psychology can touch upon elements of the functioning of our bodies in what may be unexpected ways for many.

Drug Tolerance in Context(Really)

2010-03-12T15:19:00.000-08:00

audio/visual version
Drug tolerance is contextual. It can vary, depending on the external environment and even the thoughts of the user. The key idea is that tolerance-related drug potency increases in unfamilar environments or mental states.

There is much research that bears this out, with experiments going back to at least 1975. Overdoses are even thought to have occurred as a result. This suggests that tolerance often has a strong element of learning, despite what many students in my substance abuse classes inititally think. You should see their faces.

This obviously has implications for addiction, as the higher the tolerance to an addictive drug, the lower the pleasure of using, but the more severe the negative consequences for abstaining. And of course, many seemingly hold the idea that familiar environments in which drug use occurs tempt addicted users. Hence, the encouragement given to many substance abuse patients is to avoid such environments, along with changing some of the ways they think about their addictions and any related problems. Perhaps the danger of patients using in novel contexts with increased enjoyment is often overlooked as a risk for relapse.

Any "highs" addicted users enjoy are not the only experiential aspects that suffer tolerance. There are many other physiological effects that are also context-dependent. For example, take the antinociceptive(pain relief) effects of opiates.

Interestingly, there is a flip side of learned tolerance. This involves the use of cues for drug consumption to elicit feelings of intoxication. There are many experiments in which participants are given alcohol placebos and report and otherwise display evidence of intoxication. There is also a humorous video here.

Finally, I offer a hypothesis. Since learned drug tolerance fails to transfer to the degree that a context is novel, it should hence diminish during laughter. Given that laughter involves gain/loss-independent expectancy violations, this would seem a safe bet(1). I'm still looking for a study to address this question. If any of you find one, please let me know.

1. Nerhardt, G. Humor and inclinations of humor: Emotional reactions to stimuli of different divergence from a range of expectancy. Scandinavian Journal of Psychology. 1970, 11, 185-195.

Does Depression Cause Neurons to Commit Suicide?

2010-03-10T15:34:00.000-08:00

audio/visual version
Sandeep Gautam has a nice post on his blog about the effects of depression on hippocampal cells.

The story is that chronically high levels of cortisol, a stress hormone, kills these neurons. Depression leads to elevated average cortisol levels, as lower moods make negative emotional responses, such as anger and anxiety, more severe. Worse, the hippocampus is also responsible for down-regulating stress levels, the shrinking mass thereof creating an inertia with respect to increases in mood, both short and long term. So, climbing out of depression is harder, the more severe the depression and the longer its duration. Fortunately, hippocampal cells are born anew with increased average mood levels over a sufficient period of time, increasing the brain's ability to downregulate stress.

I interpret this as representing the physiological mechanism by which low average mood levels demand higher net levels of reinforcement over the longer term to reduce depression-related risk aversion, in the risk averse. This serves the behavioral economic purpose of requiring more evidence that an environment long seen as hostile to the goal of secure reproduction has become more hospitable. This is the equivalent of not trusting someone who is long seen as a jerk, but acts somewhat nicer on a given day. The trust in the change doesn't come overnight, and nor should a trust in what is normally an inhospitable enviornment.

Coming Soon: Auditory Posts

2010-03-08T15:31:00.000-08:00

audio/visual version
I am in the process of converting my blog posts into audio and am proceeding as quickly as time allows. There will be a link at the top of most posts allowing you to listen instead of read, or do both. Feel free to let me know what you think!

Neural Utility Paper with a Great Chart

2010-03-06T12:03:00.000-08:00

I just found a great chart in a fascinating Shizgal paper on the neural basis for utility. The paper is available for free.

The chart takes one from neural stimulation to behavior(click to enlarge):

Notice the matching law equation I refer to and reinterpret in my first post on this blog.

No Free Lunch, or Will for that Matter

2010-03-05T20:27:00.000-08:00

Audio/Visual Version

I was in a conversation the other night and was asked whether I believe in free will. I don't, and haven't for sometime. I have many reasons, including the fact that I see no reason why we can't explain all of human action and cognitiion without it. But last night, I thought of a new reason that should be obvious.

As long as we have needs and resources are scarce, there can't be anything like free will, at least in the either/or sense. We will always ultimately be controlled by such needs, toward the goal of passing on our genes. But, what of people who claim free will exists in a limited sense, like my interlocutor?

I've never bought this concept. At best, they can say that we sometimes have free will to a degree. But, assuming that "free will" refers to a conscious decision process, the processes by which conscious and unconscious decisions are made are mostly the same. The same needs exist, along with the same laws of learning. The latter just in a metacognitive sense with respect to consciousness.

Another Busted Myth: 5 Senses

2010-03-03T22:16:00.000-08:00

I may as well post this now, for those who like shorter, punchier offerings. It is commonly taught and repeated that we have 5 senses. Well, we don't. We have at least 7. Below is a section from my very last post, which was on the subject of learning:

...senses include sight, hearing, touch, smell, pain, proprioception, and some vestibular system functions. The latter two are not commonly thought of as senses, but demonstrably are. Proprioception is revealed as the ability to know the orientation of your limbs, even though you are not using sight, hearing, touch, or pain reception to supply such information. The vestibular system allows you to know the orientation of your entire body, without the use of the above mentioned first five senses, when the system is relatively unperturbed. Hence it offers critical input facilitating walking or other activities that require balance.

Learning: A Section from My Anger Management Handout

2010-03-03T21:42:00.000-08:00

I am too busy and lazy right now to offer a simple post on anger, so below is a barely altered section from an anger management handout I offer students. I start from the perspective of learned expectations.

