Explain why the workings of memory are more reconstructive than people imagine them to be.

Psychology Twelfth Edition

Chapter 10 Memory

Reconstructing the Past

• LO 10.1.A Explain why the workings of memory are

more reconstructive than people imagine them to be.

• LO 10.1.B Describe three conditions under which

confabulation is especially likely to occur.

• LO 10.1.C Summarize the evidence indicating that

eyewitness testimony can be susceptible to memory

errors.

• LO 10.1.D Explain the conditions under which children

might provide reliable versus unreliable eyewitness

testimony.

The Manufacture of Memory (1 of 3)

• Unlike a digital recorder or video camera, human

memory is highly selective and is reconstructive.

• It is more like watching a few unconnected clips

and then figuring out what the rest of the recording

must have been like.

• People add, delete, and change elements in ways

that help them make sense of information and

events.

The Manufacture of Memory (2 of 3)

• In reconstructing their memories, people often

draw on many sources.

• They take bits and pieces and build one integrated

account.

• They often experience source misattribution, the

inability to distinguish information stored during an

event from information added later.

The Manufacture of Memory (3 of 3)

• Shocking or tragic events do hold a special place

in memory.

– So do some unusual, exhilaratingly happy events.

• Yet even these vivid flashbulb memories tend to

become less accurate or complete over time.

• People typically remember the gist of a startling,

emotional event.

• But over time, errors creep into the details; after a

few years, some people even forget the gist.

The Conditions of Confabulation

• Because memory is so often reconstructive, it is

subject to confabulation.

– the confusion of imagined events with actual ones

• Confabulation is especially likely when people

have thought, heard, or told others about the

imagined event many times.

• They thus experience imagination inflation.

• The image of the event contains many details, or

the event is easy to imagine.

The Eyewitness on Trial (1 of 2)

• The reconstructive nature of memory also makes

memory vulnerable to suggestion.

• Eyewitness testimony is especially vulnerable to

error when:

– the suspect’s ethnicity differs from that of the witness

– leading questions are put to witnesses, or

– witnesses are given misleading information

The Eyewitness on Trial (2 of 2)

Figure 10.1

The Influence of Misleading Information

Elizabeth Loftus

(Loftus & Greene, 1980)

Children’s Testimony (1 of 2)

• Like adults, children often remember the essential

aspects of an event accurately.

• However, they can also be suggestible, especially

when:

– responding to biased interviewing by adults

– asked questions that blur the line between fantasy and

reality

– asked leading questions

– told what “other kids” had supposedly said

– praised for making false allegations

Children’s Testimony (2 of 2)

Figure 10.2

Social Pressure and Children’s False Allegations

(Garven et al., 1998)

In Pursuit of Memory

• LO 10.2.A Distinguish between recall and

recognition tasks in explicit memory, and

distinguish between priming and relearning in

implicit memory.

• LO 10.2.B Describe the basic characteristics of

three memory systems according to the

information-processing model, and note the

challenges to this view proposed by parallel

distributed processing.

Measuring Memory (1 of 2)

• The ability to remember depends in part on the

type of performance called for.

• In tests of explicit memory (conscious

recollection), recognition is usually better than

recall.

• Recognition for visual images is particularly

impressive.

Measuring Memory (2 of 2)

• Implicit memory is measured by indirect methods

such as:

– priming and

– the relearning method

• In tests of implicit memory, past experiences may

affect current thoughts or actions.

• This can occur even when these experiences are

not consciously remembered.

Models of Memory (1 of 3)

• In information-processing models, memory

involves the:

– encoding

– storage, and

– retrieval of information

• The three-box model proposes three interacting

systems:

– the sensory register

– short-term memory, and

– long-term memory

Models of Memory (2 of 3)

• Some cognitive scientists prefer a parallel

distributed processing (PDP) or connectionist

model.

• This model represents knowledge as connections:

– among numerous interacting processing units

– distributed in a vast network, and

– all operating in parallel

• The model is similar to neurons of the brain.

– The ability of units to excite or inhibit each other is

constantly adjusted to reflect new knowledge.

Models of Memory (3 of 3)

Figure 10.3

Three Memory Systems

The Three-Box Model of Memory

• LO 10.3.A Explain the functions, duration, and location of

the sensory registers in the three-box model of memory.

