Sadness can have an effect on how we perceive colours, a new study suggests, finding that people who were at a low ebb emotionally were less capable at identifying colours on the blue-yellow axis.
Trying to correctly identify colours is unlikely to be high up on your list of priorities if you're in a despondent mood, but it's an interesting insight into how different areas of the brain interact with each other, and how our emotional state of mind can affect the workings of our physical bodies.
"Our results show that mood and emotion can affect how we see the world around us," lead researcher Christopher Thorstenson from the University of Rochester in the US said in a press release. "Our work advances the study of perception by showing that sadness specifically impairs basic visual processes that are involved in perceiving colour."
The idea that emotion affects vision isn't a completely new one, but Thorstenson and his team wanted to specifically investigate the link between sadness and colour perception.
The researchers asked 127 undergraduates to watch an emotional film clip and then complete a visual judgement task. The clip shown was either a stand-up comedy routine or a melancholy animated short, and both bits of footage had been previously proved to induce feelings of sadness or amusement.
Having been emotionally manipulated, the volunteer students were then shown 48 patches and asked to identify their colour - those who had watched the sad clip were less accurate at identifying colours, but only on the blue-yellow axis. On the red-green axis, there was no difference between the two groups. The experiment was repeated with a new set of volunteers, this time using a sad clip and a neutral clip (a screensaver designed to elicit no emotional response): again, the same effect was notable in the glum participants.
Is this perhaps where the phrase "feeling blue" originates? No one's quite sure. The use of "blue" as a synonym for "sad" goes back to the 14th century and Chaucer.
"We were surprised by how specific the effect was, that color was only impaired along the blue-yellow axis," says Thorstenson. "We did not predict this specific finding, although it might give us a clue to the reason for the effect in neurotransmitter functioning." He stopped short of drawing any broad conclusions from the findings, and says that follow-up studies are essential if we're to find some practical use from the discovery.
The team's work has now been published in Psychological Science.