MEMORY

• Memory


  The retention of what we learn and experience
• Atkinson and Shiffrin (1968) - Multi-store Model of Memory

  • Sensory Register
  • Short-term Memory
  • Long-term Memory
  • Consolidation
  • Retrieval
• Sensory Register


  Encodes items as they are received. Duration lasts for ¼ of a second for visual information and 4 seconds for anything auditory. It has the capacity to hold all sensory experiences.
• Iconic Memory


  Visual sensory memory
• Echoic Memory


  Auditory sensory memory
• Crowder (1993) found that the sensory register only retains information for a few milliseconds, but holds onto echoic memory for two to three seconds
• The sensory register is not under cognitive control, it is an automatic response to the reception of sensory data by the sensory organs, it is the first storage system within the Multi-store Model
• Sperling (1960) explored the sensory register by flashing up a 3x3 grid of letters, indicated by either a high, mid or low tone. Recall of letters was found to be very high, indicating the capacity of the sensory register to also be fairly high
• Short-Term Memory


  Encodes mainly acoustic information. Duration lasts between 18-30 seconds. The capacity is 7±2 items, however this can be increased by chunking.
• Baddeley (1966) found evidence to show that information in the Short-Term Memory can be coded for semantically, acoustically or visually, but that the main encoding system is acoustic
• Baddeley concluded that coding for the Short-Term Memory is mainly acoustic as the acoustically similar items caused confusion
• Chunking


  Grouping items into separate chunks, with each chunk constituting to a single item
• Jacobs (1887) developed the digit span technique to measure the capacity of the Short-Term Memory. The researchers gave participants four digits then asked them to recall them in the correct order, increasing the number of digits each time. They found that digit span was around 9.3 for digits and 7.3 for letters
• Peterson and Peterson - Participants learn a list of trigrams then count back from a three digit number to prevent rehearsal. The duration is found to be 18-30 seconds
• Long-Term Memory


  Encodes mostly semantic information (based on meaning.) The duration a lifetime and capacity is unlimited.
• Bahrick (1975) looked at 392 participants from Ohio aged 17-74. They obtained their high school yearbooks and they tested recall in several ways, photo-recognition and free recall of names. Those who were tested within 15 years of graduation were around 90% accurate in photo recognition. After 48 years, recall declined to around 70%. Free recall was not as good, after 15 years this was around 60% dropping to 30% after 48 years
• Murdock's Primacy and Recency Effect


  • Primacy= The person has enough time to rehearse the words so they enter the Long-Term Memory
  • Recency= The words near the end are still present in the Short-Term Memory
  • Asymptote= These words have been present too long to be found in the Short-Term Memory but not long enough to have been rehearsed into the Long-Term Memory
• HM suffered from severe epilepsy and in an attempt to solve this, Scoville removed his hippocampus, resulting in the loss of his Long-Term Memory. However, HM's Short-Term Memory remained in tact, suggesting that the Long-Term Memory and Short-Term Memory are two separate memory stores. His Long-Term Memory of events that occurred before the surgery and his Short-Term Memory remained in working order but he was unable to form new long term memories, also highlighting the importance of consolidation
• KF suffered brain damage following a motorcycle crash and underwent brain surgery as a result. He was able to store new Long-Term Memory memories, despite his Short-Term Memory being damaged, refuting the claims of the Multi-store Model that memory processing and storing occurs sequentially, travelling from the Short-Term Memory to the Long-Term Memory. KF's visual Short-Term Memory also remained in tact whilst his verbal Short-Term Memory did not, suggesting that Short-Term Memory is not a unitary store as the Multi-store Model suggests
• Alcoholics can develop Korsakov's syndrome, in which they forget all new material and are unable to transfer information from the Short-Term Memory to the Long-Term Memory, supporting the notion of separate stores. They also have issues with the consolidation of information from the Short-Term Memory to the Long-Term Memory
• Flashbulb memories are highly significant memories of emotional/traumatic events. These contradict the Multi-store Model as they appear to travel directly to the Long-Term Memory without the need to be rehearsed
• The Multi-store Model places an overemphasis on rehearsal, whilst it is important, in everyday life we rarely rehearse information, yet have we are able to remember many things
• The Multi-store Model oversimplifies the Short-Term Memory and Long-Term Memory with the view that the structures operate in a single unitary fashion
• Baddeley and Hitch - Working Memory Model

