Explain theories of forgetting and factors affecting the reliability of memory, including eyewitness testimony.

What this dot point is asking

The models of memory studied earlier explain how information is stored; this dot point explains why it is lost or distorted. The TASC memory module treats forgetting and reliability as a distinct content area because it has its own named theories and studies.

Theories of forgetting

• Decay (trace decay): memory traces fade over time if not used, mainly affecting short-term memory. Peterson and Peterson's trigram study supports rapid decay without rehearsal.
• Interference: other memories disrupt recall. Proactive interference is when older memories disrupt newer ones (an old password intruding when you try to recall the new one). Retroactive interference is when newer learning disrupts older memories (a new phone number making the old one hard to recall).
• Retrieval failure: the information is stored but cannot be accessed because the right cue is missing. Tulving's encoding specificity principle says recall is best when cues at retrieval match those present at encoding, explaining context-dependent and state-dependent forgetting.
• Motivated forgetting: Freud's idea of repression, where distressing memories are pushed into the unconscious to protect the self. This is hard to test scientifically and remains controversial.

The reliability of memory

Memory is not a recording. It is reconstructive: we rebuild a memory each time we recall it, filling gaps with expectations, schemas and later information. Bartlett's "War of the Ghosts" research showed people unconsciously altered an unfamiliar story to fit their own cultural expectations each time they retold it. This reconstructive nature makes memory vulnerable to distortion.

Eyewitness testimony

Eyewitness testimony is a person's account of an event they witnessed, often used in court. Because memory is reconstructive, it can be distorted by leading questions and post-event information, a problem with serious justice implications.

Elizabeth Loftus and Palmer (1974) showed participants a film of a car crash, then asked how fast the cars were going when they "hit", "smashed", "collided", "bumped" or "contacted" each other. The verb changed the estimate: "smashed" produced higher speed estimates than "hit". A week later, those given "smashed" were more likely to falsely recall broken glass, although there was none. The wording of the question had altered the memory itself.

Factors affecting accuracy

Beyond leading questions, accuracy is reduced by anxiety and the weapon-focus effect (attention narrows to a weapon, away from the culprit's face), by the passage of time, and by the misinformation of post-event discussion. Accuracy can be improved with the cognitive interview, which uses context reinstatement and open recall rather than leading questions.

Putting it together

To answer a forgetting question, match the scenario to a theory: fading without use is decay, competing memories is interference, a missing cue is retrieval failure, and distressing material being blocked is repression. To evaluate reliability, explain that memory is reconstructive and use Loftus and Palmer to show how leading questions create the misinformation effect, then note remedies like the cognitive interview. This pairing of theory and named study is what full-mark answers contain.