Monday, October 14, 2019

Are Eyewitness Identifications Reliable?

Are Eyewitness Identifications Reliable? Eyewitness testimony is one of the most commonly employed forms of direct evidence presented in court and is often more persuasive to juries than circumstantial evidence. Memory is often defined as the processing, storage and retrieval of information acquired through learning. Throughout your day, thousands of sights, sounds, smells and other stimuli from the external environment flood your sensory receptors. All this information, whether paid attention to or not, is briefly held in your sensory memory. Sensory memory is the entry point of memory, where new incoming sense-based information is stored for a very brief period. Short-term memory is a memory system with a limited storage capacity (7 +/- 2 items) and duration. Information is stored temporarily, and assuming that no rehearsal process is used, can be retained fairly well for the first few seconds, but for a longer time than sensory memory. After about 12 seconds, however, recall starts to decline and by 18-30 seconds almost all information disappears if it has not been renewed in some way. The duration can be enhanced if some rehearsal is involved. Long-term memory refers to memory system that stores almost an unlimited amount of information, which can be stored over a lifetime with rehearsal. It comprises of two different systems called declarative memory (specific facts and events) and procedural memory (actions and skills that have been learned previously). Recall and recognition also play a role in the process of retrieving information. Recognition is the ability to elicit stored material (memory) through the use of a cue (Eg. A photo line-up). Recall on the other hand is the ability to elicit stored material without externally providing any type of cue. The reliability of information is an important factor when it comes to identifying suspects and alleged offenders and providing a testimony at trials. Factor One – Age: During circumstances in which a child is a witness to an event, the credibility of that child and whether their testimony is reliable, is often questioned. Young children are able to testify, however they must be found competent before they can do so. The child must be able to understand the obligation of telling the truth, and the effects of lying. If the child is deemed unfit to testify, their prior statements to counsellors, doctors, or law enforcement may be used at trial. Article one: The purpose of first study conducted was to determine whether children as young as 6 or 7 years of age could understand and perform the task of identification, and whether decisional bias and committing fewer false alarms increases with age. Forty eight children were recruited, twenty five male and 23 female. The children were separated into two groups, 2 separate conditions (stealing vs. helping). They were all shown a short video individually, showing four men, dressed in identical red shirts in a soccer locker room. At the end of the video it shows one of the men walking out with two sports bags, one with a New York Yankees logo on it, which had previously been brought in by one of the other men. Each child was given instructions before and after watching the video, which were designed to frame the act, as a moral transgression (stealing) or pro-social (helping). The participants in the stealing condition were asked to identify the man who stole the bag. The others in the helping condition were asked to help the owner of the bags find him to give him a reward. After seeing the film, the participants were asked to say what they had witnessed, what happened in the film, and if they failed to mention that nature of the act (stealing or helping), the experimenter did. The children were then shown a series of photographs, presented sequentially, and for each photo, they were asked to identify whether it was or was not the man. The photos were all taken against an identical neutral background, with them being head-and-shoulders shots with each individual earing the same red t-shirt. In the end the children were asked if they had any questions and were praised for their cooperation, they were then allowed to choose a coloured pen as a reward and given a certificate of appreciation. The data supported the performance hypothesis that, younger children would apply a more negligent criterion when making eyewitness judgements of moral transgressions. The results show th at children in the younger age groups were more prone to make false alarms than children in the 11-14 years age group, and children in the youngest age group were more likely to be very sure that a person was guilty of stealing when he was not, compared to those in the older age groups. In conclusion, younger children are not as reliable when it comes to being an eyewitness to an event. Article two: There is usually a delay from the time a crime is witnessed and a suspect being apprehended, this allows the suspect to undergo a change in appearance, for example changing their hairstyle or hair colour. It is unclear how adults’ and children’s identification abilities compare when the suspect changes their appearance. In a recent meta-analysis, with simultaneous presentation, it showed that children over 5 were as accurate as adults in producing comparable correct identification rates. This study manipulated a suspect’s appearance (hair colour style) to produce ‘no change’ conditions (line-up members match the suspect’s appearance at the time of the crime) versus ‘change’ conditions (line-up members do not match the suspect’s appearance at the time of the crime). Both children and adults were tested. 239 adults were recruited from the introductory psychology participant pool at a university in Eastern Ontario, Canada, an d 96 children recruited from local elementary schools in Eastern Ontario, Canada. Upper body photos were taken resembling the suspect with short, grey hair, or dark mid-length hair. From the assortment of photos, six photos of men that matched the suspect’s description with short, grey hair and six photos that matched the suspect’s description with longer, darker hair were selected to for the line-ups. Two target-present line-ups were conducted, one line-up consisted of six photos, which consisted of five line-up members who had short, grey hair and the suspect’s photo (with short, grey hair). The second line-up consisted of six photos, which consisted of five line-up members who had longer, darker brown hair and the suspect’s photo (with longer, darker, brown hair). There were also target-absent line-ups conducted, one line-up consisted of five foils with short grey hair, with the suspect’s photo replaced with a matching male. The other line-up co nsisted of five foils with darker brown hair with the suspect’s photo replaced with a matching male. The results show that in a meta-analysis comparing the children’s and adults’ correct identification rates, children as young as 5 years of age were found to be able to select the suspect from a group of photos containing the suspect, at a rate comparable to adults. This changed however, when the suspect’s didn’t match his appearance at the time of the crime. For both children and adults’, there was a decrease in their correct identification rates when the suspects appearance changed, they both had great difficulty in correctly identifying the guilt suspect. One reason for a