Psychology

Psychophysiology is a division of psychology involved in the physiological aspects of psychological matters.  It is primarily concerned with the association between psychology and brain reactions (Carlson  Buskist, 2007). A lot of concepts are part of contemporary psychophysiology. These concepts include brain waves, measures of skin conductance, the activities of the muscle, cardiovascular measures, and movements of the eyes among others. Psychophysiological processes are capable of providing information about a lot of aspects in human body. They have provided new possibilities in the area of legal investigations. Polygraph is an instrument that uses psychophysiology concept to detect lies. The polygraph tests capture physiological responses as an individual responds to queries. This test is based on the belief that untrue responses will give physiological reactions that can be calculated. It calculates physiological reactions that results from the nervous system. It is based on the theory that a lie results to nervousness (Gamer et al., 2006).This provides the first Psychophysiological method used in lie detection.

Polygraphs have been employed in investigations to gather evidence. Polygraphs have been employed in legal cases to provide evidence by examining a suspect or the witnesses. In most countries and also in most states in America, the use of polygraph to gather evidence is accepted. Polygraph produces the most accurate results in providing court evidence. However, this is only true when the test is administered by a very qualified examiner. This means that polygraph procedure require that those carrying out the test are properly trained. Lie detectors do not operate as their name implies. They do not detect lies (Simpson, 2008). These tools operate to determine if deceptive character is being exposed. The examiners look out for important instinctive reactions in an individuals system when that individual is put through stress. This kind of stress is particularly linked to deception. This is what is reflected in the polygraph. The changes in the test could show that a person is not saying the truth, but the explanation is usually given by the person conducting the examination. This is the reason why the person requires to be well trained in conducting the test and interpreting the results. The psychophysiologist requires to be well trained to be able to do this. In case where they are well trained, they are capable of interpreting the results to the highest degree of accuracy. In many court cases, evidence that could not be gathered by any other investigation method can be acquired through the use of polygraph. Although the use of polygraph results has generated a lot of controversy, they have been used extensively as evidence (Carlson  Buskist, 2007).

One of the greatest issue with polygraph testing lies with the way the results are tallied. There is a way that the figures will be calculated and a right answer will be obtained, and there is a way they will be calculated and a wrong answer will be gotten. This fact raises doubts on the accuracy of the procedure. This kind of doubt was evident in the supreme court of America in 1998. This was during the case of United States vs. Scheffer (Simpson, 2008).Most people accepted the fact that there is no agreement as to the fact that polygraph results are reliable. The validity of the method has also been questioned. Some researchers argue that instead of being a test, the procedure has been made into an intrinsically interrogation instrument that is not standardized and one whose precision cannot be proven. This argument is supported by the fact that some people can appear nervous even when they are not lying. When such people are exposed to the polygraph, they will be proven liars hence get punished unjustly (Gamer et al., 2006).

In the military, polygraphs have been employed as a qualification for clearance. This is where the method is employed to detect whether a person is honest enough to be incorporated as a military officer. This method is very important in such institutions to detect and deter spying. It is very useful in preventing entry of dangerous people into the military especially during this time when terrorism is on the rise (Simpson, 2008). This method is more crucial as prevention to espionage. These tools are also important as they act as a way of scaring off individuals who are likely to engage in espionage. In this case, a person who has wrong intentions in joining the military is likely to be scared by the prospect of being examined through this method. Such a person will have very minimal probability of joining the forces. This kind of procedure was used on James Nicholson. This man was employed by Criminal Investigation Agency, but he was later found guilty of spying. He was exposed to thorough investigation that led to the conclusion that he was interacting with external intelligent force. It is the results of the polygraph that led to investigations, where he was found guilty and apprehended. This makes the use of the test for Espionage and Sabotage a security tool for a country, especially from external invasion (Gamer et al., 2006).
 
The use of test for Espionage and Sabotage can also encourage spying. This can happen in case a person is thrown out of the military for past or minor offences that are discovered in the examination process. A number of people have gone through such experiences leading to fury and disappointment. Such a person is capable of doing anything to get back at the organization. It is in such moments that most of them go out and sell the information they have about their country to the enemies. Such a case happened with Edward Lee Howard. This man was examined through a polygraph where he admitted to have committed petty crimes. He was thrown out of the Criminal Investigation Agency as a result. This made him furious, causing him to give information concerning the Criminal Investigation Agency to the USSR (Simpson, 2008).

Psychophysiological tests have been in use with sex perpetrators for a long time. In most states in America, polygraph is a must in giving parole or probation to such criminals. This procedure has also been employed in rehabilitation of sexually-related crimes. It is used to determine the probability of such a person repeating the crime in future. In such a process, questions concerning inner thought, desires and urges are asked. This information is also used in determining the treatment procedure for such a person. Predators or aggressive criminals in such crimes are tested for unintentional sexual urge when exposed to provoking images associated with their offences (Carlson  Buskist, 2007).
This method is very crucial in protecting real and potential victims of such offences. It makes it possible for the courts to make decisions in relation to sexual offences. It is important to protect the society from potential danger. This is made possible through the use of polygraph. Decisions based on observable characteristics could be so deceiving. It is important to understand the mind of such people to know whether they are potential danger or not.

The disadvantage in this method is that it is possible to detain a person who has the capacity to reform in case the machine provides wrong results (Carlson  Buskist, 2007).

Conclusion
Due to development in technology and use of computers in polygraph, they are becoming more and more accurate. This has also increased their application in many fields. Technology improves capability while at the same time reducing the size of the appliance. Despite the many controversies that surround this field, it is clear that this will not deter its use. In fact, in future, these methods are going to be more popular and their application more spread.