The Spark of Life: Electricity in the Human Body

by Ashcroft, Frances

  In ECT, a brief electric shock is applied across the head. Its magnitude is sufficient to produce a severe seizure akin to that of a grand mal epileptic fit. Because the shock stimulates the part of the brain that controls the motor nerves, the muscles convulse and the limbs become rigid. Our limbs are controlled by two sets of opposing muscles, one of which contracts and the other which relaxes when we make a movement. ECT stimulates both sets of muscles so that they contract simultaneously, making the limbs stiff and rigid. In the past, the convulsions could be so great that they even broke the patient’s bones, but these days a muscle relaxant is administered to stop the muscle spasms and a general anaesthetic is also given. Usually patients are given several treatments, a few days apart.

  Sylvia Plath describes her experience of electric shock therapy in a powerful way in several of her writings, such as The Bell Jar and ‘The Hanging Man’:

  By the roots of my hair some god got hold of me.

  I sizzled in his blue volts like a desert prophet

  The nights snapped out of sight like a lizard’s eyelid:

  A world of bald white days in a shadeless socket.

  A vulturous boredom pinned me to this tree.

  She was adamant she never wanted it again.

  ECT was widely used in the 1950s and 1960s, but is much less common today, following the introduction of effective anti-depressant drugs. NICE, the UK’s National Institute of Health and Clinical Excellence, advises that it should only be used to treat severe depression, severe mania or catatonia (muscle rigidity), and only when other treatments for these conditions have proved ineffective (at least a third of people with severe depression fail to respond to drugs). Ironically, given its history, ECT is no longer recommended as a treatment for schizophrenia.

  Although its medicinal use is well established, ECT remains a controversial procedure. Whether it really works, and how well, is highly contentious. Some medical reports conclude that it is effective at relieving depression in the short term, whereas others have found no significant difference one month after therapy when compared to a placebo. In many cases the effects seem to be temporary and weak in the absence of concomitant drug treatment, and there is no evidence that it lowers the suicide rate of depressed patients. Yet some patients testify it has caused a dramatic improvement in their condition, ridding them of depression and enabling them to live a normal life once again – even to return to a high-profile career. This probably reflects the heterogeneity of the disease: clinical depression is unlikely to have a single cause.

  Unfortunately, ECT is not without side-effects. All patients experience some short-term memory loss, presumably because the brain circuits associated with short-term memory storage are disrupted: indeed, this is one reason why short-term memories are believed to be stored as electrical signals. The accompanying amnesia has the singular advantage that most patients do not remember being given the shock. However some patients suffer permanent memory loss. Ernest Hemmingway, who had ECT in 1961, told his biographer: ‘What is the sense of ruining my head and erasing my memory, which is my capital, and putting me out of business? It was a brilliant cure but we lost the patient.’

  If the effectiveness of ECT is unclear, how it might work is even more uncertain. The massive shock affects the electrical activity of brain cells, causing them to fire at very high rates and generating an electrical storm similar to that seen in an epileptic seizure. One argument is that this leads to a massive release of chemical transmitters from nerve cells. As these chemicals control our moods, and the balance between them is thought to be disturbed in mental disorders, it is argued an increase in the concentration of certain transmitters may be responsible. But our brains are delicately balanced organs and what is needed is the right transmitter, at the right place, for the right amount of time – ideally without any increase in chemicals with opposing effects. How such fine adjustments can be achieved with something as crude as ECT is far from clear.

  In the past ECT was exploited by some mental institutions to subdue troublesome patients. This abuse famously came into prominence in 1975 when Jack Nicholson starred in One Flew Over the Cuckoo’s Nest, a film based on Kevin Kesey’s novel of the same name, in which electric shock therapy was used by Big Nurse to instill fear in inmates and ensure they remained docile and acquiescent. It caused a sensation and led to a heated public debate on the use of ECT. Currently, one of the most controversial aspects of its use concerns whether it can be given without the patient’s informed consent: this differs between countries, but it is legal in the UK and USA (although judicial consent may be necessary).

  A Shocking End

  A. S. Byatt’s novel Still Life has a shocking ending – it concludes with the accidental death of the heroine, Stephanie Orton Porter, who is electrocuted by an ungrounded refrigerator in her own kitchen as she is trying to rescue a trapped sparrow. Byatt was once almost electrocuted in the same way herself, but was saved by her husband. As we all know, mains electricity can be dangerous. But how, exactly, does it kill you?

  For a person to be electrocuted, sufficient current must flow to ground through their body to stop their heart, paralyse their respiratory muscles or severely damage their organs. The amount it takes to kill a person is small, only about 50 milliamps, which is why homes in many countries are protected by safety trip-switches that disconnect the electricity supply if they detect a dangerously high flow of current to ground. In the UK, such devices typically trip out in response to 30 milliamps of current flowing for about 30 milliseconds. The settings are even lower in the United States - around 5 milliamps for 30 milliseconds. This is because lower currents can also be dangerous; a current of 15 milliamps is enough to cause your muscles to contract so vigorously that you cannot let go of a live wire.

