Cognition Midterm 2

Ch 6-8

Memory

• Processes involved in retaining, retrieving, and using info about stimuli, images, events, and skills after the original information is no longer presents.

• Active any time some past experience has an impact on how you think or behave now and in the future.

Atkinson and Shiffrin (1968)

developed model of memory that includes sensory→ short-term→ long-term.

Sensory Memory

• Initial stage that holds all incoming information (sensory stimulation) for seconds or fractions of a second

• Info decays very quickly

Short-term Memory

Holds five to seven items for about 15-20 seconds

Long-Term Memory

can hold a large amount of info for years or even decades

Control Processes

Active processes that can be controlled by the person

• Rehearsal

• Strategies used to make stimulus more memorable

• Strategies of attention that help you focus on specific stimuli

Persistence of Vision

Retention of the perception of light

• Trail of light from a moving sparkler

• Frames in film

Sperling (1960)

Measured the capacity and duration of sensory memory

• An array of letters is flashed quickly on a screen

• Participants are asked to report as many as possible

• Average report was 4.5/12 letters (37.5%)

Partial Report Method

Participants heard a tone that told them which row of letters to report

• Average report was 3.3/4

• Participants could report any of the rows

Delayed Partial Report Method

Presentation of tone delayed for a fraction of a second after the letters were extinguished

• Performance decreases rapidly

Iconic Memory

Brief sensory memory of the things we see

• Responsible for the persistence of vision

Echoic Memory

Brief sensory memory of the things that we hear

• responsible for the persistence of sound

Short-Term Memory Storage

• Stores small amounts of info for a brief duration

• Includes both new info received from the sensory stores and info recalled from long-term memory

Measuring the duration of short-term memory

• Read 3 letters, then a 3-digit number

• Begin counting backwards by 3s

• After a set time, recall 3 letters

• After 3 seconds of counting, participants performed at 80%

• After 18 seconds of counting, participants performed at 10%

• Reduction in performance is explained by decay, the vanishing of a memory trace due to the passage of time and exposure to competing stimuli

How many items can be held in short-term memory?

Digit span: How many digits a person can remember

• Typical result: 5-8 letters

Change Detection

Chunking: Small units can be combined into larger meaningful units

• Chunk is a collection of elements strongly associated with one another but weakly associated with elements in other chunks

Ericsson and Coworkers (1980)

Trained a college student with average memory ability to use chunking

• Student demonstrated an initial digit span of 7

After 230 one-hour training sessions, the student could remember up to 79 digits

• Performance was achieved by chunking them into meaningful units

Working Memory

• Similar to short-term memory

• Baddeley and Hitch (1974)

• Limited-capacity system for temporary storage and manipulation of information for complex tasks such as comprehension, learning, and reasoning

• Set up to process different types of info simultaneously

• Function is hampered when similar types of info are presented simultaneously

Working Memory vs Short-Term Memory

• STM hold information for a brief period of time

• WM is concerned with the storage, processing and manipulation of information, and is active during complex cognition

The Phonological Loop

Phonological Similarity Effect:

• Letters or words that sound similar are confused

Word Length Effect;

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

• Rehearsing long words and producing them during recall takes longer

Articulatory Suppression

Speaking prevents the rehearsal time of items to be remembered

• Reduces memory span

• Eliminates word length effect

• Reduces the phonological similarity effect for reading words

The Visuospatial Sketch Pad

The creation of visual images in the mind in the absence of a physical visual stimulus.

Shepard and Metzler (1971)

• Their study employed the mental rotation task.

• Tasks that called for greater rotation took longer

The Central Executive

This process acts as the attention controller

• allows attention to be focused, divided, and switched

• controls suppression of irrelevant info

• Preservation: Repeatedly performing the same action or thought even if its not achieving the desired goal

Episodic Buffer

• Backup store that communicates with long-term and working memory components.

• Holds information longer and has greater capacity than phonological loop or visuospatial sketch pad

Damage to Prefrontal Cortex

• The prefrontal cortex is responsible for processing incoming visual and auditory information.

• Monkeys without a prefrontal cortex have difficulty holding information in working memor

Funahashi and Coworkers (1989)

Single cell recordings from monkey’s prefrontal cortex during a delayed-response task

• Neurons responded when stimulus was flashed in a particular location and during delay

• Information remains available via these neurons for as long as they continue firing.

Stokes (2015)

Information is stored in short-term changes in neural networks

(a) Activity state, showing that some neurons in the network (blue circles) are activated by the incoming stimulus.

(b) Synaptic state, showing connections that have been strengthened between neurons in the network (blue lines).

(c) Activity associated with the memory.

Long-Term Memory

• archive of info about past events and knowledge learned

• Works closely with working memory

• Ranges from a few moments ago to as far back as one can remember

• Recent memories are more detailed

Serial Position Curve

Created by presenting a list of words to a participant, one after another

• Primary effect: tendency for the beginning of a list of words to be better remembered than the middle

• Recency effect: tendency for the end of a list of words to be better remembered than the middle

Coding

Refers to the form in which stimuli are represented in memory

Visual and auditory encoding occurs in short and long term memory

Semantic Encoding

Also occurs in short and long term memory

Wickens and Coworkers (1979)

Studied semantic encoding

• interference enhanced by meanings of words

Semantic Coding in Long Term Memory

• Recognition Memory: the ability to identify a previously encountered stimulus

• Sachs (1967): do participants remember word or meaning

H.M.

