Memory
The process of using info. that was obtained in the past in order to generate some cognitive function in the present
Memory Process
Encoding- the initial process of info. that it is represented in the NS
Storage- info. encoded by the NS remains encoded in some form for a longer duration than immediate processing
Retrieval- being able to cognitively access stored info. for a given purpose
Measures of Memory
Capacity
Duration
Capacity
How much info. a memory sys. can hold
Certain types of memory can process more/less info. compared to others
STM < LTM
Duration
How long info. remains in a memory sys.
Some types of info. are lost very quickly from memory, while others are retained for a lifetime
A childhood phone # > This morning’s breakfast
Modal Model of Memory
3 types of memory w/ its own capacity & duration
Sensory memory
STM
LTM
2 different kinds of memory storage
For current tasks- STM
For long-term storage - LTM
Visual of the Modal Model of Memory
Sensory Memory
Function: Briefly stores the info. just encoded by sensory organs
Purpose: Holds memory in place before it is selected by attention & passed on to STM
Short-Term Memory
Function: Store attended information from Sensory Memory for 15-30 secs
Purpose: Hold info. that can be repeated/rehearsed for encoding
Only encoded info. is moved to LTM for future retrieval
Ex. repeating a phone number someone just told you for recall at a later time
Chunking
Any combination of letters, numbers, or sounds that constitute a meaningful whole
The capacity to chunk info. into larger units depends on engaging LTM where patterns of previously encountered combinations are held.
The approx. capacity of auditory STM is 7 +/ -2 chunks
Ex. PEMDAS: Parentheses, exponents, multiplication, division, addition, subtraction
Duration of STM
Theoretically forever, as long as you can rehearse the info.
Rehearsal
The repetition of info. in STM which reactivates the initial encoding
Ex. Grocery trip: milk, eggs, bread
Proactive Interference
Info. causes you to forget something you could learn in the future
First learn (material A) > then learn (material B)
Retroactive Interference
Info. causes you to forget something in the past
Then learn (material A) > first learn (material B)
Working-Memory Model
… STM is an active workspace in which info. is manipulated for a given task
Visual and Verbal Task Exp.
… suggest that visual and auditory memory are processed separately from one another and do not interfere w/ one another
Visuo-Spatial Sketchpad
Visual component of the WM model
Hold info. in the NS while also having the ability to analyze & manipulate it
Phonological Loop
Auditory component of WM model
Allows auditory info. to be repeated so it can be used and/or analyzed
Central Executive
Coordinates b/w the phonological loop and the visual sketchpad
Determines what info. makes it into STM in the first place
Research suggests that ind. differences in STM capacity (the fact that some people can remember more items than others) may be due to differences in the ability to filter out irrelevant info. from memory
Individual Differences
… correlated w/ measures of general intelligence
Relationship likely due to developmental factors- more space in working memory could bolster other cognitive capacities including: visuo-spatial capacity, math performance, reasoning ability
Neural Basis of STM/WM
Auditory WM activates auditory regions of the brain (temporal lobe)
Visual WM activates visual regions of the brain (occipital lobe)
Prefrontal cortex & frontal lobe may be where the central executive is located
Neurological Differences in STM & LTM
Behavioral differences b/w STM & LTM suggest that there may be distinct memory sys.s
Amnesia
Amnesia
Severely impaired LTM due to brain trauma
Retrograde Amnesia
Difficulty remembering events that occurred leading up to the event
Memory lost before the event
Anterograde Amensia
Difficulty remembering any new info. they encounter
Memory lost after event
Case Studies
H.M- Deficits in LTM
C.W - Deficits in both STM/LTM
K.F - Deficits in STM
Encoding Specificty
Serial Position Effect- primacy and recency effects
Levels of Processing- superficial, intermediate, deep, we remember more when we deeply process the meaning of something
Memory Retrieval- mnemonics help
The brain encodes associations b/w experiences & the world
Experiences <> world
Allows us to make predictions about or environment
Different Types of LTM
Explicit/declarative memory
Episodic memory
Semantic memory
Episodic > semantic
Implicit memory
Explicit/Declarative Memory
Memories that we can verbally describe or declare
Episodic Memory
Memories of event that have happened directly to us is in our lives
Can recall sensory info. in sequence
Likened to a mental time travel
Semantic Memory
Memoires w/ info. w/o sensory details
The meaning of words, your address, phone number…
Implicit Memory
Info. that is encoded & stored, then retrieved outside of consciousness
Includes procedural memory as well as prejudice > automatic neg. judgements of an ind/gp, even if the judgement/attitudes are outside of conscious awareness
Procedural Memory
Learned abilities to perform an automatic behavior/action
Walking, swimming, bicycling
The brain has encoded patterns of movements
Is particularly immune to forgetting compared to other types of memory
Familiarity Effect
People tend to rate something more favorably if they have encountered it before (music, photos)
Even of they don’t remember seeing them
Propaganda Effect
Ind.s presented w/ statements that they had heard before were more likely to rate them as true compared to never-before-heard statements of accuracy
Autobiographical Memory
Episodic memories about events we’ve experienced & semantic memories of basic facts about ourselves
Studying ABM
Cannot study ABM like other types
Must rely on retrospective reports through personal interviews
Has limitations:
Lack of control, order of encoding, undetermined accuracy
Directive ABM
Allows for retrospection on past experiences to inform & guide current actions
Social ABM
Allow ppl to share experiences & create social bonds
Self-Representational ABM
Allow ppl to look into the past to inform behavior to act consistently w/ a self image & maintain a stable identity
Self-Memory System
AB knowledge base- stores info. & facts about past life events
Comparable to LTM & WM sys.s
AKA cold storage- active workspace for pulling up memories
Goal: coherence- supporting our existing beliefs about ourselves & the world
