Psychology and the Brain, Research Paper Example

Psychology and Psychological Research

Psychology is the science that studies how people behave and how they think. It studies the mind. It tries to generate general theories and conclusions about human behavior through the use of experiments and observation.

Much research in psychology is based on psychological experiments. These experiments can be qualitative, i.e., basically descriptive of observed behaviors, or quantitative in which specific measurements are correlated with observations. For example, electroencephalographic (EEG) recordings, or functional magnetic resonance imaging (fMRI) or similar techniques may be used to correlate observed behaviors to functional brain states. Because the science is primarily interested in human behavior, experimentation with human subjects is constrained by ethical considerations. Sometimes animal studies can be substituted, thus, the classical conception of psychological experiments as training rats to learn mazes.

Furthermore, a variety of types of studies can be used in psychological research. In addition to doing both qualitative and quantitative studies, some psychological experiments are “controlled” where the experiments are conducted in a laboratory under strictly controlled conditions. Others are “field” experiments, in which the subjects of the study are out in the real world, in an environment where the influences on the subjects are not controlled or limited by the experimental design.  Another way of classifying experiments in psychology is whether  they are “longitudinal” or “cross-sectional” studies. A cross-sectional study might, for example, sample all ninth-graders at a particular school in a given year. This, in effect, takes a snapshot of those subjects at that moment in their lives. A longitudinal study might start with a  class of first-graders, and re-test those same students every year until they graduate from high school. Such a study allows observing a group of people over a long period of time, to see how they develop and change. It tracks development over time, rather than taking a measurement at a single moment in time.

One frequent method of research in psychology is to use a survey. This can be effective, but it’s important that the questions in the survey have been carefully designed to be sure they elicit the information that is really desired. Furthermore, there is always a concern in questionnaires about whether the subjects filling them out are providing truthful information. In addition to issues of truthfulness, there are problems with simple mis-remembering of the requested information.

Like all experimental sciences, the quality of the results from psychological research studies can vary quite a bit. Because human behavior is innately interesting, novel psychological research studies are frequently reported in the press. Pawlik-Klenlen reports on several characteristics of high-quality studies that can help distinguish preliminary or poor study design. The first issue, according to her, is whether the study used human or animal subjects. Human experiments have more direct application to people than studies done on animals, even primates. The second question to consider is what group did the subjects come from. A survey of teenagers in the Latino barrio may not be too applicable to retirees living in Palm Springs. The number of subjects used in the experiment is also important. Typically, statistical significance improves with larger groups of subjects. A quality research institution, such as a research hospital, a university, or a medical school also generally will generate well-designed studies. Finally, the media outlet reporting the research is also important. A study published in a major peer-reviewed journal will have more credibility than one that is first announced in USA Today. (Pawlik-Klenlen, 2008).

Another important area of psychological research is the study of the brain and how it functions. Psychologists try to correlation behavior with brain activity through the use of EEGs, fMRIs or other brain imaging technologies to try to determine how the brain controls behavior. Thus, it is important to understand the basic structure of the brain.

Structure of the Brain

The brain consistsof three major subdivisions, the brain stem, the cerebellum, and the cerebrum. (Clark, et al., 4).  It is believed that the brainstem is the oldest part of the brain in evolutionary terms, with the cerebellum developing next, and the cerebrum the latest part of the brain to develop.

The brainstem sits at the top of the spinal cord and includes the medulla, the pons, and the midbrain. The medulla is like an extension at the top of the spinal cord, with the pons on top of that and the midbrain above that. The cerebellum sits behind and above the midbrain.  The cerebrum includes the two large, lobed hemispheres that are commonly considered to be “the brain” in common usage. (Brain Injury Association of NY State, no date; Clark, et al., 5-8, ).

The cerebrum, or cerebral cortex, is really similar to two thin sheets of brain cells, called neurons, folded up to create two hemispheres. It is common that the left hemisphere of the cortex controls the right side of the body, and the right cerebral cortex controls the left side of the body. The two thin sheets of neural cells, perhaps only a half-dozen cell layers thick, are similar to wadded up pieces of paper, crumpled up to fit inside the space of the skull. An adult’s brain has the equivalent of just under  3 square feet of cerebral cortex wadded up to comprise the two halves of the cerebral cortex. The two halves of the cerebral cortex are connected through a communications channel called the corpus callosum that allows synchronization and coordination of the two sides. (The Medical News, no date ).

Neuroanatomists and psychologists are still determining how the brain operates. Although not all brain functions are understood, significant progress has been made in understanding how the brain works.

Brain Functions

According to the National Institute on Drug Abuse (NIDA), the brain stem is responsible for controlling basic life functions, such as the beating of the heart, breathing, and sleep. The limbic system, part of the cerebellum, processes emotions, including both pleasure and pain. Thus, much behavior has roots in the limbic system. It is believed that such sensations as hunger and cold are mediated by the limbic system. The cerebrum has a number of lobes that are associated with different “higher” brain functions. For example, there are areas that control understanding visual stimuli, odors, taste, hearing, as well as areas that control and such higher functions as speech, memory, planning, foresight, and so on. (NIDA, no date; NIH, 2010, p. 15).

The basic cellular unit of the brain is the neuron. While there are several types of neurons, the basic cell is a small core with many connections—typically thousands of connections in the cerebrum—to other neurons. These connections are electrochemical in nature. The cells don’t actually touch, but instead have a tiny “synaptic gap” between them. An electrical impulse travels from the center of the cell out its connections to the synaptic gap. There, special chemicals called neurotransmitters are squirted into the gap from the source cell to the receiving cell. That chemical allows the signal to transmit across the gap to the receiver, where special receptors receive the neurotransmitter chemical. That essentially signals the receiver cell to fire an electrical signal, which  travels to the center of the receiver cell for additional processing. Meanwhile, back at the synaptic junction, other chemicals, called transporters, recycle the neurotransmitter chemicals, returning them to the original cell where they turn off the transmitter cell’s signal. (NIDA, no date).

