Week 4 Slides Flashcards
What is Memory?
- Encoding
- Retaining
- Retreiving
Using Information about:
- Stimuli
- Images
- Events
- Ideas
- Skills
After the original information is no longer present
Any time something in the past impacts your thinking or behaviour in the future
Remember Ebbinghaus 1885
How quickly is information lost over time
Short-term Memory
- Learning or recall everything was in the STM once
- Continuously being refreshed
What is Remembering
- What experiences are remembered?
- How is this experience stored
- How is it retrieved once storied
Memory is Hypothetical
Memory Processes and Structures can be inferred
Grant 1976
- Found that when samples are presented for longer peoples performance would be more accurate
- Proposed that sample leaves neurological trace
- Trace decays over time
- % correct represents the strength of the trace
- Downward slope of accuracy indicates decay
- Traces were parallels so strength and decay were independent of each other
Define Memory
- Memory is the process involved in encoding, retaining, retrieving, and using information about stimuli, images, events, ideas, and skills after the original information is no longer present.
Can Memory be a Process?
- A process that is being used when the past impacts how we think or behave in the future
- Short-term Memory has limited capacity
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Delayed Matching to Sample procedure
- Used to measure memory
- Participant is shown a sample stimulus
- After a X time, a pair of test stimuli is shown
- Select the test stimulus that matches the earlier sample stimulus.
Trace Decay
- Visual stimulus leaves a trace
- Trace decays over time
- Decay rate is constant
- Decay is not dependent of the strength of trace
- Trace can be messed with
Modal Model of Memory
- Atkinson & Shiffrin 1968
- Sensory Memoery
- Short-term memory
- Long-term Memory
- Rehearsal
- Output
Called Modal Model because . . .
Contains features of many memory models taht were being proposed in the 60’s
Control Processes
- A process that can be controlled by someone
- Rehearsal
- Strategies of attention
What Control Processes work Best?
- Atkinson & Shiffrin 1977 - Proposed that rehearsal improves memory
- Craik & Lockhart 1972 - Proposed Levels of Processing Theory
It’s not the amount of processing but the quality of processing that results in best memory retention
Levels of Processing Theory
- Craik & Lockhart 1972
- Quality and depth of encoding is more important for long term memory than rehearsal
Persistence of Vision
- Continuing to see a stimulus even after it has disappeared
- The effects of sensory stimulation that are retained for a brief time
Sperling 1960
- Measuring capacity and duration of Sensory Memory
- Letter array flashed for 50ms
- Participants asked to report as many as possible
- Whole Report Method
- Partial Report Method
- Delayed Partial Report Method
Whole Report Method
- Sperling 1960
- Array flashed for 50ms asked to report as many as possible
- Average 4.5/12 reported
Partial Report Method
- Sperling 1960
- Heard tone after matrix presented
- Each sound told them what row to report
- Able to report 3.3/4 on average from any row
Delayed Report Method
- Sperling 1960
- Presentation of tone delayed by one second after visual stimulus shown
- Performance decreased rapidly
- Average 1/4 letters reported
Results Sperling 1960
- Decrease in recall due to rapid decay of Iconic Memory
- Visual Stimulus hits our visual receptors and is stored in the STM
- This stimulus decays decays rapidly in under a second
Iconic Memory
- Brief sensory memory of things we see
- Responsible for Persistence Vision
- Corresponds to Atkinson & Shiffrin’s Modal Model of Memory
Echoic Memory
- Similar to measuring capacity of visual stimulus measures auditory stimulus
- Sounds also persist in the mind
- This is called Echoic Memory
Echoic Memory
- Brief Sensory memory of things we hear
- Responsible for Persistence of Sound
- Echoic Memory lasts for a few seconds
- Darwin et al 1972
Recall
- Reporting stimulus after a delay of presentation of the stimulus
- Can be measured as a percentage
- Can be visual and auditory
Peterson & Peterson 1959
- Read 3 letters then 3 numbers
- Count backwards by 3’s
- after delay recall 3 letters
- After 3 second delay people had 80% recall and after 18 seconds had 10%
- Reduced performance due to decay due to the passage of time
Keppel & Underwood 1962
- Looked closely at Peterson & Peterson
- Subjects memory for letters on trial 1 was high
- After a few trials performance dropped
- Poor after 18 second delay
- Data from Peterson & Peterson was a result of poor performance on later trials
Interference
Keppel & Underwood
- Proactive Interference
- Retractive Interference
Rapid forgetting from Peterson & Peterson was not due to extended delay but interference from earlier stimulus in the trial
