What is Memory?

Memory is the section of the brain that controls and influences our ability to encode, store, retain and recall information. These functions enable us to learn from experiences and observation and adapt our behaviours and understanding. 

Each function of the memory is vital as every process is necessary for the brain to store memories, learn and influence our behaviour. Encoding begins the cycle of creating a new memory. As our senses perceive an environment/experience, encoding allows the information received to be understood and stored within our short term or long term memory (STM) or (LTM). Information received can be encoded in three main ways; Visual, Acoustic and Semantic. As emotion is recognized to increase attention, we are more likely to remember emotionally charged events over less-stimulating experiences.

Once information has been encoded, the process of a new memory continues into the second stage of memory known as ‘Storage’.  Storing refers to the process of new information received, being stored into our memory. Without strong rehearsal, information in the short-term memory decays if it is not stored in the LTM. When a new memory has been successfully encoded and stored into the LTM, the third stage of the process begins, this is called ‘Retrieval/Recall’ which refers to the ability to recover information from storage.

Multi-Store Model of Memory 450

The Multi-store model of memory (MSM) proposed by Atkinson and Shiffrin (1968), gives insight into how we store information that has been processed. The theory suggests that the brain has access too three distinct memory stores, known as the Sensory Memory, the STM and the LTM. 

The MSM states that the process of memory works in three stages through sensory information (sight, sound, smell, taste and touch).  The information received is stored in the Sensory Memory, at this stage, the information will either decay within a second or if given attention, will transfer into the STM. Due to the limited capacity believed to be 5-9 items of information in the STM, information with less priority will decay.

Once the information has transferred from the sensory memory into the STM, it will decay after 30 seconds if not rehearsed. Information stored in the STM is lost through either displacement or decay, as capacity is limited, and new information received can hold priority over old information, the new information can replace previous information stored. This is supported by Miller’s study (1956), Miller also proposed that our STM stores in ‘chunks’ rather than individual forms of information, such as numbers or letters.

When information stored in the STM is rehearsed, it is encoded into the LTM. The LTM has an unlimited duration and information can be retrieved by transferring information from the LTM into STM. This is supported by Bahrick et al. (1975), a study in which Bahrick explored the LTM. The Information can be recalled from the STM and transferred into the conscious mind.

The findings of this experiment enable researchers to further explore the STM and the MSM. Researchers such as Baddeley and Hitch who were able to develop the understanding of the STM. Using the research from this study, Baddeley and Hitch were able to structure the working model memory (WMM).

The theory has high face validity as it provides simple understanding of the structure of memory stores and how they are linked. The theory is applicable to daily life as it explains primacy and recency effects in memory, this is supported by the research done by Glanzer and Cunitz (1966), using the HM and KF case studies.

A criticism of the MSM is that it explains the memory process in basic form with little depth. The theory does not consider more than one type of LTM and does not account for when declarative LTM is damaged in anterograde amnesia patients. Baddeley and Hitch (1974) supports a more intricate STM, by explaining that it is composed through mutable memory stores and processes. Atkinson and Shiffrin originally explained rehearsal to be “maintenance rehearsal”, which was later suggested by Shiffrin that rehearsal is more complex, this is supported by Raaijmakers, and Shiffrin (2003).

Working Memory Model 350 words

The original Working Memory Model, developed by Baddeley and Hitch (1974), was created in order to further understand the process of memory in more detail than the Multi Store Model of Memory. The theory suggests that our memory is processed through four main components; The Central Executive, the Phonological Loop, the Visuo-Spatial Sketchpad and the Episodic Buffer

The Central Executive memory store, receives information from either our senses or the Long-Term Memory. Once the information has been received, the Central Executive store directs attention to specific tasks and information into one of three different memory stores. This is supported by research done at D’Esposito et al. Using MRI scans, researchers were able to see that the prefrontal cortex was activated when simultaneously performing verbal and spatial tasks, but not when performed separately.

