Neuroscience
We like to think we see things how they are. Often, however, what we actually see is based less on the outside world and more on what our brain expects to be there, like a kind of mentally-generated virtual reality.
Now psychologists in Germany have demonstrated this in an elegant experiment involving people’s memory for the colour of everyday fruit and vegetables.
Karl Gegenfurtner and colleagues presented 14 participants with strangely coloured fruits on a computer screen – for example a pink banana – against a grey background. The participants’ task was to adjust the colour of the onscreen banana until it blended exactly with the grey background. It sounds easy, but the participants couldn’t do it because as they adjusted the colour, they compensated not just for the banana’s actual pink pigmentation, but also for a yellowness that only existed in their mind, thus leaving the banana with a slight bluish hue. That is, their memory for the typical colour of a banana was interfering with their performance.
By contrast, the participants didn’t have any trouble adjusting the colour of anonymous spots of light to make them blend in with the grey background – thus suggesting it wasn’t some quirk of the experimental set-up that was causing the participants difficulties with the fruit and veg.
Moreover, when presented with a banana that had been correctly adjusted to perfectly blend in with the grey background, the participants reported that it looked slightly yellow – a percept generated by their own mind, not by the actual colour of the banana.
“Our results show a high-level cognitive effect on low-level perceptual mechanisms”, the researchers said.
_________________________________
Hansen, T., Olkkonen, M., Walter, S. & Gegenfurtner, K.R. (2006). Memory modulates colour appearance. Nature Neuroscience, DOI:10.1038/nn1794.
Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.
Link to related review paper.
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Neuroscience
Why it's so hard to find a blue banana
We like to think we see things how they are. Often, however, what we actually see is based less on the outside world and more on what our brain expects to be there, like a kind of mentally-generated virtual reality.Now psychologists in Germany have demonstrated this in an elegant experiment involving people’s memory for the colour of everyday fruit and vegetables.
Karl Gegenfurtner and colleagues presented 14 participants with strangely coloured fruits on a computer screen – for example a pink banana – against a grey background. The participants’ task was to adjust the colour of the onscreen banana until it blended exactly with the grey background. It sounds easy, but the participants couldn’t do it because as they adjusted the colour, they compensated not just for the banana’s actual pink pigmentation, but also for a yellowness that only existed in their mind, thus leaving the banana with a slight bluish hue. That is, their memory for the typical colour of a banana was interfering with their performance.
By contrast, the participants didn’t have any trouble adjusting the colour of anonymous spots of light to make them blend in with the grey background – thus suggesting it wasn’t some quirk of the experimental set-up that was causing the participants difficulties with the fruit and veg.
Moreover, when presented with a banana that had been correctly adjusted to perfectly blend in with the grey background, the participants reported that it looked slightly yellow – a percept generated by their own mind, not by the actual colour of the banana.
“Our results show a high-level cognitive effect on low-level perceptual mechanisms”, the researchers said.
_________________________________
Hansen, T., Olkkonen, M., Walter, S. & Gegenfurtner, K.R. (2006). Memory modulates colour appearance. Nature Neuroscience, DOI:10.1038/nn1794.
Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.
Link to related review paper.
- At What Age Do Girls Prefer Pink?
Crudely speaking, the psychological field of gender development is split between those who see gender differences as learned via socially constructed ideas about gender, and those who believe many gender differences are actually “sex differences”,...
- How Your Mindset Can Cause A Traffic Accident
There's a storm of sensory information out there in the world but your brain can only process so much at once. To cope, it's armed with an attentional spotlight that allows you to focus on what you're interested in and ignore the rest. This...
- How Wishing To Appear Racially Colour-blind Can Backfire
“I haven’t got a sign on the door that says white people only. I don’t care if you're black, brown or yellow - you know, Orientals make very good workers”, David Brent, from the BBC comedy The Office. Like gender, age, hair colour and other...
- How We See Half The World Through The Prism Of Language
Whereas I might say a jumper is blue or red, female acquaintances of mine refer to all sorts of gradations in between, such as navy blue, shocking pink, and many others that I can’t even recall. But does the richness of their colour vocabulary mean...
- Learned Fear Of People Who Are Different
Some people are predisposed to fearing those whose skin colour is different from their own, in much the same way they are predisposed to fearing snakes and spiders. Andreas Olsson and colleagues presented participants with two photos, one of a black male...