More Japanese switch between using standard Japanese and various dialects according to who they are speaking with, a National Institute for Japanese Language and Linguistics survey has showed.

The institute has been conducting a survey once every 20 years to look into the changes in the use of Japanese by residents of Tsuruoka, Yamagata Prefecture, an area that is believed to be little influenced by other dialects.

The latest survey was conducted on some 800 people in 2011, following similar surveys in 1950, 1971 and 1991.

The institute showed the people a picture of a cat and asked them what it is, and 97 percent of them answered in standard Japanese in the latest survey, compared with 63 percent in 1950. When they were asked to describe it using a dialect, 88 percent were able to pronounce the word in a correct dialect, the institute said.

Meanwhile, nearly 60 percent of the respondents of the latest survey said they use standard Japanese when speaking with visitors from outside the region, compared with less than 40 percent in 1950.

"As the society became more mature, dialects are regarded as something which should be conserved with pride," explained Senshu University lecturer and former institute researcher Takahito Abe, who was involved in the survey.