Module 5 - Memory Structures

Atkinson & Shiffrin

proposed Modal Model, memory divided into storage systems

Modal Model

sensory → short-term → long-term memory flow

Sensory Memory

acts as early stage of perception, holds raw sensory input

Iconic Memory

visual sensory memory, brief image "imprint" (like lightning)

Echoic Memory

auditory sensory memory, brief sound retention

Sperling (1960)

showed 12 letters for 50 ms, participants recall ~4-5

Whole Report

limited recall (~4-5 items), suggests capacity limit

Partial Report

cued to recall one row, recall ~9/12, shows more info was stored

Sperling Conclusion

sensory memory holds more info than we can report

Delay in Recall

reduces performance, sensory memory fades quickly

Short-Term Memory

temporary storage requiring rehearsal

Rehearsal

repeating info maintains it in short-term memory

Recency Effect

better recall of last items, still in STM

Primacy Effect

better recall of first items, rehearsed into LTM

George Miller

"magic number 7 ± 2" capacity of STM

Chunking

grouping information increases STM capacity

Trace Decay

memory fades over time without rehearsal

Interference

disruption of memory (more common than decay)

Proactive Interference

old info interferes with new learning

Retroactive Interference

new info interferes with old memories

Brown-Peterson Paradigm

shows rapid STM decay without rehearsal

Long-Term Memory

large capacity storage, difficult retrieval

LTM Encoding

based on meaning (semantic), not surface features

STM vs LTM

STM = surface features, LTM = meaning

Bahrick

"permastore," memories lasting decades (50+ years)

Retrieval Cues

triggers that help access stored memories

Context-Dependent Memory

environment helps retrieval

Working Memory

limited workspace for processing + storage

Central Executive

directs attention and controls subsystems

Phonological Loop

stores and rehearses verbal information

Visuospatial Sketchpad

stores and manipulates visual/spatial info

Episodic Memory

personal experiences tied to time and place

Semantic Memory

general world knowledge