Memory

MAR 3503

January 24, 2012

Basic memory processes

• Encoding– Codes can be acoustic, visual, or semantic

• Storage– Can store episodic, procedural, or semantic

memories

• Retrieval– Can be done via recognition or recall

Sensory memory

• “Holding cells”– Holds information from the sensory registers until

it can be processed further

• Fleeting• Brings continuity to the world• Only some is passed on for further processing

Short-term (working) memory

• Holds limited amounts of information until it is:– Used in response– Stored more permanently– Lost

• Information can be encoded:– Acoustically (ECVTGB or HLEITF)– Visually– And other ways (e.g., kinesthetically)

STM capacity

• Is determined with a memory span test

• “Magic number” thought to be 7 +/- 2

• Capacity can be increased by “chunking”

• 7 meaningful units, rather than 7 letters or numbers

STM: The importance of rehearsal

•Ps given a list of nonsense syllables•Told to count backwards (to prevent rehearsal)•Stopped after certain number of seconds, tested for memory of syllables

Peterson & Peterson, 1959

Long-term memory

• …Holds information more permanently after it has been transferred from STM

• Potentially unlimited capacity

• Usually involves semantic coding– Surface features are less important

A model of memory

Sensory memorySensory memory Short-term (working) memory

Short-term (working) memory

Long-term memory

Long-term memory

Environmental inputEnvironmental input ResponseResponse

Encoding Storage

Retrieval

How LTM and STM interact

How LTM and STM interact

• The serial position curve• Primacy effect– Early items in list remembered well because you had

time to transfer them into LTM• Recency effect– Later items in list remembered well because they’re

still in STM• Obvious implications for– Lists– Commercials

The seven sins of memory

• The sin of transience• The sin of absent-mindedness• The sin of blocking• The sin of misattribution• The sin of suggestibility• The sin of bias• The sin of persistence

Transience

• Memories are connections between neurons in the brain– Without use, these connections weaken or even

disappear

• Forgetting– Information is likely still there, just not being

retrieved properly

LTM: How do we get info to stay in?

• Rehearsal– Transmits info to LTM, strengthens connections

between neurons– Not just any rehearsal though (some work better

than others)

• Best: Elaborative rehearsal/elaborative encoding– This helps us create cues for remembering

Elaboration• Ps saw 40 adjectives• For each, they were

asked to indicate:– Whether it was in

uppercase letters– Whether it rhymed with

XXXX– Whether it meant the

same as YYYY– Whether it described

them • Their memory for the

adjectives was testedRogers et al., 1977

How LTM is organized

OREOOREO

chocolatechocolate

brownbrown

mudmud

piepie

bakerybakery

cookiecookie

sliceslice

milkmilkcowcow

farmfarm

flourflour wheatwheat

cakecake

golfgolf

Associative Network

Principles of an associative networks

• Spreading activation• Priming– …Activating a node in memory– A primed, or activated, node may then activate

other nodes and may trigger associated behaviors• One implication– The more associations a node (e.g., a product)

has, the better its chance of getting activated/retrieved

Retrieval from LTM

• Retrieval cues– Pull information from long-term memory into

short-term memory

• Which cues will be effective?– Encoding specificity• The best cues for retrieval are the ones that were there

at encoding

Retrieval: Context dependence

Cues can be very broad. Memory can be helped by similarities between the encoding and retrieval environments. Godden & Baddeley, 1975

Retrieval: Context dependence

• Retrieval is better when the conditions of retrieval match the conditions of encoding– Under water– Classroom– Mood– Odors– Chemicals

Encoding(Learning)Encoding(Learning)

Retrieval(Test)

Retrieval(Test)

Cues and context

Cues and context

Absent-mindedness

• Lapses of attention that result in failing to remember information – Info that never gets encoded properly – Info that is available in memory by is overlooked at

the time we need to retrieve it• Divided attention often at fault– Prevents us from transferring info to LTM– Interferes with recollection (specific details of event)

but not familiarity (remembering that an event happened)

Absent-mindedness• Failures of retrospective memory– Not remembering something that happened in the

past– Divided attention often at fault

• Prevents us from transferring info fully to LTM, or creating the right cues

• Interferes with recollection (specific details of event) but not familiarity (remembering that an event happened)

• Failures of prospective memory– Not remembering something that you’re supposed to

do• Time-based cues easy to forget• Event-based cues easier to elaborate on, more likely to

succeed

Blocking

• Two types of interference– Retroactive interference• Learning new info interferes with the memory of the

old

Blocking

• Interference, continued– Proactive interference• Old knowledge interferes with ability to learn

something new

– Part-list cueing• Learn a list• Recall for part of the list is cued• The partial retrieval can block recall of the rest of the

list– Ex. “We’re better than Tide and Cheer”

Blocking

• Names are very commonly blocked– Name retrieval comes after visual and conceptual

memory, which can interfere with the name• They’re also only tenuously linked to a name

– Also partly due to there being only one name per person, so you can’t fall back on a synonym

• The tip of the tongue effect

Tip of the tongue

• Most common for infrequent words– Lack of use weakens connections between lexical

and phonological aspects of words• They still exist; that’s why you can know what the first

letter is

• “Ugly sisters” play a part– The related but incorrect words that you come up

with– Like part-list cueing—blocks the true word from

coming forth

Misattribution

• Another reason why the filing cabinet metaphor isn’t right

• Deese lists and lures• Schemas can be activated at encoding and

misapplied– (Similar to miscategorization)– Leads to schema-consistent recall• Can work in a marketer’s favor• Or against it

Suggestibility

• The power of the question– Watch a tape of a car

accident– How fast were the cars

going when they…?

Contacted? 31.8 mph

Hit? 34.0 mph

Collided? 39.3 mph

Smashed? 40.5 mph

•1 week later: Did you see any broken glass when they:•Smashed: 32% yes•Hit: 14% yes•Control condition (no verb): 12% yes

Loftus & Palmer, 1974

Bias• Our desires and beliefs guide our memories– Just as the format of a question can shape the answer, so

can the answer we want to give shape the answer we actually give

• Stereotypes influence what we recall about others– People “remember” women were more emotional than

men last month– People are more likely to “remember” Black-sounding

names correspond to criminals than White-sounding names

• We’ll talk about biased memories more later in the semester

Persistence

• Ever get a song stuck in your head?• The opposite of the other sins—remembering

something you want to forget• Usually negative memories fade faster than

positive ones (see bias, too)—why don’t these?– Continual reminding– Cues too common or too strong– Suppression backfires

Why the irony?

• Two processes:– Automatic target search: automatically “looks for” the

unwanted (to-be-suppressed) thought all during the suppression period, and if it finds the target it alerts the controlled distracter search to focus on something else

– Controlled distracter search: operates when the person implements the plan to think of something else. But when cognitive resources are scarce or stretched to the limit (for instance, under cognitive load, as when you are asked to remember a number for later recall), this distracter search may fail

Ironic sexism

Summary• How can memory be improved?– Rehearsal and chunking keeps info in STM longer

• This may aid transfer to LTM– Elaborate encoding (including self-relevance) encourages

integration into LTM– Retrieval and encoding should occur under similar

conditions– Interference should be minimized

• But, what’s stored might not be the same as what’s retrieved. Watch out for– Schemas– Leading questions

Next time

• What are attitudes? • How do we form them?