As of 2017, there are five task fMRI protocols. Each uses the 2017 HCP fMRI protocol with TR = 800 ms.
1st: Hand grip
| Target force | 50% |
| Total duration | 414 scans |
| Baseline | 75 scans |
| Task duration | 38 scans |
| Number of repeats | 3 |
| Repeat interval | 113 scans |
2nd: Valsalva
| Target pressure | 30 mmHg |
| Total duration | 414 scans |
| Baseline | 75 scans |
| Task duration | 23 scans |
| Number of repeats | 3 |
| Repeat interval | 113 scans |
3rd: Inspiratory Loading
| Target pressure | -30 mmHg |
| Total duration | 414 scans |
| Baseline | 75 scans |
| Task duration | 25 scans |
| Number of repeats | 3 |
| Repeat interval | 113 scans |
4th: Breath hold
| Total duration | 414 scans |
| Baseline | 75 scans |
| Task duration | 38 scans |
| Number of repeats | 3 |
| Repeat interval | 113 scans |
5th: Stroop
| Total duration | 224 scans | |
| Baseline | 0 scans | |
| Task type duration | 56 scans | |
| Number of repeats | 2 | |
| Repeat interval | 168 scans | 3 x 56 |
Rationale behind order
- Hand grip
- The easiest task to understand
- Gets people used to seeing screen, task on/off
- It is related to the hand grip max, which was the last thing performed (as people go into the scanner)
- Valsalva
- Most important, so do as soon as possible
- Most important, so do after a run-through with hg - subjects already familiar with viewing screen
- Inspiratory loading
- Next most important
- Closely related to Valsalva
- Breath hold
- Equally important to inspiratory loading
- Simpler, easier to do at end when subject may be tired
- Stroop
- Exploratory, so least important if we don't get it
- Short, can easily determine if will get completed within time
- Different to everything else
- Can set up button box when walking into scanner during previous tasks (plug in box, set up configuration, test key entries)