Day 78 of 150 Speed Difficulty 7/10
Each extra item in memory costs ~38 ms to scan
Quick answer
Each extra item in memory costs ~38 ms to scan. Today's question (Sternberg memory scanning) asks about a finding from Sternberg, S. in 1966. The correct option is It increases roughly linearly with set size, by ~38 ms per additional item — full explanation, primary source, and glossary cross-links below.
Today's question
In Sternberg's classic memory-scanning task, participants memorize a short list, then judge whether a probe was in it. How does response time scale with list length?
Reveal the answer and explanation
Correct: B — It increases roughly linearly with set size, by ~38 ms per additional item
Sternberg (1966) gave participants memory sets of 1–6 digits, then tested whether a probe digit had been in the set. Response time grew roughly linearly with set size, at about 38 milliseconds per item, with similar slopes for present and absent probes. Sternberg argued for an exhaustive serial scan — the comparison process keeps going through every list item even when a match has been found. Whether scanning is truly serial or merely parallel-with-capacity-limits has been debated for decades, but the linear set-size function itself remains one of the most replicable findings in cognitive psychology.
About the source
Sternberg, S. (1966). High-speed scanning in human memory. Science, 153(3736), 652–654.
Every Cognition Bible question cites a primary source — a paper, book chapter, or monograph that exists, that we can point to on Google Scholar, and whose finding the question accurately summarizes. No fabricated authority strings, no name-drops without paper-level grounding.
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