Chapter 2: Biology and Human Potential
Life is a rat race
In the first chapter, we saw how an experiment conducted with pigeons provided important insights into the self-control process. At the end of each chapter, I will consider implications of the material to achieving your own potential. You might be wondering how this could be possible in a chapter describing human biology. Think of the implications of neuroplasticity. By making environmental manipulations, you can actually “rewire” your brain. What may surprise you is that studies measuring EEGs and MRIs with humans have demonstrated that physical activity affects the brain. It is known that the cortex and hippocampus atrophy in the aged. Experimental studies with other animals (primarily rats and mice) have demonstrated that exercise can actually increase the number of nerve cells in the hippocampus (Brown, Cooper-Kuhn, Kempermann, van Praag, Gage, & Kuhn, 2003; van Praag, H., Shubert, Zhao, & Gage, 2005; Eadie, Redilla, & Christie, 2005).
You are probably aware of the many benefits of exercise. The Public Health Service concluded exercise was one of the most significant ways in which humans could improve their health (Powell, & Paffenbarger, 1985). Consistent aerobic exercise has been found to reduce the likelihood of developing hypertension (high blood pressure), heart disease, type II diabetes, and osteoporosis (thinning of the bones). A good way to understand research is to use the scientific schema I described in Chapter 1. Ask yourself to describe out loud or in writing the question being investigated, the procedures used to investigate the question, the research findings, and the conclusions. It is often helpful to try to imagine yourself as a research subject. I am sure it is easy for you to imagine being on a treadmill or exercise bike with electrodes attached to your head to take EEG readings. That would enable us to observe the effects of independent variables (e.g., duration of exercising, speed, the incline on a treadmill or resistance on a bike) on a dependent variable (e.g., changes in EEG recordings).
In order to obtain more precise data regarding the effects of exercise on the brain, it is necessary to examine the brain itself rather than simply recording EEG or obtaining MRI scans. This type of invasive research can only be conducted on other animals. You may be wondering, how is it possible to study the effects of exercise on rats and mice. Are there rat and mice gyms or health clubs? Do they have swimming pools, bikes, and treadmills? The answer is, sort of (Figure 2.15).
Figure 2.15 Rat in a running wheel.
One study compared the effects of moderate and more intense exercise on two types of learning and on changes in the presence of neural plasticity-related proteins in the hippocampus and amygdala (Liu, Chen, Wul, Kuol, Yu, Huang, Wu, Chuang, & Jen, 2009). Both groups were taught to swim to the end of a water maze and to avoid shock in another apparatus. Then, one group of mice engaged in self-paced wheel running for four weeks and another group received more intense workouts on a treadmill. Both groups were then retested on the two tasks and underwent surgery to assess changes in their brain chemistry. After their four weeks of exercise, both groups improved their performance in the water maze. Only the group given the more intense treadmill workouts improved on the more difficult shock avoidance task. It was determined that this group increased the levels of specific proteins in both the hippocampus and amygdala whereas the self-paced group only experienced increases in the hippocampus. The authors concluded that different exercise routines can differentially affect learning and brain chemistry.
In Chapter 1, I listed examples of the behaviors my students have targeted in self-control projects. Many students are interested in improving their cardiovascular fitness by engaging in aerobic exercises (i.e., involving sustained rhythmic activity). According to the American College of Sports Medicine (ACSM) Physical Activity Guidelines for Americans (Garber, 2011), one should engage in 1-1/4 hours (75 minutes) of intense (e.g., jogging or running) or 2-1/2 hours (150 minutes) of moderate (e.g., brisk walking) exercise per week. You can break up the activity into sessions lasting at least 10 minutes. For example, you could walk briskly for half an hour on five different days, or 50 minutes on three different days, etc.
Usually, for exercise projects, students assess the frequency, duration, and intensity of exercises they would like to perform. In Chapter 5, we will discuss application of learning principles to modify behavior. However, if you would like to try a self-control intervention before then, you could implement an adjusting criterion procedure. In the case of aerobic exercise, start by obtaining baseline data on the frequency, duration, and (when applicable), the intensity of your sessions. If you do not exercise at all, try a minimal amount (e.g., five or ten minutes) on three different days. Once you have stable baseline data, you will be ready to adjust the criterion upward in order to earn a reward. For example, you could require a ten per cent increase (to five and a half or eleven minutes). If you earn the reward three sessions in a row you can increase the criterion by an additional ten per cent, and so on until you reach your ultimate objective. The reward could be something tangible such as a treat (but watch out for the calories!) or money, or an enjoyable activity such as reading, listening to music, playing video games, engaging in social networking, etc. Make sure you leave sufficient time to study for your courses, though. Otherwise you will need to implement an adjusting criterion procedure on study time!