Psych Exam 2

Modal Model of Memory

• Includes sensory memory, STM/WM, and LTM

Sensory Memory (definition)

• High capacity for very temporary storage of incoming sensory information

  • Pre-conscious/pre-categorical

  • Separate stores for each sense

• Sensory info enters in parallel and decays rapidly

  • Visual (iconic) < 1s

  • Audio (echoic) < 4s

Short-Term Memory (basic definition)

• Limited capacity short-duration store where we actively process and manipulate information

• Capacity: 7 plus or minus 2 chunks

• Duration (without rehearsal): < 20s

Long-Term Memory (basic definition)

• Capacity and duration are unlimited

• Encoding: information in STM/WM that we process/rehearse enough goes to LTM

• Retrieval: information can be transferred back into STM/WM

Sperling Iconic Memory Experiment

• Showed a grid of 12 characters very briefly and participants reported what they’d seen

• Whole report (say all 12): mean 4.3 characters

  • Sensory memory fades fast

• Partial report (say just one row)

  • Delay → mean 1.5 characters

    • Duration of sensory memory is short

  • No delay → mean 3.3 characters

    • Capacity is high

• Report just letters of numbers → couldn’t do it

  • Sensory memory is pre-categorical

Capacity

• Digit Span Task can measure capacity

• Chunking: based on meaning/top-down processing

Peterson & Peterson Trigram Experiment

• See a trigram, complete a filler task during an (IV) retention interval, recall trigram (DV)

• Found that as retention interval increased, mean proportion recalled decreased similar to Ebbinghaus’ forgetting curve

Why do we forget from STM?

• Decay: according to Peterson & Peterson, memories decrease in strength over time

• Interference from other information

  • Proactive (old interferes with new) and retroactive (new interferes with old) interference

  • Keppel & Underwood took data from Peterson & Peterson

  • Only looking at the performance for the first trial, the difference in proportion recalled was much less and increased as more trials occurred

  • Perhaps information from earlier trials in LTM interfered with new trials, causing STM to appear to decay faster

Difference Between STM and WM

• Working Memory (Baddeley and Hitch) takes into account that we are processing chunks of info in STM

• Better explains complicated mental math and multi-tasking

Operation Span (OSPAN)

• Tests the working part of WM

• See an equation, decide whether it’s T/F, read a word → output: list words

Baddeley’s Model of WM

• Central Executive: modality independent director of operations

• Modality dependent subsections

  • Visuo-spatial sketchpad (visual STM)

  • Phonological loop (auditory STM)

  • Episodic buffer

Visuospatial Sketchpad

• The creation of visual images in the mind in the absence of a physical thing

• Evidence: when mentally rotating an object, the more it must be rotated, the longer it takes for your brain to do it

Phonological Similarity Effect

• Letters with similar sounds often get confused in memory

Word Length Effect

• Memory for lists of words is better for short words than long words

• Reading speed is long → takes longer to rehearse

• Indicates people are reading words aloud in their head

The Serial Position Curve

• Primacy effect: the first few words get more rehearsal time so go to LTM

• Recency effect: the last few words are still in the WM loop

• Double dissociation:

  • Increasing the retention interval (+ filler task) gets rid of recency effect, not primacy effect

  • Decreasing the speed of words spoken increases primacy effect, no impact on recency effect

Amnesia

• Retrograde: can’t retrieve existing memories

• Anterograde: can’t encode new memories

• Temporal lobes + amnesia

  • Many surgeons treated neurological illness by taking out part of the brain → unintended cognitive impairments

HM

• Surgery for epilepsy destroyed 2/3 of hippocampus and part of amygdala (bilateral temporal lobe resection)

• Results

  • Seizures improved, normal IQ

  • STM/WM intact

  • LTM severe deficits: retrograde amnesia for 3 years before surgery, anterograde amnesia

Clive Wearing (conductor)

• Hippocampus damaged by a virus

• STM/WM intact

• Anterograde amnesia, some retrograde amnesia but remembers his wife

Patient KF

• TBI from a motorcycle accident

• Impaired STM/WM

  • Digit span = 2

  • Couldn’t repeat words

  • Very limited recency effect

• Intact LTM

Testing Memories

• Explicit tests

  • Free recall

  • Recognition

• Implicit tests

  • Word fragment completion (fill in blank w/ first word that comes to mind)

  • Lexical decision task (is this a real word?

