Application of Human Memory Models to Eye Witness Evidence

Psychological research has developed a number of models of human memory and more recently applied research has helped to explain the fallibility of memory under various conditions. 

Critically consider how this research relates to eye witness memory and whether eye witness evidence should be considered to be reliable in the courtroom.


Eyewitness testimony is defined as oral reports given from individuals who were present at the occurrence of an incident/event in relation with what they saw and can recall which would be relevant and presented as evidence at the courtroom. Specifically, eyewitness testimony is a process in which the eyewitness professes to perceive a particular individual as one who committed a particular offence. The police do this through mugshots, line-ups, identification parades in order for the eyewitness to recognise the possible offender (NIJ, 2009). Eyewitness statements provide the central leads in securing criminal convictions, but that does not always imply that the evidence is substantial (Graham,2003). According to Kebbell and Milne’s (1998) study, witnesses found to play a vital role in the most criminal examination. This study also reported that three-quarters of police officers thought that eyewitness rarely or never made a mistake, which is not accurate. The criminal justice system is facing one of the most crucial problems in its administration due to potential eyewitness testimonies being regarded as unreliable. Miscarriages of justice considered to be one of the greatest substantial legal issues which played a vital role in psychological research. In particular, psychological studies have been concerned with miscarriages of justice involving the wrongful conviction of an innocent individual being sent to prison, and in many cases for many years (Wells et al.,1998). When scientific psychology was being introduced in the early 1900s, articles started to appear regarding mistaken eyewitness identification (Whipple, 1909).  As research has suggested, many academics observed for many years this ongoing issue regarding wrongful convictions and many studies have been carried out. For instance, Borchard stated in his study that 45% of 65 unlawful convictions were as a result of eyewitness error (Borchard, 1986) and Rattner concluded that 52% of 205 unlawful convictions resulted from eyewitness error (Rattner, 1986). Both of these studies had been carried out before DNA testing being discovered. In recent years, DNA testing played a significant role in the discovery of wrongful convictions regarding innocent people.

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An example is the innocent project. The Innocent project is an organisation that reviews old cases of individuals that were wrongfully convicted through DNA testing, and it aims to restructure the criminal justice system to avert any upcoming prejudice. It was reported that “approximately 71% of wrongful convictions are caused by inaccurate eyewitness statements” (NEIP). On the other hand, it is also known, that the human memory is not perfect regardless of how strong or weak, that could pose adverse effects on the administration of justice (Walls, 1993).  This paper will first describe theoretical assumptions about human memory, go through the stages and errors, analyses memory phenomena through memory theory and models in order to be able to conclude how reliable or not eyewitness testimony is, given on the theory and if should be considered to be reliable in court. This paper aims to explore based on the literature and through psychological research some of the factors and reasons that may influence the memory process of eyewitness and conclude whether or not it should be considered as a reliable source of evidence.

Human memory

“Memory is the means by which we draw on our past experiences in order to use this information in the present” (Sternberg, 1999). Memory is the term given to the methods associated with the capacity and consequent retrieval of data. Psychologists in general divide memory into three distinct phases; the acquisition of information (encoding), the retention of information and the retrieval of previously learned information (memory recall) (Melton,1963). Human memory is fundamentally associative, implying that another snippet of information is better and more easily recollected if it tends to be related with previously obtained information that is solidly secured in memory.

Stages of memory processing


The Acquisition is the perception of the original event. Encoding is the crucial first step to creating a new memory. It enables the object (or individuals) of interest to be converted into an idea that is kept inside the mind and be able to recall it later. The information that comes into memory is essential during that stage; for example, attention theorists would suggest that attention is essential. People remember the things they pay attention to.


The retention of information is the period that passes between the event and the personal recollection; it is sometimes being referred to as the “storage of information”. The period is the retention stage. It is understood as ‘for how long an individual can keep certain information in his/her memory?’. In a crime scenario, the retention period is immediately after the crime occurred, up until the point the police contact the eye-witness in order to interview them about what happened. In that stage, the eyewitnesses have to recall this information. This period can be concise, but it can also be very long depending on when the police are going to contact the eyewitness. The longer the period, the worse their memory and may even lead to the eyewitness testimony be regarded as unreliable. Many recording methodologies have been considered by psychologists in order to improve the retention stage.Research suggests that, as individuals learning, they should think of the significance of the events and what they mean and then try to link this new information into things they already relate (Craik & Lockhart, 1972)



This when an individual recalls back information in order to give an accurate of events. Memory is constructive and is not like a video recorder, thus will not be able to remember in great detail what happened. Endel Tulving claimed that “the key process in memory is retrieval” (1991, p. 91). Recall and recognition are the two essential kinds of retrieval phase. In a recall stage, the witness is given some specific circumstances and requested to provide an oral report of what they saw. In the recognition stage, the witness is provided with some pictures of objects of interest (or individuals) and asked to show whether any of them were presented in a crime occasion. In a crime scenario, there are two retention periods; firstly, it is when the eyewitness is going to be interviewed by the police and secondly when he/she be called to testify in court.

