Analyses of visual awareness and qualia by psychophysical methods

近年来，在脑科学解释意识的背景下，有关视觉意识和感觉的问题得到了积极的研究。在本研究中，我们利用心理物理学的方法进行了一些实验研究，使我们能够直接接近和分析主观体验。首先，对视觉模态补全现象进行了研究，认为这是一种对被遮挡物体产生强烈意识的现象，没有生动的感质。相比之下，在模态补全的情况下，我们实际上可以感知完成表面的质量。我们比较了情态完成和情态完成的心理物理结果。因此，正如Ramachandran（1998）和Gregory（1998）在理论上提出的那样，我们从心理物理学上证实，意识在输出端提供了灵活性，而质质在输入端保证了不可撤销性，并具有标记当前的功能。接下来，我们初步假设视觉感和意识之间存在弱相关性，并根据意识和感觉的高低激活程度将各种绘画分为四组。在每一组中，我们都发现了与颞下皮层和感觉模块功能相关的绘画的共同特征。也有人认为，当我们看到视觉错觉时，我们会感到独特的感觉，而对错觉发生的意识是体验虚幻人物的重要组成部分。视错觉特有的感质和幻觉意识相互作用，在大多数情况下产生视觉娱乐。最后指出，注意的强弱并不影响视觉质量感的内容，但质量感的存在有利于注意的合理分配。如上所述，厘清意识、感质和注意之间的关系将是科学意识研究发展的一个非常重要的问题。

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.