Memory and Information Processing

Input – Sensory information in the environment

Encoding – Turning sensory information in to a form that can be stored

Acoustic Encoding – Storing sounds in memory

Visual Encoding – Storing visual information

Semantic Encoding – Storing meaningful information

Output – Recalling information (e.g.: behavioural response)

STM – Input first enters the STM store (temporary store) where it lasts for around 18 seconds. The STM holds about 7 items of information and encodes information acoustically through repetition of information. If information is rehearsed, it can be transferred to the LTM (evidence for Daniel Willingham’s learning theory).

LTM – Encoding in LTM is mainly semantic but can also be visual or acoustic. The LTM can potentially hold unlimited amounts of information and can last for minutes or up to an entire lifetime.

Information in our STM can be forgotten through displacement (when STM becomes “full” and new information pushes out older information. In LTM, memory can decay if the memory trace hasn’t been used for a long time or may be overwritten by new information (interference).

Richard Atkinson and Richard Shiffrin (1968) MSM

The multi-store model of memory consists of the sensory register, STM and LTM. The sensory register is the store that receives all of the sensory information around us and holds it very briefly. If we pay attention to some of this sensory information, it is transferred into our STM but if we do not focus on it then it decays.

Types of sensory registers: iconic memory – for visual information; echoic memory – for auditory information; gustatory memory – for information about taste; olfactory memory – for information about smell; and tactile memory – for information about touch and texture.

STM – Information in the STM store lasts for 15-30 seconds but can be longer if rehearsed. The STM is modality free (doesn’t store only a particular type of sensory information). George Miller (1956) found that the avg. STM can hold between 5-9 chunks (groups) of memory.

LTM – Potentially unlimited information can last indefinitely in an LTM store. The LTM is thought to be organized according to meaning (semantically).

Strengths –

  • Has Support – Case studies of patients with brain damage and amnesia shows distinct separate STM and LTM stores
  • Ben Murdock (1962) serial position effect supports theory

Weaknesses –

  • Overstates role of rehearsal as not all pieces of information need to be rehearsed and could just be meaningful
  • Cases of patients with amnesia have more than one type of LTM (e.g.: Clive Wearing)

Ben Murdock (1962) found that there is a tendency to recall more words at the beginning (primacy) and end (recency) of a list as words at the beginning have been rehearsed often so are transferred into the LTM whereas those at the end are still in the STM.

Clive Wearing impaired his memory that stored personal events but other parts of his memory were intact such as his memory of how to play the piano suggesting the existence of more than one type of LTM store.

Lloyd Peterson and Margaret Peterson (1959) Short-term Retention of Individual Verbal Items

Background – By rehearsing, we can store information in out STM. They could test this only by interfering with the rehearsal process. To prevent participants from rehearsing, the Petersons got them to count backwards in threes.

Aim – To test the true duration of the STM

Procedure –

Experiment 1

  • 24 students
  • Had to repeat trigram (three consonants) out loud (e.g.: LTG, NPF, BZL)
  • Immediately had to count backwards in 3s or 4s from any 3-digit number said by the experimenter
  • When signalled by a red light the student had to recall the trigram
  • Each student read aloud 8 times with time delays of 3, 6, 9, 12, 15 & 18 seconds
  • The procedure was repeated 48 times using different trigrams.

Experiment 2

  • Same tasks but participants were given time to repeat the trigram before counting

Results –

Experiment 1

  • The longer each student counted backwards, the less able they were to accurately recall the trigram.
  • 80% correctly recalled trigrams after 3 second. Less than 10% accurate recall after 18 seconds

Experiment 2

  • The extra time increased the frequency to recall.
  • However, they showed a similar decline over time.

Conclusions – Information in our STM fades rapidly and only 10% can be recalled after 18 seconds if not rehearsed

Strengths –

  • The study used fixed timings when they counted backwards and lack of extraneous variables such as noise which could affect memory, making study scientific due to standardized procedures
  • The study helps us in real life as it suggests you should revise in small chunks and take precaution to avoid distraction as they can affect retention

Weaknesses –

  • The study lacks mundane realism (realistic, every day task).

Understanding Amnesia

Amnesia – Memory loss (often through disease, accident or injury)

Anterograde Amnesia – Memory condition where new long-term memories can’t be made. Patients have an intact short-term memory but their ability to transfer information from short term to long term memory is damaged.

