Whenever a crime takes place, eyewitnesses who are present on the scene can help the police or authorities when the crime is being investigated. However, eyewitness memory can be affected by a series of factors.
One of the factors that can affect eyewitness memory is stress. Whenever a person witnesses a violent crime, his response is almost always one that generates a stressful response to the stressor imposed by the crime. This stressful response is the defensive response which is heavily studied by psychophysiologists (e.g., Klorman, Wiesenfeld Weissberg, 1977). This defensive reaction is the physiological response (increased blood pressure, muscle tone and acceleration in heart rate) resulting when attention control is highly dominant (Tucker and Williamson, 1984). The activation mode, which is one of the two neural control systems that regulates a human’s response to the environmental demands, has three important characteristics. These are: (1) a bias against stimulus change, (2) a tonic readiness for action, and (3) processing under tight attention controls. Some of the tasks that elicit the dominance of activation mode include activities which increase cognitive and/or somatic anxiety such as vigilance, escape, avoidance or ‘pressure’ tasks (Deffenbacher, 1994). When assessing the effectiveness of a condition of heightened stress, it should be compared with another condition that is demonstrably lower in stress (or even free from stress), where the arousal mode of attention control is predominant (Tucker and Williamson, 1984). When the activation mode is dominant, there is a notable deceleration of heart rate and lowered blood pressure (Lacey and Laceym 1974). Deffenbacher (1994) concluded that if a task elicits the arousal mode of attention control, the memory will be enhanced for the most important and informative aspect of the stimulus display. On the other hand, if the activity elicits the activation mode of control, memory can be either enhanced or reduced, depending on the amount of cognitive anxiety and physiological activation present.
Another factor that can affect eyewitness memory is age. Younger adults are more likely to make better witnesses than older adults or young children (O’Rourke, Penrod, Cutler, & Stuve, 1989; Valentine, Pickering, & Darling, 2003). Not only are elderly witnesses more prone to poorer memory that comes with poor perception and processing, they may also show certain patterns of false memory (Aizpurua, Garcia-Bajos, & Migueles, 2009).
The viewing conditions also play a part in eyewitness memory. When it comes to face recognition, four factors are important: exposure time, delay, attention and arousal, and weapon focus. The duration a witness has to look at the face of the offender affects their capacity to recognize the same face subsequently (MacLin, et al., 2001). This is often referred to as the exposure/study time. During an investigation it is of utmost importance that, when relying on eyewitness testimony, it is taken under consideration that varying exposure times can have a massive influence on the accuracy of identification and there is always the risk of false identification.
Furthermore, the rate of accuracy can also be influenced by time delay ‘ the time between seeing the offender and identifying him/her. Barkowitz and Brigham (1982) noted that the accuracy of facial recognition decreased after long intervals; the longer the delay, the greater the chances of false identification.
...(download the rest of the essay above)
About this essay:
This essay was submitted to us by a student in order to help you with your studies.
If you use part of this page in your own work, you need to provide a citation, as follows:
Essay Sauce, Eyewitness memory. Available from:<https://www.essaysauce.com/criminology-essays/eyewitness-memory/> [Accessed 22-09-19].
Review this essay:
Please note that the above text is only a preview of this essay.