Figure 5.3 A 3 × 3 Letter Matrix Like Those Used in Sperling’s Iconic Memory Research On each trial, a different letter matrix is shown for 50 milliseconds. In the full-report procedure, participants attempt to recall all of the letters in the matrix. In the partial-report procedure, participants get an auditory cue following the matrix that tells them which row to report—high-pitched tone, recall top row; medium-pitched tone, recall middle row; and low-pitched tone, recall bottom row. The row that is cued is varied randomly across trials, so the participant has no way of knowing which row will be cued on any particular trial. In addition, the time between the letter matrix presentation and the auditory cue is varied.