LTM, STM, Working Memory
Chapter 5
Memory
Attention
dealt with capacity limitation, but with simultaneously arriving information ability to carry out several activities at the same time is restricted by total amount of mental effort that is available for distributing to these activities
Memory
capacity limitation, but focus on fact that people are limited in the number of items they can keep active in memory this limited capacity influences performance on a variety of tasks
Extensiveness Definition
Memory is the process involved in retaining, retrieving, and using information about stimuli, images, events, ideas, and skills after the original information is no longer present.
Caption: Flow diagram for Atkinson and Shiffrin's (1968) model of memory. This model, which is described in the text, is called the modal model because of the huge influence it has had on memory research.
Modal Model of Memory
Atkinson & Shiffrin (1968, 1971) theory of memory
Emphasizes interaction among sensory store, STM, LTM Modal model: stages with different durations Structural features
Sensory store: Preserves info for a few hundred milliseconds, or seconds STM
Limited in __________ and __________ Information is lost within 15-30 seconds if it is not rehearsed
LTM
Unlimited in capacity and holds info over a much longer interval, but it often takes a fair amount of effort to get information into it
Control processes
Strategies that a person uses to facilitate acquisition of knowledge
Rehearsal: ______________ of information Coding: attempts to place the information in the context of additional, easily retrievable information, such as mnemonic phrase or sentence Imaging: imaging (creating visual image to remember verbal information--old memory trick recommended by Cicero in ancient Rome for learning long lists or speeches) Retrieval from LTM so it can enter into STM
Atkinson and Shiffrin (1968): Components of memory do not act in isolation
Caption: What happens in different parts of Rachel's memory as she is (a and b) looking up the phone number, (c) calling the pizza shop, and (d) memorizing the number. A few days later, (e) she retrieves the number from longterm memory to order pizza again. Darkened parts of the modal model indicate which processes are activated for each action that Rachel takes.
Sensory Memory
Sensory Memory
Brief retention of the effects of sensory stimulation Visual Icon, or Iconic Memory
Visual stimulus lingers in our mind (sparkler's trail of light, film) Sperling's Measuring the Visual Icon Experiment Figure 5.6 (flashed letters for 50msec)
Echoic Memory Importance of Sensory Memory
Collecting information, Holding information, Filling in blanks
STM vs. LTM
Different types of memory Serial Position Effect
Primacy effect
Better recall for words at beginning of list Suggested to occur because words in sequence were to transferred LTM
Recency effect Research
Effects are removed when prevent rehearsing by counting backwards at end of list (recency effect disappears b/c time for storage in STM has been too long) When all words on the list are presented at a slower pace, there is increased memory b/c had time to rehearse
Differences in Coding
Coding refers to the way information is represented Visual coding (____________ coding) Phonological coding (__________ coding) Semantic coding (__________ coding) All above in both STM and LTM, but most common for STM is phonological, and semantic for LTM
Coding in STM
Information can be coded both visually and phonologically Experiment with Chinese language symbols Semantic coding also possible
Proactive interference: information learned previously interferes with learning new information Release from proactive interference Important: P and M groups did not have equal release from PI; meat more similar to fruit than professions; Since word categories are important here, it suggests that the meaning of the words played a role; or there was semantic coding in STM taking place as well
Coding in LTM
Semantic dominant
Properties of STM
Capacity of STM
7 2 and chunking
Duration Problems with Model
Poor STM but intact LTM Can do more than one task at a time May be components may function separately
Working Memory
Definition
A limited capacity system for temporary storage and manipulation of information for complex tasks such as comprehension, learning, and reasoning Differs from STM:
WM consists of a number of parts Function is to manipulate, rather than store
3 Components of WM
Phonological Loop
Holds verbal and auditory information 2 parts
storage, which holds the memory trace which fades in about 2 seconds unless it is refreshed by (2) rehearsal, or repetition Storage is passive, while rehearsal is active
Visuospatial Sketch Pad
Holds visual and spatial information
Central Executive
Pulls information from LTM and coordinates activity of phonological loop and visual-spatial
Operation of the Phonological Loop
Phonological Similarity Effect
Confuse similar sounding words
Word Length Effect
Memory for lists of words is better for short words than for long words Larger words fill up the capacity of the phonological loop
Articulatory Suppression
Interference in phonological loop (e.g., recall) if asked to repeat something over and over
Visual-spatial Sketch Pad
Demonstrations show that working memory is set up to process phonological and visualspatial information separately so it can handle different types of information simultaneously, but has trouble handling similar types of information that are presented simultaneously
John ran to the store to buy some oranges. (Say yes if noun or no if not a noun)
The bird flew out the window to the tree. (Point to Y if noun or N if not noun)