Positive Effects Of Stress

‘‘Stress’’ is a term which generally portrayed negatively by the people. Dhabhar (2002) defined ‘‘stress’’ as events which involves a stimulus which consists of a stimulus which is called as stressor which triggers a response in the brain and subsequently activates the physiological fight or flight or fright response in the body (Dhabhar and McEwen, 1997, 1999 as cited in Dhabhar 2002). Stress can be distinguished by its duration. Dhabhar (2002) defines acute stress as stress that stays for a period of minutes to hours, while chronic stress as stress that remains for several hours a day for weeks or months. In contrast to the general idea that stress and stressors have negative impacts to health, this review examines the potentially beneficial

Beylin & Shors (2001) investigated the effects of stress on trace conditioning. During trace conditioning, there is a time gap in between the conditioning stimulus (CS) with the unconditioned stimulus (US), and thus a trace of memory of the CS must be maintained until the US occurs after it has stopped. In this experiment, Beylin & Shors (2001) used a 500 milliseconds trace intervals between a white noise burst CS and a periorbital shock US on male rats. In the first experiment, male rats which exposed to 90 brief (1 second), low-intensity (1 mA), and irregular intervals of tail-shocks with a trace intervals of 500 milliseconds has shown to facilitate the acquisition of excitatory conditioning 24 hours later. In contrast, exposure to 30 irregular intervals of tail-shocks did not give this observation. In their second experiment, rats which have learned the conditioned eyeblink response are stressed and examined their response to additional trials of training. The results show that subsequent performance of trace conditioning did not change.

The effect of acute stress exposure on learning performance in humans have been investigated by Duncko et al. (2007) using eyeblink conditioning and spatial navigation. The experiment involves healthy men participants which were exposed to acute cold pressor stress by immersion of dominant hand into ice water for 60 seconds. The result

In this experiment, the vaccine contains three viral strains, A/Panama, A/New Caledonia and B/Shangdong. A significant increase in antibody responses to A/Panama strain was shown in women which were exposed to exercise stress and mental stress immediately prior to influenza strain vaccination compared to control. Importantly, this finding has extended the results of animal studies in which acute stress enhances antibody response to immunization (Silberman, Wald and Genaro (2003); Persoons et al (1995)). However, there was no evidence of higher antibody response in men in this