• LO 10.3.B Explain the functions and duration of short-

term memory, and contrast the leaky bucket and working

memory approaches to understanding this “box” of

memory.

• LO 10.3.C Describe semantic categories and four forms

of long-term memory, and explain how primacy and

recency illustrate the serial-position effect in transferring

information from short-term to long-term memory.

The Sensory Register: Fleeting

Impressions

• In the three-box model, incoming sensory

information makes a brief stop in the sensory

• The sensory register momentarily retains it in the

form of sensory images.

• Information that does not quickly go on to short-

term memory vanishes forever.

• The fleeting nature of incoming sensations is

beneficial; it prevents “double exposures.”

Short-Term Memory: Memory’s

Notepad (1 of 3)

• Short-term memory (STM) retains new information

for up to 30 seconds (unless rehearsal takes

place).

• In short-term memory, the material is no longer an

exact sensory image.

• Instead, it is an encoding of one, such as a word

or a phrase.

• This material either transfers into long-term

memory or decays and is lost forever.

Short-Term Memory: Memory’s

Notepad (2 of 3)

• The capacity of STM is extremely limited but can

be extended if information is organized into larger

units by chunking.

• A chunk can be:

– a word

– a phrase

– a sentence

– an image

– and it depends on previous experience

Short-Term Memory: Memory’s

Notepad (3 of 3)

• Early models of STM portrayed it mainly as a bin

for the temporary storage of information.

• But many models now envision it as a part of a

more general working-memory system.

• Working memory permits us to:

– control attention

– resist distraction, and therefore

– maintain information in an active, accessible state

Long-Term Memory: Memory’s Storage

System (1 of 8)

• The capacity of long-term memory seems to have

no practical limits.

• The vast amount of information stored there

enables us to:

– learn

– get around in the environment, and

– build a sense of identity and a personal history

• But it must be organized to make it manageable.

Long-Term Memory: Memory’s Storage

System (2 of 8)

• Words (or the concepts they represent) are often

organized by semantic categories.

• Evidence on the storage of information by

semantic category also comes from cases of

people with brain damage.

• Many models of long-term memory represent its

contents as a vast network of interrelated

concepts and propositions.

Long-Term Memory: Memory’s Storage

System (3 of 8)

• Research on tip-of-the-tongue (TOT) states shows

that words are also indexed in terms of:

– sound and

– form

• Information in long-term memory may also be

organized by its:

– familiarity

– relevance, or

– association with other information

Long-Term Memory: Memory’s Storage

System (4 of 8)

• Most theories of memory distinguish skills or

habits (“knowing how”) from abstract or

representational knowledge (“knowing that”).

• Memories can take different forms, such as:

– procedural or

– declarative

• And within declarative memories, either:

– semantic or

– episodic

Long-Term Memory: Memory’s Storage

System (5 of 8)

• The three-box model is often invoked to explain

the serial-position effect in memory.

• Serial-position effect: The tendency for recall of

the first and last items on a list to surpass recall of

items in the middle of the list.

• The model can explain the primacy effect.

• However, it cannot explain why a recency effect

sometimes occurs after a considerable delay.

Long-Term Memory: Memory’s Storage System (6 of 8)

Figure 10.4

Part of a Conceptual Grid in Long-Term Memory

Long-Term Memory: Memory’s Storage System (7 of 8)

Figure 10.5

Types of Long-Term Memories

Long-Term Memory: Memory’s Storage System (8 of 8)

Figure 10.6

The Serial-Position Effect

The Biology of Memory

• LO 10.4.A Outline the process of long-term

potentiation in the formation of memories.

• LO 10.4.B Evaluate the evidence that memories

are not stored in any one “place” in the brain.

• LO 10.4.C Summarize the evidence that memory

can be influenced by emotion and hormonal levels.

Changes in Neurons and Synapses (1 of 3)

• Short-term memory involves temporary changes

within neurons.

• These changes alter their ability to release

neurotransmitters.

• Long-term memory involves lasting structural

changes in the brain.

– neurons

– synapses

Changes in Neurons and Synapses (2 of 3)

• Long-term potentiation seems to be an important

mechanism of long-term memory.

