[My book ‘Why Torture Doesn’t Work: The Neuroscience of Interrogation’ (Harvard UP) can be preordered from Amazon (.com) – more details at end of post]
Marathon Man, starring Dustin Hoffman and Sir Laurence Olivier, is a classic of the paranoid thriller genre that was so popular during the 1970’s. It is also renowned for an extended and graphic torture sequence. Dustin Hoffman plays Thomas “Babe” Levi, who is a candidate for a PhD in History. His brother Henry (known as Doc), played by Roy Scheider, is a secret US government agent. The plot is a gripping one involving government intrigue, a quest for diamonds and a very unpleasant wanted Nazi war criminal, Dr. Christian Szell (played by Laurence Olivier). Hoffman’s character is kidnapped by Olivier’s subordinates, is tied up, and physically restrained. Olivier’s character is a skilled dentist and uses his skills as a dentist to try to torture Hoffman into revealing information regarding his (Szell’s) safety. Olivier, as Dr. Szell, is paranoid, and asks Hoffman repeatedly “am I safe?” or “is it safe?”. Hoffman does not know to what Olivier is referring, and is unable to answer his questions. He suffers terribly as a result. Szell first threatens, and then drills into Levi’s teeth – without using anaesthesia.
It is difficult to watch, for the torture of an innocent lacking the knowledge which will allow him to terminate the torture session is visibly a terrible thing. The torture perpetrated via the teeth is a fantastic plot device: who does not know toothache? Teeth consist of an outer, calcified surface, known as the enamel; an inner layer of dentin; and a root canal containing “pulp”. Pulp contains blood vessels and nerves and is astonishingly sensitive to painful stimuli, such as excesses of heat, cold, dental caries or trauma. The pain from such a procedure is something that anyone who has undergone dental treatment can easily empathise with, if only by imaginative extension. So prevalent is our fear of dental pain that dental phobias (properly known as dentophobia) affect, in Western societies, somewhere between 7% and 13% of the population.
The head possesses a set of specialised nerves called the “cranial nerves”. There are 12 pairs of these nerves in total, emerging directly from the brain. These nerves serve functions such as the sense of smell (olfactory nerve); vision (the optic nerve), and eye movements (the oculomotor nerve). Teeth are served by subdivisions of the trigeminal nerve (cranial nerve V). The trigeminal nerve is the largest of the cranial nerves. It is a complex nerve, divided into three major components – ophthalmic, maxillary and mandibular. The trigeminal nerve has sensory functions, as it conveys inputs from the face, the teeth and the tongue to the brain. It also has motor functions, assisting the chewing (mastication) of food and the movement of the tongue. It sends a major projection to the trigeminal nucleus of the pons, located in the brainstem. This nucleus contains a “homunculus”, which is a map of the surface of the body in the brain. This map of the body represents the component parts of the body, from which it receives inputs. This in turn is relayed to the highest centres of the brain; to the thalamus and the cortex, from where stimuli rapidly enter consciousness, especially stimuli that are associated with pain. The application of a drill to the unanaesthetised tooth will cause terrible, immediate and inescapable pain. Surely someone subjected to this procedure would reveal whatever information they have? But, here despite the evidence pointing to Babe as someone in possession of needed information, the seemingly reasonable assumptions made by Szell are simply wrong, and Babe suffers terribly as a result.
Brave human subjects in Switzerland (see abstract below) have undergone brain imaging so that we can understand how the brain processes the pain associated with trauma to the teeth. Remarkably and bravely, twenty-one healthy volunteers allowed themselves to have electrical stimulation of the canine teeth and the incisor teeth, while lying in a brain scanner. A constant current was applied to the particular tooth, above the pain threshold for that tooth, as measured by a perceived pain intensity scale. Pain thresholds and intensities are measured through numeric estimates provided by participants. Scales can be used where participants rate a stimulus on scale from 0 (no pain at all) to 10 (the worst pain imaginable). Humans are superb at calibrating their own sensations of pain – for obvious adaptive reasons. Electrical stimulation of the teeth produced a wide range of activations throughout the brain and, in particular, widespread activation of the pain matrix (the brain structures involved in the processing of pain). Other brain areas were observed to have been activated as well, and especially parts of the brain particularly concerned with cognition and emotion.
The oil of cloves offered by Szell as a pain killer will not be adequate for the job, as it is a topical anaesthetic, diluted by blood and spit. Injury-induced discharge in his cranial nerves will continue (chronically) until some form of dental repair is undertaken. Grim.
Front Hum Neurosci. 2011; 5: 12.
Published online 2011 February 7. Prepublished online 2010 July 28. doi: 10.3389/fnhum.2011.00012
Taking Sides with Pain – Lateralization aspects Related to Cerebral Processing of Dental Pain
The current fMRI study investigated cortical processing of electrically induced painful tooth stimulation of both maxillary canines and central incisors in 21 healthy, right-handed volunteers. A constant current, 150% above tooth specific pain perception thresholds was applied and corresponding online ratings of perceived pain intensity were recorded with a computerized visual analog scale during fMRI measurements. Lateralization of cortical activations was investigated by a region of interest analysis. A wide cortical network distributed over several areas, typically described as the pain or nociceptive matrix, was activated on a conservative significance level. Distinct lateralization patterns of analyzed structures allow functional classification of the dental pain processing system. Namely, certain parts are activated independent of the stimulation site, and hence are interpreted to reflect cognitive emotional aspects. Other parts represent somatotopic processing and therefore reflect discriminative perceptive analysis. Of particular interest is the observed amygdala activity depending on the stimulated tooth that might indicate a role in somatotopic encoding.
Keywords: toothache, fMRI, dominance, cerebral, amygdala, cerebral cortex, lateralization
My book ‘Why Torture Doesn’t Work: The Neuroscience of Interrogation’ can now be preordered from:
Torture is banned because it is cruel and inhumane. But as Shane O’Mara writes in this account of the human brain under stress, torture should never be condoned because it does not work the way torturers assume it does.
In countless films and TV shows such as Homeland and 24, torture is portrayed as a harsh necessity. If cruelty can extract secrets that will save lives, so be it. CIA officers and others conducted torture using precisely this justification. But does torture accomplish what its defenders say it does? For ethical reasons, there are no scientific studies of torture. But neuroscientists know a lot about how the brain reacts to fear, extreme heat and cold, starvation, thirst, sleep deprivation, and immersion in freezing water, all tools of the torturer’s trade. These stressors create profound problems for memory, mood, and thinking, and sufferers predictably produce information that is deeply unreliable—and, for intelligence purposes, even counter-productive. As O’Mara guides us through the neuroscience of suffering, he reveals the brain to be much more complex than the brute calculations of torturers have allowed, and he points the way to a humane approach to interrogation, founded in the science of brain and behavior.
Torture may be effective in forcing confessions, as in Stalin’s Russia. But if we want information that we can depend on to save lives, O’Mara writes, our model should beNapoleon: “It has always been recognized that this way of interrogating men, by putting them to torture, produces nothing worthwhile.”
- Face Ache: The woman who lost teeth for nothing (bbc.co.uk)
- Ways to Overcome Your Fear of Going to the Dentist (jennymillerlexingtondentist.wordpress.com)