General Principles of Human Factors - Literature review Example

Eyewitness Testimony – Factual or Not There have been numerous instances where eye-witness testimony turned to be inaccurate or completely false. Forinstance, Donald M. Thomson, an Australian psychologist and attorney was wrongfully arrested on charges of rape in 1975. A night before his arrest, he had appeared on a television show. The victim who testified that Thomson was her attacker was actually watching his show aired on TV before the attack took place. As Thomson had a solid alibi, i.e. he was on the TV show live during the attack on the woman; charges against him were dropped after realizing that the victim had confused the rapist’s face with Thomson’s face that she saw on the television screen (Hayasaki 2014). This is not an isolated instance. According to the Landmark report released by the National Academy of Sciences, there have been 318 wrongful convictions in the US since 1989 that have been overturned by DNA evidence and 72% of these were attributed to erroneous eye-witness testimony (Innocenceproject.org 2014). According to a research project quoted by The Guardian, 33% of eye witnesses identified the wrong perpetrator from high quality, close-up video footage (Rowley 2009). As is evident, an eye witness’s account of a crime may differ from what really happened despite the witness being fit and healthy, and providing an honest account according to his recollection. This could be attributed to a number of psychological and environmental factors some of which are discussed here. Leading Questions and their Influence on Eye-Witness Testimony Research has shown that misleading information that is obtained after an event can lead eyewitnesses into reporting events or items they did not really see. One of the major works in this segment is that of Elizabeth Loftus, who was the first to indicate that questions asked by an interviewer were responsible for introducing wrong information in the memory of an eyewitness. In their research, Loftus and Palmer (1974) showed that leading questions affect memory recall. A leading question is a question asked by an authority in such a way that it suggests a particular answer to the eyewitness. The account of an eyewitness can be distorted by the nature of the questions the witness is responding to in an interview. When memory recall is free and self-initiated, it results in an accurate account of events. On the other hand, when it is probed through the use of suggestive interview questions, there are chances that this could jumble up the arrangement of the chronology of the stored information, resulting in an inaccurate recall of events (Wells et al. 2006). Loftus and Palmer (1974) demonstrated this phenomenon experimentally. They showed films of automobile accidents to research participants and asked questions about the films. When they framed the question as, “About how fast were the cars going when they smashed into each other”, the respondents gave higher estimates of speed than when they were asked questions using verbs such as “bumped”, “collided”, or “hit”, instead of the stronger word “smashed”. Merely changing a verb in the question resulted in inaccurate responses. A week later, the test was retaken. It was seen that subjects who were earlier asked the question with the “smashed” verb, were this time asked whether or not they saw broken glass in the video. They responded saying yes, even though broken glass was not actually present. It is thus evident from Loftus and Palmer’s research that the questions asked post event can cause a reconstruction in the memory of that event. In yet another research, Loftus asked participants to view an accident of a green car (Zaragoza, Belli and Payment 2006). She later exposed these participants to misleading questions which suggested that the car was blue, after which participants showed a tendency to say the car was blue-green. This indicates that the participants reported information that was a blend of both original and post-event information. This phenomenon, where leading questions alter the post-event retelling by eyewitnesses, is termed ‘misinformation effect’. It is important to note however that Loftus’ research was a lab experiment and therefore may not be a good simulation for real-life as people could behave differently in a real accident scenario. For instance, they could be more anxious, or could develop better or worse recall ability. Since the experiments were based on college students, and much like any other social science experiment, it cannot however be ascertained as to how generalizable these findings are to the real world (Cutler and Penrod 1995). Also, as pointed out by Fruzetti et al. (cited in PBworks 2007), it is not easy to distort the memory of a witness for key details such as the murder weapon used in an event (PBworks 2007). Memories that Develop Post-Event The misinformation effect is not just limited to leading questions. Evidence suggests that eyewitnesses exposed to misleading or erroneous information tend to develop false memories of events that deviate from what actually happened. In an investigation, Loftus, Miller and Burns (1978) showed