Abstract
It is said that human dorsal stream seems to play a role in processing tool information and reading letters.Continuous Flash Suppression (CFS) is a visual masking technique used for detecting the information processed in the dorsal stream. In CFS, high contrast dynamic random-noise pattern is presented to the dominant eye and low contrast static image is presented to the nondominant eye for 200ms while subjects wore red/green anaglyph glasses. We used this technique to clarify what attributes of tools are processed in the dorsal stream and found that this stream processes elongated shapes but does not process the tool category specifically. Additionally, we are conducting further study to clarify the relationships between dorsal stream and reading function. The current results indicated that some information of letters in right parafoveal vision can be processed in human dorsal stream. CFS would be convenient tool to unveil the function of dorsal stream. However this technique remains some open issues. For example, the cortical information blocked by CFS is unclear and the relationships between this technique and specific brain region. In future, the na ture of CFS should be elucidated using various functional imaging techniques.
