Memory: Models and Research

Methods

Chapter 5Cognitive Psychology

Who is the president of the United States? What is today’s date? What did you have for breakfast? What does your best friend look like, and what

does your friend’s voice sound like? What were some of your experiences when

you first started college? How do you tie your shoelaces?

The means by which we retain and draw on

our past experiences to use that information in the present.

As a process, it refers to the dynamic mechanisms associated with storing, retaining, and retrieving information about past experience.

Memory

Encoding – you transform sensory data into a

form of mental representation.

Storage – you keep encoded information in memory.

Retrieval – you pull out or use information stored in memory.

3 Operations of Memory

Tasks Used for Measuring Memory

RECALL VS. RECOGNITION MEMORYIMPLICIT VS. EXPLICIT MEMORY

Recall vs. Recognition Tasks

You produce a fact, a word, or other item from

memory. ex. Fill-in-the-blank and most essay tests.

Require expressive knowledge, in which you have to produce an answer.

Ex. “The term for persons who suffer severe memory impairment is ___________”

Recall

You select or otherwise identify an item as being one

that you have been exposed to previously. Ex. Multiple choice or true or false tests.

Referred to as tapping receptive knowledge. Receptive means “responsive to stimulus”. You respond to stimuli presented to you and decide whether you have seen them before or not.

Ex. “The term for people with outstanding memory ability is (1) amnesics (2) semanticists (3) mnemonists , or (4) retrograders.”

Recognition

3 Main Types of Recall Task

SERIAL RECALLFREE RECALLCUED RECALL

You recall items in the exact order in which

they were presented.

For example, remember the following list of comedians in order: Stephen Colbert, Jon Stewart, David Letterman, Conan O’Brien, Jay Leno

Repeat the digits in exact order, 2-8-7-1-6-4

Serial Recall

You recall items in any order you choose.

Ex. Repeat the items in the list in any order in which you can recall them: Dog, pencil, time, hair, money, restaurant

Free Recall

Read each word aloud at a rate of

about one per second. Cover up each word as you read, to avoid rereading any items. Alternatively, you can ask a friend to read these words aloud to you. After reading or hearing the words, close the book and try to recall as many words as you can. Do not be concerned about the order of recall. You can write them down in whatever order you like.

Free Recall Test

Brick lamp Truckgoat Stove cabbageApple baseball Doortree Book windowLadder Rifle pencil

Free Recall Test

You are first shown items in pairs, but during recall

you are cued with only one member of each pair and are asked to recall each mate.

Also called “paired-associates recall” For example, you could ask people to learn the

following pairings: Colbert-apple, Stewart-grape, Letterman-lemon, O’Brien-peach, Leno-Orange, and then ask them to produce the pairing for Stewart (grape).

Cued Recall

Implicit vs. Explicit Memory Tasks

Participants engage in conscious recollection.

Ex. They might recall or recognize words, facts, or pictures from a particular prior set of items.

Ex. “Who wrote Hamlet?”

Explicit Memory

We use information from memory but are not

consciously aware that we are doing so.

Ex. you can read the word in the photo without problems although a letter is missing.

Everyday you engage in many tasks that involve your unconscious recollection of information.

Implicit Memory

Word-completion tasks

Based on the priming effect Participants received a word fragment, such as the

first three letters of a word. They then complete it with the first word that comes to mind. For ex. Imp_ _ _ _ _

Priming is the facilitation of your ability to utilize missing information.

In general, participants perform better when they have seen the word on a recently presented list, although they have not been explicitly instructed to remember words from that list.

Priming Task

Word-completion task

Memory for processes Examples: riding a bike, driving a car Many of the activities that we do every day fall

under the purview of procedural memory; from brushing your teeth to writing.

Procedural Memory

Procedural Memory

Rotary Pursuit Task

Requires participants to maintain contact between an L-shaped stylus and a small rotating disk.

When a new disk or speed is used, participants do relatively poorly. But with the same disk and speed, they do as well as they had after learning the task, even if they do not remember previously completing the task.

Mirror Tracing

A plate with the outline of a shape drawn on it is put behind a barrier where it cannot be seen.

With practice, however, participants become quite efficient and accurate with this task.

Used to study the impact of sleep on procedural memory.

Rotary Pursuit Task

Mirror Tracing

Postulates that only one task is needed to

measure both implicit and explicit memory.

The model assumes that implicit and explicit memory both have a role in virtually every response.