that when subjects are exposed to irrelevant or misleading information, it is bound to produce less accurate response about a past event. In fact, the closer the exposure of misleading information is to the time of final questioning, the more impact it has on final recall. Information to which an eyewitness is exposed post-event, whether it is misleading or consistent, is integrated into his memory of that event (Loftus, Miller and Burns 1978). Another phenomenon, called “destructive updating”, has also been reported where contradictory misleading information post-event replaces the original memory and thus the original information is permanently erased from memory (Zaragoza, Belli and Payment 2006). This is however subject to controversy. For instance, McCloskey and Zaragoza through a Modified Test Procedure showed that misled subjects, when given an opportunity, have an “overwhelming tendency” to select the misleading alternative as true. However, when the misleading option was not given during interview, they had the ability to remember the original event details as accurately as those who were not exposed to misleading information (Zaragoza, Belli and Payment 2006). Therefore, although information gained along the way does impair or alter the memory of an event, it does not completely erase it. This conclusion however is still under debate and there is no definitive conclusion yet. It is however evidenced that memory is impaired, whether or not completely erased. Emotional Underpinnings Another factor that comes into play when an individual goes through or sees a traumatic event is emotions. Experimental evidence suggests that high level of emotional arousal and stress experienced during an event results in poor recall of details (PBWorks 2007). On the contrary though, research into ‘flash-bulb-memories’ provides evidence that under certain circumstances, the memory is actually improved by an emotionally charged event (PBWorks 2007). This exceptional case apart, experiments have shown that negative emotions do have a distinct influence on recall, altering it but not completely impairing it. For instance, in their experiment on the influence of negative emotion on certain aspects of eyewitness recognition and recall, Houston et al. (2013) made two important findings: firstly, they showed that emotional participants gave a more complete description of the perpetrator when compared to neutral participants, however they were less able to describe what the perpetrator actually did to the victim; secondly, although emotional participants were better able to describe the perpetrator, they were less able to identify him from a photographic lineup as compared to neutral participants. Therefore, although emotions did not affect their recall of the perpetrator, they did result in wrongful judgement when they were asked to choose from a photographic lineup. Similar findings were made by Morgan et al. (2013) whose research on 800 military personnel showed that memories of stress-inducing events are “highly vulnerable to modification”, especially when the emotional subject is exposed to misinformation, even in the case of individuals (like military personnel) whose “level of training and experience might be thought to render them relatively immune to such influences” (p. 11). It is also seen that when eyewitnesses retell an event emotionally, they tend to have a less detailed and erroneous ability to recall as compared to those who retell an event factually rather than emotionally (Soleti et al. 2012). Experimental studies on the influence of emotions on memory are however much debated because in laboratory simulations, the subjects are not exposed to a high degree of personal threat or alarm, as is experienced during a real-life event. Therefore, such a simulation may not activate the neurobiological system in the same fashion as does a realistic threatening event (Morgan et al. 2013). Schema and Memory Reconstruction A schema is a set of ideas that are preconceived in the brain and which are used by the brain to interpret and perceive new information. Human memory relies on these schemas which are generalised perceptions of things based on experience (PBWorks 2007). Schemas act as fillers in memory, as they fill out information in everyday memory in places where individuals miss out on precise details. Because of this, individuals could mistakenly recall events which never actually happened because they make sense in a specific schema. Reconstructive errors of memory are thus attributed to these schemas. Subjective perception is another psychological factor that influences the manner with which an individual presents the stored information of a real event. In the process of reception of sensory information like pain, sound or smell, sense is made out of them, both consciously and unconsciously, which allows the information to blend in with the already existent information in the brain. The manner with which individuals perceive environmental stimuli differs from one individual to another. Subjective perception is influenced in an individual right from childhood, through learned experiences. The nature with which one person would perceive