across the seven game levels. The graph shows a linear decline in accuracy for the first four game levels (76.1%, 74.5, 74.5% and 7l.6%) respectively. Level 5 shows an increase in accuracy (78.7%) leaving it the game with the best overall mY EP accuracy of all levels. By levels six and seven (73.6% and 72.2%) respectively, the MVEP accuracy declines linearly from level 5. The game level with
the worst accuracy was level 4 (71.6%). An Analysis of Variance ANOVA test was conducted between the best and worst performing game levels (level 5 and level 4 respectively) and returned a value of p=O.OI, suggesting the differences in accuracy are statistically significant. An ANOVA test between level 4 and level 7 (Crash Bandicoot with and without white button background) revealed a result of p=0.69 revealing the difference between these two levels are not statistically significant. A further ANOVA test was conducted taking into account all game levels and returned a value of p=O .18 suggesting that the difference in accuracy for all levels are not statistically significant.
80
Fig. 11 shows the graph of the test 2 analysis which shows similar trends of test 1 analysis above. In this graph we can see an increase in level 2 (80.6%) over level 1 (79.4%) but this drops again by level 3 (78.2%). Again, levelS produces the best accuracy (83.6%) and level 4 produces the worst accuracy (72.8%) of all levels. Also to note in this graph, the most graphically complex game -level 6 produces the second best accuracy achievement (80%). Level 7 obtained higher classification results (75.1 %) than the level 4 (72.8%) suggesting that the moving game objects surrounding the m YEP buttons did not adversely affect the accuracy of the system. ANOVA results comparing the best (levelS) and worst (level 4) game presentations for test 2 return a value of p=0.05 showing the statistical significance of the results. ANOVA comparing the level 4 and level 7 provide a value ofp =0.65 showing that the results are not statistically significant. Taking all levels into account, ANOVA results for test 2 returned a value ofp=0.45.
igure II. Graph to show the mean Target vs. non Target Single Trial (training) (test 2) accuracy across all game presentations.
Fig. 12 shows the results for the test 3 analysis. As can be seen a drop in mY EP accuracy from level 1 (79.2%) to level 2 (78.5%) and again at level 3 (70.8%). Level 4 (70.8%) produced the same results as the level 3 with these levels having the worst overall accuracies. Once again, level 5 obtained the highest accuracy (83.5%) of all levels and level 6 following with the second highest accuracy (79.6%). As with the previous analysis tests, these results also show level 7 with no white background surrounding the mY EP buttons produced a higher accuracy (74.6%) than level 4 with the white background (70.8%). ANOVA results between level 4 and level 5 game levels return a result of p=O.03 indicating the results are statistically significant. ANOVA between the two levels 4 and level 7 return a value p=0.48, furthering the point that the results are insignificant. ANOVA using all game levels provide a value of p=O.31, again suggesting that the difference in mY EP accuracies using all games are not significant.