IBP: Introduction to cognitive psychology

Chapter 6: Long-term memory

Long-term memory:  the mechanism which enables us to store information and experiences in a lasting fashion, for possible retrieval at some point in the future.

Memory process:

1. Input stage: where newly perceived information is being learned or encoded
2. Storage stage: where the information is held in preparation for some future occasion
3. Output stage: where the information is retrieved from storage

The first memory experiments:

• Ebbinghaus and the forgetting curve: a list of non-sense syllables would be learned, and then retested after a certain retention interval, where scores were plotted as a ’forgetting curve’
  • Forgetting curve: memories tend to dissipate over a period of time
• Interference and decay: theories on why memories dissipate over time
  • Decay: memories fade away with the passage of time, regardless of other input.
  • Interference: memories are actively disrupted by the influence of some other inpu
  • Retroactive interference: memory scores for the learning of one list are considerably reduced by the subsequent learning of a second list.
• ‘Decay with disuse’ theory: Thorndike suggested that decay only affects memory traces which remain unused for a long period
• Retrieval-induced forgetting: there may be inhibitory mechanisms at work in the brain, which actively suppress unretrieved memories

Meaning, knowledge and schemas:

• Bartlett’s schema theory: we perceive and encode information into our memories in terms of our past experience
  • Eyewitness testimony for a crime or accident can be distorted by subsequent events as well as by previous knowledge
• Scripts (a form of schemas): provide us with a general framework and help us understand events and the behavior of others
• Mnemonic: a technique or strategy used for improving the memorability of items, e.g. by adding meaningful associations

Input processing and encoding

• Levels of processing theory: the processing of new perceptual input involves the extraction of information at a series of levels of increasing depth of analysis, with more information being extracted at each new level
• An orienting task: essentially a set of instructions which are intended to direct the subject towards a certain type of processing
  • Example: Acoustic    orienting    task: “does this word rhyme with bat?”
  • Semantic orienting task: does this word fit the sentence “the cat sat on the…”
  • Structural orienting task: “Is the word in block capitals?”
• Revised levels of processing theory: structural, acoustic and semantic forms of processing are assumed to take place simultaneously and in parallel rather than in sequence
• Elaborative and maintenance rehearsal:
  • Rehearsal is commonly employed as a method of retaining a piece of information
  • Elaborative rehearsal: the formation of associative connections with other memory traces, and this occurs most effectively where meaningful associations can be found (t assists relational processing)
  • Maintenance rehearsal: input is merely repeated without further processing (assists item-specific processing)

Retrieval and retrieval cues

• Two main ways of testing retrieval: recall and recognition
• In recognition test, the original test material is presented again at the retrieval stage, whereas in a recall test they are not
• Spontaneous recall: requires the generation of items from memory without any help
•  Cued recall: retrieval cues are provided to remind us of the items to be recalled
•  Recognition: the original test items are re-presented at the retrieval stage
• Generate and recognize theory: explains that recall and recognition are fundamentally different processes, and that recall involves an extra stage – so recall is more difficult than recognition
• Retrieval success is closely related to the number and quality of retrieval cues available
• Encoding specificity principle: retrieval cues will only be successful if they contain some of the same specific information which was encoded with the original input
  • memories are more easily retrieved if external conditions at the time of retrieval are similar to those that existed when the memory was stored
• Chance of retrieving a memory trace depends on the amount of feature overlap between input and retrieval information, which is the extent to which features of the trace stored at input match those available at retrieval
• Transfer-appropriate processing: the most effective type of input processing will be whatever offers the closest match with the available retrieval cues
• Context-dependent memory: revisiting or reinstating an earlier context serves as a retrieval cue
• State-dependent memory: retrieval can be assisted by the reinstatement of a particular mental state at retrieval which was also present at the learning stage
• Memory can be mood-dependent too

Memory systems

• Tulving: Long-term memory contains separate memory systems
  • Episodic memory: our memory for events and episodes in our own lives
  • Semantic memory: our general knowledge store
• Mandler: recognition involves two different retrieval processes
  • Familiarity: deciding whether or not an item has ever been encountered before (controlled)
  •  Recollection: when and where the item was encountered (automatic)
• Explicit memory: conscious memory
• Implicit memory: unconscious memory, whose influence can be detected by some indirect test of task performance

Retrieval practice and retrieval inhibition

• Testing effect: actively testing a memory improves its subsequent retrievability
• New theory of disuse: a memory trace which is not retrieved will eventually become inaccessible, whereas a frequently retrieved memory trace will be strengthened and becomes easier to retrieve in the future
• Retrieval-induced forgetting: practicing the retrieval of a memory trace not only strengthens that trace, it also inhibits the retrieval of rival memory traces
  • Only occurs as a consequence of actually retrieving an item, and not from passive study such as re-reading test items
• Phobic responses may be strengthened by repeated retrieval, which might also suppress other less distressing memory responses to the same stimulus
• Reconsolidation:  the retrieval of a stored memory presents an opportunity to make that memory stronger or weaker before it is put back into storage

Memory in everyday life

• Ecological validity: the extent to which the conditions of a research experiment resemble those encountered in real-life settings
• Most people tend to recall more autobiographical information from recent years than from the distant past
• ‘Reminiscence bump’: older people tend to recall an increased amount from their early adult years
• ‘Infantile amnesia’: most people remember nothing at all from the first two or three years of their lives
• Flashbulb memory: a subject’s recollection of details of what they were doing at the time of some major news event or dramatic incident (e.g.: 9/11)
• Eyewitnesses are susceptible to reconstructive errors based on previous knowledge and expectations, but also on information acquired after the event
  • They should be questioned as soon as possible after the event
  • Should not be taken at face value, these memories are not 100% reliable

Resources: An Introduction to Cognitive Psychology: Processes and Disorders 3rd edition (Groome, David)