memory

Meaning: Memory is the encoding, storage, and retrieval of information. In the information-processing model, sensory memory holds input briefly, attention moves some of it into working (short-term) memory, and rehearsal or meaningful encoding moves some into long-term memory. Working memory holds about seven items, plus or minus two, and chunking stretches that limit. Long-term memory is explicit (declarative: episodic for personal events, semantic for facts) or implicit (nondeclarative: procedural skills, priming, conditioning). Explicit memory depends heavily on the hippocampus; skills rely more on the cerebellum and basal ganglia.

On the MCAT: Expect a scenario to classify, or a free-recall list showing the serial position effect: early items are recalled well (primacy, through rehearsal into long-term memory) and so are the last items (recency, still in working memory). A delay or distraction before recall mainly lowers recency. Forgetting is explained by decay, interference (proactive: old material disrupts new; retroactive: new material disrupts old), or retrieval failure.

Common confusion: Riding a bike is procedural and implicit, not episodic; recalling the day you learned to ride is episodic and explicit. Also, retrieval is reconstructive rather than a playback, so later information can alter a memory.