The brain thrives on regularity, and as a result, getting enough natural light and managing stress levels during the coronavirus crisis are critical to aiding sleep, says neuroscientist and host of 'The Superbrain', Sabina Brennan.

Speaking on RTÉ's Today with Seán O'Rourke, Ms Brennan said that changes to our lives due to Covid-19 will undoubtedly affect our sleep patterns.

Sleep is regulated by three mechanisms, she said.

The circadian rhythm over 24 hours, ranging from deep sleep to wake time.

Deep sleep, she said, usually happens between 2am and 4am, and during 1pm and 3pm, which is why we experience the "afternoon dip".

The hormone melatonin plays a role in our natural sleep-wake cycle. Natural levels of melatonin in the blood are highest at night.

Ms Brennan said the release of this in the evening is like a "call to sleep".

The third factor is adenosine which, she said, is a sleep chemical, which is cleared out of your system by morning and builds gradually during the day.

"Like a pressure to sleep, which is why you feel drowsy in the evening to night time," she said.

"Since a lot of people are now working from home, they may not have to get up as early to catch the bus to work, and so they are taking that extra hour in bed, which means that they are not able to get to sleep at their normal time of 11pm," said Ms Brennan.

"They should use that extra hour in the morning to exercise, which is critical to our ability to sleep."

Getting enough natural light in your day will also aid sleep and it is particularly important for older people who may be cocooning.

"It is critical when you wake up to expose yourself to natural light," she said. 

"It is really important during Covid, particularly older people, to go outside for at least half an hour a day, even put your head out the window, to get some natural light.

"In the evening, start dimming the lights in your house so that your body realises that it is night time.

"Make sure your bedroom temperature is cool. Your core temperature needs to drop by one degree in order for you to be able to get to sleep."

Stress and sleep are "fundamentally interlinked", Ms Brennan said.

"The stress of the virus, and all that comes with it, is affecting our sleep patterns. 

"The associated stressors of job losses and the future after the virus are affecting us. Also, we must remember that we are now spending 24 hours a day with people that you would normally only spend 3-4 hours with."

Managing stress levels are critical to aiding sleep, she said.

"We can't do anything about Covid, other than do what we've been told to do by health authorities. What we can't change, we need to learn to accept.

"If you are in a threatening situation, you need to reach out for help. If you have lost your job, but can't do anything about it until after the virus, then focus on what you can do. Focusing on what you are doing at a particular point in time is a form of meditation," she said. 

Ms Brennan advised that people who are experiencing stress should allocate a time of day to think about that stressful issue, or to write the issue down on paper.

"Say to yourself, I will deal with this at 11am each day. If a thought comes into my head at 3pm, then say, 'okay, I will think about that tomorrow at 11am'.

"Writing things down is helpful because it gets it out of your head and on to the paper. Otherwise your brain will continue to remind you about it."