Scientists reveal what 'visions from God' could really be

For centuries, people have described experiencing events that, at the time, could only have been attributed to an intense religious vision. These experiences include witnessing sudden blinding lights, swirling colours and even entire heavenly cities, often accompanied by intense pain in the head.

However, the cause of such visions may be explained as a medical phenomenon rather than a spiritual one. Neurologists have compared the strange sights seen during these apparently religious visions to symptoms of intense migraines, which can sometimes be accompanied by a migraine 'aura'. This 'aura' is categorised by both auditory and visual hallucinations, almost always featuring bright flashing lights and zigzags, known as 'fortification patterns'.

In the most intense of these symptoms, one could even undergo an 'out-of-body experience'.

Whilst perhaps not the explanation for all of these reported visions of God, it can certainly be aligned to particular accounts from those who have experienced the phenomenon throughout history.

12th-century German philosopher and composer Hildegard von Bingen described her religious epiphany as similar to what we now know as a migraine aura.

Speaking on von Bingen's experiences in her wellbeing book Holistic Health Secrets, French author Mélanie Schmidt-Ulmann described the philosopher as experiencing 'reflections of living light', which von Bingen referred to as 'umbra viventis lucis'.

The philosopher described herself in her writings as seeing a "great star, most splendid and beautiful, and with it an exceeding multitude of falling sparks with which the star followed southward".

She continued: "Suddenly they were all annihilated, being turned into black coals... and cast into the abyss so that I could see them no more".

She also outlined the feeling of a pain "so intense that it threatens to kill me".

In an era where medical studies were not as advanced as today, it is highly understandable that such visions would be attributed to a divine presence, as even today the visions leave people sometimes questioning reality and what they have just witnessed.

Migraines affect around 10 per cent of the world's population, but it is only a third of these whose symptoms include witnessing the strange phenomena that comes with a migraine aura.

The exact neurological activity that occurs during such experiences is still being studied, but scientists are starting to gain a clearer understanding on the subject.

Speaking to MailOnline, Dr Philip Holland, a neuroscientist from King's College London, described some of the science behind the hallucinations.

"It's essentially a wave of excitation that travels across the cortex. If that happens in your visual cortex, that's what causes visual symptoms like flashing lights.

A potential neurological cause for this unusual symptom is a slow wave of altered brain activity called cortical spreading depression, which can lead to temporary changes in nerves and blood flow within the brain.

Research has led scientists to believe that migraine and the aura are separate conditions, although described by Dr Holland as "related", where the wave of aura activity sensitises nerves at the surface of the brain which can trigger headaches in some people.

This isn't to say that migraine auras are the only cause of such hallucinations, as science is uncovering more every day about the brain and its role in phenomena such as hallucinations.