Analyses of visual awareness and qualia by psychophysical methods

近年来，在脑科学阐释意识的背景下，有关视觉意识和感受质的问题得到了积极的研究。本研究采用心理物理学的方法进行了几项实验研究，这些研究使我们能够直接接近和分析主观经验。首先，视觉非模态完成是一种现象，它产生对被遮挡物体的强烈意识，而没有生动的感受质。相比之下，在模态完成的情况下，我们实际上可以感知完成曲面的质量。我们比较了非模态和模态完成的心理物理研究结果。因此，我们从心理学的角度证实了意识在输出侧提供灵活性，而感受质在输入侧保证可重复性，并具有标记现在的功能，正如Ramachandran（1998）和Gregory（1998）理论上所建议的那样。接下来，我们尝试性地假设视觉感受质和意识之间的弱相关性，并根据意识和感受质的低或高激活水平将各种绘画分为四组。在每一组中，我们都发现了绘画作品在大脑颞叶皮层和感觉模块功能方面的共同特征，同时也表明，当我们看到视错觉时，我们会感受到独特的感受质，而对错觉发生的意识是体验错觉图形的一个重要组成部分。视错觉所特有的感受质与错觉意识相互作用，在大多数情况下产生视觉娱乐。最后指出，注意力的强弱并不影响感受质的内容，但感受质的存在有助于注意力的合理分配。如上所述，阐明意识、感受质、注意力是科学意识研究发展的一个重要问题。

Recently, the problems concerning visual awareness and qualia have been vigorously investigated in the context of brain science elucidating consciousness. In the present study, several experimental researches were carried out using psychophysical methods which enable us to approach and analyze subjective experiences directly.Firstly, the visual amodal completion was investigated as a phenomenon which produces strong awareness of occluded objects without vivid qualia. By contrast, in the case of modal completion, we can actually perceive the quality of the completed surfaces. We compared the psychophysical findings on amodal and modal completion. Consequently, we psychophysically confirmed that awareness provides flexibility on the output side, while qualia guarantee irrevocability on the input side and have a function of flagging the present, as Ramachandran (1998) and Gregory (1998) have theoretically suggested.Next, we tentatively assumed a weak correlation between visual qualia and awareness, and classified various paintings into four groups by the combination of low or high activation levels of awareness and qualia. In each group, we found the common characteristics of paintings in relation to the functions of the inferior-temporal cortex and the sensory modules.It is also suggested that we feel unique qualia when we see visual illusions and the awareness of the occurrence of illusions is an essential constituent in experiencing illusory figures. The qualia specific to visual illusion and the awareness of illusions interact with each other, producing visual amusement in most cases.Finally, it is pointed out that the strength of attention does not affect the contents of visual qualia but the existence of qualia facilitates the proper allocation of attention.As mentioned above, clarifying the relationships among awareness, qualia, and attention would be a very important problem for the development of scientific consciousness study.