Table 1.
Sample characteristics.
Fig 1.
Set-up of the SRTT and the dual task.
Left: The SRTT. Interleaved random and sequence blocks. The differences in reaction time and percent accuracy between the last two random blocks and the last two implicit blocks, evaluated before and after a break, were used as measures of implicit sequence learning. Right: The dual task. Interleaved single and dual task blocks. The differences in reaction time and percent accuracy between the single blocks and the dual blocks as well the performance of correctly counting the plus signs, were used as measures of dual task ability.
Fig 2.
Implicit sequence learning outcomes of the SRTT on the group and individual level.
(A) and (B): A value above zero indicates implicit sequence learning as measured by lower RTs for the last two sequence blocks compared to the last two random blocksbefore (left) and after (right) the break. (C) and (D): A value above zero indicates implicit sequence learning as measured by higher accuracy for the last two sequence blocks than for the for last two random blocks before (left) and after (right) the break. Each boxplot shows the median (the thin line), the mean (the short bold line), the 25th and 75th percentiles (the hinges), and the range from the smallest to the largest value if not exceeding 1.5 times the interquartile range (the whiskers).
Fig 3.
Reaction time and accuracy of the SRTT.
(A) Means and standard errors (+1,––1) of the RTs over all blocks for the two groups. (B) Means and standard errors (+1,––1) of accuracy over the all blocks for the two groups. The squares indicate the blocks used for the descriptive statistics of implicit sequence learning where the performance on the random blocks was compared with the performance on the sequence blocks.
Fig 4.
Outcomes of the dual task with performance on the group and individual level.
(A) and (B): A score higher than zero indicates a cost of the dual task for that individual/group and outcome. (C): Performance on the counting task with one point given for each correct answer with a maximum value of 5. (D): Performance on the counting task by a scoring system (3 points for the correct answer, 1 point for the answer closest to the correct answer and 0 points for other answers) with a maximum value of 15. Each boxplot shows the median (the thin line), the mean (the short bold line), the 25th and 75th percentiles (the hinges) and the range from the smallest to the largest value if not exceeding 1.5 times the interquartile range (the whiskers).
Fig 5.
Reaction time and accuracy of the dual task.
(A): Means and standard errors (+1, –1) of RTs over all blocks for the two groups. (B): Means and standard errors (+1, –1) of accuracy over all blocks for the two groups.
Table 2.
Awareness of the sequence in the SRTT.