Working Self- a set of current personal goals that determine how the base is accessed
Major distinguishable periods in our lives that have a specific beginning & end time (grade school, living in a city, first job)
ABM Base
Lifetime periods - general events
Relationship theme < first date, second date
Work theme < working in the corner office
Event-specific knowledge
Decay of SMS
Most events we experience are not stored as episodic memories- even if we keep some semantic memories, we may not have episodic elements
The dissolution of event-specific knowledge, leaving only general events or lifetime periods
Maintain episodic memories for hours or days > most fade into semantic memories > some are completely forgotten
Memory Retention
Emotion
Importance
Life Stage
Importance of an event has a large impact in whether it is remembered
We tend to remember both pos. & neg. events:
1st kiss & birth of a child
Death & breakup
Infantile Amnesia
Most adults remember very few or no episodic memories before the age 2-4 yrs, does not affect implicit memory as much as explicit
Hippocampal change
The hippocampus (LTM consolidation) is underdeveloped until age 4
Neurogenesis
Production of new neurons
Building the brain could cause memories to be overwritten
Lang. abilities
Juvenile lang. abilities
Ability to reconstruct episodic memory may depend on lang. for “story telling”
State-dependent learning
Differential emotional reactions to events
Highly emotional events remembered…inability to retrieve old memories
Flashbulb Memories
Memories of a high-emotion event that many people experienced at the same time
9/11, Challenger disaster, MLK Assassination, JFK Assassination
Ppl tend to believe that their memories of these events
Maintain vivid details of events
Are branded into memory permanently
Do not decay over time
Not immune to forgetting, but are better remembered < provoke an emotional response, leading to better encoding, thinking & talking about them promotes consolidation
Culturally dependent:
Event relevance & subsequent flashbulb memory formation depends on one’s identity
Constructive Nature of ABM
Memories are interpretations of events & the world
Can be flawed & false, much like perceptual processes
Eyewitness testimony is inherently flawed
Lang. & emotions can bias “eyewitnesses”
Ch 6 Summary
6.1 Encoding is the initial processing of information. Storage is how
inform is maintained across time, and retrieval is your ability to access the stored information. Memory can be measured by examining the capacity and duration of different systems.
6.2 The modal model of memory has three components: sensory, short-term, and long-term memory. Sensory memory refers to the initial processing of information from our sensory systems (e.g., visual and auditory). Information can be maintained in short-term memory if it is actively rehearsed but will likely be lost otherwise. Information is then passed to long-term memory, which can hold large amounts of information
across your lifespan.
6.3 The working memory model for short-term memory has been theorized to have three distinct stores of information to explain how you actively think and cognitively manipulate information. These three stores are the visuo-sketch pad, phonological loop, and central executive.
6.4 The neural basis of short-term/working memory is not located in one specific region. The modality-specific regions are found to be active in working memory tasks. Frontal lobe regions are thought to be primarily responsible for central executive tasks.
6.5 Recurrent neural networks are a class of neural-network models
applied to sequential data that contain 'recurrent' nodes that loop their output back into themselves as inputs, allowing them to process past and current inputs simultaneously.
Ch 7 Summary
7.1 Neuropsychology gives us information about the dissociation of short-term, long-term, episodic, and semantic memory.
7.2 Rehearsal is essential to moving information from short-term to long-term memory. Certain conditions make information more likely to be moved into LTM, including order to presentation, level of processing/encoding, and the environment in which encoding/retrieval took place. Additionally, the times and level at which information is repeatedly observed impacts LTM.
7.3 Explicit/declarative memories are those that we can verbally describe, episodic memories are those of events that happened directly to us in our lives, and semantic memories are memories with information, but no sensory detail. Implicit memory is memories that we may not be consciously aware of, but can be assessed using the Implicit Association Test. These types of memory have neural and behavioral differences.
7.4 Synaptic and system consolidation allows the brain to condense memories for storage in LTM (sometimes indefinitely). This occurs through the creation of new connections between neurons. Although the role of relevant neural structures is debated (i.e., the hippocampus), this process allows the brain to maintain memories across time.
Ch 8 Summary
8.1 Autobiographical memory (AM) serves as guide for our intentional action and can increase social cohesion through shared experience and a stable self representation. AMs can be organized into broad tiers of lifetime periods, then more specific related sequences of general events, and finally into more detailed memories of event-specific knowledge.
8.2 We do not retain memories from early life (~before the age of 4 years). This could be due to changes in the brain, social experience, and/or cognitive development.
8.3 Emotion leads to better memory encoding and retrieval due to increased amygdala activation. Highly emotional events can lead to flashbulb memories, which are more resistant to forgetting, but can still be impaired over time. Despite their fallibility, people are highly confident of these memories.
8.4 Memories are subjective interpretations of events. They are vulnerable to manipulation including the introduction of false information and the fabrication of false memories. This is especially consequential for the legal system that is highly dependent on eye-witness testimony. Errors in eye-witness memory and subsequent convictions has been addressed by the Innocence Project, which aims to exonerate wrongfully convicted individuals who were prosecuted based on eye-witness testimony.
8.5 The PFC, medial temporal lobe (specifically the hippocampus), and amygdala are all involved in AM construction, retention, and retrieval.