When we receive acoustic information into our central executive store, it is transferred into the Phonological Loop. The Phonological Loop has two sections in which memory is processed; The Phonological Store and The Articulatory Process. The Phonological Store holds information in a “speech based” form and can briefly store acoustically encoded information. The Articulatory Process allows “inner voice” rehearsal of information stored in the phonological store.

When we receive visual information into our Central Executive store it is transferred into the Visuo-Spatial Sketchpad. It is responsible for storing visual information, mental planning and manipulating mental images. There are two sections to the Visuo-Spatial Sketchpad, the Visual Cache, which processes the storage of information and the Inner Scribe, which acts as a rehearsal mechanism.

As the Central Executive has no memory storage capacity, the Episodic Buffer works as a ‘general storage space’ to store different types of information. It has a limited capacity and communicates within the three stores and the Long-Term Memory.

Once information has been transferred from the Central Executive to one of the three stores, if the information holds enough precedence, it will transfer to the Long-Term Memory. The information can then be recalled if it does not decay, although some information can stay stored but cannot be retrieved.

The research from this experiment has developed the idea of the STM as suggested by the MSM and supports the theory that the STM is more elaborate with multiple storing processes. The WMM details the complexities of the process of memory in depth and

The model has high applicability and reliability as it has substantial experimental evidence and can account for things such as, verbal reasoning, problem-solving and visual and spatial processing. The KF Case Study supports the WMM as it gives evidence that there are separate STM components for visual and verbal information.

A criticism of the experiment is that it does not explain how people who have visual impairments or difficulties can have quality spatial awareness without visual information. Lieberman states that blind people have exceptional spatial awareness without any visual information.

Another area that could be developed further is the lack of evidence to support the central executive’s function. The WMM only explores research within the STM and does not describe in detail the process of LTM.

Theories of Forgetting

Trace Decay is a theory of forgetting that refers to the biological explanation for forgetting. It proposes the idea that when we make new memories and information is received in the short-term memory, this information leaves a psychological trace in the brain, this is due to the neurons being activated. This trace is known as an engram.

The theory suggests that individuals forget due to the automatic decay of the engram. The theory states that the timeframe for which information is held in the short-term memory if not rehearsed, is between 15 to 30 seconds. After this time, Trace decay occurs and the engram decays.

The theory argues that in order to be able to recall memories, we must rehearse them. This theory has limited ecological validity due to the fact that it gives insight into why we remember information better when it has a strong emotional correlation, but does not explain why we remember information that requires no conscious awareness in our procedural memory.

In 1959, Peterson and Peterson performed an experiment using the Brown and Peterson method. Using a similar technique, 24 participants were asked to recall trigrams presented to them after intervals of time, as the experiment progressed, the intervals increased in time. Retroactive interference was used as a method to prevent rehearsal. Participants had to count backwards from a random number given to them until they were signalled to stop. They found that as the time intervals increased, the ability to remember reduced. This experiment supports the trace decay as it provides reliable evidence for specific time-capacity in the short term memory. However, it could also be argued that trace decay occurs due to displacement, as the participants of the experiment were receiving new information in their short term memory, therefore displacing the trigrams.

Eye Witness Testimony and Misleading Questions 250 words

Eyewitness testimony is a type of evidence used in the legal court system that relies on the memory of an eyewitness.

The Loftus and Palmer study (1974) explores how misleading information influences eye witness testimony. There were two experiments performed that reviewed their hypothesis. The independent variable of the second experiment was the participle used and the dependent variable is what the participant believed they witnessed.

Loftus and Palmer wanted to see if an individual’s memory can be influenced by the interpretation of language. 150 participants were asked to watch a one-minute video which contained a short scene of a car accident, they were then split into three groups and two groups were asked a different leading question about what they had witnessed. The independent variable was influenced by the use of language in the question.

A week later the participants were asked to re-watch the film and recall what they had witnessed. The participants that had the word “smashed” in their leading question were more than twice as likely to recall witnessing broken glass, even though, there was no broken glass in the video. The results of this experiment support the theory that leading questions can influence eye witness testimony. There is low ecological validity to the study, as there are many factors that interfere with memory and recall that cannot be replicated in a testable environment.

