Comparative study of figure perception by nonhuman and human primates

研究了非人类灵长类动物对几何图形的知觉：a)庞佐错觉的知觉；b)视觉搜索操作。为了研究错觉知觉，研究人员训练恒河猴和黑猩猩在电脑显示器上辨别水平条的绝对长度。当条形长度超过预定长度时，接触两个报告位置中的一个位置被加强，而当条形长度小于预定长度时，接触另一个位置被加强。吧台上叠加着各种各样的背景人物。当汇聚的线条重叠时，随着目标条接近上下文线的顶点，两个受试者物种的“长”报告的比例增加。研究表明，这两个物种都感知到了庞佐错觉。情境人物视角的增加并没有增强错觉。目标条和背景图形之间的差距被认为是这种错觉的一个重要决定因素，但目标条上下的图形背景也影响了这种错觉的数量。对日本猴子的视觉搜索能力进行了测试。受试者必须触摸多个分散注意力的人物中奇怪的目标人物。得到两个主要发现：a)在垂直条形中很容易发现斜条，但在前者的图形中很难找到后者。从而发现了搜索的不对称性。B)当目标由倾斜和条形纹理相结合来确定时，视觉搜索较慢。这些发现与人类的表现相似。

Perception of geometric figures by nonhuman primates were studied in terms of : a) perception of the Ponzo illusion and b) visual search performances. For the study of illusory perception, rhesus monkeys and chimpanzees were trained to discriminate absolute length of horizontai bars on the computer display. Touching one of the two report locations was reinforced when the bar was longer than a predetermined length and touching the other location was reinforced when the bar was shorter than that. A variety of context figures were superimposed on the bar. When the converging lines were superimposed, the proportion of the "long" reports by both subject species was increased as the target bar approached the apex of the context lines. It was demonstrated that both species perceived the Ponzo illusion. The increase of perspectives of context figures did not enhance the illusion. The gap between the target bar and the context figures were suggested as an important determinant of this illusion but figural contexts above and below the target bar also affected the amount of this illusion. Japanese monkeys were tested for their visual search performances. The subjects had to touch the odd target figure among number of distracter figures. Two major findings were obtained : a) oblique bars were easily detected among vertical bars but the latter figures were difficult to find among the former figures. Thus search asymmetry was found. b) visual search was slow when the target was defined by the conjunction of inclination and the texture of the bars. These findings were similar to human performances.