Memory and Forgetting
This section tests the stage model of memory, its subtypes, and the explanations of forgetting. Expect questions on capacity and duration, interference direction, and the serial position effect.
Memory systems
- Atkinson-Shiffrin: sensory memory, short-term memory and long-term memory.
- Sensory: iconic about 0.5 second, echoic about 3 to 4 seconds.
- STM: about 7 plus or minus 2 chunks, roughly 18 to 30 seconds without rehearsal; rehearsal and chunking extend it.
- LTM: episodic (events), semantic (facts), procedural (skills); explicit versus implicit.
- Baddeley's working memory: phonological loop, visuospatial sketchpad, central executive, episodic buffer.
Forgetting
- Ebbinghaus: the forgetting curve is steepest early.
- Causes: decay, encoding failure, interference, retrieval failure, motivated forgetting.
- Proactive interference: old learning disrupts new. Retroactive interference: new learning disrupts old.
- Serial position: primacy reflects LTM, recency reflects STM.
- Amnesia: anterograde affects new memories; retrograde affects old memories.
Worked example
A student learns Spanish, then French, and finds Spanish vocabulary harder to recall. Reasoning: retroactive interference, because the newer learning disrupts the older.
Traps
- Proactive and retroactive interference are frequently reversed.
- STM capacity is chunks, not unlimited.
- Most forgetting is retrieval failure, not physical loss.