Expectations:

Expectations are learned or unlearned predictions about the occurrence or non-occurrence of at least two stimuli, or events. Stimuli, or a stimulus in the singular, is anything that is detectable by your senses, or any representation of thereof within your brain. These senses include sight, hearing, touch, smell, pain, proprioception, and some vestibular functions. The latter two are not commonly thought of as senses, but demonstrably are. Proprioception is revealed as the ability to know the orientation of your limbs, even though you are not using sight, hearing, touch, or pain reception to supply such information. The vestibular system allows you to know the orientation of your entire body, without the use of the above mentioned first five senses, when the system is relatively unperturbed. Hence it offers critical input facilitating walking or other activities that require balance. Detection of stimuli can occur with or without your conscious awareness, but what is conscious awareness and is there an unconscious awareness?

Of Two Minds

The brain has many separate memory systems, but we will only focus on the two broadest categories. The first is explicit memory, which is memory that you can consciously, if not always consistently, recall. The second is implicit memory, and it changes and can be recalled without need of conscious awareness, though you may have some awareness it is occurring. The senses feed these two memory systems in order from the implicit to the explicit.

The implicit has more direct and immediate attachment to emotional centers in the brain, such as the amygdala, and hence has the first opportunity to affect the emotions that drive your behavior. This is why you sometimes react emotionally without having time to “think” first.

The explicit system takes a longer course, with the detour to the implicit, eventually sending signals to the prefrontal cortex, which facilitates conscious memory and thought. Then, some conscious thought may be stimulated, as non-activation of the amygdala (emotions) allows and then the circuit is completed when signals travel back to the amygdala. This is how your thoughts can influence your emotional responses. As mentioned above, the implicit system dominates at the expense of the explicit as emotions become stronger. Perhaps you’ve noticed that it is harder to consciously recall certain information that is otherwise easily retrievable when you are upset. You may also notice how much harder it is to think. This is one of the reasons it is critical to avoid anger responses in the first place, as will be covered in more detail later

The implicit memory system is “recording” or learning associations between stimuli or events, even as your conscious mind may be focused on other things. It records through the senses, so you can only learn what your senses are in a position to detect. With this in mind, learning can take place on two levels simultaneously, though, the implicit dominates. This is how phobias are learned, for example, and can be triggered sometimes by stimuli you may not consciously notice, but which trigger extreme emotional responses and behavior you cannot necessarily consciously control. The same is true of traumatic memories, or the learning of any kind of information. Hence, to understand what expectations are and how they develop, one must understand the basic principles of learning. The basic physiology has just been covered for our purposes, so we now move to what is going on in the external world, as detected by your brain.

Learn the Basics

Some of the basic principles of learning include processes of generalization, discrimination, and transitivity, all with respect to two or more stimuli.

Generalization involves carrying learned stimuli associations of one context, referred to as a predictive context, to another. Associations, in the simplest form, merely involve the detected tendency of at least two stimuli to occur together or be seen as similar in some way. For example, someone new to the planet may notice a motor vehicle for the first time and see that it has four wheels. Upon seeing another on different street, the alien begins to generalize the expectation that motor vehicles will have four wheels. The expectation grows, the more four-wheeled vehicles the alien sees in different situations. Hence, generalization can occur either by noticing the same relationship among stimuli in a new overall, distinguishable context, or by simply “automatically” seeing two situations as similar, without the need to sense it directly in the first place. This latter ability to generalize is known as transitivity, which will be covered in a moment.

First, however, discrimination simply involves the ability to distinguish two stimuli or two situations or contexts from each other. It is the ability to detect and notice differences that may or may not be relevant for the outcome of importance to the observer. An example of discrimination might involve our alien first witnessing many cars with four wheels, but then encountering a motorcycle with 2 wheels, and hence, since cars and motorcycles are easily distinguishable in a number of ways, making the discrimination between motorcycles and cars, expecting four wheels on cars and two on motorcycles. The more motorcycles the alien sees, the more generalized the discrimination becomes, and hence the greater the expectation that motorcycles will have two wheels. So, discriminations depend on generalization, either directly or indirectly, for this form of learning to occur.

Generalization takes place indirectly through transitivity. This is the innate ability to immediately recognize that, for example, if a = b and b = c, then a = c. This can occur automatically, without the need for any direct training as it is commonly conceived, and is naturally facilitated by the structure of the brain and the automatic way elements of stimuli that are similar are associated. It is this process that allows for generalization or the generalization of discriminations to occur through the process of imagination and is in fact the very stuff of imagination. So, for example, the alien can now imagine a motor vehicle with three wheels, or any number of wheels, without first seeing one. The alien can expect that a three-wheeled vehicle may exist or would be possible to build.

These three different processes of learning are complementary and can feed each other in constant loops. This fact, along with those of first focus above, goes a long way in describing what thinking and learning are. However, there is another property of learning worth noting, before turning to motivation to complete our description of anger responses.

This property is called blocking. This is when a previously learned association, either learned directly in the sensory environment or indirectly through transitivity, literally “blocks” the learning of other associations. Blocking occurs due to the practical limitations of our brain and sensory systems. We can only detect and process so much information at one time, and so we will only expend our limited resources in proportion to what we deem important. In other words, the environment often presents us with more information than we can process at any one time and we implicitly and or explicitly make choices about what to use our limited sensory and thought capacity to focus on. Hence, there is information in the environment that we may process late, relative to our welfare, or perhaps not at all. To illustrate, during his first minutes on earth, our alien may have noticed that there are at least two types of motor vehicles, one with four wheels and another with two. So, spending some time making and thinking about these observations, the alien suddenly notices that his delicate, relatively light-deprived skin is getting red. The alien has now learned a new lesson, though all too late, as his sensory focus and attention was on the cars and motorcycles going by. That is, that the earth’s sunlight is too intense for his delicate skin and he must now seek shelter or cover.

