Week 3 MSM (learning and cognition 2) Flashcards
Sensory, short-term and long-term memory systems, Encoding, storage and retrieval, Capacity and duration
What is memory?
A set of storage systems and processes for encoding, storing, and retrieving information acquired through our senses and for relating this information to previously acquired knowledge
Memory is the mental representation of
knowledge within memory systems stored within neural networks of the brain.
Proposal of Multi-Store Model of Memory Theory
The model was first proposed by Atkinson and Shiffrin (1968) in the early days of the “cognitive revolution’.
MSM stores
- Memory consists of three “stores” (think systems in terms of the terminology I have been using).
1. Sensory memory
2. Short-term memory (working memory).
3. Long-term memory.* The three stores can be distinguished based on how long memory is retained (duration), and how much information can be stored (capacity).
Encoding
The processes involved in attending to and acquiring information from experiences and mental processes
Encoding aids in the:
- Registration of information in sensory regions of brain
* Attention to elements of an experience
Interpretation and integration of experience with prior knowledge
Storage
Encoding produces representations of information that are consolidated in memory traces stored in networks of neurons throughout the brain.
Storage aids in:
- Different kinds of memories are stored in different networks.
- Storage capacity and duration differ between the different memory systems.
Retrieval
- “Remembering”, “knowing” and ”doing”
- Everything from personal reminiscence of past experiences, recalling facts, executing practiced motor skills, to conditioned responses.
- Explicit and implicit retrieval processes
- A reconstructive and (sometimes) error-prone process that changes the memory trace through ‘reconsolidation’ after retrieval.
Encoding Storage and Retrieval Diagram
Sensory Memory
- A temporary, sensory-based representation of input received through sensory channels.
- Provides a buffer (‘holding area’) between early sensory processes and later cognitive processes.
- Only some of the information stored in sensory memory will be retained.
Iconic Memory is
visual memory
Echoic Memory is
auditory memory
Capacity and Duration of
- Brief duration (decays quickly)
* Large capacity (relative to STM).
Sperling’s Study aim of Sensory Memory
George Sperling (1960) used a series of ingenious experiments to determine the capacity and duration of iconic memory
Experiment, 4 students & colleagues of Sperlings
Sperling Study 1:
Shown 12 letters for ~50 milliseconds
Asked to write down as many letters as they could recall
Sperling Study 2:
Shown 12 letters, then a tone (high, medium or low) would sound which indicated the line of letters which they should recall
Sperling Results
Suggests that the image of all the letters was stored in iconic memory after the image left the screen, but not for very long (ie unlimited capacity, duration of 0.3 seconds)
* Sperling found that participants could name only 4 of the letters on average. * However, they reported feeling like they briefly had access to a visual image of the entire display, but that it faded more quickly than they had time to read the letters. * It was as if the information was being read from a rapidly decaying (fading) icon.....
Iconic Memory Capacity explored in Sperling
- Sperling felt that the full-report method was likely to have underestimated the true capacity of the iconic trace.
- He devised the partial-report method that I describe in the following slides to test his theory that the capacity of the visual icon was much greater than just 4 items
Iconic Memory Duration explored in Sperling
- A simple modification of the partial report method allowed Sperling to estimate the duration of the iconic trace.
* He systematically varied the retention interval between turning off the stimulus array and presenting the cue for which line to report.
* He found that memory performance reduced to one item after approximately 500 milliseconds (half-a-second).
Overarching of Sperling
- Sperling’s methods provide an elegant demonstration of using behavioural measures to test theories about the properties of an internal cognitive process.
- Sperling’s full report method was intended to provide a measure of visual sensory memory capacity. However, the results underestimated the capacity of visual sensory memory because: the time required for verbal reporting of more than 3-4 letter names exceeded the duration of the iconic trace
- Part of the development of cognitive-behavioural methods and theories, and rejection of radical Behaviourism.
- The duration of the iconic memory trace is approximately 500 milliseconds