Some people can smell sounds, see smells or hear colors, according to researchers Juan Lupiáñez Castillo and Alicia Callejas Sevilla of the University of Granada in Spain.
The two believe these abilities called synaesthesia exist in all newborns and that some adults — as many as 1 out of 1,000 — retain this skill, but many do not realize it. Their research has appeared in the journals Cortex, Experimental Brain Research, and Consciousness and Cognition.
Some of Callejas' conclusions show possessing these abilities may slant a person's perceptions of certain sights and smells.
"There are people for whom time units evoke colors," Callejas wrote in his research. "It is also common for a synaesthete to see colors when listening to words, sounds in general or music notes (people who can see music, for instance). There are also cases, although fewer, where people can see colors in flavors, others perceive flavors or experience touch sensations when listening to different sounds, some link flavors to touch sensations, etc."
People who see words in certain colors, such as the word "dog" as red, may react negatively to seeing the word presented in a different color, said Callejas.
'When a person with grapheme-color synaesthesia indicates that the word table is blue, it is quite probable that if he or she ever sees the same word written in a color other than blue, this word will appear to him or her as wrong and consider it a mistake," the authors wrote.