  • Savings in relearning

Long-Term Memory

• Explicit (declarative) memory: can be consciously retrieved

  • Episodic: specific experience

  • Semantic: generalized knowledge

• Implicit (non-declarative) memory: a change in behavior as a result of experience

  • Procedural memory

  • Priming: when presentation of a stimulus influences later processing of the same or similar stimulus

  • Classical conditioning

Double Dissociation between Episodic and Semantic LTM

• Yes semantic, no episodic

  • Clive Wearing

  • Kent Cochran

• No semantic, yes episodic

  • Patient MN

  • Patient LP

• Other fMRI evidence shows retrieving episodic and semantic memories activate different parts of the brain

Procedural Memory

• LTM for skills involved in particular tasks

• Procedural memory tasks: teach new procedural skills

  • Ex: HM got better at mirror tracing even though he never remembered having done the task

  • Ex: Clive Wearing improved piano, didn’t remember writing in his book but gravitated towards it

• Generally: amnesia patients have intact priming/implicit/procedural memory

Claparede and Amnesiac Implicit Memory

• Introduced himself every day

• Shocked amnesiac patient one day, and she refused to shake his hand the next day

Future Memory

• Ken Cochrane: couldn’t imagine the future

• Some brain areas used for episodic recall and imagining future events

  • In both cases, your brain is performing a simulation

• Constructive episodic simulation hypothesis: memory is constructive and used to simulate future events

Memory in the brain

• WM: mostly pre-frontal cortex

• LTM: likely distributed across whole cerebral cortex

  • Memory stored through LTP

• Hippocampus: likely involved with both

• Semantic vs. episodic

  • Double dissociations suggest separate locations

Interplay Between Episodic and Semantic Memories

• Most things start as both episodic and semantic → lose episodic over time

• Repisodes: repeated episodes get merged into a generalized representation over time

• Semantic memory is enhanced when connected to an episodic memory

• Semantic memory influences episodic memory through directing attention

Encoding: Level of Processing Theory

• Retrieval is dependent on how well information is encoded

• Shallow processing

  • Maintenance rehearsal

  • Little attention to meaning

  • Processing of physical features

• Deep processing

  • Elaborative rehearsal

  • Focusing on meaning of words and relationships between concepts

Encoding Strategies

• Grouping/organization

  • Structure of organization can cute memory

  • Words from structure can cue other words

• Imagery (mental images)

• Self-reference effect: memory is better if you relate a word to yourself

• Generation effect: generating material yourself enhances learning and retention

Encoding specificity and TAP

• Encoding specificity: retrieval cues are most effective to the extent that they are similar to conditions of encoding

  • Context dependence: overlap of external state

    • Ex: scuba diving study, uses spreading activation

  • State dependence: overlap of internal state

    • Ex: marijuana study

• Transfer appropriate processing: memory performance is dependent on the amount of overlap of cognitive processes at encoding and retrieval

  • Ex: rhyme task vs. semantic task

  • Crossover interaction: performance best when type of processing is similar at encoding and retrieval

Illusions of Learning

• Fluency of reading because of re-reading does not mean better memory

• Familiarity effect

• Highlighting: shallow processing

Mnemonics

• Fancy encoding and retrieval strategies

• Pegword method: prememorize a word with each number and associate with images

• Method of loci/memory palace: imagine things you want to remember in different locations in a place you know well

Methods of enhancing retrieval

• Testing Effect/Retrieval Practice: being tested on new material results in better memory

  • Demonstrated by Roediger and Karpicke: participants studied text passages, more retrieval led to more memory after a longer retention interval

• Spacing Effect: distributed practice is better than massed practice

Retrieval Cues

• Stimuli encoded along with internal and external aspects of experience

• Retrieval is facilitated by extent to which encoding situation and retrieval situation are similar

Consolidation

• Transforms new memories from fragile to more permanent state

• Synapses and LTP: synaptic, faster

• Systems: gradual reorg of connections, slower

  • Over time, hippocampus may not need to be involved bc cortical areas may form connections on their own

• Sleep helps consolidation

  • Less retroactive interference?

Autobiographical Memory

• Memory for your own life

• Multidimensional (all 5 senses + spatial + thoughts/emotions)

• Functions

  • Directive (to solve new problems)

  • Social (develop and maintain bonds)

  • Self-representative (maintain identity)

  • Adaptive (internal regulation of mood)

Memory and the Self

• Experiencing self: WM (short, rich, most moments lost without a trace)

• Remembering self: LTM, representative moments (beginning, peak, end)

• Theory: Self-Memory System

  • Life story

  • Themes (education, work, relationship)

  • Lifetime periods

  • General events

  • Episodic memories

Emotion and Memory

• Emotions: biologically-based responses to events/situations that are seen as personally relevant

  • Usually involve changes in physiology

• Amygdala involved in encoding emotionally arousing events

• Emotional arousal (increased cortisol) → better encoding

• Emotional stimuli → better remembered and attracts more attention

• Related to state-dependent memory (emotion can be a retrieval cue)

• Emotional events may be rehearsed more frequently

Childhood Amnesia

• As adults, we can’t retrieve anything from our first few years of life

• Brain development?

  • Implicit memory: very early, some structures present at birth

  • Episodic memory: frontal lobes not functional until 1+ years, hippocampus developing into childhood

• Sense of self?