In extreme cases, blocking can not only delay learning, but prevent it entirely, permanently. For instance, if one develops a learned habit of focusing on only certain elements of a situation or even abstract concepts, one can easily miss differences either present from the beginning or that arise later. This can even occur with imagination, though imagination also offers another way to check against blocking. Can you imagine how this can occur?

To mention another example, in the experimental case, rats that are trained to press a lever to receive a food pellet after seeing a red light will later fail to learn to press in response to a yellow light of similar brightness, if the yellow light is first presented after learning to focus on the red light occurs. In this case, the yellow light is then presented alone and the rat will not press the lever for food.

It is important to refer to two previous concepts here, which are those of implicit and explicit memory. The newer and/or more complex the learning that is occurring, the more sensory and conscious (explicit) processing that is required. As associations are better learned, the behaviors they help motivate depend increasingly on implicit memory as learned behaviors become increasingly automatic, eventually occurring with little or no thought. This is what we call “habit” formation, and it occurs at a rate and in proportion to the sensory intensity, subjective importance, and distinguishability of the relevant stimuli.

That's the end of the section from my handout. There is more to mention here though regarding the complexity of the environments in which brains learn. One of the implications is an explanation for why people often seem to repeat mistakes, even many, many times.

Below is a section of a recent blog post:

I submit that the tasks brains are engaged are often much more complex than seems commonly perceived. All stimuli, or everything our senses can detect, become predictors for goal attainment, but usually not immediately. A process of generalization is needed, even across seemingly unrelated contexts such as different rooms in a house, or even different states of mind. For example, school children who test in the room they learn the material in perform better on average than those who are tested in a different room.

But, what if the predictive context is large and varied? Apply the counting rules in probability, and the complexity of even a "simple" task is revealed. For example, consider a mother who needs help from three kids raking the yard, and one to vaccum the house, simultaneously. Apply the permutation rule, and there are 24 different ways to assign the children to these tasks. That is, (4)(3)(2)(1) = 24. Of course, some permutations are more helpful than others, and an educated guess might mean mom can narrow down the relevant possibilities. Still, choosing the optimal permutation(s) can be very difficult, if not nearly impossible given practical limitations.

Of course, the number of permutations, which I sometimes call the permutation space, because I think it sounds cool, can be much, much greater(See other examples in the link above). Numbers can even easily get into the trillions and much higher still. This is especially true when permuation spaces are dynamic, such as in the stock market, or in social relationships. Perhaps this is a fundamental reason, along with the status quo bias and some other factors, investors often lose money seemingly employing the same strategies each time, or wives stay with abusive husbands, in many cases, trying many ways to stay with the abuser while trying to keep him calm. The actual, "blind" dynamic permutation space can be terribly, and indeed, incalculably vast,...

Busted Myth: 10% of Our Brains

2010-03-03T01:35:00.000-08:00

I often hear it said that we only use about 10% of our brains with the implication, explicit or implicit, that we might be able to find ways to use more of our brain capacity for thinking. Nothing could be further from the truth. The brain is chock-full with needed function, with no room for waste.

The brain has to construct our entire sensory experience, facilitate coordinated motor activity(allow for movement), store all of our relevant memories, calculate the costs and benefits of behavior, facilitate mood and emotional responses, provide a networked inborn language development faculty, and provide for many reflexes, among other duties.

It wouldn't make sense to have unused capacity in the brain, as the resources needed to keep neurons(brain cells) alive, along with carrying the dead weight in the head would be energetically wasteful. This is why unused brain cells naturally die in a process known as apoptosis.

This is just one of many myths about the brain.

Energetic Behavior

2010-03-03T00:53:00.000-08:00

The economics of behavior ultimately boil down to the efficient use of energy, as energy is obviously required for all behavior. In this sense, one can approach behavior as one does physics, at least in terms of mood and motivation.

Some of the implications are interesting. For example, a principle that applies in microeconomics is also applicable here. It is the requirement that marginal benefit equal marginal cost. To summarize for the present purpose, the energy expended on a given behavior will equal the subjective benefit, as either considered in units of energy or mood, with the latter being the ultimate currency into which all needed resources are converted.

I see mood as simply the sum of all options for net beneft(benefit - cost), discounted for time. So, not only will the energy expended in behaviors associated with each option reflect net motivation, which is obvious, but over a range of behaviors, can also reveal average mood, as previously more precisely defined.. This is when compared to some baseline measurements, which means to compare newer observations to older ones. So, the rate of change of average energy expenditure with respect to average net benefits will correspond to a range of the curve for mood, or a range on the derivative of the mood curve, to be more specific. This gives the average mood level.

The measurement of oxygen consumption, just one among other approaches, can reveal energy consumption. The measurement can be made with a respirometer, for example.

I will post about other approaches to measuring mood a various later times.

The Unmeasured Self

2010-03-01T15:19:00.000-08:00

I was watching a discussion this morning on youtube titled The Role of Psychotherapy in the Age of Neuroreceptors and Genes, and I have some thoughts. First though, I'd like to offer a context.

Imagine you went to your family doctor complaining of adominal pain. Your doctor refers you to an oncologist. The oncologist has just diagnosed you with a form of cancer that has an 18% fatality rate. It can also lead to increased risks for a host of other health problems short of death, such as cardiovascular diseases, reduced immune responding, and a general lethargy that could affect both your professional and personal lives.

He based his diagnosis on a family history and some rather personal questions about your lifestyle and habits, including a few questions about your medical history. He started explaining the treatment process, when you interrupt him with a question. You ask him if he will utilize more precise diagnostics, like various scanning technologies such as MRIs. He tells you that they are unnecessary and that he is sure enough about your diagnosis to to begin treatment.

