NEW DELHI: The brains of people who watched a TV programme with a bright, artificial-looking background were actually more like the brains of a TV show with a darker background, new research has shown.
A study published in the journal Brain and Cognition, from researchers at the Karolinska Institute in Stockholm and University of Toronto, looked at the brains from 1,000 people and compared the contrast of the brain scans of those who watched television programmes that were “bright and bright” and those that were dark and dim.
The study, conducted by scientists at the Swedish Karolin Institute in Sweden and the University of Montreal, suggests that the brain of those watching television shows that are “bright” may have a more complex representation of light and dark.
The team also looked at how the brain responds to contrast between dark and bright images and showed that contrast is particularly strong in the brain areas that process visual information, and which are associated with vision and the visual system.
The findings have implications for how we view the world and how we process information, said lead author Sjoerd Jansson, a research fellow at the Centre for Experimental and Clinical Neuroscience at Karolinos University.
“We have a lot of evidence that people who perceive a dark image to be darker tend to have a stronger response in certain parts of the visual cortex to bright images, whereas those who perceive bright images as having a lower response tend to see the bright image as a bit more dark,” he said.
“It’s a pretty simple explanation.
When we are looking at a dark background we are reacting to a perceived difference in brightness, whereas when we see a bright background, we are responding to perceived differences in contrast.
We have a very good understanding of how the visual brain processes information.”
A more detailed analysis was also conducted by the researchers on the brains that process a person’s gaze in a dark room and the brains for the same people that are looking in a bright room.
The researchers found that the brains in the “bright light” group showed more connections to different parts of a visual cortex that are associated more with the perception of contrast, while the brains associated with dark perception showed more connection to the same areas of the cortex that process light and contrast.
The brain regions that were most sensitive to contrast were the temporal cortex, which processes visual attention, and the frontal lobe, which deals with vision, the researchers found.
The research also showed that people with higher levels of grey matter in these regions had a stronger effect on contrast perception.
“The brighter the background, the less sensitive are the temporal and frontal lobes to contrast.
In other words, if we look at a bright screen and the contrast is low, it’s more difficult for us to notice this contrast and we tend to look away,” Jansson said.
The results suggest that this is because the areas of a person that process information in the temporal lobe are not the areas that are involved in the processing of visual information.
“As you look at the dark screen, you’re paying attention to contrast, but you’re not really paying attention there,” he added.
“So, we may think of a screen as dark, but the information you’re receiving there is very different.”
The study also found that contrast in the brains was associated with activity in the frontal cortex, where we process visual attention.
This study has implications for what people do in the face of a bright environment, said co-author Raimond Söderberg, a professor of neuroscience at Karolanos University.
If we’re looking at something in the dark, we need to be paying attention.
So the temporal areas that we pay attention to in dark environments tend to be involved in that attention, he said, adding that it’s possible that people can compensate for this difference in contrast perception by turning their attention to the bright environment.
“People can compensate because it is the contrast that they are paying attention towards.
But it’s also the contrast in other parts of their visual field that they need to compensate for.
We don’t know how that happens,” Sögerberg said.
“If people pay attention in dark, they don’t compensate for that contrast.
And so we have this gap between our ability to compensate and how our brains work.
This study is a really important step to understanding how the perception and processing of contrast can change in different environments.”
The team will now look at how contrast perception differs between people in different parts or parts of different brains.