Figure 7.

a, Shift magnitude (localization error) for peripheral targets (from Fig. 6, open symbols) plotted against values for central targets (from Fig. 6, filled symbols) during alternating fixation. Each data point is mean localization error for a single subject during trials 13–26, when central and peripheral targets (seven each) were interleaved. In a, b, and d, asterisks indicate that the slope or intercept (based on a straight-line equation) is statistically different (p < 0.05) from the ideal of 1.0 (diagonal solid line) or 0.0, respectively. A shift in central auditory space is accompanied by a simultaneous shift in peripheral auditory space, suggesting that changes in eye position alone invoke the effect across the entire frontal field without previous exposure to specific target locations. b, Shift magnitude during the alternating (see Fig. 6) as opposed to sustained (see Fig. 5d) fixation task for each subject. The magnitude of the shift was proportionally smaller during alternating fixation, suggesting that the long-term component of the shift is more accurately captured during sustained fixation. c, The steady-state magnitude (y_∞) plotted against the time constant (τ) of the shift during alternating fixation for each subject. The magnitude of the shift averages to 6.25° (intercept) independent of the time constant (slope, −0.004; p = 0.79 relative to 0.0). d, Predicted change in peripheral spatial gain (target − Ctr fixation) plotted against the actual values. Predictions are based on a first-order exponential model (see Materials and Methods) and data from the alternating and target fixation tasks and account for 72% (slope, 0.72) of the change in peripheral gain. Alt. Fix., Alternating fixation; Shift Mag., shift magnitude.