Memory Models and Encoding

• Robert Louis Stevenson said, “I've a grand memory for forgetting".

Multi-Store Model of Memory

• Memory contains sensory, short-term, and long-term components
• Sensory memory consists of iconic, echoic, and haptic elements
• Short-term memory involves attentional control and working memory
• Long-term memory is divided into implicit and explicit forms
• Implicit memory is non-declarative and non-conscious, including procedural and priming aspects
• Explicit memory is declarative and conscious, with episodic and semantic components

Working Memory Model

• Four components guide the process of memory
• Episodic buffer accesses information from long-term memory
• Visuospatial sketchpad helps with spatial layout
• Phonological loop counts windows
• Central executive guides the process

Encoding Explicit Memories

• Short-term memory requires maintenance rehearsal for encoding and learning
• Encoding leads to memory recall after a retention interval

Optimizing Memory

• Review work regularly in shorter sessions for the spacing effect
• Focus on key material at the beginning and end for primacy and recency effects
• Link new information to existing knowledge for depth of processing

Deep Encoding

• Deep encoding leads to better retrieval
• Self-reference effect is linked to identity.
• Memory is better when adjectives are used to describe you vs. common words (Leshikar et al., 2015)
• Generation effect involves active rehearsal
• Memory is better when generating words (Norman et al., 1978)

Mnemonics

• Mnemonics aid memory
• Method of Loci is also known as Memory Palace and Technique
• Mnemonics involve choosing a familiar location and imagining moving through it
• This associates items to remember within places in the space, creating a "map" of new information

Forgetting

• Decay Theory explains that memories are lost over time due to disuse
• Interference theory suggests interference is responsible for forgetting
• Encoded memories are labile and need consolidation into stable long-term memories
• Pre-consolidation periods make memories susceptible to disruption from interfering information

Interference Effects

• Interference has effects on memory
• Proactive interference occurs 'forward in time'
• Prior information interferes with encoding new memories
• Trouble learning new phone number because old number keeps popping up
• Retroactive interference occurs 'backward in time'
• Newly learned information interferes with prior encoded memories
• Trouble remembering an older password after forming a new one

Testing Interference

• Proactive Interference Testing:

• An experimental group learns a Mulligatawny Soup recipe then Broccoli Cheese recipe

• A control group rests, then learns the Broccoli Cheese recipe

• The experimental group remembers fewer ingredients

• Prior information (Mulligatawny Soup) interferes with memory of the Broccoli Soup

• Retroactive Interference Testing:

• An experimental group acquires a vanilla cupcake recipe, then a cheesecake recipe

• The control group learns a vanilla cupcake recipe and then rests

• The experimental group remembers fewer ingredients

• New information is interfering with memory of vanilla cupcake recipe

Similarity Effects

• Similarity to what is learned leads to mingling and interference
• Group Dessert learns a vanilla cupcake recipe, then a cheesecake recipe
• Group Dessert learns a vanilla cupcake recipe, then a Broccoli Cheese recipe
• Group Dessert remembers fewer ingredients

Optimizing Memory

• Remember Severance by cooking stew afterward rather than watching Adam Scott

Agenda

• Encoding specificity hypothesis
• Explicit memory which includes a distinction episodic and semantic memory
• Special type of episodic memory called flashbulb memories
• Distortions in memory

Encoding Specificity

• Memory retrieval is better when there is overlap with encoding
• Context is source of overlap
• Context includes internal state (e.g., mood), external environment, and processing
• Endel Tulving studied this
• Overlap determines retrieval success

State-Dependent Learning

• Internal context is state-dependent
• Alcohol dependent learning (Goodwin et al., 1969)
• Encode sober, retrieve sober group performed best

External Context

• Study looked at deep-sea divers
• Encoded and retrieved words either on land or underwater
• Participants recalled more words when the context matched

Transfer-Appropriate Processing

• The overlap between processes during encoding and retrieval determines memory strength
• Study found that shallow and deep processing lead to better match
• Context matters.

Conscious Memory

• Explicit conscious memory is divided into episodic and semantic memory
• Episodic memory is recollecting unique events within a specific time and place
• Semantic memory shares cultural knowledge and connects the self, outside time or place

Episodic vs Semantic

• Episodic memory is retrieving what, where, and when of an event
• Semantic memory is the non-retrieval of learning, just what is known

Pop Quiz

• I ordered nachos from the taco truck before my lecture last week (episodic)
• Key ingredients for nachos are cheese and tortilla chips (semantic)
• I love all type of Mexican food (semantic)

Semantic Dementia

• Semantic memory in the brain: Semantic dementia
• Semantic dementia affects temporal poles
• It is early on in disease
• The disease relatively spares episodic memory tasks
• Impaired at word naming and picture matching tasks (semantic memory)
• Irish et al., 2016 studied visual matching in patients

