Table II.
Performance statistics for the various algorithms as percentage of scansa
| Segmentation | Correct‐error discrimination | State | ||||
|---|---|---|---|---|---|---|
| Correct | Mean error | Hit rate | F Alarms | d‐prime | Accuracy | |
| Day 1 | ||||||
| fMRI without HMM | — | — | 68.5% | 48.3% | 0.44 | 42.2% |
| Behavioral/Forward | 30.4% | 4.17 | 5.9% | 1.1% | 0.73 | 29.4% |
| Behavioral/Viterbi | 43.5% | 3.11 | 25.0% | 6.7% | 0.82 | 40.1% |
| fMRI/Forward | 45.5% | 3.83 | 38.7% | 25.6% | 0.37 | 38.7% |
| fMRI/Viterbi | 60.9% | 1.5 | 40.0% | 24.0% | 0.45 | 47.4% |
| Both/Forward | 65.6% | 1.83 | 27.4% | 12.4% | 0.55 | 54.7% |
| Both/Viterbi | 75.9% | 1.07 | 37.2% | 13.4% | 0.78 | 61.9% |
| Day 5 | ||||||
| fMRI without HMM | — | — | 69.6% | 42.4% | 0.70 | 52.9% |
| Behavioral/Forward | 32.3% | 4.15 | 0.5% | 0.1% | 0.51 | 36.7% |
| Behavioral/Viterbi | 45.6% | 3.68 | 27.8% | 12.3% | 0.57 | 42.3% |
| fMRI/Forward | 42.5% | 4.83 | 38.7% | 21.0% | 0.52 | 44.2% |
| fMRI/Viterbi | 68.9% | 0.97 | 45.2% | 18.4% | 0.78 | 58.3% |
| Both/Forward | 75.0% | 1.63 | 33.4% | 10.1% | 0.85 | 67.6% |
| Both/Viterbi | 82.0% | 0.66 | 54.9% | 16.9% | 1.08 | 71.9% |
a
Segmentation statistics are calculated on all scans; other statistics exclude 11 warm‐up scans. “fMRI without HMM” is based on conditional probabilities only.