Figure 1.
Task sequence of fMRI sessions.
The session for each task included an instruction period, a resting period (in which only a fixation point was displayed), and a task period. Subjects were instructed to stare at a fixation point throughout the session and to select the correct digit as quickly as possible after a pair of digits was displayed. Instructions about which digit to select (larger/smaller) were visually presented before the beginning of each block (fMRI task).
Figure 2.
Average response times of 4 conditions.
Error bars indicate standard errors of mean. The result of two-way ANOVA showed significant main effects of distance and choice, but no interaction between the two.
Table 1.
ANOVA table of response time analysis.
Figure 3.
Brain areas activated under each condition.
(A) Red areas showed greater activation in the task than in the rest period. LC: the larger digit choice; SC: the smaller digit choice; LD: Large distance; SD: Small distance. The threshold p-value under each condition was 0.001 (uncorrected). (B) Comparison between the brain areas that were activated under the SC and LC conditions with p-values lower than 0.001 (uncorrected). The number at the upper left of the picture in each section indicates the y-level on the MNI coordinates. (CUN: cuneus/precuneus, TPJ: temporo–parietal junction, INS: insula, ACC: anterior cingulate cortex, SFG: superior frontal gyrus, STS: superior temporal sulcus, PreCG: precentral gyrus).
Table 2.
MNI coordinates and statistical details for areas that were activated in each condition.
Table 3.
MNI coordinates and statistical details for areas that activate in contrast [SC – LC].
Figure 4.
Average BOLD signal change from the rest in areas indicated in Figure 3b.
Error bar indicates S.E.M. LC: the larger digit choice; SC: the smaller digit choice; LD: large-distance; SD: small-distance.
Figure 5.
RT-related BOLD signal change.
(A) Parametric contrast of regions activated in proportion to the measured RT of each condition (SC/SD>SC/LD>LC/SD>LC/LD) (p<0.05, FWE corrected). The hair line indicates intra-parietal sulcus (IPS). (B) BOLD signal intensity at MNI coordinate (−26, −58, 50).
Table 4.
MNI coordinates and statistical details for areas that change activity in relation to RT.