Participants in Sperling's experiment stared at a screen on which three rows of letters were flashed for just one-twentieth of a second.

Participants in Sperling's experiment stared at a screen on which three rows of letters were flashed for just one-twentieth of a second. If Sperling sounded a high-pitched, medium-pitched, or low-pitched tone within _____, the person could recall the letters in the upper, middle, or lower row.