Process-Dissociation Model

Intelligence and the Importance of Culture

in Testing

Measure skills and knowledge that relate to

the cultural experiences of the test-takers.

Culture-relevant tests

Models of Memory

The Traditional Model of Memory

Richard Atkinson and Richard Shiffrin (1968) proposed an alternative model that conceptualized memory in terms of

three memory stores:Sensory store

Short-term storeLong-term store

2 structures of memory:

Primary memory – holds temporary information currently in use.

Secondary memory – holds information permanently or at least for a very long time.

William James

Stores – structures for holding information

Memory – the information stored in the structure

The stores are hypothetical constructs —concepts that are not themselves directly measurable or observable but that serve as mental models for understanding how a psychological phenomenon works.

Atkinson-Shiffrin model

This emphasizes the passive storage areas in which memories are stored; but it also alludes to some control processes that govern the transfer of information from one store to another.

The initial repository of much information that

eventually enters the short- and long-term stores.

Capable of storing relatively limited amounts of information for very brief periods.

ICONIC STORE – a discrete visual sensory register that holds information for very short periods.

Sensory Store

George Sperling (1960) – made the initial

discovery regarding the existence of the iconic store.

He addressed the question of how much information we can encode in a single, brief glance at a set of stimuli.

Whole-report procedure – participants report every symbol they have seen

Partial-report procedure – participants need to report only part of what they see.

Sperling’s Discovery

Display from a Visual-Recall taskH B S T

A H M GE L W C

These data suggest that the iconic store can hold about 9 items. They also suggest that information in this store decays very rapidly.

Averbach and Coriell (1961): iconic memory can be erased.

Backward visual masking –mental erasure of stimulus caused by the placement of one stimulus where another one had appeared previously.

To summarize, visual information appears to enter our memory system through an iconic store. Erasure occurs if other information is superimposed on it before there is sufficient time for the transfer of the information to another memory store.

Subsequent Refinement

Capable of storing information for somewhat

longer periods but of relatively limited capacity as well.

It holds memories for a few seconds and occasionally up to a couple of minutes.

In general, our immediate (short-term) memory capacity for a wide range of items appears to be about seven items, plus or minus two.

Short-Term Store

An item can be something simple, such as a digit,

or something more complex, such as a word.

Ex. 10100100010000100010010, 100, 1,000, 10,000,

1,000, 100

If we chunk this string of numbers into larger units, we probably will be able to reproduce easily the 21 numerals as 6 items.

Capable of storing information for very long

periods, perhaps even indefinitely.

Here we keep memories that stay with us over long periods. We hold in it information we need to get us by in our day-to-day lives—people’s names, where we keep things, how we schedule ourselves on different days, and so on.

Long-Term Store

Wilder Penfield addressed this question while

performing operations on the brains of conscious patients afflicted with epilepsy.

He used electrical stimulation of various parts of the cerebral cortex to locate the origins of each patient’s problem.

His work was instrumental in plotting the motor and sensory areas of the cortex.

He found that patients sometimes would appear to recall memories from their childhoods.

These data suggested to Penfield that long-term memories might be permanent.

What is stored in the brain?

Permastore – refers to the very long-term storage of information, such as knowledge of a foreign language and of mathematics.

Schmidt and colleagues (2000) studied the permastore effect for names of streets near one’s childhood homes. Indeed, the author just returned to his childhood home of more than 40 years ago and perfectly remembered the names of the nearby streets.

These findings indicate that permastore can occur even for information that you have passively learned.

The Levels-of-Processing Model

PhysicalPhonological

Semantic

Postulates that memory does not comprise three or even any specific number of separate stores, but rather varies along a continuous dimension in terms of depth of encoding (Craik & Lockhart, 1972).

There are theoretically an infinite number of levels of processing (LOP) at which items can be encoded through elaboration—or successively deeper understanding of material to be learned (Craik & Tulving, 1975).

The deeper the level of processing, the higher, in general, is the probability that an item may be retrieved.

Levels-of-Processing Framework

Physical – visually apparent features of the

letters.

Phonological – sound combinations associated with the letters (e.g., rhyming)

Semantic – meaning of the word

Participants show very high levels of recall

when asked to relate words meaningfully to the participants by determining whether the words describe them.

The highest levels of recall occur with words that people consider self-descriptive.

Objects can be better remembered, for example, if they belong to the participant.