Episodic Memory

• Episodic memory is located in the hippocampus
• Damage to the hippocampus impairs episodic memory
• Patients cannot copy images after a delay
• Semantic memory is preserved
• Patients show normal facts and general knowledge
• Vargha-Khadem et al., 1997 studied patients

Types of Consciousness

• Memory retrieval engages types of consciousness
• Anoetic consciousness is implicit memory with no awareness or personal engagement
• Noetic consciousness is semantic memory with awareness with no personal engagement
• Autonoetic consciousness is episodic memory with awareness and personal engagement ("Mental time travel")

Reappearance Hypothesis

• Episodic memory trace is recalled the same way at each retrieval
• It is reproduced, not reconstructed
• Clinical observations show recurrent memories are unchanged from the original event, in cases like PTSD
• Involuntary memories come to mind with no retrieval attempt; often emotional and repetitive
• Suggestion that memories reappear for highly emotional memories

Flashbulb Memories

• Flashbulb memories is a special type of memory
• Form for form events that are:
• Emotionally arousing
• Surprising or shocking
• Important to the self and have consequence
• Examples
• COVID lock down
• The Queen dies
• Thought to be supported by special mechanisms which lead to repetitive detail to recall, resistant to forgetting (Brown & Kulik, 1977)

Are Flashbulb Memories special?

• Participants recalled two memories in detail
• 9/11 (flashbulb event)
• everyday autobiographical event
• I was wearing a Hawaiian shirt because I was celebrating a birthday when the phone rang
• Scored the details used to describe the memories
• Collected ratings of memory vividness, held belief and confidence
• Talarico & Rubin, 2003
• Recall Scored detailed descriptions across retrievals -Details didn't change over time (consistent details) -Details changed over time (inconsistent details)

Change over Time

• Flashbulb and everyday memories change over time
• Flashbulb memories have more confidence (belief, vividness) over time
• Talarico & Rubin, 2003 study
• Flashbulb memories change
• Flashbulb event: The 1997 verdict for the O.J. Simpson murder trial
• Participants recalled the verdict, rated emotional reaction
• Initial review, after 15 months things had changed with 50% recollections changed, 32 months 70% recollections changed

Flashbulb Memories pt. 2

• Schmolk & Squire 2000 shows there can be a 40% major distortions of memories
• Flashbulb memories: Do not reappear
• Flashbulb memories are not recurrent recordings of events
• Flashbulb memories change over time and are not resistant to memory distortion, even if memory feels strong
• Distinction between subjective and objective memory
• Must accept the theory that memories are reconstructed

Distortion

• Memory retrieval involves constructing our memories
• Constructing memories means these memories are susceptible to distortion
• Two examples
• Use general knowledge and semantic memory (schemas) to infer the way things "must have been"
• Insert false information into the constructed memory, affecting later retrieval

Schemas

• Schemas (semantic memory) distort memories
• Schemas organize and categorize information, provide expectations about how things should occur
• Bartlett (1932): The War of Ghosts experiments
• Content: young men hunting seals in a river with unfamiliar supernatural details
• Did not match Western folk story structure (schema)
• Examined how the story changed with repeated retrievals

Ghost Experiment

• Participants remembered a simplified version of the story and became more conventional with repeated retrievals
• Omissions and alterations to match Western schema
• Excluded uncommon details; "a black thing rushed out of his mouth"
• Changed uncommon activities to conventional activities, according to their schemas of how the world works such as hunting seals became fishing
• Schemas lead to false memories
• Study scenes associated with schema-consistent items removed
• Classroom without a chalkboard
• Auditory word recognition test for items from the scenes
• Studied items: "Desks"
• Schema-related lures: "Chalkboard"
• Non-schema-related items: "Ball"
• Miller and Gazzaniga, 1998

False Memories

• Schemas can connect autobiographical memories
• Other false memory effects can include
• Misattribution which causes a familiar feeling to lead to incorrect associations
• Misinformation that can add Details to memories during retrieval

Misattribution and Misinformation

• Retrieving familiar information from the wrong source (place) causes misattribution
• Failure in source monitoring (not remembering where or when accurately)
• Leading questions can cause false memory formation (Loftus and Palmer (1974))
• The misinformation effect can cause questions to be phrased in a leading manner that affect recollection

Implanting Memories

• Participants recalled childhood experiences recounted by their parents over three experimental sessions
• A false memory was added to the list of experiences by a experimenter suggesting an An overnight stay in a hospital
• In the 3rd session 20% of people had a false memory this event (Hyman et al., 1995)
• Memories consolidation explains false memories
• Experiences are encoded and then consolidated into long-term memory trace
• The formation of stable cortical representations of memories are active
• Memories that are retrieved are reconsolidated
• Retrieval shapes a memory trace
• Adaptive angle: Why we have a constructed memory