Table 3.
Comparison of the new SMF model with three earlier approaches
| Shared Gaze Feedback |
Independent Controllers |
||||
|---|---|---|---|---|---|
| Comparison Criterion | SMF | Daye et al. (2013) | Freedman (2008) | Kardamakis et al. (2010) | |
| Behavior | |||||
| 1 | Accuracy (ΔG < OMR) | Y | Y | Y | Y |
| 2 | Accuracy (ΔG > OMR) | Y/E | Y/D | Y/D | |
| 3 | Eye/gaze velocity profiles with single or double peaks | Y/E | Single/D | Y/D | Y/D |
| 4 | Functional fixation without perfect integrators | Y/E | N | N | N |
| 5 | Maximum eye deviation not necessarily aligned with switching (OPN on); early turnaround | Y/E | Y/E | N | N |
| 6 | NL scaling of final eye/head contributions with initial gaze error or target eccentricity | Y/D | N | Y/D | Y/D |
| 7 | Main sequences (size, duration, velocity) | Y/E | Y/D | Y/D | Y/D |
| 8 | Corrective gaze drifts during “fixation” (slow phase) | Y/D | N | N | N |
| 9 | Soft eye position/gaze velocity saturation | Y/D | Y/D | N | N |
| 10 | Nystagmus in passive VOR and visual pursuit | Y/E | N | N | N |
| Cells | |||||
| 11 | OPN switching levels | Y | N | N | Y |
| 12 | Saturation on SLBNs and decay during saccade | Y/E | Y/E | N | N |
| 13 | Modulation of SLBN and VO activity by external head perturbations | Y/D | SLBN/D | N | N |
| 14 | Modulation of PVP in saccade and fixation intervals | Y/D | N | N | N |
| 15 | Eye and head motoneural activity | Y | Y | Y | Y |
| Robust gaze accuracy/trajectory | |||||
| 16 | Robust gaze accuracy with diverse parameter sets and variable eye/head trajectories | Y/E | Y/E | N | N |
| 17 | Robust gaze trajectory with diverse parameter sets and variable eye/head trajectories | Y/E | N | N | N |
| 18 | Unaffected gaze accuracy by head perturbations during saccades | Y/D | Y/E | N | N |
| 19 | Unaffected gaze trajectory by sustained “nonreversing” head perturbations during saccades | Y/E | N | N | N |
| 20 | Robust gaze trajectory for diverse initial conditions (H0, E0, (H0), …) | Y/E | N | E0/D | E0/D |
| 21 | Robust gaze accuracy with independent gaze and head goals | Y/E | Y/E | N | N |
| 22 | Robust gaze trajectory with independent gaze and head goals during the saccadic phase | Y/E | N | N | N |
| Lesions | |||||
| 23 | Gaze shifts without OPNs (no slow mode); identical to control | Y/E | |||
| 24 | Gaze shifts without SLBNs; very slow “saccades” | Y/E | N | N | N |
| 25 | Saccades stop without SC rostral zone | Y/E | N | N | |
| 26 | Gaze shifts overshoot with acute vestibular lesions | Y/E | N | N | N |
For comparisons: Y, yes; N, No; E, emerging property; and D, designated property; field is blank if the criterion was not reported or D (by design) if intentionally selected a priori; see methods for details. The models of Freedman (2008) and Kardamakis et al. (2010) use independent controllers for eye and head after decomposition. ΔG, gaze shift size; OMR, oculomotor range; OPN, omnipause neurons in NRI; SLBN, short-lead burst neuron; VO, vestibular-only cells in VN that respond only to passive head movements; PVP, position-vestibular-pause cells in VN that carry vestibular and eye position signals (Fuchs et al. 2005; Roy and Cullen 2004); E0 and H0, initial eye and head position; ˙H0, initial head velocity.