Calculated by obtaining the sum of the subject's response times (in milliseconds) over all the 'assessed' trials during Stage 1.
Note that: the first two trials of Stage 1 are not included since they are accompanied by voice instructions; and so are regarded as practice for the purposes of this measure calculation.
The response time for a single trial is measured from the appearance of the stimuli; up to the time where the subject made their final choice for that trial.