Performance as a function of polar angle at isoeccentric locations across the visual field is known as a performance field (PF) and is characterized by two asymmetries: the HVA (horizontal-vertical anisotropy) and VMA (vertical meridian asymmetry). Exogenous (involuntary) spatial attention does not affect the shape of the PF, improving performance similarly across polar angle. Here we investigated whether endogenous (voluntary) spatial attention, a flexible mechanism, can attenuate these perceptual asymmetries. Twenty participants performed an orientation discrimination task while their endogenous attention was either directed to the target location or distributed across all possible locations. The effects of attention were assessed either using the same stimulus contrast across locations or equating difficulty across locations using individually titrated contrast thresholds. In both experiments, endogenous attention similarly improved performance at all locations, maintaining the canonical PF shape. Thus, despite its voluntary nature, like exogenous attention, endogenous attention cannot alleviate perceptual asymmetries at isoeccentric locations.

性能作为视场中等偏心位置上极角的函数，被称为性能场（PF），其特征是两个不对称性：HVA（水平-垂直各向异性）和VMA（垂直子午线不对称））。外来的（非自愿的）空间注意力不会影响PF的形状，类似地在整个极角上也可以提高性能。在这里，我们调查了内源性（自愿）的空间注意力（一种灵活的机制）是否可以减弱这些感知上的不对称性。20名参与者执行了定向辨别任务，而他们的内在注意力要么直接指向目标位置，要么分布在所有可能的位置。使用不同位置的相同刺激对比来评估注意力的影响，或者使用单独滴定的对比阈值来评估不同位置的难度。在这两个实验中，内源性注意力在所有位置都类似地提高了性能，并保持规范的PF形状。因此，尽管它具有自愿性质，例如外在注意力，