|Budget Amount *help
¥7,000,000 (Direct Cost : ¥7,000,000)
Fiscal Year 1998 : ¥1,500,000 (Direct Cost : ¥1,500,000)
Fiscal Year 1997 : ¥5,500,000 (Direct Cost : ¥5,500,000)
We questioned whether the findings of previous research about categorization in which artificial visual patterns were used as stimuli in experiment are applicable to the categorization of natural visual pattern. Nine studies were conducted. In Study 1, the effect of type of feature change (whole or part deletion ; symmetric or asymmetric change) on recognition of butterfly or bee photographs was investigated. In Study 2, the contribution of each feature towards recognition of butterfly and bee pictures was investigated. In Study 3-6, the asymmetric effects of deletion and addition change of a single discrete feature toward recognition were examined, using butterfly photograph (in Study 3), cat photographs (in study 4), single object picture (in Study 5), and room scene (in Study 6). In Study 7-9, the developmental trends of the effects of deletion and addition change toward recognition of butterfly or cat photograph were investigated. These studies showed the following. First, the change of each physical feature affected recognition performance differently, Second, in recognition of butterfly and bee photographs, additions were easier to correctly recognize than deletions. Conversely, in recognition of cat photographs, deletions were easier. Third, the deletion or addition change of feature constructing natural pattern affected impression ratings for changed patterns. This result suggested that asymmetric confusability effect was mediated by impression change. Fourth, children showed the same trends of asymmetric confusability effects with adults.