painful occurrences would be entirely different from those of the other and these subjective perceptions are influenced by an individual’s socio-cultural background. When an eyewitness is reporting an account that involves information that can be influenced by subjective perception like painful incidents during an accident, the eyewitness’ account would be detached from reality in relation to the individual’s perception of pain (Kensinger & Corkin 2013). Frederick Bartlett first proposed the concept of schemas and conducted a large number of experimental studies on this subject. In one experiment, he gave participants unusual and complex stories such as The War of the Ghosts, and asked them to retell them six or seven times over a period of time (Brain 2001). He observed that the stories became altered and distorted each time they were retold. The stories became shorter, more westernized and many objects were inaccurately recalled. This suggested that the participants were not recalling information precisely and were rather making a “best guess” according to their own understanding. What Bartlett concluded was that humans try to recall events in such a way that it is it is consistent with their schemas and therefore, memory is the “imaginative reconstruction of experience” rather than the actual recalling of an event (p. 56). Therefore, in the case of eyewitnesses, the recall of an event may not be accurate because of the influence of their imaginative reconstruction of events. Conclusion Eyewitness’ accounts of events have time and again proven to be inaccurate in a significant number of cases. Even if an eyewitness is healthy and without any psychological or mental disorder, there is a probability that he would confidently provide erroneous information despite being honest in intention. A number of factors have been attributed to this phenomenon. Evidence suggests that leading questions asked during an interview could suggest new information to the eyewitness, thereby distorting his memory of that event. It is also seen that false memories develop after the event due to exposure to misleading information. Emotions are also associated with impaired recall of information and also affect judgments while pointing out the perpetrator of a crime. On the other hand, it is also seen that the tendency of the brain to act on schemas and reconstruct the memory of an event inaccurately may also be one of the reasons why eyewitnesses wrongly recall an event. All these conclusions are however not definitive as they are different under different circumstances and also because the associated research is conducted under laboratory conditions which are very different from a real-life traumatic experience. However, it can be ascertained through real-life survey data and research experiments that eyewitness testimony may not always be accurate. References Brain, Christine (2001), Advanced Psychology: Applications, Issues and Perspectives, Cheltenham: Nelson Thornes. Cutler, BL, & Penrod, SD (1995), Mistaken Identification: The Eyewitness, Psychology and the Law, Cambridge: Cambridge University Press. Hayasaki, Erika (2014, November 19), “The End of Eyewitness Testimonies”, Newsweek, accessed 24 May, 2015 at Houston, KA, Clifford, BR, Phillips, LH, & Memon, A (2013), “The emotional eyewitness: the effects of emotion on specific aspects of eyewitness recall and recognition performance”, Emotion, 13(1), pp. 118-28. Innocenceproject.org (2014), “National Academy of Sciences Releases Landmark Report on Memory and Eyewitness Identification, Urges Reform of Police Identification Procedures”, Innocenceproject, accessed 24 May, 2015 at . Kensinger, EA & Corkin, S (2003), “Effect of negative emotional content on working memory and long-term memory”, Emotion, 3, pp.378–393. Loftus, EF, Miller, DG, & Burns, HJ (1978), “Semantic Integration of Verbal Information into a Visual Memory”, Journal of Experimental Psychology, 4(1), pp. 19-31. Loftus, E & Palmer, JC (1974), “Reconstruction of Automobile Destruction: An Example of the Interaction Between Language and Memory’”, Journal of Verbal Learning and Verbal Behavior, 13, pp. 585-589. Morgan, CA et al. (2013), “Misinformation can influence memory for recently experienced, highly stressful events”, International Journal of Law and Psychiatry, 36, pp. 11-17. PBworks (2007), “Eye witness testimony”, As-psychology.pbworks.com, accessed at 24 May, 2015 at . Rowley, Sylvia (2009, August 18), “Wrongful conviction throws spotlight on unreliability of eyewitness evidence”, The Guardian, accessed 24 May, 2015 at . Soleti, E et al. (2012), “Does Talking About Emotions Influence Eyewitness Memory? The Role of Emotional vs. Factual Retelling on Memory Accuracy”, Europe’s Journal of Psychology, 8(4), pp. 632–640. Wells, GL, Memon, A & Penrod, SD (2006), “Eyewitness Evidence”, Psychological Science, 7, pp.45–75. Zaragoza, MS, Belli, R, & Payment, KE (2006), “Misinformation effects and the suggestibility of eyewitness memory”, In M. Garry & H. Hayne (Eds.), Do Justice and Let the Sky Fall: Elizabeth F. Loftus and Her Contributions to Science, Law, and Academic Freedom (pp. 35-63), Mahwah, NJ: Lawrence Erlbaum Associates. Read More