Retrograde Amnesia – Memory condition affecting recall of memories prior to an injury to the brain. It may be limited to only the traumatic incident or a certain time frame but patients may even forget who they are and where they come from.

Henry Molaison underwent brain surgery to relieve himself from seizures associated with epilepsy. His hippocampus was damaged resulting in him suffering from both types of amnesia – he could only recall childhood memories but not his experiences of a few years before surgery.

Frederic Bartlett (1932) Theory of Reconstructive Memory

Bartlett proposed that memories are not stored as an exact form as in a computer but are brief outlines, which recalled are elaborated by a person’s general knowledge about similar events and the memories go through active reconstruction. Active reconstruction means that our memories are not exact copies but are influenced by our prior knowledge and our expectations known as schemas. Schemas are built through personal experiences, culture and stereotypes and influence memory by –

  • Omissions – Leave out unpleasant or irrelevant detail
  • Transformations – We change details to align to our own schema
  • Familiarisation – Details are changed to make them suitable
  • Rationalisation – We add in details to fit our schemas

Strengths –

  • Real-world practical applications such as helping us understand why memory can get distorted and allows the police to use cognitive interviews (designed to ensure that the witness does not actively reconstruct an event and avoids omissions and transformations)
  • Conducted research using stories and images which is a realistic view of memory and therefore his theory is ecologically valid.

Weaknesses –

  • As he analysed all his findings himself, his research may be subjective.
  • He was more interested in each participants’ memories rather than the use of standardized procedures and controls.

Bartlett’s (1932) War of The Ghosts

Background – Bartlett used folk stories to test his theories out. The story used to test reconstruction and schema theory was known as the ‘War of Ghosts’ and was unfamiliar to the participants (from Cambridge University) as it would cause them to rely on their schemas to recall it.

Aim – To test the nature of reconstructive memory using an unfamiliar story by looking at whether personal schemas influence the remembrance and retelling of a story

Procedure –

  • Participants read the story of the WOG twice.
  • They then had to recall the story using serial reproduction and repeated reproduction.
    • Serial Reproduction – A technique where participants retell storied to each other to form a chain.
    • Repeated Reproduction: Where participants retell a story over and over again
  • Serial reproduction – retell it 15-30 mins later.
  • Repeated reproduction – write out the story 15 mins later, recall it after minutes, days, hours, months and years.

Results – Bartlett used qualitative analysis. For both types of recall, participants were found making changes and connections (rationalisation). E.g.: ‘something black came out of his mouth’ to ‘a man’s dying breath.’ Also, omissions were made if the details were unfamiliar or they were simplified. ‘E.g.: canoe’ to ‘boat’ and ‘hunting’ to ‘fishing’. For repeated reproduction, the rewrites tended to follow a similar form or the outline of the first reproduction

Conclusions – Participants did not recall accurately but were influenced by schemas and altered details to fit their schema which was evidence for the active and constructive nature of memory.

Strengths –

  • Remembering a story is an everyday test of memory
  • The study was replicated and the same results were found using various studies
  • Results were gathered using qualitative analysis

Weaknesses –

  • The story was not familiar, illogical and contained strange words
  • Results were gathered using qualitative analysis
  • Participants read the story at their own pace and recalled their version after different timed intervals so there was a lack of standardized procedures

Reductionism and Holism

Reductionism – Theory of explaining something according to its basic constituent parts. It is associated with scientific methods where factors affecting behaviour can be isolated and controlled. It is a desirable scientific practise but results can be overly simplistic as other causes may be ignored (e.g.: Explaining aggression as an inherited trait due to a gene causes other factors – like upbringing or the interaction between the aggression gene and other influences – to be ignored).

Holism – Theory of explaining something as a whole. Associated with qualitative methods to gain greater insight into the causes of behaviour in a person. It is regarded as unscientific and can be difficult to achieve. The findings apply only to a particular individual and aren’t generalizable.

Atkinson and Shiffrin’s Multi-store Model of Memory is reductionist as it describes memory in parts with specific functions. Bartlett’s work is holistic as he used qualitative analysis and spent considerable time establishing the character and background of his participants to understand how their schemas were formed.