  Electrocution was a relatively common occurrence when electricity was first introduced, and even experts were killed. As Hilaire Belloc succinctly put it,

  Some random touch – a hand’s imprudent slip –

  The Terminals – flash – a sound like ‘Zip’!

  A smell of burning fills the startled Air –

  The Electrician is no longer there!

  It almost happened to me. Late one night, I was wiring up a high-voltage amplifier for use in my experiments. Being tired and careless, I accidentally touched the printed circuit board. I received a shock of almost 400 volts (DC) and ended up on the other side of the room, thoroughly shocked and badly frightened, with an arm that hurt all down its length. Yet it did not kill me. This is because it is the current that kills you rather than the voltage and, happily, in my case the current was very small, even though the voltage was very high. For the same reason, the shock produced by static electricity generators like the Van de Graaf machine used to produce spectacular ‘lightning shows’ in science museums, which may be millions of volts in magnitude, will not kill you – although it may make you jump and your hair stand on end – because the current is both momentary and very tiny.

  But amps and volts are bound together in an eternal embrace by Ohm’s Law, which states that volts equals amps times resistance. Volts are also dangerous because they drive the current through the body. Their ability to do so depends on the resistance they encounter: the higher the resistance, the more volts are needed to produce the same amount of current flow. Our skin has a certain resistance to an electric current and you probably won’t feel anything if the voltage is less than 30 volts AC. If your skin is wet, however, its resistance falls and the threshold for electrocution is reduced. Thus both volts and amps are potentially lethal, depending on the magnitude and duration of the shock received and the resistance of your skin.

  The War of the Currents

  Electrocution is not always accidental. It is used as a means of capital punishment in several countries. The development of the electric chair is an extraordinary twisted tale of power, corruption and a desire to reduce suffering, and it went hand in hand with the choice of whether AC or DC electricity should b
e used to power the embryonic electric grid.

  In electric circuits, current is defined as the flow of electrons through a conductor, such as a wire. If the current flows in one direction only it is known as direct current (DC), and if the direction of current flow alternates in a cyclical fashion it is known as alternating current (AC). Batteries supply direct current, but mains electricity is supplied as alternating current. The reason that mains electricity is supplied as AC current is because its magnitude can be easily increased or decreased using a transformer. This means that electricity can be carried at very high voltages (hundreds of thousands of volts) in overhead power lines but stepped down to normal household levels when it reaches your home. This is less feasible for DC current, which is one reason that AC electricity finally won out in the ‘battle of the currents’ and was adopted worldwide. In European countries AC current switches direction 50 times each second, whereas in the USA there are 60 cycles per second; the magnitude of the voltage supplied also differs, being 110/120 volts in the USA and 240 volts in Europe. The reason for these differences is largely historical.

  Competing to ‘electrify’ New York city in the late 1880s were, on the one hand, Thomas Edison and, on the other hand, George Westinghouse and Nikola Tesla. Edison advocated the use of direct current and his Electric Light Company, in which his fortune was invested, was set up using DC power (at 110 volts). Unfortunately, power transmission at 110 volts is very inefficient and the voltage drops off so rapidly that each house would have to be within a mile or so of a power station – hence many power stations would have been needed to light New York. Increasing the thickness of the copper supply wires allowed the current to be increased without the wire melting but at a considerable economic cost. The other possibility would have been to make the transmission voltage more than 110 volts. However, this was not an option because there is no way to easily drop the high voltage to a lower one in a DC system. This fact also necessitated supplying different power lines for equipment that ran at different voltages. Imagine if different circuits were needed to power your washing machine, electric kettle and computer, and you will appreciate how inconvenient that would be.

  Tesla contended that an AC system was a better option, and invented a means of generating and supplying AC power that was bought by Westinghouse’s company. The advantage of this system was that electricity could be supplied at very high voltages in the distribution cables, so enabling it to be transmitted over long distances with less loss of power. It could then be stepped down to a lower (and safer) voltage at the house. Many fewer power stations were therefore needed, and only one power line to each home was required, as transformers could be stationed within the house to supply voltages at different levels.

  The advantages of the Tesla/Westinghouse system quickly became obvious. Edison counter-attacked by arguing that AC current was highly dangerous and staged a series of gruesome public executions to prove it. In front of a large press audience, a stray cat or a puppy was placed on a sheet of tin and subjected to 1,000 volts from an AC generator – with predictable results. In one instance, the executioner almost electrocuted himself, being blown across the room by the shock, his body ‘wrenched apart as though a great rough file had been pulled through it’. Seeking greater publicity, Edison electrocuted the elephant Topsy. It also did not escape his notice that a person would provide even better propaganda.

  Old Sparky

  On 6 August 1890, the New York prison authorities executed the condemned murderer William Kemmler using the electric chair. It was the first time it had been used and it was not a success. The first shock was too weak and failed to stop his breathing, so that the current had to be switched on for a second time. As the New York Times wrote, ‘it was an awful spectacle [. . .] far worse than hanging [. . .] so terrible that words fail to convey the idea’.

