Two Kinds of False Memory Share One Dial
Meaning-based and sound-based memory traps feel different. A new experiment suggests both may rise from the same underlying signal — with confidence thresholds doing the rest.
The Memory Trap
Read a list containing bed, rest, dream and tired, and the missing word sleep can later feel familiar. Swap meaning for sound-alike words and memory can manufacture a different sort of intruder. Psychologists have often treated these semantic and phonological errors as products of separate processes.
A new Psychological Science study tested that split with 227 English-speaking university students. Participants completed meaning-based and sound-based false-memory tasks, made old-or-new decisions and then classified recognised words as specifically remembered or merely known.
The Glitch
The expected surface pattern appeared. Meaning-related lure words attracted more “remember” responses, while sound-related lures produced more “know” responses. Yet two different analyses found that both patterns sat on a single underlying dimension of memory strength.
- A signal-detection model reproduced the data with one evidence scale.
- “Remember” responses behaved like a stricter decision threshold than “know” responses.
- State-trace analysis found a monotonic relationship across both tasks.
- Meaning-related material produced stronger false recognition without requiring a separate memory system.
Different illusions can be the same signal crossing different lines.
What It Means
The result challenges an appealing story in which vivid false recollection and vague false familiarity reveal distinct mental machinery. A person can use different labels for experiences generated along one continuous strength scale.
This does not show that every false memory has one cause. The experiment used controlled word lists and recognition judgments, not detailed autobiographical memories, eyewitness testimony or implanted life events. It tests a specific distinction inside a classic laboratory paradigm.
Reality, Recalibrated
The unnerving part is not that the brain stores two counterfeit versions of the past. It is that one noisy evidence signal can feel qualitatively different after crossing an internal criterion.
Memory's glitch may be less like a forged file and more like a confidence dial with no truth detector attached.