Figure 6.

Chronic (Day 29) treatment related change in multitasking performance averaged across pre-dose, 2 h and 4 h post-dose assessments. Scores for each measure were converted into standardised Z score with a positive score indicating improved performance in order to analyse data together. Data shown are estimated means (plus SE) derived from the LMM analysis, using Day 1 pretreatment baseline data and age as covariates. The Z scores are plotted with an increased score indicating improved performance. The top panels show subtraction accuracy (errors) and tracking accuracy data; the bottom panels show subtraction speed (total number) and tracking accuracy data. In both top and bottom panels the left-hand panels show comparisons of mean Day 29 data averaged across the two concomitantly performed task outcomes (serial subtractions/tracking), and the right-hand panel shows comparisons conducted on the separate task outcomes. The data for tracking is the same in both analyses. t, p < 0.1, *, p < 0.05; ***, p < 0.001 in comparison to placebo.