memory

• Multi Store Model of Memory

  Atkinson and Shiffrin proposed the MSM. It is a structural model wherein memory flows in a linear way. It consists of the sensory register, short-term memory (STM) and long-term memory (LTM) which are all separate unitary stores.
• Information flow in the MSM

  1. Stimulus from environment passes into sensory register

  2. Information then passes into the STM if attention is paid to it

  3. If maintenance rehearsal occurs, information passes into the LTM
• Short-term memory (STM)


  • Limited store that codes acoustically with a capacity of 5-9 items and a duration of 18-30 seconds unless it is rehearsed
  • Maintenance rehearsal increases the duration of time information can be held in STM
• Long-term memory (LTM)


  • Potentially permanent store for information that's been rehearsed for a prolonged time
  • Codes semantically and capacity is believed to last a lifetime
  • To recall information it must be transferred from LTM to STM (retrieval)
• Tulving's model of Long-Term Memory (LTM)


  • Procedural memory - stores information about how to do things (non-declarative)
  • Semantic memory - stores knowledge about the world (declarative)
  • Episodic memory - stores events in our lives at a specific time (declarative)
• Case study on patient KF

  Supports the WMM as it suggests there are separate stores in STM, one to process visual information and one to process auditory information
• The WMM has low population validity as it is based on a case study of a single individual with a unique brain damage
• Leading question


  A question that wrongly implies something about an event or crime
• Loftus and Palmer's study


  Shows that the phrasing of a question influences participants' memory of an event
• The Loftus and Palmer study lacks mundane realism as it used an artificial task of watching a video of a car crash, making it difficult to generalise the findings to real-life eyewitness situations
• Yerkes-Dodson law


  Proposes that the relationship between anxiety and the accuracy of eyewitness testimony is not a simple one, as different levels of anxiety affect accuracy differently. Too little or too high anxiety would result in poor recall, but an optimum level of anxiety would result in higher accuracy.
• Kohnken et al.'s meta-analysis


  Found that the cognitive interview technique increased the amount of correct information recalled by 41% compared to the standard interview, suggesting it is an effective technique for improving the accuracy of eyewitness testimony
• The cognitive interview technique also increased the amount of incorrect information recalled by 61%, which is a weakness as it could lead to false positives and wasted police time, reducing the effectiveness of the technique
• Not all techniques used in the cognitive interview are equally effective, as Milne and Bull found that only certain aspects, such as report everything and context reinstatement, produced better recall than the standard interview
• miller's research capacity STM


  he used the digit span technique, gave ppts a string of unrelated digits which increased by one each time the ppts recalled the sequence correctly. the digit span was measured until ppts could no longer recall. found that capacity was (limited) 5-9 items and that capacity of memory could be increased if information was placed in meaningful chunks.
• retrieval failure due to absence of cues

  forgetting occurs when info is in LTM but can't be accessed due to lack of memory cues !
• context dependent forgetting

  forgetting occurs due to lack of external cues to trigger recall ,, bc environment is different at recall when info was coded = forgetting is more likely. eg!! may forget info learnt when sitting in classroom to when they sit in exam hall.
• state dependent forgetting

  lack of internal cues to trigger recall ,, bc person's internal physical/emotional state is different at recall to when info was coded = forgetting more likely. eg!! forget a dance routine on stage bc they may have been calm when learning but is anxious on stage.
• RTS CONTEXT DEPENDENT FORGETTING

  godden + baddeley ,, scuba divers given list of words to learn either on land/under water ,, then asked to recall list in either same setting or opposite ,, found that ppts were more likely to forget words 40% accuracy when tested in opposite location to where they'd learnt the words. = suggests that due to lack of external memory cues forgetting more likely !
• what did baddeley argue ab context dependent :(

  he stated that context effects are not very strong. contexts must be very different b4 an effect is seen. eg it is very difficult to find an environment as different from land as under water. in contrast = learning info in one room and recalling in another is unlikely to result in forgetting bc environment are generally not different enough. therefore ! RF due to lack of contextual cues may not actually explain much forgetting in everyday life.
• RTS NEGATIVE EFFECTS OF ANX ON EWT

  valentine + mesuit ,, used objective measures such as heart rate to divide ppts in 2 groups of either high/low anx. ppts had taken part in london dungeon labrinth. asked to immediately recall physical details about actor. found that high anx lowered accuracy of ewt significantly = high levels do have neg effect of immediate eye-witness recall of stressful event.
• cognitive interview intro

  developed by FISHER + GEISELMAN. used by police to witnesses after they've seen a crime 2 gain most accurate and detailed memory possible. use open questions where witness isn't interrupted and can expand on answers.
• cognitive interview ao1

  1 - recall everything = asked to report all details of event even if it seems irrelevant. improves EWT as it acts as a trigger to recall events.

  2 - context reinstatement = witness asked to mentally place themselves back at event and imagine environment eg emotions. improves EWT as using context + state dependent cues may help to trigger memories that are stored in the LTM so appear forgotten but not easily accessible due to retrieval failure

  3 - recall in reverse = report everything that happened in diff chronological order (end 2 start). improves EWT as prevents witness from schema (stating what they expect to happen) + prevents dishonesty as harder to lie.

