Visiual nature

Dopamine is thought to be the "pleasure chemical," producing a feeling of bliss. Norepinephrine is similar to adrenaline and produces the racing heart and excitement. According to Helen Fisher, anthropologist and well-known love researcher from Rutgers University, together these two chemicals produce elation, intense energy, sleeplessness, craving, loss of appetite and focused attention. She also says, "The human body releases the cocktail of love rapture only when certain conditions are met and ... men more readily produce it than women, because of their more visual nature."
(From:http://people.howstuffworks.com/love.htm )
I need to translate it to Chinese, but I can't decide how to translate "visual nature". I want to know how you explain it in English.