Treatment will involve a painless, weekly procedure that the doctor says is often effective, though different patients are more responsive to certain doctors than others. After asking him how you'll know your getting better, he tells you that he'll chiefly base your treatment progress assessment on how you say you're feeling and whether you think it's working.

Would you feel comfortable with this diagnostic and treatment approach? Yet, this is exactly what psychotherapists offer their patients with major depressive disorder, which is fatal in about 18% of cases and can greatly contribute to the other maladies mentioned above, among many others. There is often not even a paper and pencil assessment offered during diagnosis, and there is usually no attempt at objective within-patient measurements of progress during treatment.

I'm not bashing psychotherapists here and I do acknowledge that widely known research demonstrates some effectiveness for psychotherapy in the aggregate. But still, how is the above situation acceptable? Is there an alternative?

I think there is. Other than advanced brain scans, which are currently expensive, but offer much hope in the future, a behavioral economic approach can be helpful. Since depression involves low moods, the implications of which have been described in previous posts, the resultant shift to lower risk aversion could certainly provide a definitive, quantifiable measure of progress.

This can be done in a number of ways, but to begin, you can measure the loss tolerance of patients seeking reward, such as in contests with monetary prizes. There can be opportunites to both win or lose money, with the patient keeping any earnings. This is an approach very widely used in psychological and microeconomic experiments. To note, of course changes in net personal income and assets will have to be controlled for, with the gains and losses in constant proportion.

To complement this approach, the rates of substitution between different options can be measured, to determine consistency with the more direct measure of risk attitudes, as can the ability to delay gratification and accept sooner losses.

There are also various ways to measure relative and absolute mood levels by recording behavioral investment, revealed as energy expenditure to obtain a given amount of reinforcement(pleasure). For example, energy expenditure can be measured with respirometers, heart rate monitors, etc. More energy will be expended- per-unit-gained as mood increases. This is similar to the determination in economics that marginal utility must meet marginal costs.

I personally favor the last approach, as it is more direct and requires controlling fewer variables, but I'm not sure if non-physicians are allowed to use such diagnostic techniques. The former approaches involving money are awkward, given the treatment context.

There are still other approaches, such as measuring stress hormones in saliva or examining asymmetrical EEG data, but these are also expensive, though certainly cheaper than MRIs and other brain scans.

Of course, with all of these approaches, stable baselines must be established to measure progress against.

So, there are conceivable ways for psychotherapists to demonstrate the effectiveness of their treatments in each individual and I hope more research will go into such approaches. The question is, will the therapists want to use them?

Duh

2010-02-26T10:46:00.000-08:00

"Prozac and Celexa Exhibit Anti-Inflammatory Effects" is the headline in a Science Daily article today.

This is conclusion is well within my paradigm. My paradigm says that risk aversion increases as mood decreases. Anxiety, being an expected loss, lowers mood, which is the net rate of intake of reinforcement. This serves the purpose of minimizing further losses of resource intake necessary for biological functioning. The subjective value of losses increases, including those involving physical injury, as all gains and losses are translated into mood.

Given evidence, such that anxiety can worsen muscle spasms,which is well-known, and that spasms serve to protect inflamed areas of the body, to protect against further injury and/or facilitate repair, this isn't surprising. Of course, we also know that stress can lower pain thresholds, conrolling for adrenaline spikes.

This is an example, not only of poor reporting, but of what seems to be the problem in the fields of the study of brain and behavior. Most researchers don't seem to have an over-arching paradigm, such as the economics of behavior to guide them.

The Definition of Insanity? No.

2010-02-24T20:12:00.000-08:00

I often hear the quote, "The definition of insanity is doing the same thing over and over again, and expecting a different result." It is attributed to Einstein everywhere I look, but I wouldn't be surprised if Einstein weren't serious when the statement was uttered. On the other hand, he did reject the uncertainty principle.

The definition, it is wrong in two ways. First, insanity is neurological. Second, even when people seem to be doing the same thing over and over, there are understandable reasons why they are. They reflect the challenges all normal brains routinely face.

What are these challenges? I submit that the tasks brains are engaged are often much more complex than seems commonly perceived. All stimuli, or everything our senses can detect, become predictors for goal attainment, but usually not immediately. A process of generalization is needed, even across seemingly unrelated contexts such as different rooms in a house, or even different states of mind. For example, school children who test in the room they learn the material in perform better on average than those who are tested in a different room.

But, what if the predictive context is large and varied? Apply the counting rules in probability, and the complexity of even a "simple" task is revealed. For example, consider a mother who needs help from three kids raking the yard, and one to vaccum the house, simultaneously. Apply the permutation rule, and there are 24 different ways to assign the children to these tasks. That is, (4)(3)(2)(1) = 24. Of course, some permutations are more helpful than others, and an educated guess might mean mom can narrow down the relevant possibilities. Still, choosing the optimal permutation(s) can be very difficult, if not nearly impossible given practical limitations.

Of course, the number of permutations, which I sometimes call the permutation space, because I think it sounds cool, can be much, much greater(See other examples in the link above). Numbers can even easily get into the trillions and much higher still. Thsi is especially true when permuation spaces are dynamic, such as in the stock market, or in social relationships. Perhaps this is a fundamental reason, along with the status quo bias and some other factors, investors often lose money seemingly employing the same strategies each time, or wives stay with abusive husbands, in many cases, trying many ways to stay with the abuser while trying to keep him calm. The actual, "blind" dynamic permutation space can be terribly, and indeed, incalculably vast, but the situation is sometimes even worse when the perceived permutation space is smaller than the actual one.