Proactive Interference
- Keppel & Underwood 1962
- Interference that happens when stimulus that was learned first interferes with learning new information
Retroactive Interference
- Keppel & Underwood 1962
- Interference that occurs when new learning interferes with remembering old learning
Zhang & Luck 2009 - Interference
- Imagine learning two languages
- Effective duration of Short Term Memory is about 15-20 seconds
- After that interference seems to take
Decay & Interference Modal Model of Memory
- We forget sensory memory because of decay
- We forget Short-term Memory because of interference
- We forget Sensory Memory due to Decay
- We forget Short-term Memory due to Interference
Short-term Capacity
- Digit Span is how many numbers you can remember in a sequence
- Most people remember 5-9 numbers
- George Miller 1965 The Magical Number Seven Plus or Minus 2
- Argued the human mind is limited to about 7 Items
Short-term Capacity - Cowan 2001
Recent studies have measured STM Capacity more accurately at 4 items
Luck & Vogel 1997 - STM Capacity
- Measure capacity of STM by using Change Detection
- The process of identifying differences in the state of an object or phenomenon by observing it at different times
- Easy with few items
- Especially harder if number of items was greater that STM Capacity (5-7 items)
Chunking - Luck & Vogel 1997
- Small units of stimulus can be combined into larger meaningful units
- A chunk is a collection of elements that have strong meaningful connections with each other
Chunking - Ericsson & Co. 1980
- Trained a college student with average memory to use chunking
- Had digit span of 7 items
- had 230 x 1 hour training classes, could remember 79 digits
- Chunking enables STM to cope with large amounts of stimulus involved in every day tasks
Short-term Memory - Alvarez & Cavanagh 2004
- Used complex objects to do change detection experiments
- Stimulus had low information squares to high information cubes
Complex Change Detection
- Subjecs ability to manage same and different judgement depended on how complex the stimulus was
- Capacity for squares was 4.4 but only 1.6 for cubes
- The larger the information in an image the fewer items can be held in STM
Summary of Sensory Memory
- SM is being able to retain the amount of stimulus over a brief period of time
- Sperling showed poorer performance after delaying was due to decay
- Two types of decay - Iconic Memory and Retroactive Memory
- SM Can register large volumes of stimulus due to chunking
- Some memory from SM is passed to STM
Summarise Interference
- New information can interfere with old learning
- Old information can interfere with new learning
- STM capacity has been revised to about 4 items
- Chunking allows more items to be stored in memory
- Alvarez & Cavanagh showed the more complicated an image was the fewer can be held in STM
Working Memory
- Role of STM extends beyond storage
- It involves transfer of info to and from Long-term Memory
- STM deals with dynamic processes that transfer info and leads to rethinking of its nature
- Proposal that STM processes all called Working Memory
Baddeley & Hitch 1974 - Working Memory
- Limited Capacity for temporary storage and manipulation of information
- Concerned with storage, processing and manipulation of information
- Active during complex cognition
Baddeley’s Working Memory Models
- Takes into account for the dynamic processes involved in cognition
- Understanding language and doing math
- People can do two things at once
- Phonological Loop
- Central Executive
- Visuo-Spatial Sketch Pad
Baddeley’s Working Memory Model
- Phonological Loop - Verbal and Auditory Information
- Central Executive
- Visuospatial Sketch Pad
Phonological Loop
- Verbal and Auditory Information
- Contains Phonological Store - has limited capacity
- Holds info for a few seconds
- Carries out Articulatory Rehearsal Process
- Assists to keep Phonological Store from decay
Visuospatial Sketch Pad
- Holds visual and spatial information
- When we form a picture in our mind
- Do tasks like solve puzzles or reading maps
Central Executive
- Phonological Loop and Visuospatial Sketch Pad attached here
- Major work of working memory happens here
- Pulls information from LTM to coordinate Phonological Loop and Visuospatial Sketchpad
- Focuses on task specifics and decides how to divide attention in a task
- Recent research says Central Executive is many separate functions
Phonological Similarity Effect
- Letters or words that sound similar can get confused
- Conrad 1964 flashed letters on a screen and got ppl to write them down
- When errors were found they tend to confuse letters that sounded similar
- F was most often confused with S or X
- Not as likely to be confused with E even thought they look similar
Word length Effect
- Memory for lists of words is better for short words
