Quirks & Quarks

What and how does someone who has been blind from birth dream?

Those who are blind dream using other sensory perceptions like sound and touch, says Lia Turner.
People who are blind may dream in sounds, sense of touch of smell. (China Photos/Getty)

"What and how does someone who has been totally blind from birth dream?" asks Norman Lylak of Ottawa, who is legally blind

Lia Turner, a fourth year cognitive science student at Carleton University in Ottawa, has the answer.

In people with sight, it's known that dreams are based on visual sensations and perceptions.

It is a misconception that blind from birth people experience a blank canvas, or nothing but jet black when they dream. Research has demonstrated that this is not the case. 

"All of us, sighted or not have a varying degree of sensory input," Turner says. "Congenitally blind individuals can actually develop other senses past what sighted individuals would have. So that would enter our dreamscape as well, depending on how intense your perceptual experience was and how that could come up in your dream space."

Basically those who are blind dream using other sensory perceptions, like auditory cues. This means they dream in sounds and sense of touch. Other senses can also be involved. 

For instance, in a Danish study, Turner says about 18 per cent of the blind participants (both congenital and later-onset) reported tasting in at least one dream, compared with 7 per cent of controls.

Nearly 30 per cent of the blind reported smelling in at least one dream, versus half that among controls.

Despite these sensory differences, the emotional and thematic content of dreams isn't much different in the blind and the sighted. Both groups reported about the same number of social interactions, successes, and failures in their dreams. They had the same distribution of emotions, and the same level of bizarreness.