Memory

Chapter 6MEMORY

Memory is the system by which we retain information and bring it to mind.

Without memory, experience would leave no mark on our behavior; we would be unable to retain the information and skills we acquire through experience.

WHAT IS MEMORY?

3 basic processes of human memory; Encoding Storage Retrieval

These processes allow us to take information, encode it in a form that can be stored in memory, and later retrieve it when it is needed.

HUMAN MEMORY AS AN INFORMATION PROCESSING SYSTEM

Three Basic Processes of Memory

Converting information into a

form usable in memory

Encoding Storage Retrieval

Retaining Information in

memory

Bringing to mind

information stored in memory

MEMORY ENCODING: TAKING IN INFORMATION

Information about the outside world comes to us through our senses, but for this information to enter memory, it must undergo a process of memory encoding, or conversion into a form we can store in memory.

Ways we encode information;Acoustically (coded by sound)Visually (coded by forming a mental picture)Semantically (coded by meaning)

Memory storage is the process of retaining information in memory.

Not all information becomes an enduring or long-term memory.

Some information is retained for only a fraction of a second.

MEMORY STORAGE: RETAINING INFORMATION IN MEMORY

Memory retrieval is the process of accessing stored information to make it available to consciousness.

Retrieving long-held information is one of the marvels of the human brain.

Some memories seem to be retrieved effortlessly, others depend on the availability of retrieval cues, cues associated with the original learning, to jog them into awareness.

MEMORY RETRIEVAL: ACCESSING STORED INFORMATION

Some memories are fleeting; others are more enduring.

The three-stage model of memory proposes three distinct stages of memory that vary with the length of time information is stored;Sensory memoryShort-term memoryLong-term memory

MEMORY STAGES

Sensory memory is a storage system that holds sensory information in memory for a very short time.

Stimuli that you bring in constantly strike your sensory receptors, forming impressions that are briefly held in sensory memory in a kind of temporary storage device called sensory register.

SENSORY MEMORY: GETTING TO KNOW WHAT’S OUT THERE

This information lasts in memory for perhaps a fraction of a second to as long as 3-4 seconds.

The sensory impression disappears and is replaced by the next one.

Iconic memory- A sensory store for holding mental representation of a visual image for a fraction of a second.

A visual held in iconic memory is so clear and accurate that people can report exact details of the image.

SENSORY MEMORY: GETTING TO KNOW WHAT’S OUT THERE

Some people can recall a visual image they have previously seen as accurately as if they are still looking at it. This is known as eidetic memory

This is also known as photographic memory (eidetic comes from the Greek eidos, meaning “image”).

Eidetic imagery is rare in adults, but it occurs in about 5% of young children.

SENSORY MEMORY: GETTING TO KNOW WHAT’S OUT THERE

Echoic memory is a sensory store for holding a mental representation of a sound for a few seconds after it registers in the ears.

Although sounds held in echoic memory fade quickly, they last about two or three seconds longer than visual images.

SENSORY MEMORY: GETTING TO KNOW WHAT’S OUT THERE

Many sensory impressions don’t just fade away into oblivion; they are transferred into short-term memory for further processing.

Short-term memory is the memory subsystem that allows for retention and processing of newly acquired information for a maximum of about 30 seconds.

SHORT-TERM, OR WORKING, MEMORY: THE MIND’S BLACKBOARD

Short-term memory relies on both acoustic and visual coding, but mostly on acoustic (ex. Repeating a phone number to yourself until you dial it).

In the 1950s psychologist George Miller did studies to determine the storage capacity if short-term memory.

Professor Miller determined that people can retain 7 items (plus or minus 2), referred to as the “Magic 7”.

SHORT-TERM, OR WORKING, MEMORY: THE MIND’S BLACKBOARD

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ROW 1

73932ROW 2

835405ROW 3

3820961ROW 4

18294624ROW 5

9284619384ROW 6

1992199319941995ROW 7

SHORT-TERM, OR WORKING, MEMORY: THE MIND’S BLACKBOARDDid you do better remembering the 7 th

row than the 5th or 6th?If you did, it is because of chunking- the

process of breaking a large amount of information into smaller chunks to make it easier to recall.

Children learn the alphabet by chunking a series if letters (that’s why they often say the letters lmnop as if they are one word)

Long-term memory is a storage system that allows you to retain information for periods of time beyond the capacity of short-term memory.

Some info can remain for days or weeks, whereas other info can last a lifetime.

Short-term memory storage is limited, but long-term storage is virtually limitless.

LONG-TERM MEMORY: PRESERVING THE PAST

Consolidation is the process by which the brain converts unstable, fresh memories into stable, long-term memories.

The first 24 hours after information is acquired are critical for consolidation to occur.

REM sleep plays an important role in consolidating daily experiences, so if you have a test the next day, make sure you get a good night’s sleep.

LONG-TERM MEMORY: PRESERVING THE PAST

Declarative Memory: Memory of facts and personal info that requires a conscious effort to bring to mind.Ex. There are 50 states, what street we live on.

Semantic Memory: Memory of facts.Ex. Which film won Best Picture last year, who wrote Grapes of Wrath.

Episodic Memory: Memory of personal experiences that constitute the story of your life.Ex. What you had for dinner last night, when you fell out of a tree when you were 10.

DECLARATIVE MEMORY: “KNOWING THAT”

Extremely stressful or emotionally arousing personal or historical events may leave vivid, lasting, and highly detailed memories called flashbulb memories.

Flashbulb memories are enduring memories of emotionally charged events that seem permanently seared into the brain.

Some flashbulb memories are accurate, but others are prone to the kinds of distortion we see in other forms of long-term memory.

FLASHBULB MEMORY: WHAT WERE YOU DOING WHEN…?

In reaching a verdict, juries give considerable weight to eyewitness testimony. Yet memory researchers find that eyewitness testimony can be as flawed and strewn with error as other forms of memory.

Psychologist Elizabeth Loftus describes how a misinformation effect may lead to distortions in eyewitness testimony from when the event happened to when the events are recalled (in court).

EYEWITNESS TESTIMONY: :WHAT DID YOU SEE ON THE DAY IN

QUESTION?”

The accuracy of eyewitness testimony involves the following factors.

Ease of recall- People who take longer to answer questions are less likely to be accurate in their recall.

Degree of Confidence- People who say with certainty, “That’s the person who did it, “ may not be any more accurate than those who admit they could be mistaken.

EYEWITNESS TESTIMONY: :WHAT DID YOU SEE ON THE DAY IN

QUESTION?”

General knowledge about a subject- People who know more about a subject are more likely than those who know less about the subject to be reliable witnesses.

Racial identification- People are generally better able to recognize faces of people of their own race than the face of people of other races.

EYEWITNESS TESTIMONY: :WHAT DID YOU SEE ON THE DAY IN

QUESTION?”

Types of questions- Leading or suggestive questions by investigators can result in the misidentification of perpetrators, whereas open-ended questions, tend to increase the accuracy of eyewitness testimony.

Facial characteristics- Faces with distinctive features are much more likely to be accurately recognized than nondistinctive faces.

EYEWITNESS TESTIMONY: :WHAT DID YOU SEE ON THE DAY IN

QUESTION?”