Even more interestingly, the question whether the distractor differed from the correct result in tens or units position was associated with different patterns of neural activation: When the distractor differed from the correct result in decade position, magnitude-related IPS activation was observed, whereas a difference in unit position resulted in language-related activation of the left insula.
On angle mismatch trials (66%), the angle of the single-probe stimulus differed from the correct intermediate angle by 20° (50%) or 30° (50%), color always mismatched.
On color mismatch trials (66%), the hue of the single probe stimulus differed from the correct intermediate hue by either 50° (50%) or 30° (50%), angle always mismatched.
Additionally, half of the distractors differed from the correct result only in the units position, while in the other half only the tens position was different from the correct result.
Half of the incorrect solution probes (distractors) differed from the correct result by ±2, whereas the distance between the correct result and the distractor was ±10 for the other half, in order to minimize parity based solution strategies [ 21- 23].
The brain region in which activity correlated with a distractor differing from the correct result by +/- 10 is depicted in Figure 5A and Table 5 (uncorrected p <.005, k = 5 voxels).
A similar problem occurs in the case of a distractor, which differs from the correct result at the tens position, because the problem has to be calculated to the end (including the computation of the correct decade digit) to decide between the two alternative results provided.
This indicated that the effect of a carry operation was only larger in large problems (312 ms and 8%, respectively) than in small problems (116 ms and -2%, respectively) when the distractor differed from the correct result at the decade digit, but not at the unit digit.
The corrected series will differ from the original series if the pre-treatment by TRAMO or regARIMA has detected outliers or calendar effects.