  4 - recall from changed perspective = recall events from another person's pov. improves EWT as prevents from reporting what they expect to happen rather than what acc happened.
• RTS cog interview

  KOHNKEN = used meta analysis of 50 studies comparing cog interview and standard interview. reported that cog had increase of 41% in correct info compared to standard interview = therefore effective bc helps witnesses recall info that's stored in memory but not easily accessible.
• KOHNKEN RTS..


  effectiveness of cog interview
• however what did kohnken :( ab cog interview

  although more information is recalled compared to standard interview (81%), often more incorrect items are recalled with a 61% increase of incorrect info recalled in cog interview compared to standard interview. called false positives. weakness bc if the info is incorrect despite recalling more it could lead to false imprisonments + wasting police time. = reduces effectiveness.
• weakness of cog interview :(

  MILNE + BULL = found that not all techniques in cog interview are equally as effective. each of 4 techniques used alone produced more info than standard interview. but also found that using combo of report everything + context reinstatement produced better recall than others. weakness as only certain aspects are useful in producing accurate recall.
• Yerkes-Dodson Law proposes that anxiety+ EWT accuracy is not a simple relationship. Diff levels of anx affect EWT accuracy. Too little or too much anx results in poor EWT recall but reach optimum level of anxiety = accuracy of EWT high, explains the differences in findings between J+S and C+H research. may be suggested that ppts in C+H's study were at optimum level of anx, resulted more accurate EWT. Whereas ppts in J+S study may have not been as anxious due to experiment resulting in less accurate EWT. Therefore resolves contradiction
• RTC j+s Christianson& Hubinette interviewed 58 real life witnesses of bank robbery - some directly threatened (bank teller - high anx) and bystanders(customers – low anx). found that recall more than 75% accurate across all witnesses, but those directly threatened had even more accurate accounts. contradicts bc compared to real life cases of those who had high anxiety, they were able to focus on key aspects of the event and were successful in the perpetrator being caught.
• Anxiety is a strong emotional and physical state that affects EWT
• Extreme anxiety has been found to negatively affect EWT as witnesses only focus on certain aspects of the event so their recall is limited
• anxiety Johnson and Scott lab exp. all ppts told to stand outside room b4 experiment began. high anx cond= sound of argument glass breaking + man walked out w knife w blood. low anx= sound of argument+ man walk out w pen and grease on hand. ppts had 2 identify man out of 50 pics. found low anx 49% identified man + high anx 33%
• RTS post event discussion. Skagerberg and Wright showed ppts 2 versions clip of mugging, 1 = mugger’s hair dark brown + 2 = mugger’s hair light brown. ppts discussed clips in pairs, each saw different versions. found that often didn't report what they'd heard from co-witness, but ‘blend’ of the two suggesting mugger had ‘medium brown hair’ rather than dark or light. Therefore, this supports BECAUSE it supports that memory contamination during post-event discussion does occur, distorting the witness’ EWT rather than just conforming to their co-witness’ response.
• research on post even discussion affected by demand characteristics. because research conducted in controlled environment (lab) w unrealistic tasks eg watching video clips of crimes. Research has found that ppts want 2 be helpful + not let researcher down, so possible that ppts from research are able to pick up on clues from task and experimenter= change their responses to fit aims of research. Eg-changing response to match co-witness after discussing the clip. lowers the internal validity of research as effects of discussing a crime on the accuracy of EWT are not being accurately measured.
• Memory contamination: When co-witnesses to a crime discuss it with each other their EWT may become altered or distorted. This is because they combine (mis)information from other witnesses with their own memories suggesting that their memories of the event have changed because of post event discussion
• Memory conformity: Witnesses go along with each other either to win social approval (NSI) or because they believe the other witness is right and they are wrong (ISI). However, unlike with memory contamination, the memory remains unchanged, but the accuracy of recall has been affected.
• strength of research on leading questions on accuracy of EWT =practical applications. principles of theory that LQ can influence accuracy of EWT led to improvements in criminal justice system+ development of cog interview. cog interview avoids use of LQ + uses variety of techniques 2 increase EWT accuracy. Eg uses open questions =“recall everything ab event” 2 trigger as many details about the event + increase accuracy of EWT without being affected by misleading info. important part of applied psychology BC could lead 2 more accurate testimonies +improve lives of people affected by crime.
• LQ affects the accuracy of EWT as the information that is implied in the question contaminates the witness’ memory and therefore witnesses recall inaccurate information.
• Loftus and Palmer. investigate whether the phrasing of a question can affect participants’ memory of an event. Lab exp. 45 American students (split into 5 groups of 9). participants were shown a video of a car crash and each group was asked a leading question with a different verb. Smashed, hit, collided, bumped, or contacted. “How fast were the cars travelling when they ****** each other?”. speed estimates in MPH. participants guessed a higher mean speed when they had ‘smashed’ (40.5mph) compared to contacted (31.8mph).
• stimulus from the environment (eg sound of someone’s name) will pass into sensory register = several stores (one for each of 5 senses) and coding in each store - modality specific. two main stores are echoic (auditory info – coded acoustically) +iconic (visual info. coded visually) Info in sensory register duration of less than a second. The capacity of the sensory register is high.