Study: Cooking up smell-o-vision technology not a good idea

You already have the 90-inch big screen HDTV, complete with surround sound, to watch your favourite episode of Top Chef Canada. Now, if only you could smell the final results of the Elimination Challenge, your sensory entertainment experience would be complete. Or so you think.

Research by fourth-year Psychology student Nikita Wong says matching odours to visual content doesn’t enhance the experience as much as you would believe. In fact, it may detract from your overall experience.

She presented her research at the 45th Annual Ontario Psychology Undergraduate Thesis Conference held recently at Western



Smells are important to many species, Wong said. But their effect on the human perception in concurrent auditory and visual stimulation has received little investigation.

So, with the participation of 35 Western students, Wong showed her audience three different types of 15-second videos – ones with matching visual, audio and odours (such as images of babies with the smell of baby oil; ones with non-matching visuals, audio and odours (such as a forest scene with the smell of cherry pie); and ones with no odours accompanying the visuals and audio at all.

Using an olfactometer – an instrument used to detect and measure odour dilution – to control the delivery of the scents, participants were randomly presented with 36 different video-odour pairings. Following each presentation, participants assessed the videos in terms of “engagement, pleasantness and emotional arousal.”

While she expected non-matching visuals-audio-odours would have a greater negative effect across the board, and, therefore, the opposite to be true for matching pairs, she discovered that wasn’t the case.

“Surprisingly, congruent odours did not enhance engagement or emotional arousal compared to a no-odour control,” said Wong, who presented her finding at the 45th annual Ontario Undergraduate Thesis Conference, held at Western May 8. “There was little difference between congruent odours and no odour on ratings of engagement and emotional arousal; however, even congruent odours reduced pleasantness ratings, suggesting all odours used were somewhat unpleasant.”

Wrong believes this could be the result of ‘cross-modal competition,’ or two senses competing against one another. In this case, the presence of an odour leads to suppression of the auditory and visual abilities, which she was able to confirm using a functional magnetic resonance imaging (fMRI) test with one of the participants.

“We looked at activity in the brain and it did decrease in the visual and auditory cortex with both congruent and incongruent testing,” Wong said. “It was surprising to see. It’s almost as if the brain is battling – ‘Do I pay attention to these smells or pay attention to the video?’”