  • Infants lack clear self-concept around which memories can be structured

  • Don’t yet understand they’re separate from their environment

  • Don’t pass Rouge test until 2

• Language?

  • Helps organize memory

  • Pre-verbal infants encode things differently so we can’t access after we have language

  • Magic Shrinking Machine study

• Social Cultural theory

  • “Maternal reminiscing”: parents differ in how much and how they talk about the past with their kids

  • More elaborative/detailed parental reminiscing: kid’s better self-concept and narrative about the past

• Context changes a lot from infancy to adulthood (ex: size)

Dr. Carolyn Rovee-Collier

• Infant memory works like adult memory but we’re not testing the right way

• Used ribbon & mobile task (2-6 mos) and train task (to 2 yrs)

• Retention increased

Reminiscence Bump (Why?)

• Self-image

  • Identity formation occurs in young adulthood

  • Memory is better for crucial self-defining events

• Cognitive

  • Encoding is best during periods of rapid change followed by stability

  • Evidence: people who emigrate to US later in life have a bump that occurs later

• Cultural life script

  • Memory is better for events that fit into the expectations of a culture

Memory and Normal Aging

• Crystallized intelligence increases

  • Word knowledge, LTM for existing knowledge

• Fluid intelligence decreases

  • LTM for new materials, speed of processing, WM

Dementia and Alzheimer’s

• Dementia: deterioration of memory and other cognitive functions bad enough to interfere with life

• Alzheimer’s: progressive neurodegenerative disease

  • Pathology: neuron death starts in hippocampus, entorhinal cortex (interface btwn hippocampus and cortex) and spreads all over cortex

    • Amyloid plaques btwn neurons form

    • Tau protein tangles in neurons form

  • Symptoms:

    • Loss of memory, language

    • Disorientation

    • Impaired perception

    • Changes in personality/mood

    • Impaired decision making

Evaluating retrieval

• Completeness: how much of what happened do you remember?

  • Forgetting: failure to access stored info

• Accuracy: how much of what you remember actually happened that way?

  • Errors and distortion: reconstructive nature of LTM

Source monitoring, false fame, and illusory truth

• Source monitoring failure: when something feels familiar, but we don’t remember the source

• False fame effect:

  • Shown a list of fictitious names

  • Later shown a mix of same fictitious and real famous names

  • Rated fame of each name, and some fake names rated as famous

  • Failure of source monitoring, priming

• Illusory truth: familiarity of statements increases their credibility

The “Room Study”

• Procedure:

  • Encoding phase: experimenter has patient wait in office

  • Test phase: free recall of waiting room

• Schema for typical academic office influenced results

DRM Procedure

• Study a list of words highly related to a missing critical word

• People often falsely remember the critical word

• Hybrid lists (phonological and semantic associations) bring out error

• Due to spreading activation

Misinformation/Suggestibility

• Loftus: showed people film of a car accident, asked how fast they were going when they smashed/hit each other

  • Estimated speed went up with smashed

• Loftus: people viewed slides showing a crossing (stop or yield sign)

  • Question asked using stop sign or yield sign influenced slide picked even though they knew question might be wrong

• Hyman et at

  • Told students about false events they had no memory of

  • 2 days later: remembered and made up details

• Loftus: lost in shopping mall

  • Told participants 4 stories (one fake)

  • 25% falsely remembered story

Associations

• Spreading activation in an associative network can lead to correct retrieval, interference, or incorrect retrieval

Context Influences (Wade)

• Viewed pictures of childhood events (1 doctored) over 2 weeks

• 50% of participants produced detailed descriptions of the false event by the end

Repressed/Recovered Memories

• Freudian psychology: memories are repressed when associated with high levels of trauma

  • Therapists used Recovered-Memory-Therapy

Smell and Memory

• Neural pathway bypasses thalamus, straight to the limbic system (amygdala and hippocampus(

• LOVER: limbic system, old memories, vivid recall, strong emotions, rare

• Odor stimuli usually close in space (fight/flight)

Music and Memory

• Activates emotion which can enhance memory

• Can take us back (especially to reminiscence bump)

• Activates many brain regions (helpful when some areas are damaged)

Eyewitness Memory

• Source-monitoring and familiarity-based errors

  • Unconscious transference to bystanders

  • Greater familiarity = greater confidence

• Misinformation effect

  • Leading questions

Other-Race Effect

• People are worse at making cross-racial identification

Improving Facial Recognition

• Other race effect interventions: lineup construction (fillers similar to suspect, say perpetrator may not be present, sequential vs. simultaneous)

• Recognition is more accurate if people can decide based on photos from different angles

Cognitive Interview

• Geiselman

• Reinstate environment mentally (eyes closed)

• Described in various orders + viewpoints

• Report all small details

• Limitations:

  • More details: recall of more incorrect details

  • Doesn’t prevent misinfo effects

  • Less effective for stressful events