Festman Yariv, Ahissar Merav
Centre for Theoreticàl & Computationàl Neuroscience, University of Plymouth, Plymouth, UK.
Neural Netw. 2004 Jun-Jul;17(5-6):849-60. doi: 10.1016/j.neunet.2004.02.006.
We studied top-down attentional effects on adaptation to two aspects of sinusoidal gratings: contrast (CTE: contrast threshold elevation for detection) and orientation (TAE: tilt aftereffect, bias in perceived orientation). Adaptation was examined under five different behavioral conditions designed to assess the effect of alertness, spatial attention and the dimension attended. Alertness increased CTE, but had no effect on TAE. Spatial attention increased TAE, but had no effect on CTE. TAE (but not CTE) was also sensitive to the attended dimension. It was greater when gratings' contrast rather than orientation was attended. The different patterns of top-down effects on CTE compared with TAE are consistent with these two types of adaptation taking place at different levels along the visual hierarchy: CTE occurs at very low-levels, where activity is affected by alertness but not by spatial attention, whereas TAE occurs at subsequent stages, which are modulated by selective attention.
对比度（CTE：检测的对比度阈值升高）和方向（TAE：倾斜后效，感知方向偏差）。在五种不同的行为条件下检测适应性，这些条件旨在评估警觉性、空间注意力以及所关注维度的影响。警觉性增加了CTE，但对TAE没有影响。空间注意力增加了TAE，但对CTE没有影响。TAE（而非CTE）对所关注的维度也很敏感。当关注光栅的对比度而非方向时，TAE更大。与TAE相比，自上而下对CTE的影响模式不同，这与这两种类型的适应性在视觉层级的不同水平上发生是一致的：CTE发生在非常低的水平，在那里活动受警觉性影响但不受空间注意力影响，而TAE发生在随后的阶段，这些阶段由选择性注意力调节。