Errors in human memory

Errors in human memory can occur at any stage of the process. Loftus (1996) emphasised in a great deal in these three phases of memory to comprehend any potential issues that may occur and prompt to false convictions. Psychological research and studies have uncovered many problems that can outbreak the reliability of eyewitness. These issues can most notably occur during encoding and retrieval stage.

Errors at Encoding

Possible errors that can occur during encoding, in acquisition phase can be due selective attention from the eyewitness, prior expectations, distance factors, lighting. Sometimes eyewitnesses being present at a crime, often witness the event under poor conditions because the event happens unexpectedly, rapidly (Culter, 1995). As a result of this, police have access to a limited amount of information.On other occasions is a direct result of the period of time the eyewitness took to see the suspect. The longer the time the eyewitness spent observing the suspect, the more will be able to encode and retrieve on the interview and identification procedures conducted by police (Laugherty et al.,1971). The effect of prior expectations and selective attention can negatively impact the encoding phase because often more consideration is given to certain details compared to other by eyewitnesses and similarly recall expectation not essentially what is in reality. Consequently, providing false pieces of proof regarding the identification of the suspect (Loftus, 1974).


Errors at Retrieval

Factors that can affect the retrieval phase can be internal and external. Leading questions can have a negative effect, and this was proven by Loftus and Palmer (1947) study. This study designed to observe if by asking leading questions can change a person’s memory of what they saw. The study involved 45 students who were shown seven films of car accidents and questioned how fast the cars were going when they…’ and the term after this sentence was altered each time to ‘contacted, hit, bumped, collided, smashed’. The study showed that the more vicious the adjective sounded, the faster the students predicted the car to have been running. Thus, they draw a conclusion, that misleading questions can alter an individual’s judgment in an event (Loftus & Palmer, 1974).  Another factor that can affect the retrieval phase is misleading information. Again, Loftus and Palmer (1974) contacted people from the previous test and raised the question whether or not they saw broken glass in the videos that were shown before; the purpose behind it was to see if including specific words in questions can create an untruthful memory. The result of this, it was more probable for students who gave faster speed estimations to say that they saw glass than those who estimated that the car was going slow. This is due to the representation an individual who predicted higher speed would hold; would assume there to be broken glass in a high-speed car accident (Loftus & Palmer, 1974).  What is understood is that it is dangerous to question a person things that can lead them to a specific answer, as people can be wrongly persecuted for a crime they did not commit.

Theories and models of memory

Theories and models of memory try to explain how human memory works from a different point of views. Some of the theories and models include Broadbent’s filter theory, Atkinson & Shiffrin Buffer model, Levels/Depth of processing and working memory theory. This paper will focus on Broadbent’s filter theory which will subsequently try to explain further, the memory phenomena.

Broadbent’s Filter Theory

The critical thing for this theory is attention. It is suggested that individuals cannot remember things if they do not pay attention to them. As it was first proposed by psychologist Donald Broadbent (1958) all other messages are deleted except physical features of messages which are utilised to choose one message for additional dispensation. He aimed to perceive how individuals could concentrate and in order to achieve he created an experiment; The split span experiment as it is called.  The experiment was designed to send a message to an individual’s right ear and then a dissimilar message to their other ear at the same time. It was essential that the participants would carefully hear both messages, simultaneously and rehash what they have listened to. Broadbent was keen on how the messages would be rehashed back and whether the participants rehash in the correct order the digits that they were listened to or rehash back what was heard in one ear pursued by the other ear. The results from the experiment he conducted showed that fewer errors were conducted during rehashing back ear by ear and this was done by most of the participants (Broadbent, 1958). However, his work has been highly rephehended by other researchers and academics, because initial investigations involved people who had never experienced surveillance and found it extremely challenging. Criticisms from Eysenck and Keane’s study (1990) come to add that the failure of inexperienced individuals to sleuth effectively is because of their little experience in the first place with this task and not because of observational system.
As it was  revealed ,  it is conceivable that the unattended memo can be examined and apprehended carefully, but participants are not unable to remember. Furthermore, later research comes to confirm that what was discussed previously has a significant effect.

Memory Phenomena

Memory phenomena in the literature are related to the encoding phase of acquisition. There are two well-supported models; the weapon focus and change blindness, and two more controversial; the own-race recognition which suggests that eyewitness only recognise people from their ethnicity and effect/bias and cross-gender identification which suggest that men recognise men, and women recognise only women. This paper will focus on the weapon focus effect through the relevant memory theory.

