Searching for letters or closed shapes in simulated electronic displays

Abstract

16 MEN COUNTED THE NUMBER OF BRIGHT SYMBOLS OF A PARTICULAR KIND IN A SIMULATED ELECTRONIC DISPLAY PRESENTING 19-59 SYMBOLS OF 8 DIFFERENT KINDS. IN SOME DISPLAYS ALL THE SYMBOLS WERE BRIGHT, IN OTHERS BRIGHT AND DIM SYMBOLS WERE MIXED. 4 SETS OF 8 SYMBOLS WERE COMPARED. TARGETS WERE MISSED LESS OFTEN FROM SETS OF CAPITAL LETTERS THAN FROM SETS OF CLOSED SHAPES (P < .01). THE PROBABILITY OF MISSING AT LEAST 1 TARGET INCREASED APPROXIMATELY LINEARLY WITH THE NUMBER OF TARGETS PRESENT (P < .01). THE RATE OF INCREASE WAS APPROXIMATELY PROPORTIONAL TO THE TOTAL NUMBER OF BRIGHT SYMBOLS DISPLAYED, AND WAS SOMEWHAT GREATER WHEN DIM SYMBOLS WERE PRESENT ALSO (P < .05). FOR A COMBINED TOTAL OF 57-59 BRIGHT AND DIM SYMBOLS, THE PROBABILITY OF MISSING AT LEAST 1 TARGET INCREASED FROM ABOUT .03 PER TARGET WHEN 10 OF THE SYMBOLS WERE BRIGHT, TO .09 WHEN 26 WERE BRIGHT. 35% OF THE UNDERESTIMATIONS WERE OF SIZE 2 OR GREATER. THE TIME TAKEN TO COUNT THE TARGETS INCREASED WITH THE TOTAL NUMBER OF BRIGHT SYMBOLS PRESENT (P < .01). DIM SYMBOLS TENDED TO BE COUNTED AS BRIGHT (P < .01). (PsycInfo Database Record (c) 2025 APA, all rights reserved)