The results from the Loftus and Palmer study are contradicted by the recorded research from the Yuelle and Cutshall study (1986), in which they unsuccessfully attempted to mislead participants. The Yuelle and Cutshall study is supported by Yerkes Dodson law (1908) as it can account for the influence of stress and recall accuracy.

Methodology 500 words

Aims

The purpose of the experiment was to see if misleading information can influence eye witness testimony. Due to the results reported in the Loftus and Palmer study (1974), I predict that the leading questions will influence the memory of the participants in this experiment. 

Design

An independent measures design has been used to conduct this experiment. There were two independent variables in this experiment; The experimental group which had leading questions and the observation of free recall for the control group. The Independent variable is how the participants memory could be influenced by leading questions, this was tested by the use of misleading information given to the experimental group, as an attempt influence their memory. 

An Opportunity Sampling technique was used to acquire 32 participants to take part in this experiment. The participants were of average health although 8 of the participants over the age of 30 had visual disadvantages requiring them to wear glasses, and 5 had hearing impairments that resulted in the need of a hearing aid. 

The 32 participants were randomly selected and split into two equal groups, the Free recall group (FR)and the Misleading Questions group (MQ).  which age ranged from 20 to 56+, 47% of the participants were male and 53% were female. Due to the nature of the experiment, the participants in the MQ group were unaware that they would be asked specifically leading questions when asked to take part, in order to ensure the results were not influenced.

Materials

The conditions of the experiment varied as the participants were tested during different times of the day and in different environments such as at their home and in college. The different environments provided an unpredictable outcome as there were many influential factors to the participants results.

The participants results were recorded through two different tables that tracked a ‘score’ based off the information they could recall. The table for the MQ group consisted of 10 misleading questions, and the table for the FR group concluded of a list of events that had occurred during the video. This method of collecting results was used as it was the most efficient and effective way to record clear results without interfering with the participants memory.

Procedure

The participants were split into two equal groups. The experiment lasted a total of two weeks, in the first week, the participants in the FR group were individually asked to watch a short video of a staged robbery. The video was viewed on either a mobile phone, iPad or laptop, and were asked to recall of what they had witnessed. The MQ group were tested in the second week, participants were asked to watch the same video in similar conditions, followed by a series of 10 misleading questions. Both groups recall accuracy was recorded on score sheets and compared. These results concluded the experiment by supporting the hypothesis that misleading information can affect eyewitness testimony.

Most effective misleading question

This table provides the overall results of the misleading questions in the experiment. The table shows that question 3 was the most-effective misleading question, the independent variable of this question was the noun “briefcase” which describes a different type of bag than the one recorded in the video. The table also records that question 8 was the least-effective misleading question, the independent variable of this question was also the noun “van” used which describes a different type of vehicle to the one shown in the video.

The misleading questions results show that the men were more likely to be influenced by misleading information.

The results show that participants between the ages of 31 and 40 in the MQ group had scored considerably lower than the participants aged 41 to 55.

The youngest and oldest participants in the Free Recall group scored the same results and, in the experiment, scored considerably higher that the participants aged between 31 and 55.

The Free Recall groups participants of male and female did not differentiate as the youngest and oldest participants had the same results.

Discussion(500/600 words)

The findings of the results support the aims, predications and hypothesis of this experiment. The recorded results suggest that misleading information can influence eyewitness testimony. The findings also provide evidence that within this experiment men were less-likely to be misled by leading questions.

The results from the Free Recall group support Millers theory of short term memory capacity (1956), as the most effective misleading question focuses on beginning of the video shown to the participants. The duration of the video is twice as long as the believed duration capacity in the short term memory of 30 seconds. This duration limitation creates a plausible correlation between the length of time of the video and what information could be recalled.

The Multi-store Model of Memory theory and theory of trace decay is supported by the results of this experiment. The scenes during the video clip produce a combination of visual and acoustic distractions, causing interreference within the memory. This interreference of the memory prevents the ability for the participant to rehearse information and therefore, previously stored information is continuously replaced with new information and is displaced. The results from both groups support the Peterson and Peterson theory of displacement (1959).

