A good night sleep can make or break your day, according to researchers at the University of New South Wales.
They say sleep deprivation can be detrimental to the brain, and a lack of sleep can also make it hard to learn new things.
“We need to get to sleep at least five hours per night to optimize our learning,” Dr Roberta Smith, an associate professor of psychology and neurosciences at UNSW, said.
Dr Smith’s research team studied how sleep was affected by how often people were exposed to light.
They were surprised to find that exposure to light had a strong impact on learning.
They found that light exposure was linked to increased learning in people who had slept in the dark for between 10 and 40 hours per week.
The researchers also found that exposure increased levels of dopamine in the brain that were linked to memory retention.
Dr Robyn Mckenzie, a neuroscientist who is the lead author of the paper, said this was a surprising finding because we have a lot of evidence that exposure increases dopamine levels.
“It’s been suggested that light may help to increase learning in older adults, but what’s the research on that?” she said.
“What we wanted to do is understand whether light exposure actually increased memory retention, which is something we do know increases learning in old age.”
Dr Smith said the research is part of a larger body of research on the effect of light on learning and memory.
“There’s a lot more to learn about light, and how light affects memory,” she said, “but it’s a big area that we’re still working out the science and understanding.”
How does light affect learning?
Dr Smith and her colleagues measured levels of the neurotransmitter dopamine in volunteers who were exposed in a lab to the dim light of the cafe bicycle.
These volunteers were also exposed to a computer screen that was brighter than normal, which had the effect on the volunteers’ brains.
When they were shown a video of the bicycle in motion, the volunteers showed greater increases in dopamine levels in the hippocampus, a brain region important in learning and cognition.
When a light-emitting diode was shone onto the bicycle, the light also stimulated dopamine levels within the brain’s reward centres.
The result was that the volunteers were able to remember more accurately the bike in motion.
Dr Mckenzies work also found a link between light exposure and changes in the structure of the brain.
“Our findings support the idea that light can affect how the brain functions and how the neural circuits are wired,” Dr Minkley said.
She said the brain may be able to process more information than it can when dark is present, and it may even need to adapt to that light if it is to learn.
“This may be one of the most important areas of the human brain,” she added.
Dr Bobbi Brown, a lecturer in neuroscience at the Australian National University, said the study also found light exposure had a big impact on brain structure.
“When we look at a brain we see activity that has a huge impact on our ability to learn,” she told news.com.au.
“But if we have to have light, it’s not going to be enough to do that, and this suggests that light is also a regulator of neural activity.”
Dr Brown said the work was important for people who work in light-polluting industries, such as manufacturing and mining, to know what they are doing could be damaging.
“They should understand what they’re doing is damaging the environment and the health of people around them, and they should be taking care of themselves,” she explained.
But Dr Mccenzie said it was important to remember that exposure of the participants to light was only a small part of their exposure to darkness.
“You also need to consider other environmental factors, like how much light you get and how much you’re exposed to, as well as the quality of your home,” she noted.
“That’s something we need to know.”
What else does light do?
Dr Mclane said a key question was how the light affects brain structure and function.
“If we think about the brain as a single structure, it means there’s a large amount of connections between neurons,” she observed.
“And these connections have to be maintained, and that’s why light is a great way to improve connectivity in the brains.”
“It seems light is an effective way of enhancing the connections between different areas of your brain, which in turn will help to improve memory and learning.”
Dr Mcneys work also has the potential to improve people’s health.
“As a result of our work, we now have a very good understanding of the role of light in the regulation of brain function and how it may have an impact on the brain and the environment,” she says.