Behavior's Big Bang Theory

First, I'd like to say my alliteration skills are still spot on. Second, this has nothing to do with the popular TV show, The Big Bang Theory. Sorry to disappoint (secretly I hope I tricked you, and you'll decide to stay anyways).

When I spoke about behavior last time, my discussion was mostly limited to defining what it is and how we look at it. To recap, a behavior is anything you do to solve an adaptive problem, and we categorize it functionally rather than structurally. For example, opening a jar of pickles solves the adaptive problem of getting food, but we don't care exactly how you opened it. You could have twisted the lid off like the majority of individuals (let's be honest, the majority of individuals actually gave it to someone else to open), but you also could have hit the jar with a sledgehammer or treated it to some explosives a la Mythbusters. Each of these techniques would have opened the jar, but some work better than others. The twisting method is quick, easy to do, and requires minimal energy. Blowing up the jar is more pleasing to the senses, but it requires access to explosives and time to set them up, generates new adaptive problems (flying shrapnel, angry neighbors, destroyed kitchen, etc), and probably obliterates the pickles in the process. So, the next two logical questions to ask are, "Where does behavior come from?" and "How do we find the right one for the job?"

Now, when we ask for the origins of behavior, we are really asking, "What causes behavior?" There are several answers to this depending on your frame of reference. Physiologically, behavior arises as an emergent property (epiphenomenon if you will) from the behavior of multiple neurons (and their effector organs) working together. I would be more specific if I could, be we actually have not yet identified most behaviors to particular networks of neurons. If you filled a backpack with headphones, the resulting tangled mess would give you a good analogy for the complexity of the brain. Untangling the mess is the job of neuroscientists, neuropsychologists, and basically anyone whose title starts with neuro. Behaviorists such as myself stick to the macroscopic world (but we still find the microscopic interesting), dividing our causes into two categories: proximate and ultimate. A proximate cause is the immediate antecedent to the behavior. For the behavior of answering the phone, the proximate cause is the phone ringing. The ultimate cause is more difficult to explain, but suffice it to say, determines why you behave due to a history of reinforcement. For example, you have to drive from Point A to Point B. You take route #1, but it's rush hour and it takes a long time to get there. After doing this several times, you take route #2. It is still rush hour, but you get from A to B much faster. Now the weekend comes. You take route #1 and get to point B in about the same amount of time as route #2, even though it's the same time of day. Gradually, your response is shaped to taking route #2 during rush hour and route #1 during weekends. The route you take (response) due to rush hour + time of day (cues) is a result of a history of reinforcement. If someone asked you why you took route #2 during rush hour, your response summarizes the ultimate cause (It is faster than route #1). So, the proximate cause explains why you behaved in one way as opposed to another, and the ultimate cause explains how you developed that way of behaving.

The mistake most people make when talking about behavior is dismissing the ultimate cause. When a guy in line at the coffee store yells at the person serving his coffee, you may be tempted to say, "He yelled at the worker because he is a jerk." That explains everything right? Jerks yell at people; it makes sense. Unfortunately, by doing that, you fell into B.F. Skinner's 3rd circle of Hell. Your reasoning is actually circular reasoning; he yelled at the worker because he is a jerk, and the guy is a jerk because he yelled at the worker. The ultimate cause is much less visible, having occurred in the past and over a period time, so it is very easy to miss. Additionally, the ultimate cause may be a product of evolution, further obscuring it. Widespread obesity can be attributed to physiologic mechanisms that evolved to prevent starvation (epitomized in meme form as, "Eat all the things!").

At this point, I've provided a partial explanation for the origin of behavior. Tune in next time for the epic finale.

Know the Difference: Allergy vs Adverse Reaction

A common question, asked at least once at every assessment. It is an important question because it is the difference between taking a drug and getting better, or say, going into anaphylactic shock. Typically, we try to avoid the latter.

However, the responses I've heard to this question indicate to me that there is a crucial misunderstanding about what an allergy is. On several occasions I've heard people say they are allergic to a drug, and when asked what reaction occurred, they respond with nausea or something of the sort. Of course, nausea can be a symptom of an allergic reaction, particularly in anaphylaxis. Usually though, nausea is a side effect of a medication, which is separate from an allergy. Now, time for some science and jargon!

An allergic reaction (Type I Hypersensitivity for those of you so inclined) occurs when IgE, a type of immunoglobulin (antibody), interacts with an allergen. IgE bound to the allergen can then bind to receptors on mast cells, basophils, and eosinophils to stimulate an allergic reaction. Mast cells in particular release large quantities of histamine (along with cytokines and other chemicals), which causes vasodilation as part of the inflammatory response. When vasodilation of the blood vessels in the skin occurs, the affected area will turn redder in color (also know as rubor). Other inflammatory agents like leukotrienes, cytokines, and prostaglandins contribute to the inflammatory response, causing further vasodilation, pain, and broncoconstriction. Usually the allergic reaction is limited to the immediate area where the allergen made contact. Anaphylaxis is a severe, systemic allergic response, involving broncoconstriction and global vasodilation, which leads to difficulty breathing and shock. Anaphylaxis is a life-threatening emergency, but is treatable with prompt intervention. The allergic response to a drug may occur in several different ways (Type I, II, or III), and the signs and symptoms will vary depending on the mechanism and severity. Rash and itchiness are the most common presentations of a drug allergy.

The reason allergic reactions should not be confused with side effects is because of the outcome. An allergic reaction to a drug can be very dangerous, so it is important to avoid it by using alternative medications. Side effects are often unpleasant, but rarely immediately life-threatening. For instance, the flushing that occurs when taking niacin is not an immune hypersensitivity reaction, even though it appears as one. Opioids like hydrocodone or oxycodone may cause nausea, but not due to an allergic response. Additionally, almost all medications have side effects, so it is harder to pick and choose in that case. This is why healthcare workers ask for the reaction associated with an allergy; they are trying to distinguish a true allergy from an unpleasant side effect.

I have two points, one for healthcare professionals and one for the general public. First, if you are asking a patient about any drug allergies, be sure to ask for the type of reaction that occurs. It is reasonable that the average individual may not know the difference between a side affect and allergy, but the RN/MD/DO/PA/NP needs to know whether there are any contraindications to particular medications. Second, if you are telling a healthcare worker about an adverse drug reaction, be sure to mention what happens when you take it. Additionally, if you are unsure about whether or not you are allergic to a medication, be sure to ask (and write down the response for that matter).

Sources

1. Drug allergies. PubMed Health. 2010. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001822/. Accessed June 21, 2012.

2. Levinson W. Chapter 65. Hypersensitivity (Allergy). In: Levinson W, ed. Review of Medical Microbiology and Immunology. 11th ed. New York: McGraw-Hill; 2010. http://www.accessmedicine.com/content.aspx?aID=6459867. Accessed June 21, 2012.

3. Papaliodis D, Boucher W, Kempuraj D, Michaelian M, Wolfberg A, House M, Theoharide TC. Niacin-induced "flush" involves release of prostaglandin D2 from mast cells and serotonin from platelets: Evidence from human cells in vitro and an animal model. J Pharmacol Exp Ther. 2008;327:665-672.