A main factor of limitation within the experiment is the sampling technique used. An opportunity sampling technique was used in order to gain participants for the experiment, this proposed a challenge in reference to choosing participants that would be good representatives. Another major influential factor is the conditions, due to the nature of the experiment, it was not realistic to perform the tests in the same location during the same time of the day for each participant. This resulted in a variety of environments and devices (in which the participants viewed the video on) being used. The different conditions may have created unintentional disadvantages or advantages that could have affected the participants visual interpretation and memory.

The participants age is a considerable limitation in this experiment as research suggests that the ability to remember weakens as individuals age. This theory is not however, reflected in the results from this experiment. The recorded results from the FR group show that participants aged 20 to 30 had scored the same percentage as those aged 55 and over, and the participants in the MQ group aged 41 and over had scored 40% more than those aged 20 to 30. Both results show that the participants between the ages of 31 and 55 in the MQ group and 31 to 40 in the FR group had scored considerably lower.

An additional limitation in the experiment is the probable bias of memory in reference to what information is prioritized within the participants memory when watching the video. This bias supports the Yerkes-Dodson Law theory (1908), as it suggests that level of arousal can improve or impair performance, presenting a correlation between memory and recall ability. Due to the nature of the video shown, participants may have become somewhat distressed, therefore, able to recall less or more information. Another influencing factor to consider that can be attributed to which information could be recalled is weapon focus, as 3 guns were shown and 1 gun was used during the video. The Loftus et al. (1987) weapon focus theory is supported by the results of this experiment.

There were two main extraneous variables in this experiment in which 40.6% of the participants had either visual or hearing impartments. This could have influenced the participants ability to priorities focus and recognize certain information within the video and inevitably influencing their recall ability.

To improve the conditions of the environment and method in which the video was shown, the location and time during the day in which every participant is tested should be the same, as this would predictably increase the fairness of the results recorded. A more successful sampling technique for this experiment would be Cluster Sampling, as it offers a better insight into the background of the participant. This sampling method would clearly distinguish which participants would be better suited for either group. Although we had details of the participants that included age and gender, some participants may have been less susceptible to misleading information or aware of the cognitive interview technique and therefore the results may become bias.

Due to the nature of the video, it was predicted that the participants would become slightly distressed. This stimulation may have increased or reduced their assertiveness. To ensure a fair advantage between participants, prior research in reference to the influence of stress and recall ability of the participants would conclude in the ability to measure how the stimulation caused by the video effects the participant’s results. An influential factor that could attribute as a disadvantage to the results are the extraneous variables, in which some participants had hearing and visual impairments. Ensuring that each participant is of equal health would create opportunity for more accurate results.

The results from this experiment record that the FR group had a better score than the MQ. This supports the experiments hypothesis and suggests that the cognitive interview technique has high validity in which misleading information can affect eyewitness testimony.

The results from this experiment suggest that the cognitive interviewing technique is a successful method in which to gain information from an eyewitness. Our results show that although misleading information can identify when an eyewitness is giving correct information, it can create unpredictable results and have a negative influence on the information given. Due to the sampling method, the results were unpredictable. This concluded in there being limited background knowledge of the participants within the experiment. Therefore, only impartial methods and results were used and recorded.

Sources;

Verywell Mind. Kendra Cherry. (2018) How Information Retrieval From Memory Works. [Online] Available from: https://www.verywellmind.com/memory-retrieval-2795007

–          Thepeakperformancecentercom. 2018. Thepeakperformancecentercom. [Online]. [5 December 2018]. Available from: http://thepeakperformancecenter.com/educational-learning/learning/memory/classification-of-memory/memory-process/

–          Psychologywizardnet. 2018. PSYCHOLOGY WIZARD. [Online]. [5 December 2018]. Available from: http://www.psychologywizard.net/multi-store-model-ao1-ao2-ao3.html