Ch 5 Flashcards
Information
The stuff of memory
Memory is
not reliable
is changeable
not like a computer’s hardrive
malleable
time (can be measured using time)
Memory (1st definition)
“The ability to retain information or a representation of past experience based on the mental processes of learning or ENCODING, RETENTION across some interval of time and RETRIEVAL or reactivation of the memory.”
Encoding
At some point information is put into the brain
Retrieval
At some later point information is retrieved from the brain
The passage of time in between encoding and retrieval
Retention or Storage
Memory Definition (Second version)
Specific information or past experiences that are recalled
Endel Tulving (1994) [Memory what is it?]
A set of processes, a set of systems
A trick that evolution that has invented to allow its creatures to compress physical time
Roediger & Wertsch (2008)
No good for answer for what memory is. The issue is that the subject is a singular noun as though memory is one thing or one type, when in actuality the term is almost always most useful when accompanied by a modifier
Modal Model (Theory)
The human memory system has 3 seperate sub systems of memory
Sensory Memory
All the information that comes though your senses which is temporarily restores and extends your moment of existence.
The retention of effects of sensory stimulation in high capacity for very brief periods of time
Has not been processed for meaning and is before any selective attention filtering.
Infor decays rapidly
Visual (iconic) ≤ 1 second
Audio (echoic) ≤ 4 seconds
Sensory memory uses your senses
Shorterm/Working Memory
Sensory information that we pay attention to makes it here
A limited capacity, short duration storage in which we actively process/manipulate the info
Capacity 7±2 chunks
Duration ≤ 20 seconds without rehearsal
Rehearsal (a control process) re-enters the same info
Long Term Memory
Encoding: info in STM/WM that we process or rehearse enough makes it into here
Retrieval: info can be transferred back into STM/WM (conscious awareness)
Capacity (unlimited)
Duration (unlimited)
For study help Refer to diagrams in PowerPoints
No Answer
LTM
Encoding -> Storage -> Retrieval
Sensory “memory
Large capacity
Very short duration ≈ 1s for visual
If you remember saccades (our eyes move 3 times per second). Sensory memory preserves visual representations across saccades
“precategorical” Information is not processed for content
How do we know what capacity and duration are?
Sperling (1960) experiments- visual memory aka iconic memory
Method:
- Showed a grid of 12 characters (numbers and letters) very briefly for 50ms
- participants had to report what they saw
- whole report: say all 12
- partial report: one row
The Point: Capacity for visual memory is high but duration is short and is not processed for meaning
Sperling 1960 Results
Whole Report
- mean # recalled about 4.3 seconds (36% of all 12 in the grid)
[Sensory memory faded faster than people could write down]
Partial Report No Delay
- mean # recalled about 3.3 characters (82% of all 4 in the row)
[Capacity was high]
Partial Report Slight Delay
- mean # recalled about 1.5 characters (38% of all 4 in the row)
[Duration is short]
Report just the letters or just the numbers
- couldn’t do it at all
[Pre-categorical: no meaning processed]
What makes a chunk?
Meaning. Grouping items together in a meaningful arrangement
Long Term Memory LTM
Covers memories that were 30 seconds ago all the way to your earliest memories in your lifetime (like up to infant)
STM/WM: Duration
We could just present some stimuli (like a list of numbers), and wait for different retention intervals then give recall test
To problem with this is that people will rehearse the numbers that they are getting tested on.
Brown Peterson task: prevented rehearsal however.
STM duration: Peterson & Peterson (1959)
Method:
- see a trigram
- filler task: have to count backwards by 3 from some big number
(ex: # seconds to do filler task [retention interval] [from 3 to 18]
- DV: recall the trigram
Why do we Forget (from STM)
- Memories decrease in strength over time
- Peterson & Peterson (1959)
Interference from other info?
Proactive Interference
Older information makes it difficult to remember newer information (refer to slide 17 in PowerPoint)
Keppel & Underwood (1962)
If Decay
Capacity is Limited
Duration is limited
Forgetting: Information is missing from STM
If Intereference
Capacity: is Unlimited
Duration: is Unlimited
Forgetting: Can’t find information
Short term memory
Chunks of info just sitting there in temporary storage
Working Memory
Not sitting but actually processing the information
A limited capacity system for temporary storage and manipulation of information for complex tasks such as comprehension, learning, and reasoning
Operation Span (OSPAN)
Testing the WORKING part of working memory
Participants do equations, solve them in their head and state whether true or false, the read a word
Baddeley’s Model of Working Memory
Phonological loop (Where verbal and auditory information is stored and manipulated) [language]. Interacts with long term memory
Visuospatial sketch pad (Visual and spatial information is temporarily stored and manipulated)[Imagery]. Interacts with long term memory
The Central Executive guides these two things
Central Executive
Some process that guides the Phonological loop and the Visio Spatial Sketch Pad
Allocates attention to one or both sub systems
The ability to point a spotlight to certain areas of your long term memory.
What is the central executive similar to?
Baddeley suggests that the central executive acts more like a system which controls attentional processes rather than as a memory store.
Visuospatial Sketch Pad
Creation of visual images in the mind in the absence of a physical visual stimulus
- Sherpard and Metzler (1971)
- Mental rotation task
- Tasks that called for greater rotations took longer
- Measured using a mental rotation task
- the ability to store and manipulate objects in space
How LTM memory is stored in the brain (Cerebral Cortex)
The formation of an engram involves strengthening of synaptic connections between populations of neurons… that are active during an event. This increases the likelihood that the same (or similar) activity pattern within this cell assembly can be recreated at a later time
Evidence For Phonological Coding (Placeholder card)
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Phonological Similarity Effect
- Letters with similar sounds often get confused in memory
- Can only occur if they are stored as sounds rather than images
Word Length Effect
Braddeley, Thompson, & Buchanan, in 1975
- Memory for list of words is better for short words than for longer words
- Longer words take longer to rehearse and produce
- Short words are easier since fewer can fit in the phonological loop
Separation of Stores (placeholder)
Next subject
Articulatory Suppression
Baddeley, Lewis, and Vallar in 1984
- Repeating a sound that is irrelevant to the task (i.e. The The The The)
- Reduces the capacity for the phonological loop
- Forces people to use their Visual Spatial Sketch Pad
Where is WM located
Mainly in prefrontal cortex
We know this because of
- Lesion studies with monkeys
- Single neuron recording with monkeys
- But….. visual cortex is involved in visual WM, and auditory cortex is involved in auditory WM
- Distributed representation (NOT completely localized)
