234487University of Tübingen, Tübingen, Germany.
28328Max Planck Institute for Biological Cybernetics, Tübinge, Germany.
Perception. 2022 Aug;51(8):549-564. doi: 10.1177/03010066221108281. Epub 2022 Jul 18.
According to the central-peripheral dichotomy (CPD), feedback from higher to lower cortical areas along the visual pathway to aid recognition is weaker in the more peripheral visual field. Metacontrast masking is predominantly a reduced visibility of a brief target by a brief and spatially adjacent mask when the mask succeeds rather than precedes or coincides with the target. If this masking works mainly by interfering with the feedback mechanisms for target recognition, then, by the CPD, this masking should be weaker at more peripheral visual locations. We extended the metacontrast masking at fovea by Enns and Di Lollo to visual field eccentricities 1, 3, and 9. Relative to the target's onset, the mask appeared at a stimulus onset asynchrony (SOA) of , 0, 50, 92, or 142 milliseconds (ms). Enlarged stimuli were used for larger eccentricities to equalize target discrimination performance across eccentricities as best as possible for zero SOA and when SOA was too long for substantial masking. At each eccentricity, the masking was weakest at 0 or ms SOA, strongest at 50 ms SOA, and weakened with larger (positive) SOAs. Consistent with the CPD, larger eccentricities presented weaker maskings at all nonzero, and particularly the positive, SOAs.
根据中枢-周围二分法（CPD），视觉通路上从较高皮质区域到较低皮质区域的反馈，在更外周的视野中较弱，有助于识别。对比掩蔽主要是指当掩蔽在目标之后而不是之前或与目标同时出现时，短暂的掩蔽会降低短暂目标的可见度。如果这种掩蔽主要通过干扰目标识别的反馈机制起作用，那么根据 CPD，这种掩蔽在外周视觉位置应该较弱。我们将 Enns 和 Di Lollo 在中央凹的对比掩蔽扩展到视野偏心 1、3 和 9。相对于目标的起始，掩蔽在刺激起始异步（SOA）为 、0、50、92 或 142 毫秒（ms）时出现。对于较大的偏心，使用较大的刺激来使目标辨别性能在尽可能接近零 SOA 的情况下在各个偏心达到最佳，并且当 SOA 太长而无法进行实质性掩蔽时。在每个偏心处，0 或 50ms SOA 时掩蔽最弱，50ms SOA 时掩蔽最强，随着 SOA 的增大（正）而减弱。与 CPD 一致，较大的偏心在所有非零 SOA 时，尤其是在正 SOA 时，呈现出较弱的掩蔽。