Weapon Focus

It is a well-supported model and can be explained entirely by theories of attention. The most relevant theory is Broadbent’s filter theory. The weapon focus effect is the propensity for eyewitnesses who watch a crime involving any weapon to coordinate their focus on that weapon consequently this leads them not be able to recollect the perpetrator’s appearance and characteristics as precisely as they would have if there were no weapon present to catch their attention. Weapon focus effect can negatively affect the investigation of a crime and cause significant problems to police who rely on witnesses’ statements as they attempt to identify a suspect. At the point where weapons are present, the eyewitness is going not going to have the capacity to remember the face of the offender nor his/her characteristics because all of his attention was drawn on the weapon. This is because weapons, knives, guns are not things that individuals see or intercut in their everyday life. Also fear and stress play a vital role here because they are objects that cause fear and stress to a person, making them think that are in danger for their life and not focusing on the face and characteristics of the suspect. Freud on one of his studies argued that tremendously painful or intimidating recollections are involuntary present at the unconscious mind leading to the fact that they eyewitnesses are unreliable as the memory of the crime is too traumatising. On a study that was conducted by Loftus et al. (1989), participants were presented with a series of pictures of a customer in an eatery. There were shown two different scenarios, in the first scenario the client has had a gun, and in the other scenario, the client carried a chequebook. Participants who viewed the gun scenario had their most attention on the gun.

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Consequently, it was less probable to identify the client in an identification procedure because they did not pay attention to client’s face or characteristics but on the gun, because it was the object that attracted their attention due to its nature. This again comes to suggest and agree with the theory of attention as mentioned earlier. Nevertheless, current data reports suggest the weapon focus effect is most likely not to impose an impact on eyewitness if they are well-informed negatively as this indicates that guns, knives, weapons etc. do not catch consideration beyond one’s control.


Various issues that can torment the reliability of eyewitness have been revealed by psychological research. They can take place during the three stages of memory; acquisition, retention, retrieval and affect the process leading to unreliability. Eyewitness testimony can be significantly unreliable as shown by the factors discussed in this paper in which an innocent person can be sent to prison because of a false conviction. Psychological systems all of these years should inform the criminal justice system which was not the case in the past. Nowadays, things started to change. There is a piece of the model, and a lot of it is based on Loftus work about how to question an individual during an interview. It is a method of questioning that aims to raise the accuracy of info recollected. Also, research helps to improve the structure of line-ups, and the increasing use of CCTV systems means that the high levels of the unreliability of eyewitness are expected to fall in the future. Having all these factors, it is essential for the criminal justice system to slightly and slowly taking a step forward, a change in structure for the better, govern the truth and seek justice with honesty in order to avoid wrongful convictions.


  • Broadbent, D. (1958). Perception and Communication. London: Pergamon Press.
  • Craik, F. I. M., & Lockhart, R. S. (1972). Levels of processing: A framework for memory research. Journal of Verbal Learning and Verbal Behavior, 11, 673–679.
  • Culter, B.L. & Pernod, S.D. (1995) Mistaken Identification: The eyewitnesspsychology, and the law. New York, NY: Cambridge University Press
  • Eysenck, M. W. & Keane, M. T. (1990). Cognitive psychology: a student’s handbook. Hove: Lawrence Erlbaum Associates Ltd.
  • Graham, M. H. (2003). Federal rules of evidence. St. Paul, MN: West Publishing Co.
  • Kebbell, M. R. and Milne, R. 1998. Police officers’ perception of eyewitness factors in forensic investigations. Journal of Social Psychology, 138
  • Laughery, K.R., Alexander, J.F., & Lane, A. B. (1971). Recognition of human faces: Effects of target exposure time, target position and type of photograph. Journal of Applied Psychology, 55, 477-482
  • Loftus, E. F., & Palmer, J. C. (1974). Reconstruction of automobile destruction: An example of the interaction between language and memory. Journal of Verbal Learning and Verbal Behavior, 13.
  • Loftus, E. F., Loftus, G. R., & Messo, J. (1987). Some facts about “weapon focus.” Law and Human Behavior, 11(1).
  • Loftus, E. (1996). Eyewitness testimony. Cambridge, MA: Harvard University Press.
  • Melton, A. W. (1963). Implications of short-term memory for a general theory of memory. Journal of Verbal Learning and Verbal Behavior, 2.
  • Moray, N. P. (1959). Attention in dichotic listening: Affective cues and the influence of instructions. Quarterly Journal of Experimental Psychology, 11.
  • National Institute of Justice //
  • Stern, L. W. 1910. ‘Abstracts of Lectures on the Psychology of Testimony’. American Journal of Psychology, 21.
  • Sternberg, R.J. (1999). Cognitive psychology (2nd ed.) Fort Worth, TX: Harcourt Brace Collages Publishers.
  • Tulving, E. (1991). Interview. Journal of Cognitive Neuroscience, 3.
  • Wells, G., Small, M., Penrod, S., Malpass, R., Fulero, SD., and Brimacombe, C. (1998) Eyewitness Identification Procedures: Recommendations for Lineups and Photospreads. Law and Human Behavior,22.
  • Whipple, G. M. The observer as a reporter: A survey of the psychology of testimony. Psychological Bulletin, 1909, 6.


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