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 deal with them. Different 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 Stress Syndrome model or GAS model. Selye was curious about how stress affected the boy. He subjected rats to various stressors and found that all rats reacted the same way. The GAS model has three phases. The first phase is the alarm phase: during this phase the body shows the first signs of stress such as increased pulse and 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 under stress, the second phase begins. During the resistance phase the body appears to return to normal, but cortisol levels in the blood rise to dangerously high levels and weaken the immune system. The body then continues into the third phase, called the exhaustion phase. At this point the body can no longer function properly. The body becomes weak and exhausted, suffers from hair loss and stomach ulcers. While Selye's research is a valid hypothesis for the physical symptoms of stress, he does not take into account the cognitive thought process of humans. Cox et al, however, took the cognitive thought process into account. He called it the transactional model of stress. This states that stress occurs as a result of a transaction, or the interaction of two things: the perceived demands of the environment and the perceived ability of the individual... at the center of the card... increased electrical conductivity in the skin. After the task the participants were asked to solve 4 puzzles, 2 of which were unsolvable so as to create frustration. Participants who took part in the random noise conditions showed the highest levels of stress. Those who took part in the predictable noise conditions had the highest stress levels and those who had no noise conditions had the lowest stress levels. Glass and colleagues suggested that random noise is particularly difficult because we "shut out" constant stimuli, but unpredictable stimuli require continuous attention, and that this reduces our ability to cope with stress. The purpose of this study is to investigate the effect of a mild noise stressor on a specific biological response. Using previous studies, stressed candidates should come out with an elevated pulse and should be sweating.