decrease in correct identification following a change in appearance is that eyewitnesses may use hairstyle as a key marker for identification. Overall the elimination procedure is the most effective when it comes to identification rates for both children and adults. Factor two – Stress/Arousal Witnessing a disturbing event (an act of violence) is likely to elicit arousal and to be stressful. Being under stress at the time of encoding can have an effect on the memory process, typically enhancing or preserving memory for emotional information, this can have an interesting implication for eyewitness accounts. Research has found that in the area of emotion and memory has provided evidence that stress influences the long-term memory processes. Article one: The goal of this study was to examine the subsequent effects of misinformation exposure on memory for a negative arousing to-be-remembered event encoded under stress. They adapted a slideshow, with materials from Payne et al. (2006), then added a misinformation manipulation 48 hours after encoding and 48 hour prior to memory testing. Sixty-eight undergraduate students were recruited through the university of Arizona subject pool. Participants were instructed to abstain from alcohol, caffeine, and exercise on days of experimental sessions. Participants were randomly assigned to a two (stress vs. control) and two (misinformation vs. no misinformation). On the first visit, the participants were engaged in a psychosocial stress induction (control task), after they were escorted to another room to few a negatively arousing slideshow. Participants returned forty-eight hours later to the lab to complete the second experimental visit. Upon arrival, the participants were told that they would be asked a series of questions, a totally of 60, relating to the slideshow the view previously two days ago. The questions for the misinformation condition had false information embedded as factual elements of the slideshow (e.g. â€Å"What did the boy have in his hands?† versus â€Å"What did the boy have in his hands besides his lunch?†). The questions were identical in the misinformed and non-misinformed groups to avoid inadvertently cuing one group with information that could potentially benefit the memory performance. The questions asked in this session were designed to expose the participants in the misinformation group to false information. Participants returned another forty-eight hours later after questioning, to complete the third and final experimental session, they were told that their memory of the slideshow would be tested. This was assessed using a recognition test that consisted of 136 questions, administered over a computer. The results showed that bei ng under stress prior to encoding affects memory for a negative event by enhancing subsequent memory. This finding supports the notion that stress influences encoding of aversive events, although stress alone did not moderate misinformation endorsement. Participants were less likely to endorse misinformation for the most negatively-arousing portion of the slideshow if they were stressed prior to encoding, and reported that they were aroused by the negative event. These participants had a more accurate memory for items that had been misinformed with the slideshow phase. The results demonstrate that, in regards to eyewitness memory, arousal induced by an event, in combination with activations of a stressed state, result in an enhanced emotional memory that is less vulnerable to the incorporation of false details, despite being exposed to direct misleading information. Article two: The goal of this study was to investigate how post-encoding stress will affect memory, depending on the thematic arousal of the initial learning period. Predicted that under high thematic arousal, post-learning stress would enhance memory for the central elements of an event, for example a cashbox grabbed by the burglar. Participants were recruited from Bielefeld University, 88 males, ages ranging from 19 to 37. The experiment consisted of four main stages, encoding of an event, manipulation of psychosocial stress, rehearsal of the event information and a recognition test for the event. The first stage consisted of the participants viewing a video-filmed event depicting a burglary. Participants in the high arousal condition should have anticipated to see a distressing, possibily violent incident in the video shown. However those in the low arousal condition were exposed to an event that was unlikely to be as distressing. In second stage, after encoding has occurred, a stress manipula tion was applied. About half of the participants were administered the Trier Social Stress Test, this induced psychosocial stress, the remaining participants were exposed to a non-stressful situation. In the third stage, the participants read a narrative description of the witnessed event, the description did however include items not shown in the original event. In the final stage the participants were given a yes or no recognition test that contained items that did appear in the video and those that didn’t. This study showed that eyewitnesses’ memory for an event was influenced by the combined effect of arousal during encoding and subsequent social stress, which was not related to the event itself. The results indicate that eyewitnesses are likely to experience arousal during observation of an event, they also may be exposed to social stress shortly after, like during an interrogation for example. There was no evidence that thematic arousal and/or post-event stress a ffected the participants’ memory for false post-event information. It is shown that age can have an effect on an eyewitness’s reliability, children are prone to forget things or take into account misleading information and believe it is true. With that being said their credibility is often questioned. Results show that younger children are more prone to making mistakes, and saying someone is guilty, even when they’re not, overall young children are not as reliable. Being under stress at the time of an event can have an effect on memory, however it does not effect on an eyewitnesses memory of an event. These studies show that eyewitnesses are still able to recall the events that happened, even after experiencing pre or post-event stress. At the end of the day, both can have an effect of the recall of information, and identifying the correct perpetrator. Reference List: Echterhoff, G., Wolf, O. (2012). The stressed eyewitness: the interaction of thematic arousal and post-event stress in memory for central and peripheral event information. Front. Integr. Neurosci., 6. doi:10.3389/fnint.2012.00057 Hoscheidt, S., LaBar, K., Ryan, L., Jacobs, W., Nadel, L. (2014). Encoding negative events under stress: High subjective arousal is related to accurate emotional memory despite misinformation exposure. Neurobiology Of Learning And Memory, 112, 237-247. doi:10.1016/j.nlm.2013.09.008 Pozzulo, J., Balfour, J. (2006). Childrens and adults eyewitness identification accuracy when a culprit changes his appearance: Comparing simultaneous and elimination lineup procedures. Legal And Criminological Psychology, 11(1), 25-34. doi:10.1348/13553250552626 Spring, T., Saltzstein, H., Peach, R. (2012). Childrens Eyewitness Identification as Implicit Moral Decision-Making. Appl. Cognit. Psychol., 27(2), 139-149. doi:10.1002/acp.2871

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