Aliasing in peripheral vision for counterphase gratings.

This study measured spatial detection and resolution acuity thresholds at 30 deg eccentricity for sinusoidal gratings of different contrast (10-90%) that phrase reverse at different temporal frequencies (0-40 Hz). Resolution performance at any contrast displayed little deterioration with increasing temporal frequency up to 10 Hz, after which it declined smoothly, indicating no definable break where performance switched from being P-cell to M-cell mediated. Detection was measurably higher than resolution acuity for all temporal frequencies at 90%. At 50% contrast, detection and resolution performance converged at approximately 30 Hz. For 10% contrast, detection and resolution performance were the same at all temporal frequencies. These results indicate that resolution performance remains largely P-cell mediated and sampling limited over a large range of contrasts and temporal frequencies.