So, here is another reason people have trouble escaping from behavioral ruts. It is due to a phenomenon known as blocking in behavioral psychology, functional fixedness(here too) in cognitive psychology, and another term in AI I don't presently recall. This is the case in which a previously learned association prevents the learning of new ones. These can occur due to explicit learning, such as failing to learn how to hit a curve ball, because you're so used to hitting other types of pitches, or due to implicit learning, even by forming associations from information already in one's head. Such implicit processes are symmetric and transitive.

Symmetry is a statement of equivalence, involving the recognition that two different elements are in fact at least functionally substitutable, in certain ways or in certain contexts. For example, cars and trucks are different in certain ways, but each are equivalent in the sense that they both provide transportation. Believing symmetries exist where they do not, or failing to recognize them when they do can obviously create problems in finding optimal paths to certain goals.

Transitivity can be summed up symbolically with: If a = b, and b = c, then a also = c. This may seem tivial, but it just takes symmetry a step further. The recognition that a previously recognized two element equivalence is in fact a three element equivalance. Of course, such perceptions can always be wrong. Incidentally, brains can make such associations without need of conscious effort, and these tendencies are features of the nature of neural networks. This is the stuff of imagination.

So, to summarize, vast permuations spaces can mean that a decision maker can be lost trying what they perceive to be new ways of obtaining the same goal. As if this weren't problematic enough, they may also be limiting their choices within a range of permutations that not only may fial to yield optimal results, but that may continually yield very bad ones. They may fail to see similarities between similar situations either due to blocking, or simply as a matter of time and energy constraints. They may likewise see situations as similar, when they are not. Is it any wonder people get trapped in certain modes of behavior?

Emotions Defined

2010-02-24T11:05:00.000-08:00

Well, behavioral economically, anyway.

What are emotions? Emotions are reactions to changes, both past, present, and future, with the ultimate implicit goals of enhancing inclusive fitness, or at least defend adaptive homeostasis. The latter refers to preventing a worsening of the situation for an organism capable of emotional responses, with respect to resource intake.

How many emotions are there? Well, I personally identify eight, including anger, joy, laughter, sadness, fear/anxiety, guilt, shame, and disgust. I'll break each of these down one at a time.

Anger involves a violation of expectations coupled with a loss. Since expectations determine behavioral investment, any violation thereof necessarily entails a loss. Also, obviously, it means that relevant expectations were unrealistic. I will write more on expectations, which involves learning theory in a later post. The exemplar experimental reference interpreted as resulting in this model can be found here.

So, the severity of an anger response is in some proportion to the subjective value of the unrewarded behavioral investment, with subjective value outlined here and here. As well-established concept demands, anger can be "pent up", as can any reinforcing behavior in which expression is restricted.

The purpose of anger is to motivate the punishment of social wrongs, to prevent their reoccurance. Displays of angry violence toward inanimate targets represents an evolutionary overhang, or a behavior adaptive in prehistoric environments, but not modern ones. More specifically, there were far fewer opportunities for the inanimate to violate expectations for most of our prehistory. The angrier one is, the more implicit memory is dominates over the explicit, at the expense of target discrimination. Hence, violent attacks on soda machines, for example.

Another example of target indiscriminance is the typical, often externally unheard, verbal assaults on inconsiderate drivers. This is obviously a wasteful activity even when heard by the offending driver, as in urban environments, strangers are unlikely to be encountered twice. The benefit of adaptive punishment is lost.

This social sensitivity with respect to strangers is due to the way we lived for most of our 200,000 or so years as a species. There was presumably less mobility, sans modern travel techology, so strangers were probably far less frequently encountered and those met were likely to be dealt with for many years. Punishment made sense.

To move on, joy is the flipside of anger. It involves an unexpected gain. Hence, the socially rewarding expression is displayed with an energy in some proportion to the newly realized "surplus" in overall intake of reward(lifted mood). This serves the purpose of reinforcing the behavior of others that enhance inclusive fitness. For evidence of increased motivation after unexpected reward, look here.

Now with laughter, there is merely a violation of expectations. There is no net gain or loss associated, although the magnitude of the novelty factor can mean that a laughter response is merely the dominate among those of competing emotions.

The presumed benefit is in the social signal that there was no gain or loss associated with violated expectations. To illustrate in everyday terms, laughter sends an important social signal when it comes from the listener of a joke that could be taken offensively. There is also the case in the situation in which a cared loved one unexpectedly falls down. There is laughter in absence of perceived injury, to the inverse degree of preceived severity. There is otherwise concern, which is a signal of social value. Similarly, when unexpected falls occur during a comedic performance, laughter ensues given the unlikelihood of injury. Finally, cruel laughter sends the signal that the suffering of another isn't valued.

This conception of laughter was original to me, but not within the field of behavioral research(1). The concept may have originated with the philosopher Kant.

Now, sadness is elicited when there is a past(currently experienced), current, or future unavoidable loss. This represents a "shortage" with respect to required intake of resources. The expression of sadness, including crying, elicits sympathy and help from social allies to get needs met that may otherwise go unmet.

I offer that the relative reluctance of men to cry could have to do with mate competition, but also social alliance against physical threats, and toward gainful physical cooperation. In short, crying can be a sign of social weakness in men. Women, on the other hand, are more likely to form mutually supportive networks with less physical competition and obviously more cooperation. Children cty more than adults, due to the relative inability to meet their own needs, when not used as a manipulative ploy.

