Day 76 of 150 Speed Difficulty 5/10
A response bottleneck slows back-to-back decisions
Quick answer
A response bottleneck slows back-to-back decisions. Today's question (Psychological refractory period) asks about a finding from Pashler, H. in 1994. The correct option is It is slowed, with the slowdown decreasing as the gap between stimuli increases (the PRP effect) — full explanation, primary source, and glossary cross-links below.
Today's question
When two stimuli requiring distinct responses arrive in close succession, what happens to the second response?
Reveal the answer and explanation
Correct: B — It is slowed, with the slowdown decreasing as the gap between stimuli increases (the PRP effect)
Pashler (1994) reviewed decades of dual-task experiments showing that the second response is reliably delayed when the inter-stimulus interval is short, with the slowdown shrinking as the gap grows — the psychological refractory period. The pattern is best explained by a central response-selection bottleneck: stimulus encoding and motor execution can run in parallel, but the act of choosing a response from a set is serial. The PRP effect places a hard upper bound on how much true multitasking the human cognitive architecture supports for choice tasks, even with practice.
About the source
Pashler, H. (1994). Dual-task interference in simple tasks: Data and theory. Psychological Bulletin, 116(2), 220–244.
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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