The Nocturnal Brain

novel techniques of studying and influencing the brain, like using magnetic fields or electrical stimulation, will offer us new insights.

Studies of cognitive performance in people who say they have insomnia do not show major differences when compared to normal sleepers, but when you separate those with normal amounts of sleep, even poor-quality and broken sleep, from those with objectively measured short sleep, it is the insomniacs with short sleep duration who have significant cognitive problems.

As a lucid dreamer, if you push your dreams towards playing the piano, perhaps this might mean you learn it more quickly

Moreover, in a quite remarkable study, researchers have been able to definitively prove lucid dreaming. Taking six regular lucid dreamers into a scanner, the researchers asked the subjects to signal the onset of lucid dreaming.

behaviours in infancy and childhood, which start out as unconscious automatic actions — crying for food, suckling, reaching for objects without any self-awareness or volition — gradually become what we perceive to be conscious, through rehearsal and ‘practice’ in a virtual space. He argues that REM sleep is a driver of the emergence of secondary consciousness — that is the degree of consciousness that differentiates us from other species, namely volition, self-awareness, reasoning, insight, abstract thinking — from primary consciousness, simple perception and emotion that other mammals experience.

In support of this, they give the example of people who have an intense desire to have a limb amputated (xenomelia) and who are sexually attracted to amputees. Their powerful feeling that one of their limbs is not part of them is thought to reflect an abnormality in how their homunculus is represented in the superior parietal lobule, and hence they are attracted to people with similar bodies.

Yet the EEG, first used in the 1920s on humans, is our equivalent of the snorkel and mask. These scalp electrodes are attempting to record brain activity through skin, fat, the skull, and cerebrospinal fluid. The strength of these signals is tiny compared to that put out by the simple act of blinking, the triggering of small muscles in the face and head. Furthermore, the deflections in those squiggly lines — originally plotted by pen on paper, nowadays on a computer screen — do not result from the electrical changes in a single neurone. Rather, it requires the accumulation of impulses synchronised between thousands or millions of neurones, more than 6 or 7 square centimetres of cerebral cortex — the thin layer of cells lining the surface of the brain — all orientated in the same axis. So the detail the EEG gives us is incredibly limited. Only large changes in huge numbers of neurones, all pointing in a similar direction, on or near the surface of the brain, are detectable

While this beneficial effect of dopamine-boosting on RLS has been known about for decades, there is a darker side to these drugs. Especially at higher doses, they can actually drive RLS, resulting in a dramatic worsening called augmentation

recent study in humans has shown that even after a single night of sleep deprivation, levels of beta-amyloid in certain parts of the brain, including the hippocampus, often damaged in Alzheimer’s, go up.

high blood pressure and blood vessel disease, sleep apnoea is also a risk factor for an irregular heart rhythm that can predispose clots to form in the heart, before shooting off to obstruct blood vessels in the brain. Sleep apnoea is also of relevance to headaches such as migraines and morning headaches, can result in increases in pressure inside the skull and can worsen the effects of Parkinson’s