Surgery removed hippocampus

• retained STM but unable to transfer info to long term memory

K.F.

Accident damaged parietal lobe

• STM was impaired (reduced digit span) but functional LTM was retained

• The patient was able to form and hold memories

Episodic Memory

Involves mental time travel

• tied to personal experience

• Self knowing

• Can be lost, leaving only the semantic

• Acquiring knowledge may start as episodic but then “fade” to semantic

Semantic Memory

Doesn’t involve mental time travel

• general knowledge, facts-“knowing”

Tulving (1985)

Defined distinction between episodic and semantic memory

K.C.

Damaged hippocampus

• no episodic memory, can relive past events

• Semantic memory intact, can remember general info about the past

L.P.

• Impaired semantic memory

• Episodic memory intact, can remember past events and create new event memories

Autobiographical Memory

Specific experiences, including semantic and episodic

Personal Semantic Memory

Semantic memories that have personal significance

What happens to episodic and semantic memories as time passes?

Forgetting increases with longer intervals after encoding

Forgetting is not an “all or nothing” process:

• Familiarity: semantic memory

• Recollection: episodic memory

Remember/Know procedure

• Semanticization of remote memories:

• Episodic details for memories of long-ago events may be lost

Prospective Memory

Remembering and performing actions to planned for later

Constructive episodic simulation hypothesis (Schacter and Addis, 2007, 2009)

• episodic memories are extracted and recombined to create simulations of future events

• This function helps us to anticipate future needs and guide behaviours

• This adaptive function is similar to mind wandering

Explicit Memory

Memories are consciously experienced

Implicit Memory

Occurs when learning from experience is not accompanied by conscious remembering

Procedural Memory

• Skill memory: memory for actions

• Implicit: no memory of where or when learned

• Perform procedure without being consciously aware of how to do them

• People who can’t form new LTMs can still learn new skills (e.g. H.M.)

Priming

Presentation of priming stimulus changes a persons response to a test stimulus

Graf and Coworkers (1985)

Repetition Priming:

• test stimulus is the same or similar to priming stimulus

• This is referred to as implicit memory

• A person doesn’t necessarily remember original presentation of priming stimuli

Perfect and Askew (1994)

Propaganda Effect: people are more likely to rate statements read or heard before as being true

• involves implicit memory because it can occur when people are many aware of previously seeing or hearing statements

• This finding has implications for advertising

Classical Conditioning

• Pairing a neutral stimulus with a reflexive response

• Involves implicit memory when a person has forgotten about original pairing of stimulus bc the response

Operant Conditioning

Leading process in which behaviours recur through reinforcement or diminish/disappear through punishments

• can be used to shape behaviour towards more desired outcome

• SHAPING is and important principle in operant conditioning because similars to using clay to make pottery, behaviour is incrementally modified

Positive Reinforcement

Adding smt as a reward for preferred behaviour

Negative Reinforcement

Removing smt as a reward for a preferred behaviour

Positive Punishment

Adding smt as a consequence to discourage a non-preferred behaviour

Negative Punishment

Removing smt as a consequence that discourage non-preferred behaviour

Getting Info into LTM

Encoding → Retrieval → Maintenance Rehearsal → Elaborative Rehearsal

Encoding

acquiring information and transforming it into memory

Retrieval

transferring memory from LTM to working memory

Maintenance Rehearsal

repetition of stimuli that maintains info but doesn’t transfer it to LTM

Elaborative Rehearsal

Using meanings and connections to help transfer info to LTM

Shallow Processing

• little attention to meaning

• focus on physical features

• poor memory

Deep Processing

• close attention to meaning

• better memory

Levels of Processing Theory

1. Physical feature = shallow processing

2. Rhyming = deeper processing

3. Fill in the blanks = deepest processing

Factors that aid encoding

• Visual imagery

• Self-reference effect

• Self-relevant or commonly used words

• Generation effect

• Organizing to-be-remembered information

• Relating words to survival value

• Retrieval practice

Gordon Bower and Coworkers

Organizing info

• create connections

• active creation

• organization: recall by groups, present in an organized way, meaningful framework

Bransford & Johnson

Presented participants with difficult-to-comprehend info

• Experimental group 1 first saw a picture that helped explain the info

• Experimental group 2 saw the picture after reading the passage

• Group 1 outperformed the others

Having a mental framework of comprehension aided memory encoding and retrieval

Relating Words to Survival Value

• Nairne had participants imagine that they were stranded on the grassland of a foreign country without any basic survival materials

• As they were imagining this, they were presented with a list of words

• Their task was to rate each word based on how relevant it would be for finding supplies of food and water and providing protection from predators

Retrieval Practice (Roediger and Karpicke 2006)

Which of re-reading the material or being tested on material result in a stronger memory trace

• Participants either:

• Reread the passage (rereading group)

