Stress is a physiological reaction that occurs in the body. Stress occurs when the body finds certain situations stressful and feels like it has no way to cope. Various stressors cause the body to react in the same way. Stress exhausts the body and leads to various diseases. Selye studied the effect of stress on the body. He created the General Adaptive Syndrome Stress Model or GAS model. Selye was curious about how stress affected the boy. He subjected rats to various stressors and found that they all reacted the same way. The GAS model has three stages. The first stage is the alarm stage: during this stage the body first shows signs of stress such as an elevated pulse and the release of cortisol into the bloodstream. This is also when the fight or flight response is activated. After about a day or two, if the body is still stressed, the second stage begins. During the resistance phase, the body appears to return to normal, but cortisol levels in the blood rise to a dangerously high level and weaken the immune system. The body then moves to the third stage, called the exhaustion stage. At this point, the body can no longer function properly. The body becomes weak and exhausted, suffering from hair loss and stomach ulcers. Although Selye's research constitutes a valid hypothesis about the physical symptoms of stress, it does not take into account the cognitive thought process of humans. Cox et al, however, took into account the cognitive thought process. He called this the transactional model of stress. This indicates that stress occurs as a result of a transaction or interaction of two things: the perceived demands of the environment and the perceived capacity of individuals...... middle of paper ..... . greater electrical conductivity in the skin. After the task, participants were asked to solve 4 puzzles, 2 of which were unsolvable in order to create frustration. Participants who participated in random noise conditions had the highest levels of stress. Those who participated in predictable noise conditions had the second highest level of stress and those who were not subjected to noise conditions had the lowest level of stress. Glass et al. suggest that random noise is particularly difficult because we "tune out" constant stimuli, but unpredictable stimuli require continuous attention, which reduces our ability to cope with stress. The aim of this study is to investigate the effect of light noise. stressor on a specific biological response. According to previous studies, stressed candidates should leave with an elevated pulse and sweating..