Fear and anxiety involve expected losses that are perceived possibly avoidable. Possible losses often took the form of physical threats from both animal preditors and conspecifics(other people) in our extensive prehistory. One implication is that the fear of predation underlies sleep difficulties for the anxious, including lighter sleep and of shorter duration. The presumed advantage is in the ability to rapidly ramp up physical arousal against night preditors. Thus, those with sleep panic attacks often leap out of bed and land on their feed with fists clenched before they even realize what has happened. Anxious insomniacs are often frequently occupied thinking of various ways of avoiding potential losses.

In the modern context, the levels of fear and anxiety experienced, as well as the nature of the triggers, are often inappropriate. One can take the example of the fear of loss of face when getting anxious around srangers, in absence of any long term social consequences in most cases.

Guilt as I conceive it is simply an opportunity cost, with respect to actions taken or forgone. It is felt when a loss to oneself, or to others that are perceived to enhance adaptive fitness is realized. Regret is very much related.

Shame occurs in proportion to a social loss of face. It sends the social signal that the disapproval of one's actions matters to the offending person. It can also signal an understanding of the nature of the offense. Shame is very much like embarrassment, but the latter does not involve a perceived loss of face, at least intitially. It is pre-consequential evaluation.

Quickly, disgust is a response stimuli(anything that our sensse can detect) associated with either harmful germs and/or toxic substances. The gag reflex is one of the allied reflexes that serves the purpose of ejecting harmful material in the process of consumption. Associated differentiated facial expressions send social warning signals on the points above. Naturally, disgust motivates the avoidance of noxious material.

Now, as a general note, as alluded to in the paragraphs on laughter, emotions can compete for simultaneous expression. The screaming demons model very much applies here, which is general feature of competing behaviors, including thoughts. This means that essentially, two or more emotions can be triggered at more or less the same time, with the experience and expression there of a difference between that of the greatest magnitude and that of the next greatest. Competing emotional responses can decay at differential rates, largely depending on the frequency of repeated , but varying triggers as a result of continued evaluation and influx of new information.

Hence, there can be net laughter, or net anger. It is commonly observed that laughter can often follow anger.
This can happen when the associated loss fades, perhaps due to compensatory gains. In that case, the importance of the mere novelty of the outcome becomes dominant, leading to net laughter.

Likewise, anxiety can be increasingly replaced with fear as an unexpected loss is perceived as increasingly unavoidable. Joy can become anger, as when what one thinks is a good deal on a car intially, later is found to be relatively expensive.

I should also mention satiation, which seems to have its own emotional experience and expressions attached, though I wouldn't personally refer to it as an emotion. When satiated, regardless of prior expectations, there tends to be a shift toward lower physiological arousal, as evidenced in a sigh, which presumably brings breathing to a slower rhythm.

As reasoned in my posts on mood linked to in the second paragraph above, mood modulates the magnitude of emotional responses. Lower moods augment negative emotion, and the reverse is true for positive ones.

I hope this post isn't too long, disorganized, or jargon-filled to be enjoyable. I will perhaps offer a simpler post on this subject in the very near future. I will also add more references to this post when time allows.

Update: I've added some references in links above for laughter, as well as the following citation:

1. Nerhardt, G. Humor and inclinations of humor: Emotional reactions to stimuli ofdifferent divergence from a range of expectancy. Scandinavian Journal ofPsychology. 1970, 11, 185-195.

Mood, this Time with Feeling (Simpler)

2010-02-22T16:43:00.000-08:00

I've decided to delay my first post about emotions to address continued feedback about the complexity of my original post on mood. I acknowledge it was bad taste on my part to begin with such an entry first off. I hope to correct that here earlier than planned..

So to jump right in, what is mood? Mood is the net rate of intake of reinforcement, past, current, and future, discounted for time. To break this sentence down, "reinforcment" in this case refers to anything that is pleasurable and is needed or wanted, minus the costs of obtaining it, which can include energy or effort expended, or any punishment that must be suffered in the process. It is the pleasure that one experiences in a given moment minus any displeasure. The displeasure can be any energy, effort, punishment or other costs for obtaining the pleasure There is a time dimension to this, as more distant expected pleasurable experiences are valued less than those that will occur more immediately.

To dig deeper, there is a minimum amount of certain resources the body needs to function, such as energy, nutrients, water, and even social interactions and there is the amount of each available to you.
In psychological terms, the resources we need are things we don't have to learn to like, which are referred to as unconditioned reinforcers(URs). These include the items mentioned above, along with things such as sugar or sex. There are also conditioned reinforcers(CRs), which are simply things you can detect that predict the eventual receipt of unconditioned reinforcers. For example, you aren't born appreciating dollar bills, but learn to like them due to the things you can purchase with them. I just introduce these terms to readers less familiar with psychology, as they may appear in later posts. By the way, psychologists refer to anything we can detect as "stimuli" or a "stimulus" in the singular.

As a brief note, notice that in the definition given above, I even include past intake. This is the recognition that not only can past pleasureable or displeasurable events be remembered, but it is actually a longer term average of mood levels that, along with present and expected future intake of peasure or pain, bias current reactions to events that temporarily change mood. For example, someone with long term depression can occasionally smile, but their longer term average mood state llimits the amount of pleasure they can experience now, while making displeasurable experiences more severe.

Neurobiologically(skip this, unless interested), this is facilitated by the death of cells in the hippocampus in the brain, which are required to lower levels of stress hormones in the body after displeasurable events. With higher average mood levels over enough time, these cells regenerate. This just gives an idea of the kind of motivational inertia low average moods demand, and is very much related to depression.

Mood shapes how we value things. The relative amount of value we place on pleasurable experiences are less when mood is lower compared to the value placed on displeasurable ones. In the absolute sense however, lower mood leads to greater values of both pleasure and displeasure, but the latter to a greater degree(change at a greater rate, with mood decreases). Similary, higher moods lead to the opposite case.

