feeling sad
Feeling sad alters the ability to see colours on the blue-yellow axis istock

Feeling sad alters the way people see colours, with two studies showing that unhappy people are less accurate at identifying colours than people who were happy or emotionally neutral. Scientists suggest the findings indicate mood and emotion can actually alters how we see the world around us.

Previously, scientists have shown how emotion can influence various visual processes – with links between feeling depressed and reduced sensitivity to visual contrast. Contrast sensitivity is a basic visual process involved in the perception of colour, so a team of researchers from the University of Rochester in New York state were looking to see if there was a specific link between mood and how we see colour.

Study author Christopher Thorstenson said: "We were already deeply familiar with how often people use colour terms to describe common phenomena, like mood, even when these concepts seem unrelated. We thought that maybe a reason these metaphors emerge was because there really was a connection between mood and perceiving colours in a different way."

Publishing their findings in the journal Psychological Science, the researchers asked 127 participants to watch an emotional film clip – either sad or funny – then complete a visual judgement task. They were shown 48 consecutive desaturated colour patches and were asked to say if they were red, green, blue or yellow.

People who watched the sad film clip were less accurate than those who watched the funny clip, but only for identifying colour patches on the yellow-blue axis. There was no difference with the red-green axis between the sad and funny groups.

A second study had people watch a sad clip or a neutral clip then carry out the same colour patch experiment. Findings were the same, with those viewing the sad clip having impaired colour perception on the blue-yellow axis. Thorstenson said: "We were surprised by how specific the effect was, that colour was only impaired along the blue-yellow axis. We did not predict this specific finding, although it might give us a clue to the reason for the effect in neurotransmitter functioning.

"Our results show that mood and emotion can affect how we see the world around us. Our work advances the study of perception by showing that sadness specifically impairs basic visual processes that are involved in perceiving colour."