  The background to the story was that the state of New York had been endeavouring to find a means of capital punishment that was more humane than hanging. A member of the commission appointed to look into the matter, Dr Alfred Southwick, recalled having seen an intoxicated man die a quick and seemingly painless death after accidentally touching a live wire. The commission reported that electrocution was a possible solution, and on 1 January 1889 the state passed a law allowing the use of an ‘electric chair’ as a way of killing convicted criminals. There was just one small problem: no electric chair existed.

  The state legislature did not specify whether AC or DC electricity should be used and left it to a committee to decide. Edison actively campaigned for AC current to be used, surmising the public would therefore not want it in their homes. He employed Harold Brown and Dr Fred Peterson to design an electric chair, and to carry out further public executions of dogs, calves and a horse using AC current, which generated considerable publicity. Given that Peterson was also on the government committee that selected the best method of electrocution, it is perhaps not surprising that AC current was finally chosen for the electric chair, thereby coincidentally stigmatizing it as too dangerous for domestic use.

  Edison and Brown had to obtain the AC generator they needed by subterfuge, as the Westinghouse company refused to sell one to the prison for the purpose. Westinghouse, seeing his business interests endangered, protested that electrocution was a cruel and inhumane punishment and paid for Kemmler’s appeal against the mode of execution. Edison was summoned as an expert witness for the state. The appeal was lost and Kemmler was electrocuted. However, the current was insufficient to cause instant death, and Kemmler was simply roasted. It was a far more agonizing way to die than hanging.

  The electric chair works by stopping the heart or frying the brain. The prisoner is strapped into the chair and wires are attached to the skin by surface electrodes moistened with a conducting salt solution. A massive electric shock is applied that causes instant brain death, and subsequent bouts of current are used to ensure that the other organs are fatally damaged. Although it remains a legal form of execution in a number of states in the USA, it is rarely used today, lethal injection being the preferred means of capital punishment.

  Edison may have been a great inventor and a brilliant businessman, but he was not without flaws, and his advocacy of the electric chair was far from glorious. It is ironic that he once boasted, ‘I am proud of the fact that I never invented weapons to kill,’ and that he supported non-violence towards animals. It also seems somewhat strange that Edison is fêted as the man who gave us universal electric light and power, given that it was the AC system that was finally adopted. A US hero, following Edison’s funeral President Hoover requested that North Americans dim their lights for one minute as a tribute to his memory. By contrast, Tesla, who actually invented the national grid, is a largely forgotten genius.

  Phasers on Stun

  Society has often dreamt of a weapon that can temporarily incapacitate an individual, instantly stopping them in their tracks without causing pain or lasting harm. The ‘stun’ mode of the famous phasers used in the TV show Star Trek is just one of many fictional examples.

  The latest real electric stun gun is the Taser. It works by stimulating your nerves so much that your muscles contract uncontrollably and you fall over, usually within two to three seconds. The Taser fires two small darts that are connected to a handheld gun by long fine cables. The darts pierce clothing and penetrate the skin, where they then serve as electrodes, conducting an electric current from the gun to your body. The stimulus causes your muscles to contract, incapacitating you for as long as the electric current continues to flow. It also hurts, because the electric current stimulates your pain nerve fibres. Indeed, it is not easy to say how it would be possible to make a device that stimulates your motor nerves, thus preventing movement, without also affecting your sensory nerves and causing pain. After allowing himself to be tasered in an effort to persuade the UK government to issue police officers with Tasers, Greater Manchester’s Chief Constable said, ‘I couldn’t move, it hurt like hell. I wouldn’t want to do th
at again.’

  Tasers are now widely used by police forces to control violent people, or those suspected of being about to cause violence. Their use is not without controversy as a few people have died as a result of being tasered. Some people may simply be more susceptible to the electric shock, but others may have received a greater electric current because they happened to have a naturally lower skin resistance, or were wet when tasered.

  Emotional Signals

  As everyone knows, when you are very nervous you become hot and clammy and the palms of your hands get damp. Some people even break out in beads of sweat. This is because the brain responds to stress by increasing the activity of the sweat glands in your skin. The salty fluid they secrete decreases the resistance of your skin and this can easily be detected simply by seeing how readily a small electric current – so small that you don’t feel it at all – passes through the skin. Skin resistance is highly sensitive to many emotions, including fear, anger and stress, and thus changes in skin resistance have been used to detect emotional changes in an individual. The psychoanalysts Carl Jung and Wilhelm Reich, for example, used it as a tool to help reveal their patients’ emotional state.

  Changes in skin resistance also form the basis of the polygraph lie detector, which measures the electrical resistance of the skin, the logic being that telling a lie will make you nervous. As might be expected, this system is not without flaws, as simply taking the test makes some people nervous while a hardened liar might not flinch.