- Takes longer to rehears long words and to produce them during recall
- Subjects remembered 778% of short words but only 60% of long words
Articulatory Suppression
- We can prevent success in phonological loop by getting them to repeat irrelevant sounds instead
- Speaking prevents rehearsal from being remembered
- Reduces memory span, word length effect and reduces phonological effect
Shephared & Metzler 1971
Experiment to decide if two unusual objects were the same or different
- Shepard & Metzler 1971
- Mental Rotation Experiment
- Experiment to decide if two unusual objects were the same or different
- Rotate image in their mind and called this Mental Rotation
Mental Rotation Experiment
Shepard & Metzler 1971
Trials that needed more mental rotations took longer
Lee Brooks 1968
- Demonstrated how interference can affect Visuospatial Sketch Pad
- Response times more that twice as long for pointing (28.2) than verbal responses (11.3)
Evidence for Central Executive
- People with Prefrontal Lobe Damage more likely to repeat actions even if it is not successful
- This repetition is called preservation
Testing Central Executive
- Vogel et al 2005
- Separated participants into high capacity and low capacity groups
- Each did a change detection task
- Event Related Potentials were measured to indicate how much space was used in Working Memory
2nd Vogel Central Executive Experiment
- Added condition where he added extra blue lines
- Caused increase in response of high capacity group
- Caused much larger increase in the low capacity group
- Some people’s central executives are better at allocation attention than others
Lexicality Effect
- Hulme et al 1991
- Words are recalled better than non words
Word Frequency Effect
- Watkins 1977
- Frequent words are recalled better that infrequent words
Language Familiarity Effect
- Thorn, Gathercole & Frankish 2002
- Words from a bilingual’s primary language are recalled better that the second language
Semantic Similarity Effect
- Baddeley 1966a
- Recall is better for semantically similar lists than non-similar
Phonological Neighbourhood Effect
Clarkson, Roodenrys , Miller & Hulme, 2017
Recall is better for words from dense phonological neighbourhoods than sparse
Redintegration Hypothesis
Long term memory has an influence on recall from short-term memory
Schweickert 1993
Items not affected by decay can be recalled from Short-term Memory
Decayed items compared to intact lexicon to replace the degraded information
Episodic Buffer - Baddeley 2009
- Back up storage that communicates between LTM and working memory
- Holds information longer and has greater capacity than phonological loop or visuospatial sketch pad
- Serves as general storage system
- Episodic Buffer as a concept is still in early stages of development
Prefrontal Cortex, Working Memory and the Brain
- Prefrontal cortex is responsible for processing incoming visual and auditory information.
- Monkeys without a prefrontal cortex have difficulty holding
information in working memory. - Called the Delayed Response Task experiment
Response Neurons Experiment
- Funahashi & Co, 1989
- Collected single cell recordings from monkey’s prefrontal cortex during a delayed response task
- Pictured - response of neurons in the monkey’s prefrontal cortex during an attentional task.
Two States of Neural Networks that Store Information
- Stokes 2015
- Neurons are not always firing in the delay period
There are at lease two states of a neural network that store information
- Activity State - Information to be remembered causes neurons to fire
- Synaptic State - When neuron firing stops, connections between neurons are strengthened
- Stokes 2015
- Neurons are not always firing in the delay period
There are at lease two states of a neural network that store information
- Activity State - Information to be remembered causes neurons to fire
- Synaptic State - When neuron firing stops, connections between neurons are strengthened
Cognitive Control
Processes that allow us to adapt and vary our behaviour from situation to situation including:
- Shifting
- Updating
- Attentional Control
- Inhibitory Control
- Working memory
- Cognitive Flexibility
These systems add up to executive functions
Executive Function
- Psychological Wellbeing but also connected to psychopathology
- EF Affects rumination, worry, poor emotion regulation
- Also connected with Schizophrenia, major depression, Bipolar, PTSD and trait anxiety
- Also associated with ADHD, Tourettes & Autism
- Sneyder et al 2015
Dysexecutive Syndrome
- Can occur through Brain injury, neurological damage or developmental issues
- Phineas Cage
Symptoms may include:
- Behavioral disinhibition
- Lack of planning and forward thinking
- Lack of self awareness
- Lack of appreciation of humor
- Lack of ability to take another individual’s perspective
- Risk taking
- Difficulty using appropriate judgment in social behavior
