Verbal Time Production as a Secondary Task: Which Metrics and Target Intervals are Most Sensitive to Workload for Fine Motor Laparoscopic Training Tasks?

Although time production is frequently used as a secondary task, research has not thoroughly investigated whether the length of the to-be-produced interval or the metric used to summarize productions affects sensitivity to mental workload. Fourteen participants produced four target intervals (6, 11, 16, or 21 s) while performing a surgical training task that required putting small beads into a cup (easy) or onto a peg (difficult). Intervals were summarized into two metrics of central tendency and four metrics of dispersion previously used in the literature. Results indicate that metrics of central tendency and shorter target intervals are more sensitive to mental workload.