Running Span

 

Participants were instructed to report the final 2, 3, 4, 5, or 6 letters presented in a list that varied from 2 to 8 letters. Instructions (Report last 2, etc.) were shown prior to each list presentation. In the original version, each of the 5 report sizes was tested with three consecutive lists, presented in random order. Then all five report sizes were re-tested in random order. Stimuli were presented at central fixation for 500ms, with 200ms ISIs. Thirty trials were administered, 6 at each report size. The dependent measure was the total number of items recalled in correct order. We also administered an “adaptive version” to determine if we could reliably estimate span with fewer supra-capacity trials. In this version participants start with a block of four trials at report size 1. If they responded correctly to at least 2 of the trials, they advanced to the next report size. This continued until they failed to get 2 of 4 trials correct for a given report size or until report size 6 was completed (maximum of 24 trials). The dependent measure was the total number of items recalled in correct order.