However, we must note that our paradigm examined neuronal discharge during head movements in the absence of gaze shifts.
Recently, Walton et al. (2007) have shown that 26% of classic gaze-related burst neurons in the superior colliculus exhibited significant changes in average firing rate in association with head movements in the absence of gaze shifts, suggesting that the superior colliculus plays a role in the control of head movements independent of gaze shifts.
Brockmann, D. & Geisel, T. The ecology of gaze shifts.
Brain activation evoked by perception of gaze shifts: the influence of context.
(A ) Measurements of gaze shifting revealed a behavioral association between the context and response phases of the task.
Similarly, the contrast of gaze shifts versus open/close eyes examining changes in regional activation should also have identified FEF.
Gaze shifting was quantified by gaze positions significantly different from baseline values (αBonf = 0.05, baseline: gray bar), and was found only in R f trials under the C + condition (upper-left panel, the timing of gaze shifts are indicated on top, where the color represents the trial type indicated on the right).
For example, the natural variability in accuracy of gaze shifts, especially in memory-guided movements (Fig. 1 B), allowed us to distinguish between target coding and coding for final gaze position.
If no gaze shift is recorded within the specified analysis period (e.g., the point of gaze does not move from the first stimulus to the second stimulus within the specified time window), the value of the SRT is determined as the last data point of the analysis window (e.g., 1,000 ms for an analysis window ranging from 150 to 1,000 ms poststimulus).
Three methods of estimating the user's point of gaze on a computer monitor are evaluated.
