Differences between Short Term Memory & Long Term Memory

(Storage)

STM stores phonetic codes

LTM stores by meaning/representation

Baddley's List Length Experiment

list length 5-10 items (STM 5, LTM 10)

relationships (phonetic similarity hat cat bat, semantic similarity rock stone pebble, unrelated hat rock desk)

Results : 5 words (unrelated = semantic > phonetic)

10 words (unrelated = phonetic > semantic)

Interpretation : STM (5) phonetic worse because confusing between words. LTM (10) semantic worse because meaning confusion

Differences between Short Term Memory & Long Term Memory

(Capacity)

Capacity 7 +- 2 items

no limitation on LTM

limitation on STM

Chunking : grouping items into meaningful units. Functionally increases STM capacity

Differences between Short Term Memory & Long Term Memory

(Duration)

Trace Duration : Brown-Peterson Task

- show 3 items for 3 seconds

- immediate recall or delay with rehersal prevention task

- results : without rehersal information doesn't last long (STM requires rehersal for maintenance, LTM doesn't require it)

reason for duration difference : forgetting (psychological process)

- STM decay (fades away)

- LTM interference (doesn't disappear, cannot get correct info out)

Simple Span Task : average number of items people can remember is 7

retrograde : can't remember what happened BEFORE the event.

anterograde : can't form new memories AFTER