Self-reference effect

Is an organized system of internal cues

regarding our attributes, our personal experiences, and ourselves.

Thus, we can richly and elaborately encode information related to ourselves much more so than information about other topics.

Self-schema

Two other variables may be of more importance: the way people process (elaborate) the encoding of an item (e.g., phonological or semantic), and the way the item is retrieved later on.

Two kinds of strategies for elaborating the encoding: Within-item elaboration – it elaborates encoding of

the particular item in terms of its characteristics, including the various levels of processing.

Between-item elaboration – it elaborates encoding by relating each item’s features to the features of items already in memory.

An Integrative Model: Working Memory

Most widely used and accepted model todayBaddeley, 2007, 2009

Unsworth, 2009

Holds only the most recently activated, or

conscious, portion of long-term memory, and it moves these activated elements into and out of brief, temporary memory storage (Dosher, 2003).

Working Memory

The Components of Working Memory

Visuospatial SketchpadPhonological Loop

The Central ExecutiveSubsidiary Slave Systems

Episodic Buffer

Briefly holds some visual images.

1. Visuospatial Sketchpad

Briefly holds inner speech for verbal

comprehension and for acoustic rehearsal. We use the phonological loop for a number of

everyday tasks, including sounding out new and difficult words and solving word problems.

2 critical components: Phonological storage – holds information in

memory Subvocal rehearsal – used to put the

information into memory in the first place.

2. Phonological Loop

Ex. Tree, pencil, marshmallow, lamp, sunglasses, computer, chocolate, noise, clock, snow, river, square, store

When subvocal rehearsal is inhibited, the new information is not stored. This phenomenon is called articulatory suppression.

Articulatory suppression is more pronounced when the information is presented visually versus aurally (e.g., by hearing).

Thus, we can remember fewer long words compared with short words. Without this loop, acoustic information decays after about 2 seconds.

Both coordinates attentional activities and governs responses.

Critical to working memory because it is the gating mechanism that decides what information to process further and how to process this information.

It decides what resources to allocate to memory and related tasks, and how to allocate them.

Involved in higher-order reasoning and comprehension and is central to human intelligence.

3. Central Executive

Perform other cognitive or perceptual tasks.

4. Subsidiary Slave Systems

A limited-capacity system that is capable of binding

information from the visuospatial sketchpad and the phonological loop as well as from long-term memory into a unitary episodic representation.

Integrates information from different parts of working memory—that is, visual-spatial and phonological—so that they make sense to us.

This incorporation allows us to solve problems and re-evaluate previous experiences with more recent knowledge.

5. Episodic Buffer

Neuroscience and Working Memory

Phonological loop – left hemisphere of the lateral frontal and inferior parietal lobes as well as the temporal lobe.

Visuospatial sketchpad – (shorter intervals) occipital and right frontal lobes, (longer intervals) parietal and left frontal lobes.

Central executive – frontal lobes

Episodic buffer – bilateral activation of the frontal lobes and portions of the temporal lobes, including the left hippocampus.

Measuring Working Memory

Tasks to Assess Working Memory

Task: old or new?

Correct answer: new

Task (a) retention-delay task

Task: old or new?

Correct answer: new

Task (b) temporally ordered working memory

load task

Task: which is most

recent?

Correct answer: 7

Task (c) temporal order task

Task: find and repeat n-

back

Task (d) n-back task

Task: reproduce in

correct order

Also referred to as a digit-span task

Task (e) temporally ordered working memory

load task

Digit Span Test

684259317274319495287652968471629479876123456789

Cover the digit sets given with a piece of paper and then uncover one set at a time. Read the set quickly, look away, and then try to recall it correctly by writing the numbers in the correct order on another sheet of paper.

Task: reproduce final

items in correct order

Task (f) temporally ordered working memory

load task

Intelligence and Working Memory

Is (3 x 5) – 6 = 7? TABLE

Recall was highly correlated with verbal ability.

Multiple Memory Systems

Endel Tulving (1972)

SEMANTIC MEMORY – stores general world knowledge. It is our memory for facts that are not unique to us and that are not recalled in any paricular temporal context.

EPISODIC MEMORY – stores personally experienced events or episodes.

2 kinds of Explicit Memory

Hemispheric encoding/retrieval asymmetry

Attempts to account for differences in hemispheric activation for semantic versus episodic memories.

