Atkinson-Shiffrin Flashcards
Memory - definition
Memory: a storage system that retains images, concepts and knowledge when the stimuli which created it no longer exist in consciousness. It depends on three sequential processes: encoding, storage and retrieval It is essential to our identity: it connects our past experiences to the present and shapes our future by enabling us to adapt to daily changes in our environment.
Sequential process: encoding
o Encoding: the process of the brain converting information into a form (electrochemical code) that allows it to be stored in our memory; memory may be improved by improving quality and length of encoding
Sequential process: storage
o Storage: refers to retaining information in the brain so that we can use it later on whereby information is stored in an organised way to make it easier for us to recover memories when we need them (note that unlike a computer hard drive, human memories are not exact replicas of information but instead are rough copies).
Sequential process: retrieval
o Retrieval: the process of getting information back from our memory so that we can use it whereby it relies on using the right cues so that we can get to the correct location in our semantic network.
Atkinson-Shiffrin Multi-store model of memory
§ Multi-store model of memory: describes three distinct levels/stores of memory and the way in which they interact with each other (sensory, short-term and long-term memory)
§ Although these three levels of memory are separate, they function simultaneously and interact with one another to enable us to encode, store and retrieve information.
§ Information flows from the sensory memory to the short-term memory and then the long-term memory; it may also go from the sensory memory directly to the long-term memory or from the long-term memory to the short-term memory.
Atkinson-Shiffrin - sensory memory
§ Sensory memory: the store for incoming, brief sensory information that enters from the external environment.
§ Virtually unlimited capacity but a very brief duration (decays rapidly).
§ Most information that enters sensory memory is ignored, however if attended to, the information is then sent to STM for processing.
§ Although the duration is very brief, it is long enough for our brain to decide whether the incoming sensory input is important enough to be transferring to our STM.
Functions of sensory memory:
§ This store acts as a filter by not processing info it prevents us from being overwhelmed by large amounts of sensory input.
§ Its rapid decay enables us to process new information, to perceive the world as smooth and ongoing, and to hear sounds just long enough to understand the whole words and sentences.
Atkinson-Shiffrin - types of sensory memory
Iconic Memory: visual sensory memory with duration of 0.3 seconds and has unlimited capacity.
o The duration of the iconic memory allows us to perceive moving pictures from a series of still frames in that the image of each still frame is stored just long enough for it to be instantly replaced by the next frame.
Echoic Memory: auditory sensory memory with duration of 3-4 seconds and unlimited capacity.
o The 3-4 seconds duration is long enough for us to link individual sounds or syllables with the next syllable, and thus rather than hearing a jumble of unrelated sounds, we hear meaningful words and sentences.
Its short duration also acts as a filter because if the duration was longer, there would be too much overlapping of sounds.
Atkinson-Shiffrin - short term memory
§ Short-term memory: a temporary working memory area which receives information from the long-term store and sensory register, and is where information for everyday functions is manipulated.
§ Limited capacity of 7±2 pieces of information and a limited duration of approx. 12-30 secs.
§ When full, new information that enters STM pushes out old information.
Function of short-term memory:
§ Holds information in awareness for a short period of time, long enough to use for mental tasks.
Chunking Information
§ Chunking: combining smaller bits of information into larger single units and ultimately increasing the capacity of information in STM.
§ Example: for mobile numbers, we tend to group up the numbers in the pattern XXXX XXX XXX rather than remember each number individually.
Atkinson-Shiffrin - short term memory - maintenance rehearsal
§ Maintenance rehearsal: refers to repeating the information to increase the chances of retaining the information in STM; unless there is interference, this solves the problem of the limited duration of STM.
§ Does not add meaning to the information or relate it to other material within LTM and, when maintenance rehearsal stops, the information will be lost 12-30 seconds later.
§ However transfer to LTM can occur if repeated often enough.
Atkinson-Shiffrin - long term memory - elaboratice rehearsal
§ Elaborative rehearsal: the process of encoding whereby we give meaning to new information and link it with other information already in LTM (helps with LTM retention).
Forms of elaborative rehearsal:
§ Salience: personal relevance; mentally linking ourselves with the material being learnt.
Atkinson-Shiffrin - long term memory
§ Long-term memory (LTM): the relatively permanent memory system that holds vast amounts of information for long periods of time.
§ Information is encoded semantically and stored in semantic networks.
§ Virtually unlimited capacity and relatively permanent duration.
§ It is believed that what goes into LTM stays there and that ‘forgetting’ is a result of not being able to retrieve it due to poor retrieval cues.
Evidence to support Atkinson-Shiffrin
Serial position effect
§ Serial position effect: in immediate free recall, items at the beginning or end of a list are remembered better than those in the middle (it includes the primary and recency effect), providing evidence for the existence of separate LTM and STM stores.
o Free recall: recalling as much information as possible in any order, without cues.
§ The primacy effect (remembering those at the start of a list) is due to them being rehearsed more and transferred to LTM.
§ The recency effect (those at the end) is due to those items stored in STM.
§ Asymptote: the items in the middle were said too early for STM ([pushed out by new ifno) and too late for LTM (not enough time for them to be transferred to LTm before pushed out by new items)
Studies of patients with brain damage
- provided evidence for a difference between short term and long term memory
- patients with anterograde amnesia (hippocampus)
- remember info up to injury, carry out procedures learnt prior
- form new procedural memories (simple skill in ball game)
- unable to form declarative memories (explicit memories) for facts and events
Criticisms
- STM and LTM must interact for chunking: doesn’t adequately explain this
- doesn’t show why encoding changes between different memory stores
- others view it as a continuum
