Memory: Stages, Model and Processing

• Memory refers to maintaining information over time

Stages of Memory

• Encoding refers to input
• Storage refers to saved information
• Retrieval refers to output

Multistore Model of Memory

• Sensory memory has a very brief duration, high capacity, detail, and basic sensory information
• Short-term memory has a brief duration, limited capacity, less detail, and elaborated concepts
• Long-term memory has a not brief direction, unlimited capacity, least detail, and is complicated (Atkinson & Shiffrin)

Memory Processing

• All information is processed into sensory memory
• Stimuli that have direct attention are passed on to short-term memory
• Only some of this information is consolidated into long-term memory (Atkinson & Shiffrin)

Sensory Memory

• Sensory memory covers all sensory systems
• Iconic memory is the visual form of sensory memory, lasting less than 1 second
• Echoic memory is the auditory form of sensory memory, lasting up to 4 seconds

Sperling's Memory Task (1960)

• Twelve letters were flashed for 1/20th of a second
• Only recalling 3-4 letters shows the effect of whole report
• An almost 100% accuracy shows the effectiveness of partial reports
• Change blindness exists

Short-Term Memory (STM)

• Only information that has dedicated attention is committed to short-term memory
• Working memory relates to short-term memory, it has limited capacity
• Failure to use information causes forgetting within roughly 20 to 30 seconds

The Magical Number 7

• The "Magical Number 7," which plus-or-minus two, sets the amount that can be held (Miller, 1956)
• Chunking (like a phone number rhythm or supercalifragilisticexpialidocious) counts as a piece of information
• Rehearsal actively holds information in working memory and includes maintenance versus elaborative rehearsal

Long-Term Memory

• Long-term memory includes theoretically unlimited capacity
• Long-term memory includes infinite duration, if the information is stored properly

Memorization Feats Performed

• Memorizing a shuffled pack of cards occurs around 33 seconds
• An impressive 1170 cards memorized occurred within 60 minutes
• 100,000 digits are recited for Pi

Long-Term Memory Types

• Explicit Memory is declarative and requires memory with conscious recall
• Episodic Memory requires events experienced
• Semantic Memory requires acts and knowledge

Memory without Conscious Recall

• Implicit Memory is non-declarative requires memory without conscious recall
• Procedural Memory relies on procedures and actions
• Conditioning happens
• Priming is a type of memory

Priming Overview

• Exposure to a stimulus influences responses to a subsequent stimulus
• Priming activates the web of associated concepts, like pepper activates the concept/memory of salt
• Influence on ones behavior happens outside of awareness

Balcetis & Dale (2003) Study on Lying

• Participants had to identify examples of lying OR flirting
• The study measured the perception of an ambiguous image
• 15% primed with "flirting" saw the word "Liar”
• 75% primed with "lying" saw the word “Liar”

Neurobiology of Memory

• Long-term potentiation increases the strength of synaptic connections when neurons fire together
• Hebb rule states cells that fire together, wire together
• Consolidation converts short-term memories to long-term memories in the brain
• More permanent cellular changes increase receptor sites

Memory Encoding Levels

• Encoding occurs reflecting its image or being visual (structural)
• Encoding occurs reflecting its sound, being acoustic (phonemic)
• Encoding occurs reflecting its meaning, or semantic relationship properties

Shallow and Deep Processing

• Remembering happens better when information encodes at deeper levels
• Shallow Processing encodes superficial properties of the thing being recalled, such as the look or sound
• Deep Processing encodes based on meaning and connection to past experience and activates new and old connections (elaboration)
• Deep Processing involves additional brain regions, like self-referential encoding (Craik & Tulving, 1975)

Memory Encoding Spaced Apart

• Rehearsing information over a span of time proves more effective than massed learning ("cramming")
• The CREB protein: Triggers genes that engage in LTP and help synaptic strengthening between neurons
• Cramming the night before an exam means weaker consolidation of material
• Sleep also helps because it increases the activity of neural patterns

Reconstruction of Memory

• Memory is reconstructive, being constructed at the time of encoding and recall, and subject to distortion
• Schemas include preconceptions about people, subjects, and events
• Retelling is biased towards whomever the person is speaking
• Confirming-or-disconfirming feedback happens
• Asking leading questions triggers the misinformation effect
• Re-consolidation happens

Emotional Memory and Stimuli

• Emotional events are self-relevant and associate with arousal
• Arousal leads to deep processing of information
• Stress hormones increase LTP and consolidation
• Powerful stimuli serve as retrieval cues

Flashbulb Memory

• Flashbulb Memories: Extremely vivid memories can be emotionally significant
• Flashbulb memories have are characteristics of frequently recalled memories
• Flashbulb Memories have are characteristics of often-inaccurate confidences

Eyewitnesses & Testimony

• Eyewitness testimony has a high belief rate (up to 80%)
• Mistaken eyewitness identification contributes to over 75% of convictions overturned by DNA evidence

Example of Eyewitness Mistake

• Marvin Anderson was sentenced in 1982 to 210 years of prison through robbery, abduction, and rape eyewitness testimony
• A flawed photo lineup and live lineup occurred
• DNA testing in 2001 proved Anderson innocent of the crime

Eyewitness Misinformation

• The Misinformation Effect: New information influences recollections of past events
• Loftus & Palmer (1974) experimented with how participants describe a traffic accident
• Estimated speed was the result of influence; smashed resulted in the highest speed

Selective Attention

• Weapon Focus demonstrates that unusual or arousing focuses can impair one's memory for other details
• Focus has attention with the weapon at the expense of other information at the setting
• The impact of Unusualness: When weapons prove unexpected, they will stand out
• The impact of Emotion/Arousal: When weapons arise, one may be likely to focus on emotional content