Figure 2. Individual SPARS ratings of each HFS train (5 trains × 26 participants) delivered to the control site (green) and the threat site (red).

Each dot represents a rating from one participant for one train. The SPARS has a non-painful range between −50 and 0, however, only the painful range (+5 to +50) is shown here because all train ratings were in the ‘painful’ range. Boxplot whiskers represent the maximum and minimum values, the ends of the box represent the upper and lower quartiles, and the horizontal line within the box represents the median.