  • Central Executive
  • Episodic Buffer
  • Visuo-Spatial Sketchpad
  • Phonological Loop
• Baddeley et al. (1975) carried out a dual-task performance study to see if performance was affected when participants were asked to carry out two tasks that used the same sub-system of the working memory. Participants were asked to track a light and describe the shape of the letter F- two visual tasks and a visual and verbal task at the same time. They had far more difficulty with the two visual tasks than the verbal and visual task. This shows that both visual tasks compete for the same sub-system whilst this is not the case with a visual and verbal task. There must be a separate sub-system to process visual input
• Paulesu (1993) PET scan monitor blood flow and did two tasks - Task one measured inner voice and inner ear, task 2 measured only inner voice. They found different areas of the brain associated with the two tasks supporting the Working Memory Model
• The concept and explanation of the Central Executive in the Working Memory Model remains vague
• Edinburgh University found evidence against the Visuo-Spatial Sketchpad when studying blind people they were still able to do spatial tasks which suggest visual and spatial stores should be separate
• Episodic Memory


  Memory of personal events. It stores personal experiences or specific events which are usually associated with a time and place
• Semantic Memory


  This store contains our knowledge of the world. Semantic Long-Term Memory and episodic are both types of explicit memory, meaning the memories require conscious recollection. These memories are not time stamped, it is less personal, and more factual.
• Procedural Memory


  This is also known as 'muscle memory' it is memory for actions or skills, such as riding bikes and brushing your teeth. These memories are only consciously recalled during the early stages of learning, they are implicit memories which require no conscious effort to recall.
• Tulving (1989)- Injected radioactive gold into participants and got them to think about semantic memories or episodic memories. Scanners monitored blood flow in areas of the brain. The two different memory tasks showed distinct patterns of blood flow, episodic memories involved increased blood flow in the front of the brain whilst in semantic memories blood flow increased towards the back of the brain. This suggests a biological basis to differences in Long-Term Memory
• HM- His episodic and semantic memory was affected following the removal of his hippocampus, however his procedural memory remained intact. (He could draw a star when looking in a mirror and improved over time.) This shows that as the cerebellum was not affected by the surgery, it must be concerned with the procedural memory whilst the hippocampus is involved with explicit memory. It also supports the idea that the Long-Term Memory is not unitary
• Clive Wearing- Suffered from a rare brain infection that left him with a moment-to-moment memory due to the damage to his hippocampus. His declarative knowledge was that he could not play the piano, however, when he was placed in front of a piano, he could play very well as a result of his procedural memory
• Cohen and Squire (1980) argued that Tulving's division of Long-Term Memory was wrong and that whilst procedural memory is one type, explicit memory should remain in one store as opposed to being split into episodic and semantic memory
• Tulving et al. (1994) used a PET scanner to monitor participants carrying out various memory tasks. They found episodic and semantic memories were recalled from the right and left hemisphere of the prefrontal cortex respectively. This supports the idea of a physical reality to the different types of Long-Term Memory and has been supported in many later research studies, further supporting the validity
• Belleville et al. (2006) showed that episodic memory could be improved in elderly people with signs of mild cognitive impairment. Trained participants performed better on a memory test than a control group. Being able to distinguish between the types of Long-Term Memory has enabled us to see that episodic memory is the most often affected by mild cognitive impairment, enabling specific treatments to be developed
• Interference


  Where two pieces of information conflict with each other, resulting in the forgetting of one or both, or in some distortion of memory. It explains forgetting mainly in the Long-Term Memory.
• Retroactive interference


  This happens when a newer memory interferes with an older one
• Proactive interference


  Occurs when an older memory interferes with a newer one