Memory

Mental Representations

• For a stimulus to be remembered it has to be represented in the mind

• A mental representation is a psychological version (mental model) of a stimulus or category of stimuli

• A neural code such as “dogs” or “cars”

Mental Representations

• Sensory Representations– Stores information in a sensory mode such as

the sound of a dog barking

• Verbal Representations– Store information in words– The concept of “freedom” is a verbal

representation

James’ Model of Memory

• William James differentiated between primary and secondary memory

• Primary– Immediate memory for information momentarily held

in consciousness

• Secondary– Stored information that can be recalled upon demand

Standard Model of Memory

• Sensory Registry (SR)

• Short term memory (STM)

• Long term memory (LTM)

Sensory Registry

• Detects that something is there

• Holds information for a fraction of a second

• Creates a mental representation that it passes onto short term memory

• Similar to a stroke on the keyboard of a computer

Short Term Memory

• Holds mental representations for up to 20-30 seconds

• Limited capacity of 5-7 bits of information – (Telephone numbers)

• Decides whether a mental representation is worth saving

• Rehearsal- A deliberate effort to retain material in STM

• Similar to a computer screen

Long Term Memory

• If one decides to save mental representations in STM they commit the data to LTM

• Once in LTM the data is stored indefinitely

• Serial position effect suggest we tend to remember data at the beginning of a sequence better than we remember data at the end of a sequence

• Similar to a hard disc on a computer

Evolution of the Memory Model

• Serial Processing Model– Stages that occur in a particular memory sequence

– Recent research questions whether this is accurate in that some memories are not consciously sent to LTM

– Some evidence that LTM influences STM

• Modules– View memory as a set of modules that can operate

simultaneously (parallel) rather than in a serial sequence

Evolution of the Memory Model

• Some LTM memories can be acted upon without conscious effort or STM

• The underlying metaphor has shifted from mind as a computer to mind as brain

Working Memory

• Working memory is the temporary storage and processing of information that can be used to:– Solve problems

– Respond to environmental demands

– Achieve goals

• Working memory is active in that the information remains only so long as one is consciously using it

Working Memory Model

• Visual Memory Store– Temporary images

• Verbal Memory Store– Based on sounds

• Central Executive– Controls and manipulates visual and verbal

stores

Working & Long Term memory

• Working Memory– Temporary storage

– Limited capacity

– Work space to accomplish goals

• Long Term Memory– Permanent storage

– Unlimited capacity

– Does not process, just stores

Chunking

• Memory technique that uses knowledge stored in LTM to accomplish goals

• Key interaction between working and long term memory

• Utilizes mnemonics such as:– SEC= Securities and Exchange Commission

– USAID= United States Agency for International Development

Forms of Long Term Memory

• Declarative– Facts and events such as September 11th

• Procedural– How to knowledge such as riding a bicycle

• Semantic– General (genetic) knowledge (cars in general)

• Episodic– Memory of a specific nature ( my first car)

Explicit & Implicit Memory

• Explicit– Conscious recollection– Recall

• Essay examination

– Recognition• Multiple choice examination

• Implicit– Behavior not requiring conscious recollection– Tying a shoe

Everyday Memory

• Memory we use in our daily activities– Functional in that it is important to us– Focuses on remembering meaningful

information

• Perspective Memory– Memory for things we need to do in the future– Our mental “to do” list

Encoding Stimuli

• Encoding– Processes used to store data in our brain

• Encoding Specificity Principle – The match between the manner in which

information is encoded and later recalled• Goal to memorize• Goal to understand• Context • Emotional state at time of stimuli

Levels of Processing

• The degree to which information is elaborated, reflected upon and processed

• Shallow– Little effort expended– Often used for multiple choice exams (details)

• Deep– A great deal of energy is devoted to an event or stimuli– Necessary for essay exams (underlying concepts)

Representational Modes

• The more ways a memory can be encoded the greater the accessibility for retrieval

• Retrieval Cues– Stimuli or thoughts that can be used to facilitate

recollection

• A special dining experience at a finer dining establishment will include:– The atmosphere of the location– The visual presentation of the food– The odors of the food

Two Strategies to Remember

• Mnemonic Devices– Systematic shortcuts– “RAW” to remember

Reading

Writing

Arithmetic

• Method of Loci– Associate new information with something

familiar

SQ3R Method

• Survey– Pager through a chapter

• Question– When beginning a section turn the heading into a question

• Read– As you read attempt to answer the questions you posed about the

section

• Recite– Mentally (or orally) answer your questions

• Review– When you finish the chapter, recall your questions and relate what

you have learned to your experiences and interests

Spacing

• Rehearsing information over a period of time is more effective than waiting until the last minute

• Cramming the night before an exam– better than not studying at all – not nearly as effective as studying over the

course of several weeks

Biology of Memory

• Network of Association– Each piece of information is stored in a node– Activating one node triggers activation in

closely related nodes

• Spreading Activation Theory– Suggests nodal networks are hierarchically

organized from narrow networks through broader connections

Schemas

• Patterns of thought that render the environment relatively predictable. Schemas fill in the missing pieces in a situation and serve to bias our perceptions

– Police officers issue speeding tickets

• An active process of reconstruction of the past

– I got a ticket once and lost my license for 30 days

• Schemas greatly influence our perception of a new event

– That officer might issue me a ticket

Seven Sins of Memory

• Transience– Memories fade away

• Absent-Mindedness– Failure to remember due to distraction

• Misattribution– Misremember source of a memory

• Suggestibility– Thinking we remember something that someone

actually implanted in our minds

Seven Sins of Memory

• Bias– Distorting the way we recall events in a way we would

rather remember

• Persistence– Retaining (rehearsing) memories we would rather

forget

• Forgetting– Inability to recall

Forgetting

• Steep drop in our ability to recall

• Availability & Access– Availability- The data is “in there”– Access- Our ability to retrieve the data

• Flashbulb Memories– Vivid memories of exciting or high

consequence events

Decay Theory

• Suggests forgetting is a result of fading memory tracts if not used

• We tend to rehearse important memories and ignore others

Interference Theory

• Proactive Interference– Previously stored memories interfere with new

information• One refers to their current partner by their

previously partner’s name

• Retroactive Interference– New information interferes with stored

memories• Your new cell # interferes with remembering your

previous cell #

Motivated Forgetting

• We actively desire to forget (repress) something or some event

– A bad argument with your parents

– A break up with a significant other