Memory 1 and 2

The Three-Memory Model

We have three systems of memory, and information flows from sensory memory to short term memory and long term memory.

Information can be retrieved from

long term memory

Span

the amount of information a memory system can hold

Duration

How can a memory system can hold information

Sensory Memory

A “Buffer” for sensory information, allows us to see the world as a seamless stream of events

Echoic Memory

Sensory memory that applies to hearing, lasts 5-10 seconds, and is useful for taking notes while professor is talking

Iconic Memory

Sensory memory that applies to vision, lasts about a second

Sperling (1960)

Participants were shown a 3x4 grid of 12 letters on a screen for 1/20 of a second. Participants were asked to name every letter they could remember seeing. They could generally only recall about 4 to 5 letters. Then a medium, low or high tone was played along with the letters, which indicated which row they should recall.

Sperling (1960) Conclusion

High Accuracy: When cued by the tone right away, participants could accurately recall almost all the letters in that targeted row. This implied that nearly all 12 letters were initially captured by the visual system, but access to that information faded before it could be recalled.

Short term memory

Where we keep information that we’re thinking about, attending to, or actively processing. Has a duration of under 20 seconds, and information either moves to long term memory or is lost

Decay

A reason for short term memory loss, memory fades over time.

Interference

A reason for short term memory loss, memories compete with and overwhelm each other

Digit Span test

Participants see x numbers one at a time, then recalls the numbers in order. X increases by 1 for each trial, which ends once participant cant recall all the numbers. Most digit spans are 7+-2 but average may be closer to 4 or 5

Chunking

Reduces memory requirements, allow sus to remember sentences longer than 7 words.

Experts can use chunking too

helps experts organize and compress complex information into meaningful patterns

Maintenance Rehearsal

Mentally repeating information to keep it in short term memory

Elaborative Rehearsal

We elaborate information to aid in recall

The Paired Associate Task

Participant must remember list of words pairs (dog-shoe, tree-pipe, key-monkey). Experimenter presents the first word in each word in each pair, participant must generate second word. Participants more successful at recall if use elaborate rehearsal

The primacy effect

We tend to remember words towards the beginner of a list

The Recency Effect

We tend to remember words towards the end of a list

The primacy and recency effects occur due to

Different memory systems (short-vs-long-term)

Bahrick (1984)

Long term study of participants who had taken Spanish in School, Spanish ability dropped 3 years after class .

Bahrick (1984) Results

Memory for Spanish was similar after 3 years as it was after 50 years

Semantic Memory

Type of long term memory, Knowledge of facts about the world

Episodic Memory

A type of long term memory, and is composed of events in our lives

Explicit memory

Intentionally recalled information that includes sematic and episodic memory (both stored in different brain regions)

Implicit memory

Information not deliberately recalled, includes habituation conditioning and procedural memory

Procedural Memory

Memory for motor skills and habits (eg. tying shoes, riding bike)

Tower of Hanoi

Task involves moving discs between three pegs; performance improves over time. Antereograde amnesiacs need to be reminded of rules everyday, but skill make improvements playing the game.

Retrograde Amnesia:

Person cannot recall information learned prior to causal event, may loose information during minutes or hours before accident

Anterograde Amnesia

Person cannot learn new information. Procedural memories may be intact.

Amnesia may be due to

Problems storing information from short term to long term, problems retrieving info from long term memory, or interference of memories

Encoding

Stage that involves putting information into memory

Storage

Stage that involves keeping information in memory

Retrieval

Stage that involves reconstructing information from memory

False memories

Information may be encoded, stored, or retrieved with errors

Flashbulb memories

emotional memories for important event, tend to be vivid, even over time

Neisser & Harsch (1992)

College students were asked about experiencing the first hearing about the 1986 Challenger shuttle explosion a few dqays after the event, and then again 2.5 to 3 years later

Neisser & Harsch (1992) results

75% showed distorted memory, 1/3 showed major changes

Implanting memories

Elisabeth Loftus and colleagues (1995,1996) asked family members of undergraduate participants to describe events from participants childhood. Participant was presented with 3 real events and 1 false event (lost in a shopping mall) and had to describe the events. ¼ recalled being lost in a shopping mall.

Impossible events can be implemented

16% of people shown Disney ads that have bugs bunny remeber meeting bugs bunny at the park

Exposure time

longer exposure a stimulus results in better memory of that stimulus

Laughery et al. (1972)

Participants saw photos of 2 male faces for either 10 or 32 seconds. Participants then had to ID faces out of 150 photos. 47% of participants correctly ID faces with 10 second exposure, and 58% of participants correctly IDed faces with 32 second exposure

Detail Salience

Obvious, central, and important factors of a situation are more likely to be recalled

Type of information

Time, speed, distance tend to be inaccurately reported. In staged fights in laboratory, people estimate the length of event by at least 2x