Introduction to Psychology

Human Memory

Lecture Outline

1) Encoding

2) Storage

3) Retrieval and Forgetting

4) Multiple memory systems

Memory• Memory is the process by which we observe,

store, and recall information– Memories may be visual, auditory, or tactile

• Memory processes may involve multiple systems– Conscious– Automatic

Encoding

• Attention:

- Spotlight analogy

• Sensory detection

• Recognition of meaning

• Response selection

Levels of Processing

• Shallow processing - structural encoding

(capital letters, what color, etc…)

• Intermediate processing - phonemic encoding (rhyming, homonyms, etc…)

• Deep processing - semantic encoding (meaning or symbolism)

Facilitating Encoding

• Elaboration

• Visual Imagery

• Self Referential Encoding

• Rehearsal and Over-learning

• Deep and Transfer Appropriate processing

• Distributed practice

• Organize information

Mnemonic Devices

• Verbal mnemonics:

- acrostics, acronyms, and rhymes

• Visual mnemonics:

- link method, method of loci, keyword

- SQ3R

Encoding Specificity

• Encoding specificity principle: Idea that ease of retrieval of a memory depends on match of encoding with retrieval – Poor recall if shallow learning is examined

using a deep processing technique• Student who reads multiple choice items in test

book and then takes an essay exam will likely not do very well

• State-dependent memory

2. Storage

• Assumes that memory consists of 3 stores:– Sensory registers

• Iconic (visual)

• Echoic (auditory)

– Short-term memory (STM)– Long-term memory (LTM)

© 2002 John Wiley & Sons, Inc.

The Information Processing Model of Memory

Characteristics of STM• STM is a variant of memory that is of limited

duration: – Information in STM fades after 20-30 seconds (without

rehearsal)

• STM has limited capacity storage– STM capacity is about 7 items of information

• Capacity is constant across cultures

• STM Involves rehearsal– Maintenance: information is repeated– Elaborative: information is related to other knowledge

Working Memory• Working memory is temporary storage and

processing of information used to – solve problems

– respond to environmental demands

– achieve goals

• Working memory may consist of three modules– Visual Memory Store

– Verbal Memory Store

– Central Executive

Working Memory Stores

• Visual memory store– A temporary image (20-30 sec) that provides information

about the location and nature of objects

• Verbal memory store – Involves storage of verbal items

• Limited capacity• Shallow: Items are processed in order of presentation and are

subject to interference

• Working memory stores are independent– Brain damage may alter visual but not verbal

LTM• LTM refers to the representations of facts, images,

actions, and skills that may persist over a lifetime• LTM involves retrieval of information• LTM is theoretically limitless in capacity• The serial position curve supports the existence of

STM versus LTM– Primacy effect reflects LTM

– Recency effect reflects STM

The Serial Position Curve

(Figure adapted from Atkinson & Shriffrin, 1968)

Recalled fromLTM

Recalled fromSTM

Working Memory and LTM

• Evidence supporting a distinction between working memory and LTM– Working memory is easily accessed, but is limited in

capacity– Neurological studies in which brain damage impairs

memory• LTM impairment: person shows normal working memory,

but cannot transfer information to LTM• Working memory deficit: person has a memory span of 2

digits, but normal LTM

– Chunking: LTM information is used to increase item size in working memory (e.g. IBM, USC, CIA)

Functional Aspects of Memory

• Recall for information may be a function of our interest in the information:– Men show better recall

for workbench construction details than details on how to make a shirt…

Networks of Association

• LTM is organized in clusters of information that are related in meaning– The network is composed of interconnected nodes – A node may contain thoughts, images, smells,

emotions, or any other information– Mnemonic devices allow one to add concepts to

existing networks

An Example of Interconnected Nodes

Varieties of LTM

• Declarative memory– Semantic: “generic” knowledge of facts– Episodic: memories of specific events

• Autobiographical

• Procedural memory: for skills• Explicit memory: Conscious retrieval of information

– Recall versus recognition

• Implicit memory: Skills, conditioned learning, and associative memory

Repressed Memories

• Retrieval failures

• Motivated forgetting

• Denial

• Repression

• Psychogenic amnesia

• False Memory Syndrome

“Seven Sins of Memory”• Memories are transient (fade with time)• We do not remember what we do not pay attention to• Our memories can be temporarily blocked• We can misattribute the source of memory• We are suggestible in our memories• We can show memory distortion (bias)• We often fail to forget the things we would like not

to recall (persistence of memory)