All statistical tests computed by accumulating the data from each subject based on ROIs that were defined based on data from the remaining subjects (and then permuting this procedure 12 times)
| Region | Difficulty by time | Difficulty by time (saccade trials) | Difficulty by time (manual trials) | Difficulty by modality by time |
|---|---|---|---|---|
| RH insula | 10.7*** | 5.30* | 7.57** | 0.28 |
| RH anterior insula | 0.15 | 2.04 | 2.06 | 3.98 |
| RH MFG | 0.00 | 0.70 | 0.18 | 0.91 |
| RH SFG | 0.09 | 0.40 | 0.03 | 0.53 |
| RH IPS | 1.86 | 9.35** | 0.24 | 4.15 (p = 0.06) |
| RH FEF | 0.00 | 0.01 | 0.00 | 0.01 |
| LH IPS | 0.38 | 8.76** | 0.11 | 3.46 (p = 0.09) |
| LH FEF | 0.00 | 0.50 | 0.81 | 1.64 |
| MFC | 0.03 | 1.11 | 0.82 | 2.18 |
| LH TPJ | 2.19 | 0.29 | 2.65 | 0.38 |
| LH SFS | 1.47 | 0.30 | 0.64 | 0.01 |
The first column contains F values for the interaction between perceptual difficulty and time over the first two data points (0–2 s), collapsed across response modality; also reported is the interaction computed separately for each response modality, and the three-way interaction among perceptual difficulty, response modality, and time. All numbers represent F values with (1, 11) df, with the exception of the values for left SFS, in which there are (1, 9) df.
↵*p < 0.05;
↵**p < 0.025;
↵***p < 0.01. RH, Right hemisphere; LH, left hemisphere.