In the brain, the strength of a signal—the “loudness” of a noise, for example—is not determined by the strength of the  electrical signal. Instead, it’s determined by the speed with which the signal repeats. A mild stimulus, for example, might result in the sensing cell firing a signal off to its receivers at a particular rate, say fire—fire—fire—fire. A very strong stimulus would fire the same strength of signal, but it would happen much more rapidly, as in: firefirefirefirefirefire. The top speed with which the neurons can fire is limited both by how fast the cells conduct electrical signals, and more critically by the speed of the chemical transport to and fro across that synaptic gap. (The Medical News, no date).

Behavior and the Brain

As noted earlier, different sections of the cerebral cortex are activated during different behaviors. People who have experienced brain damage from injury or disease (stroke, hemorrhages, or tumors, for example) have provided useful information of what behaviors are affected when parts of the brain are damaged. While in general, the control of the body is lateralized (i.e., the right brain controls the left side of the body and vice versa), when a stroke in the left side of the brain damages control of, for example, the right arm motion, rehabilitation therapies can literally retrain the undamaged right brain to take over those functions.  Thus, one key aspect of the brain is that it is plastic, that is, it can adapt and change. Psychologists consider this plasticity as learning.

As noted earlier, the brain controls the body’s behavior in large part. The brainstem operates the “automatic” operations of the body. This includes such behaviors as the beating of the heart, respiration, and so on. The midbrain appears to be the seat of emotions. As the limbic system, it controls impulses such as hunger and thirst, thus driving behaviors such as finding and ingesting food and drink. But the key controller of most voluntary behaviors is the cerebral cortex. It processes sensory information of taste, smell, sight, hearing, and touch, thus helping the brain make sense of the world. It controls voluntary body motions, allowing control of body movements such as walking, swimming, running, jumping, as well as the fine movements that allow writing, typing, sewing, and so on. It also is where language is processed, and it controls speech, allowing people to communicate with each other.

Drugs and Behavior

Addictive drugs of all types, from alcohol to cocaine, interfere in how brain cells communicate with each other. Drugs such as marijuana and heroin can mimic the behavior of certain neurotransmitters, causing brain cells to activate. Thus, these drugs generate false messages that may warp the user’s perceptions and behaviors. Other drugs, such as cocaine and amphetamines, interfere in the recycling of the neurotransmitters. In effect, this causes an amplification of the neural electrical signals, much like passing a voice through a microphone amplifies the voice. (NIH, August 2010, p. 21).

Ultimately, most of the addictive drugs also operate on the limbic system of the cerebellum, activating the “pleasure” systems that make the user believe the drug is a wonderful experience. Because the limbic system controls emotions, this can result in a sensation of euphoria, which is likely to make the user want to repeat the experience over and over. (NIH, August 2010, p. 21). The NIH claims that certain addictive drugs release these pleasure-center chemicals between two and ten times as powerfully as a natural reward would. The effects can also start earlier and last longer than natural rewards (such as eating food when hungry). (Ibid., p. 22).

Because the brain controls the ingestion of food and drink, addictions also begin in the brain. Scientists have discovered that there are actual cognitive differences between addicts and non-addicts in how impulsive choices are made. Addicts tend to have a genetic mutation that depresses a neurotransmitter dopamine, a chemical shown to suppress impulsive behaviors. Thus, those with addictions tend to be more prone to impulsive choices. (The Medical News, 28 December, 2007).

Conclusions

Psychology is the study of both mind and behavior. It is an experimental science, using a variety of experimental techniques to study the mind and brain. The brain is the controller of the body. It controls the autonomic operations of the body in the midbrain, the emotions and pleasure centers in the limbic system of the cerebellum, and the higher functions of sensory processing, thinking, language, and so on in the cerebral cortex. The brain operates through a complex electrochemical response operation. When addictive drugs are ingested, they interfere in the operation of the brain’s electrochemical operations, and interfere both with the limbic system and sensory processing. There is also evidence that addictions interfere in impulse control, making addicts more prone to impulsive choices.

References

Brain Injury Association of New York State. (No Date). LearnNet. Web. Retrieved from: http://www.projectlearnet.org/about_the_brain.html

Clark, D.L. Boutros, N.N., & Mendez, M. F. (2010). The brain and behavior: An introduction to behavioral neuroanatomy. Cambridge: Cambridge University Press. Print.

The Medical News. (No date). “Human Brain Structure.” Web. Retrieved from: http://www.news-medical.net/health/Human-Brain-Structure.aspx

The Medical news. (28 December 2007) Brain imaging shows there may be a cognitive difference in people with addictions. Web. Retrieved from: http://www.news-medical.net/news/2007/12/28/33780.aspx

National Institute on Drug Abuse. (No Date). Drugs and the Brain.  Web. Retrieved from: http://drugabuse.gov/scienceofaddiction/brain.html

National Institutes of Health. (August 2010). Drugs, Brains, and Behavior: The Science of Addiction. U.S. Dept. of Health and Human Services. NIH Pub No. 10-5605. Web. Retrieved from: http://www.nida.nih.gov/scienceofaddiction/sciofaddiction.pdf

Pawlik-Klenlen, L. (May 2 2008). Evaluating Psychological Research: How to Spot Good Scientific Experiments in Human Behavior. Web. Retrieved from: http://www.suite101.com/content/valuable-psychological-research-a52604

Wikipedia.  Psychology/Research methods. Web. Retrieved from: http://en.wikipedia.org/wiki/Psychology#Research_methods