Psychologists divide memory into three sequential processes: encoding (turning sensory input into a code the brain can store), storage (holding that code over time) and retrieval (bringing the stored material back into conscious awareness).
Encoding
Encoding can take three main forms:
- Acoustic encoding stores material by its sound. We rehearse a phone number ("oh-seven-five-three…") and confuse similar-sounding letters (P and B).
- Visual encoding stores material by its appearance — the shape of a face, the layout of a street.
- Semantic encoding stores material by its meaning — what a word means, the gist of a story.
Baddeley (1966) demonstrated that short-term memory relies mostly on acoustic encoding (participants struggled with acoustically similar words like cat, mat, hat) while long-term memory relies mostly on semantic encoding (participants struggled with semantically similar words like big, large, huge after a delay). This is a foundational study you can cite to evaluate the multi-store model.
Storage
Storage is about capacity (how much), duration (how long) and type of code (how stored). Each memory store has different specifications:
- Sensory register: very large capacity, ¼–½ second duration, modality-specific code (iconic visual, echoic auditory).
- Short-term memory: 7±2 items (Miller, 1956), 18–30 seconds without rehearsal (Peterson & Peterson, 1959), mostly acoustic code.
- Long-term memory: potentially unlimited capacity, lifetime duration, mostly semantic code.
Retrieval
Retrieval can be triggered by:
- Recall — bringing material to mind without prompts ("Name the seven dwarfs").
- Recognition — picking the right answer from options (multiple choice).
- Cued recall — partial prompts ("the dwarf who…" + a clue).
Recognition is almost always easier than recall because the cue (a face, a word) reduces the search space. Retrieval cues can be internal (mood, physiological state) or external (location, sights, sounds at the original event), which connects to context-dependent memory (Godden & Baddeley, 1975 — divers recalled lists best in the environment they learned them).
Why the three-process distinction matters
Because forgetting can occur at any of the three stages. If you can't recall a name at a reunion, you might never have encoded it deeply enough; the trace might have decayed in storage; or the cues at the reunion might not match the cues at first meeting (a retrieval failure). Exam answers earn marks by spotting which stage is being tested in a given scenario, and by linking the process to a relevant study.
Common misconceptions to avoid
- "Memory is like a video recorder" — no; it's reconstructive (Bartlett).
- "Forgetting always means the memory is gone" — often the trace exists but cues are missing.
- "Encoding and storage are the same thing" — they aren't; you can store something poorly because it was never encoded richly (e.g. a name heard in passing).
AI-generated · claude-opus-4-7 · v3-deep-psychology