Preliminary study on the cognition by vision

Can the dolphin count?

抄録

Dolphins are expected to possess a highly developed visual information processing system. However, there are few studies investigating how they perceive the outer world by vision. In the present study, we examined the capability of solving complex problems that were visually guided, in terms of counting ability of items. A male beluga was trained to use Arabic numerals (1, 2) to name the number of items such as one or two fins and balls. The subject was able to discriminate the number of objects and he could name them using those numerals. Though it was not verified that those numerals were used as symbols in the present study, our results revealed that the dolphin was capable of solving complex problem visually guided and supported that it had a highly developed visual information processing system.