Chimp Test (Iconic/Eidetic and Spatial Memory)
Description
An iconic/eidetic and spatial memory task based on the famous Ayumu chimp memory test. Participants must memorize spatial positions of numbered boxes displayed briefly on a grid, then click them in numerical order.
About This Test
Numbers appear on a 5×8 grid. In the masking task, numbers remain visible until the first click, then all hide. In the limited-hold task, numbers are shown briefly (210-650ms) then all masked before clicking begins. Participants click boxes in numerical order (1, 2, 3, etc.). Correct clicks turn green, incorrect clicks turn red and end the trial. The masking task uses adaptive difficulty (4-9 items), while limited-hold tasks use fixed 5-item sequences.
Test Details
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Scientific Background
Original Task References:
These references describe the original task that this PEBL implementation is based on.
- Inoue, S., & Matsuzawa, T. (2007). Working memory of numerals in chimpanzees. Current Biology, 17(23), R1004-R1005.
Data Output
chimptest-trial-{subnum}.csv
Scoring and Interpretation
Accuracy: Proportion of trials completed correctly (allCorrect=1).
Mean correct items: Average number of items recalled before first error.
Limited-hold performance: Percentage correct on 5-item sequences at different display durations (650ms, 430ms, 210ms).
Note: This task became famous when Ayumu the chimpanzee outperformed university students, but typical human performance varies with practice and age.
About This Test
An iconic/eidetic and spatial memory task based on the famous Ayumu chimp memory test. Participants must memorize spatial positions of numbered boxes displayed briefly on a grid, then click them in numerical order.
Category: Memory
Estimated Duration: 10 minutes
Available Translations: 7 languages
Documentation Sources:
Test description file, Test implementation, Parameter schema
Documentation Status: Complete