• Take a recall test (testing group)

• Then tested recall after delay; testing group performed better

• Testing Effect

Effective Studying

• Elaborate

• Generate and Test

• Organize

• Sleep

• Avoid “Illusions of Learning”

• - Rereading

• - Fluency

• - Familiarity

• Be an “Active” note taker

Retrieving Info from LTM

Retrieval → Cued-Recall

Retrieval from LTM

Process of transferring info from LTM back into working memory (consciousness)

• Most of our failures of memory are failures to retrieve

Cued-Recall

Cue presented to aid recall

• Increased performance over free recall

• Retrieval cues most effective when created by the person that uses them

Improving Learning and Memory

Distributed vs massed practice effect

• difficult to maintain close attention throughout a long study session

• studying after a break gives feedback about what you already know

Encoding Specificity

We learn info together with its context

Baddeley’s (1975)

Diving experiment

• Best recall occurred when encoding and retrieval occurred in the same location

State-Dependent Learning

Learning is associated with a particular internal state

• Better memory if person’s mood at encoding matches mood during retrieval

Matching the Cognitive Task (Morris et al. 1977)

Transfer-appropriate processing:

phenomenon whereby the results of a memory task will be better if the type of processing used during encoding is the same as the type during retrieval

Consolidation (Muller and Pilzecker 1900)

Transforms new memories from fragile state to more permanent state

• Synaptic consolidation occurs at synapses, happens rapidly

• Systems consolidation involves gradual reorganization of circuits in brain

Information Stored at Synapses

Hebb (1948):

• Learning and memory represented in the brain by physiological changes at the synapse

• Neural record of experience

Long-Term Potentiation (LTP)

• Enhance firing of neurons after repeated stimulation

• Structural changes and enhanced responding

Retrograde Amnesia

Loss of memory for events PRIOR to the trauma

Graded Amnesia

Memory for recent events is more fragile than for remote/past events

• Sub type of retrograde amnesia

Anterograde Amnesia

Inability to form long-term memories after the trauma

Standard Model of Consolidation

• Retrieval depends on hippocampus during consolidation; after consolidation hippocampus is no longer needed

• Reactivation: hippocampus replays neural activity associated with memory

Multiple Trace Hypothesis

• Questions the assumption that the hippocampus is only important at the beginning of consolidation

• The hippocampus has been shown to be activated during retrieval of both recent and remote memories (Gilboa et al., 2004)

• The response of the hippocampus can change over time (Viskontas and Coworkers, 2009)

Consolidation and Sleep: Enhancing Memory

Steffan Gais and Coworkers (2006)

• Students learn a list of 24 pairs of English-German vocabulary words

• The “sleep” group studied the words and the went to sleep within 3 hours

• The “awake” group studied the words and remained awake for 10 hours before getting a night’s sleep

• Awake group had higher percent of forgetting

Ines Wilhelm and Coworkers (2011)

• Participants learned a task and where told either that they would be tested on the task

• Expected group had higher percentage of correctly completing the task

Reconsolidation

Reactivating a consolidated memory makes it fragile/labile again, requiring new protein synthesis to be re-stored

Rat Study (Nader):

• Blocking protein synthesis (anisomycin) during reactivation erases the fear memory. (injecting without reactivation leaves the memory intact)

Human Study (Hupbach):

• Reactivating List A prior to learning List B causes List B items to intrude into List A recall, showing that memory reactivation allows modifictation/updating

Multidimensional Memory

• Spatial

• Emotional

• Sensory components

Greenberg and Rubin (2003)

• Patients who can’t recognize objects also experience loss of autobiographical memory

• Visual experience plays a role in forming and retrieving AM

The Multidimensional Nature of Autobiographical Memory

Cabeza et al. (2004):

• Comparing brain activation caused by autobiographical memory and lab memory

• Participants viewed: Photographs they took (own photos)

• - Prefrontal Cortex (information about self)

• - Hippocampus (recollection)

• Demonstrates the richness of autobiographical memory

• Photographs taken by someone else (lab-photos)

Events remembered well

• Significant events in a person’s life

• Highly emotional events

• Transition points

• Participants over 40 asked to recall events in their lives:

• Memory is high for recent events and for events that occurred in adolescence and early adulthood (between 10-30 years of age)

Reminiscence Bump

• Self-Image Hypothesis

• Cognitive Hypothesis

• Cultural Life Script Hypothesis

• Personal events are easier to recall when they fit the cultural script

Self-Image Hypothesis

• Memory is enhanced for events that occur as a person’s self image or life identity is being formed

• People assume identities during adolescence and young adulthood

• Many transitions occur between ages 10 and 30

Cognitive Hypothesis

• Encoding is better during periods of rapid change that are followed by stability

• Evidence from those who emigrated to the US after young adulthood indicates reminiscence bump is shifted

Cultural Life Script Hypothesis

Each person has:

• A personal life story

• An understanding of culturally expected events

Memory for “Exceptional” Events

• Emotional events are more easily and vividly remembered

• Emotion improves memory, becomes greater with time (may enhance consolidation)

• Brain activity in amygdala:

• - For example, the tendency to attend to a weapon during a crime