Figure 2. The latency of response (response time in seconds) to an “alarm light” was used as a measure of vigilance (see text for details). The figure depicts the range of data for each of four task categories for EARK ([square, open]) and MAN (*symbol*). The box contains 50% of all of the data, whereas the dark line depicts the median value in that group. The minimum and maximum values in each group is shown by the upper and lower bars. The response latency during record keeping was not statistically different between EARK and MAN. In both record keeping groups, subjects had significantly slower responses when observing or adjusting the TEE when compared with record keeping, observing monitors, or adjusting intravenous lines (*P < 0.05). Subjects in both groups had faster response latencies when observing the monitoring array ((dagger)P < 0.05 compared with all three other tasks).