The basic concept is very simple. The more of something you have, generally the less of that something you want or need. And of course, the reverse is true. To use a familiar example, if you are eating potato chips, the hungrier you are, the less likely you are to share chips. But no matter how hungry you are, if you have enough chips, you will be willing to share them. The same is true with money, of course, as first outlined by Daniel Bernoulli quite some time ago.

I will now briefly present a curve, which has the same shape as the one in the Bernoulli link above, to clarify the way mood affects how we value units of pleasure and displeasure(gains and losses):

Ignore the equation in this graph, unless interested, in which case you can learn more here and here.

You notice above the now familar term "reinforcement",a nd then and "reponse rate." Perhaps not surprisingly, net reinforcement(again, pleasure - displeasure), should determine how much of our resources, such as time, energy, etc., we invest in a given behavior. Hence, you see the relationship between a response rate and reinforcement rate, the former of which can also be considered simply as energy expenditure.

This sort of curve would also fit the relationship between the subjective values placed on gains and losses(pleasure and displeasure) and those on objective gains and losses, the latter if not for the influence of mood. Replace "reinforcement rate" on the horizontal axis with "objective gains and loss values" and "response rate" with "subjective gains and loss values" on the vertical. Now consider any point on this curve to correspond to a specific mood level.

Whether you think about it or not, every behavior you engage in involves a prior calculation of expected gain - expected loss, in the objective sense. A gain will move mood up on the curve and a loss, down on the curve. So, the subjective difference between an expected gain and loss changes depending on the mood level. Moving up on the curve means that both gains and losses are valued less, and the difference is greater in favor of net gains, compared to objective gains and losses. Similarly, moving down on the curve means that both subjective gains and losses grow in value, but those of losses more quickly. .

So, mood is like a general currency in which all pleasure and displeasure is converted. You can refer to the net units of mood, or pleasure - displeasure, .as units of reinforcement, or use the terms economists use, such as utils or even units of demand. You can even just use "units of pleasure". It's not really imporant, unless trying to discuss these concepts with people in related fields.

To sum up, this is very similar to the income effect, in which the higher the monetary income, the less you value each additional dollar earned, all else being equal. For example, see the curve below:

Utility is the same as net pleasure for our purposes, or you can say "net motivation."

This final illustration makes it easy to consider some effects of changes in mood. When mood decreases, there is a shift in preference toward more "profitable" behaviors. These include the things that bring us the most pleasure, quickest. Good examples are sex, recreational drugs, and high calorie foods containing fat and sugar. It is perhaps anecdotally clear that when we feel down, we are more susceptible to sexual seduction, drinking alcohol, or eating comfort foods. This is just as a company that becomes less profitable begins to shift resources to more profitable operations, cutting or eliminating less profitable ones. There is generally a need for more income, or a higher rate of intake of resources. You may also realize that this explains why people who are depressed also have more trouble delaying gratification with implications for procrastination, among other difficulties. Perhaps it is also clear why negative emotional responses are more severe when mood is low.

Speaking of depression, the above now gives us a good model. Depression is a motivational trap in which as mood decreases, again, the subjective values of gains and losses both increase, but those of losses more quickly. Hence, the seeming confusion resulting when there is a greater desire or need to engage in certain behaviors, but less motivation to do so. This is seen particularly in many depressed patients, especially women, who may not seek sex as much when depressed, but may be more likely to engage in it when offered with relatively less effort required. On the other hand, some become more aggressive when seeking sex, if the costs of doing so are sufficiently low. From a prescriptive point of view, this supports the need for psychotropic drugs to help pull patients out of this often self-feeding motivational trap. This should increase the ability of patients to then invest their time and other resources (including attention) in counseling for greater benefit.

Finally, why do we have mood and why does it work this way? Well, these mood-related effects help motivate us to conserve more of our resources the lower the availability of them becomes. Though it may seem maladaptive for the brain to work this way, and it is in the modern environment, in an environment of relative scarcity it makes a lot of sense. Such environments are those we inhabited within the stereotypical hunter-gatherer groups for our 200,000 year prehistory.

I hope I avoided getting too technical here, while offering enough information to explain this conception of mood. I will appreciate any feedback on my success in his sense.

Early Blog Feedback

2010-02-21T18:41:00.000-08:00

Some of the early feedback on this blog mentions the need to present my perspectives in simpler terms, so that the less-familiar will be able to easily follow. I am aware of this problem and will soon move to a phase with much simpler posts. I am not trying to be a jargon head!

I am just trying to initially lay the foundations for the ideas and issues that will be discussed here over time. Hence, I have to balance relative simplicity with relative completeness, and the latter unfortunately must currently dominate. But, this is only for a short time.

Future posts will include simpler presentations of these foundations with applications in addressing subjects such as perspectives on related news, depression, self-esteem, anhedonia, personality, suicide, abnormal psychology, learning, and evolutionary context, to offer a quick list. I hope early readers will be patient with me a bit longer while I finish these denser posts.

The Role of Neurotransmitters in Mood and Motivation

2010-02-21T10:43:00.000-08:00

Here I will describe the basic relationships between mood, motivation, and neurotransmitters as an extension of the model of mood and motivation offered in my first post to this blog. I will not offer many links to research on well-established phenomena, such as the role of 5-HT serontonin in mood.

5-HT serotonin is the proxy for mood in my models. It is the neurotransmitter reponsible for the negatively- accelerated curve that represents mood-related net motivation and feelings of positive affect. This involves the relationship between objective and subjective weights on gains and losses in the risk-averse(80% of people) genotypes. Incidentally, risk neutral curves are linear and risk-seeking positively hyperbolicly accelerating.