• It likely underlies many and perhaps all forms of

learning and memory.

• It involves an increase in the strength of synaptic

responsiveness.

Changes in Neurons and Synapses (3 of 3)

• Neural changes associated with long-term

potentiation take time to develop.

• This helps explain why long-term memories

require a period of consolidation.

– However, memories probably never completely solidify.

– The act of remembering can make them unstable

again.

• Sleep plays a role in ensuring consolidation of

new information.

Where Memories Are Made (1 of 5)

• The amygdala is involved in the:

– formation

– consolidation, and

– retrieval of emotional memories

• Areas of the frontal lobes are especially active

during short-term and working-memory tasks.

• The efficient encoding of words and pictures

involves:

– the prefrontal cortex and

– parts of the temporal lobes

Where Memories Are Made (2 of 5)

• The hippocampus plays a critical role in the:

– formation and

– retrieval of long-term declarative memories

• Other areas are crucial for the formation of

procedural memories.

– the cerebellum

Where Memories Are Made (3 of 5)

• Studies of patients with amnesia suggest that

different brain systems are active during:

– explicit and

– implicit memory tasks

• The long-term storage of declarative memories

possibly takes place in cortical areas.

• These areas would have been active during the

original perception of the information or event.

Where Memories Are Made (4 of 5)

• The typical “memory” is a complex cluster of

information.

• The various components of a memory are

probably stored at different sites.

• All of these sites participate in the representation

of the event as a whole.

Where Memories Are Made (5 of 5)

Figure 10.7

Brain Areas Involved in Memory

Hormones, Emotion, and Memory (1 of 2)

• Hormones are released by the adrenal glands

during:

– stress

– emotional arousal

• These hormones can enhance memory:

– epinephrine

– norepinephrine

Hormones, Emotion, and Memory (2 of 2)

• These adrenal hormones cause the level of

glucose to rise in the bloodstream.

• Glucose may enhance memory directly or by

altering the effects of neurotransmitters.

• However, the effective dose of glucose is narrow.

• Too much can impair cognitive functioning instead

of helping it.

How We Remember

• LO 10.5.A Describe some major strategies that

contribute to memory retention, and give an

example of each.

Encoding, Rehearsal, and Retrieval (1 of 3)

• Some kinds of information, such as material in a

college course, require effortful encoding.

– as opposed to automatic encoding

• To retain such information, we might have to:

– select the main points

– label concepts, or

– associate the information with personal experiences or

with material we already know

• We must make the material digestible.

Encoding, Rehearsal, and Retrieval (2 of 3)

• Rehearsal of information:

– keeps it in short-term memory and

– increases the chances of long-term retention

• Elaborative rehearsal is more likely to result in

transfer to long-term memory than is maintenance

rehearsal.

• Elaboration involves:

– association of items with stored or factual information

– analysis of the physical, sensory, semantic features of

an item

Encoding, Rehearsal, and Retrieval (3 of 3)

• A related strategy for prolonging retention is deep

processing, or the processing of meaning.

• Deep processing is usually a more effective

retention strategy than shallow processing.

• Retrieval practice is necessary if a memory is

going to be consolidated.

– For students, short quizzes and repeated testing can

have large benefits.

Why We Forget

• LO 10.6.A Summarize the processes of decay,

replacement, interference, and cue dependent

forgetting, and explain how each contributes to our

understanding of forgetting.

• LO 10.6.B Explain why claims of repressed

memories should be greeted with a strong

skeptical reaction.

• LO 10.6.C Discuss three reasons why childhood

amnesia is likely to take place.

Mechanisms of Forgetting (1 of 6)

• Forgetting can occur for several reasons.

• Information in sensory and short-term memory

appears to decay if it does not receive further

processing.

– memories fade with time if not accessed

• New information may erase and replace old

information in long-term memory.

– just as writing over the contents of a hard drive will

obliterate the original material

Mechanisms of Forgetting (2 of 6)

• Proactive and retroactive interference may take

place.

• Similar items of information interfere with one

another in either storage or retrieval.

• The information may get into memory and stay

there, but it becomes confused with other

information.

Mechanisms of Forgetting (3 of 6)

• Cue-dependent forgetting may occur when

Explain why the workings of memory are more reconstructive than people imagine them to be.

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