According to this model, there is greater activation in the left than in the right prefrontal hemisphere for tasks requiring retrieval from semantic memory. In contrast, there is more activation in the right than in the left prefrontal hemisphere for episodic-retrieval tasks.

HERA

Parallel distributed processing model

The key to knowledge representation lies in the connections among various nodes, or elements, stored in memory, not in each individual node.

PDP

Consists of many different nodes. Unlike in semantic

networks, it is not a single node that has a specific meaning, but rather the knowledge is represented in a combination of differently activated nodes.

This integrated view suggests that part of the reason we humans are as efficient as we are processing information is that we can handle many operations at once.

Effectively explains priming effects, skill learning (procedural memory), and several other phenomena of memory.

See page 213

Connectionist Network

Is the resulting activation of the node.

Prime – a node that activates a connected node.

Ex. Remembering going to a Chinese restaurant: when and where we ate and whom we were with (episodic), nature of the food we ate (semantic), the skills we learned such as eating with chopsticks (procedural), and the embarrassment we felt when we spilled the tea (emotional).

Priming effect

Mnemonist – someone who

demonstrates extraordinarily keen memory ability, usually based on using

special techniques for memory enhancement.

Synesthesia

Experience of sensations in a sensory modality different from the sense that has

been physically stimulated.

A process of producing retrieval of

memories that would seem to have been forgotten.

Sometimes loosely referred to as, “unforgetting.”

Unusual power or enhancement of memory, typically under abnormal conditions such as trauma, hypnosis, or narcosis.

Hypermnesia

Deficient Memory

AmnesiaAlzheimer’s Disease

Amnesia

Severe loss of explicit memory.

Retrograde Amnesia

Individuals lose their purposeful memory for events prior to whatever trauma

induces memory loss.

Anterograde Amnesia

The inability to remember events that occur after a traumatic event.

Infantile Amnesia

The inability to recall events that happened when we were very young.

A disease of older adults that causes dementia

as well as progressive memory loss.

First identified by Alois Alzheimer in 1907.

Dementia – loss of intellectual function that is severe enough to impair one’s everyday life.

Alzheimer’s Disease

Atrophy – decrease in size of the brain; especially in the hippocampus and frontal and temporal brain regions.

The brains of people with the disease show plaques and tangles that are not found in normal brains.

Plaques – dense protein deposits found outside the nerve cells of the brain.

Tangles – pairs of filaments that become twisted around each other.

The symptoms are of gradual onset, and the progression is continuous and irreversible.

Donepezil (Aricept) – may slightly slow progression of the disease but that it cannot reverse it; slows destruction of the neurotransmitter acetylcholine in the brain.

Memantine (Namenda or Ebixa) – inhibits a chemical that overexcites the brain cells and leads to cell damage and death.

The incidence of Alzheimer’s disease increases exponentially with age. About 1% of people between 70-75 years of age experience an onset of Alzheimer’s. But between ages 80-85, the incidence is more than 6% a year.

Early-onset, linked to genetic mutation, before even 50 years of age and sometimes as early as the 20s.

How Are Memories Stored?

Frontal lobe – store semantic and episodic memories. Motor cortex – procedural memories Prefrontal cortex – short-term memories Temporal lobe – formation and storage of long-term

semantic and episodic memories and contributes to the processing of new material in short-term memory

Amygdala – vital to the formation of new emotional memories

Hippocampus – plays a pivotal role in the formation of new long-term semantic and episodic memories.

Cerebellum – plays an important role in the storage of procedural memories.

The biological basis of memory

1. Describe two characteristics each of sensory

memory, short-term memory, and long-term memory.

2. Compare and contrast the three-store model of memory with one of the alternative models of memory.

3. Imagine what it would be like to recover from one of the forms of amnesia. Describe your impressions of and reactions to your newly recovered memory abilities.

4. How would your life be different if you could greatly enhance your own mnemonic skills in some way?

Quiz

1. What is rehearsal?2. Name three mnemonic devices.3. How do we retrieve data from short-term

memory?4. Name and define two types of interference.5. What is the recency effect?6. What is the difference between interference

and decay?7. What is autobiographical memory?8. What are repressed memories?

Assignment

Kellogg, R. T., (2007). Fundamentals of

Cognitive Psychology. SAGE Publications

Sternberg, R.J., Sternberg, K., and Mio, J. (2012). Cognitive Psychology, 6th edition. Cengage Learning.

References