As previously mentioned, the subjective values of both gains and losses increase as serotonin decreases, and this effect is reflected in the changes that occur in dopaminergic activity. More specifically, there is an inverse relationship between serotonergic and dopaminergic activity. As dopamine is well-established as the facilitating neuromodulator of arousal, the Yerkes-Dodson law demonstrates the relationship between dopamine functioning and net motivation(task performance) with some precision. Hence, the relationship between serotonin and dopamine as it relates to motivation is also well-established.

It should also be noted that this relationship also underlies increased severity of negative emotional responses when dopamine is increased without antecedant increases in serotonin. This is witnessed in those who consume stimulants such as cocaine, but can be attenuated at times by the increases in serotonin, in a reverse of the typical cause/effect relationship. When negative affect is triggered in this case, emotional responses such as anger will sometimes lead to violent expression. The effect of relative dopamine levels or genotypic sensitivity can be modeled by the addition of a multiplier to the equation for net motivation(call it "d").

To move onto the roles of other neurotransmitters, opiods are proxies for gains, with decreased arousal; decreased GABA for losses for fear/anxiety(expected risks/losses), with concomitant increased arousal(dopamine).

It is by now clear what the roles of the above neurotransmitters are and how they interact to determine mood and motivation. Effects on specific emotional responses will be addressed in a later post.

About This Blog

2010-02-11T01:57:00.000-08:00

I don't know much about blogging. As the gap in time between my first and this post illustrates, I haven't previously had much interest. I now hope to use this forum to share what I suspect are some unique perspectives on human behavior, from a behavioral economic point of view.

The topics addressed here will at times touch upon nearly every aspect of the human experience and posit answers to long pondered mysteries. Topics will include learning, the nature of mood and emotions, motivation, and the many implications. My goal will be to try to avoid making my posts overly complex, but sufficiently detailed to properly convey ideas as precisely and completely as relevant. I ask that any readers let me know how successful I am in this regard.

Many readers will find that my approach involves a very different way of thinking about why we behave as we do. Hence, it is important to approach this blog with an open mind if you're to appreciate the ideas expressed here.

Update: I will be improving the number and quality of references, as needed. On the later, I will replace single references merely consistent with my models, with examplar papers, reviews, and meta-analyses. This is a time consuming process and I want to get most posts before returning to these matters.

What is Mood? A Behavioral Economic Definition

2009-06-14T22:46:00.000-07:00

This first post may seem at least a bit technical, despite the simplifications. I just want to offer some of the more precise foundations of the approach this blog will discuss. Simpler, more concise posts on mood will follow. I start with an operationalized definition of mood, which I represent as what we really mean when we talk about higher or lower states of affect.

Mood simply represents the sum of the perceived available, temporally discounted net reinforcing options, or the baseline rate of intake of reinforcement, in the context of a required net inake. For example, at a given level of energy expenditure, there is a required net caloric intake. The net intake of this specific category of reinforcer (energy) is translated into mood, which is the ultimate currency in the brain.

Around 80% of people are risk/loss averse, meaning they value losses more heavily than gains. This is increasingly true as mood decreases, because there is the equivalent of the wealth effect operating on the brain. Hence, as mood decreases, net reinforcement shifts toward more immediate, more "profitable" gains, as resource conservation occurs. This is manifest as greater tendencies toward promiscuous behavior, preference shifts toward higher calorie foods (unless body image supresses it), and drug abuse. Also, because the value of losses loom ever greater than that of gains, negative emotional responses are augmented while positive ones are diminished.

This can be summed up nicely here with a greatly simplified, but relevantly complete mathematical expression of net motivation. U = N [ g / ( h + g ) - L / ( h - L )], where U = net utility or net motivation (subjective net expected gain or loss, or you can call this simply demand), g = objective gain, L = objective loss or response cost, h = baseline rate of intake of reinforcement, or "have" (mood), and N = required rate of reinforcement (Need). Ultimately, this is a model relating the required rates of intake of unconditioned reinforcers to the resources perceived available, with the ultimate goal being to optimize inclusive fitness, or reproductive success. This is a reinterpretation of the various matching law models.

This would explain why, for example, girls with relatively higher stress levels actually enter puberty earlier than girls with lower stress. The brain makes an economic calculation based on environmental input indicating an environment relatively hostile to reproductive success, and hence a higher quantity reproductive strategy is selected for. Girls who have higher stress and enter puberty earlier have more sexual partners on average and have sex earlier than those with lower stress levels.

This equation models depression as well, and clearly defines the crux of the problem. Those who are depressed, perhaps seemingly paradoxically, value gains more heavily, but net motivation decreases because the value placed on losses increases at a greater rate as mood decreases. This is consistent with research, demonstrating, for example, that participants diagnosed with depression are willing to expend less energy for reinforcement, but consume more than the non-depressed when response costs are reduced.

Increases in net motivation allow for greater behavioral investment in seeking natural reinforcement, which can lead to habits, with proper psycho-education, that can maintain higher mood levels sans medication. This should be the ulitmate goal of any plan to treat non-purely neurological depression.

This model also predicts that anti-depressants will offer little beneft for the dysthymic, as the curve for net subjective value (utility) flattens as mood increases. This prediction is consistent with experiment and other data. The model also suggests explicit roles for dopamine in mood and motivation, as it represents the subjective magnitude of gains and losses. Hence, the model predicts the inverted U-shaped curve for the effects of stimulants on net motivation, and the effects of stimulants on attention and negative emotional behavior.

This is a self- and externally consistent model of mood, emotions, and motivation. Hopefully, this post can allow one to begin to see where this model comes from. Those wanting more references, or who have any questions about how the dots connect, don't hesitate to ask. This is not extremely complex, but it is a different way of thinking about mood, motivation, thinking, and behavior for many.