Information processing in imagination using nonverbalizable visual stimuli

In groups of 20 to 25, 146 undergraduates were tested as to their ability to mentally combine two shapes. They were to pick the correct choice from 5, 7, 9, 11, 13, or 15 alternatives. The shapes were previously proven to be effectively unverbalizable but recognizable and discriminable. Contrary to expectation, there was no negative decrement in performance with increasing numbers of incorrect alternatives.