DR WAN NORHAIDA WAN ABDULLAH

12 DEC 2010

MEMORY

CONTENTS

INTRODUCTION STAGES OF MEMORY DISORDERED OF MEMORY

Introduction

Memory is a process by which information is encoded, stored and retrieved

Memory is intrinsically linked to learning and involves: The learning of associations The learning of skills The storage of information The learning of new information (anterograde

memory) The recall of previously learnt information

(retrograde memory)

Stages of memory

Encoding/registration

•Visual coding•Phonological Coding•Semantic coding

Storage •Sensory memory•Short term memory•Long term memory

Retrieval •Recall•recognition

Encoding/registration

The initial processing of information enabling it to be assimilated (requires attention)

Information is encoded in the form of: 1. Visual code

Based on a mental picture of the object2. Phonological code

Based on the sound and names of the object3. Semantic code

Based on a meaningful association that the objects have

Storage

1) Sensory memoryCharacteristics 1. Contains all information initially acquired by

the organ senses:1. Echoic-auditory2. Iconic-visual3. Haptic-touch

2. Short lasting – 0.5 sec (visual), 3 sec (auditory)

3. Only attended stimuli are transferred into the next storage

Maximum number of immediately recallable item is called span of apprehension

How many items can you recall? Typically 3 or 4 items Maybe larger, but hard to ascertain

due to measurement difficulty

Storage

2)Short term memory Primary/working memory Characteristics1. Contains conscious information2. Lost in about 20-30 seconds3. Information rehearsed/elaborated

will be transferred to long term memory

Encoding in STM require selective attention

Many STM problems are related to lapse of attention

Information in STM are encoded in the form of:

1. Visual code2. Phonological code

Information stored in STM lasted in about 20 seconds

The capacity of STM to store information is very limited (7+2)

Information in STM is lost due to 1. Natural decay2. Displacement of old item with the new

ones

Retrieval of information from STM require serial search

Serial search refers to a search in which items are examine one at a time

STM can be boosted by the process of chunking

Chunking refers to combining bits of information into meaningful units

Read the following BGI  TAE  LTE  GDO  THE

Can you recall the information

Now try againTHE  EAT  DOG  BIG  LET

Easier isn’t it? – Try this one

LET  THE  BIG  DOG  EAT

A lot easier isn’t it, that explains ‘chunking’

i.e. combining bits of information into meaningful units

Long term memory

Secondary memory Permanent storeCharacteristics1. Information are stored via elaboration

process from short term memory

Elaboration refers to a variety of processes that facilitate information retention (eg. Transforming an object into visual image; associating an object with a meaning ect)

2. The size of LTM is unlimited3. Information retrieved from long

term is placed back in STM Information are encoded in long term

memory using semantic code Information are stored by adding a

meaningful connection to the objects

Following registration needs few minutes for consolidation

Coding in LTM can be visual, acoustic and semantic ..requires motivation

LTM can be Declarative ( knowing that)

Declarative can be episodic ( knowing when)

Semantic (knowing about) Procedural (knowing how)

Declarative –episodic: LTM for event and places-autobiographical memory that is clear and explicit

Declarative –semantic: explicit LTM of meaning of words

Procedural: Implicit LTM concerning skills

Retrieval

Recall information from LTM-STM Explicit : memories are recalled

completely with subjective temporal awareness

Implicit: no conscious recollection or temporal awareness.

Forgetting

The loss of information from memory-retrieval failure

Unlike STM, Forgetting in LTM usually results from a lost access to information

In STM, forgetting is due to? Have you experience an inability to

recall a point in examination and only to have it once you get out of exam room?

Interference The learning and recall of an item is

influenced by new learning in between as this disrupt consolidation of original item

Can impair retrieval

Recall that we stored information in LTM by adding meaningful association (cue or keyword)

Interference cont… Many times the same cue is used for

several objects

If we try to use that cue to recall an items, other objects may be activated and interfere with information retrieval

Decay theory : With time memories faded. Forgetting is

time-dependent

LTM retrieval is facilitated by1. Organization of information into

categories

2. Context in which the information was encoded

Memory and Emotion

1. Rehearsal2. Flashbulb memories3. Retrieval interference via anxiety4. Context effects5. Repression

Rehearsal

Human tendency to repeat, talk, think about emotionally charged situation (positive and negative) than the neutral one

Rehearsal facilitate transfer from STM to LTM

Flashbulb memories

A vivid and relatively permanent record of the ‘circumstances’ during which one learned an emotionally charged situation

Tsunami victims

Anxiety

Severe anxiety can hinder information retrieval Imagine yourself in an exam room You are unable to answer the initial

question which carry half of the total mark

You may likely to find yourself unable to answer the subsequent questions

Context effects Context facilitate memory retention

Recall is best when the emotional states during which the information is retrieved match that during encoding

When you encode an information in a happy mood, its easier to retrieve the information when you are in a happy mood.

Repression

Based on the Freud’s theory of the unconscious

Storing a traumatic experience in the unconscious i.e. intentional forgetting

Allowing such experience to enter consciousness would cause the individual overwhelmed by anxiety

Test of memory

Recall of past personal life event Recall of recent personal event STM: recall of simple name and

adress after 5 minutes, repeating sentence, digit span

General knowlegde test

Disordered of memories

Anterograde amnesia Retrograde amnesia