What this exercise trains
A grid fills with near-identical symbols and one that differs. Find it before the timer expires, and the next grid gets denser and the difference subtler.
This is a visual search task of the kind used to study selective attention. Performance depends on how efficiently you scan and how well you ignore distractors, which is a different ability from reasoning — people who score well on matrices are not automatically fast here.
Training exercises are not a scored assessment. For a measured result across four reasoning domains, take the free IQ test, and see our methodology for how that score is worked out. More exercises are on the training page.