Deffenbacher, Bornstein, Penrod, and McGorty (2004) conducted a meta-analytic review to determine the effects of high levels of stress on eyewitness memory. It was argued that much of the confusion in determining the effect of stress on memory was due to the fact that many studies do not actually push participants to a high enough level of stress. This review excluded all studies that did not elevate participants' stress level to elicit a defensive response or mode of activation of attentional control. This defensive response as defined by Deffenbacher et al is characterized by a pronounced change in physiological measures of stress. These measures include increases in heart rate, blood pressure, and muscle tone (2004). Two meta-analyses were conducted in this review. One attempted to determine whether stress had an impact on an individual's facial recognition ability. Moderating variables that might influence the results of these studies were also examined. The second analysis looked at the accuracy of eyewitnesses' recall of details and the impact of stress. Additionally, the effects of other variables that may have influenced recall of details were also examined. The conclusion of the first analysis was that stress indeed had a negative effect on the accuracy of eyewitness identification (Deffenbacher et al., 2004). This is the expected result, however numerous other variables have been found to impact whether eyewitness memory is affected by stress. These variables were; type of training, research paradigm, presence or absence of a staged crime and age of the witness. The type of training, i.e. target present (TP) or target absent (TA), has been found to moderate the effect of stress on memory. The current target lineups had quite a… middle of paper… that seen in studies that used other methods to cause stress. Deffenbacher et al. They produced important findings that stress has a negative impact on memory both in terms of identifying and remembering details. However, only studies that caused a particular type of stress were examined. Studies that produced only orienting responses in participants were included, whereas studies that produced a defensive response were used. Included (2004). Furthermore, stress had to be controlled directly by the experimenter. Naturalistic studies were not included. Finally, the studies had to demonstrate that stress was actually induced and could not simply be assumed to have occurred. Works Cited Deffenbacher, K. A., Bornstein, B. H., Penrod, S. D., & McGorty, E. K. (2004). A meta-analytic review of the effects of high stress on eyewitness memory. Publication of the Faculty of Psychology