Epilepsy, temporal lobe epilepsy (TLE), the amygdala, and the hippocampus:
In temporal lobe epilepsy (TLE), rather than convulsive seizures or loss of consciousness, patients usually have extraordinary subjective experiences. They my experience autoscopy, the sensation of leaving one's body. They may also present with hypergraphia, an overwhelming urge to write, religiosity, or both. The subcortical structures in each temporal lobe thought to be responsible for these kinds of rich and dramatic feelings are the amygdalae and the hippocampi.
Before we discuss TLE symptoms including hypergraphia and religiosity, a note about epilepsy in general is in order. The National Institute of Neurological Disorders and Stroke provides the following information: "Epilepsy is a brain disorder in which clusters of nerve cells, or neurons, in the brain sometimes signal abnormally. In epilepsy, the normal pattern of neuronal activity becomes disturbed, causing strange sensations, emotions, and behavior or sometimes convulsions, muscle spasms, and loss of consciousness." Regarding consciousness, the Epilepsy Foundation identifies another symptom of epilepsy, an "absence seizure," which is "a lapse in consciousness with a blank stare that begins and ends within a few seconds."
The abnormal neural activity that causes epileptic seizures can have several causes—brain damage including developmental abnormalities, physical injury to the brain including head trauma and stroke, and infectious illnesses such as meningitis. A family history of epilepsy is considered a risk factor for the illness. According to the Epilepsy Foundation, "Brain function—from cell membrane to level of neurotransmitter substances to other biochemical mechanisms—is controlled by individual genes that, if damaged or mutant, may lead to seizures. The search is on for genes which may be directly linked to a specific type of epilepsy."
Hypergraphia, religiosity, and anatomic loci:
As mentioned above, hypergraphia is an overwhelming urge to write. Such copious writing could be construed as compulsive but this classification does not adequately explain symptoms. Religiosity can be defined as overly developed piety or religious zeal and is sometimes linked together with hypergraphia as a complex symptom. One of my goals in creating CorticalBrain.com is to clarify how neural activity over which we have little control can dictate our behavior–including such obsessive activity as hypergraphia and religiosity. In some cases, such as an epileptic seizure, the link between neural activity and abnormal behavior is well accepted. Other behaviors, however, such as hypergraphia and religiosity, are not so easily attributed to neural activity because they often appear to be rational and well thought out. A person beset with hypergraphia or religiosity often considers his or her behavior as being willful.
In Seized: Temporal Lobe Epilepsy as a Medical, Historical, and Artistic Phenomenon (1993), Eve LaPlante notes the observations of Norman Geschwind, a twentieth-century Harvard neurologist. In evaluating some of his epileptic patients, Geschwind found that hypergraphia often occurred among patients who imbued their experiences with religious and moral significance. (It should be noted here again that the amygdala and hippocampus are nestled within the temporal lobe.) LaPlante adeptly explains Geschwind's theory that over-activity within the temporal lobe "enhances the tissues' normal functions of emotion and memory, causing patients to feel experiences unusually deeply, to imbue those experiences with religious or moral significance, and to record them compulsively in drawing or writing."
Waxman and Geschwind, in Hypergraphia in Temporal Lobe Epilepsy" (1974), report:
The phenomenon of hypergraphia, or the tendency toward extensive and, in some cases, compulsive writing in temporal lobe epilepsy is described in seven patients, in each of whom there was electroencephalographic demonstration of a temporal lobe focus. Unusually detailed and strikingly copious writing was evidenced in each patient. Six patients provided documentation of their extensive writing, which often was concerned with religious or moral issues. A seventh patient claimed to have written extensively, but refused to exhibit his writings. Aggressiveness, religiosity, and changes in sexual behavior in temporal lobe disorders have been described previously. The hypergraphia of temporal lobe epilepsy appears to be part of a specific behavioral syndrome of special interest because of its association with dysfunction at specific anatomic loci.
An important thing to remember is that Geschwind and his colleagues, although criticized at the time, were correct in suggesting that the unusual behaviors associated with TLE might have, as LaPlante puts it "a distinct anatomical base." Again, the temporal lobe structures most likely to contribute to highly-charged emotional behaviors like hypergraphia and religiosity would be the amygdalae and the hippocampi. In "Norman Geschwind's Contribution to the Understanding of Behavioral Changes in Temporal Lobe Epilepsy: The February 1974 Lecture" (2009) Devinsky and Schachter discuss Geschwind's progress in revealing that it was an abnormality or lesion in the limbic system (which includes the amygdalae and hippocampi) that accounted for the unusual symptoms of TLE. They write: "This neurobiology accounted for the overarching increased interictal [between seizures] emotionality that underlay the increased religious interests, hypergraphia, increased aggression, increased moral and philosophical concerns, viscosity, and seriousness (lack of humor). Hyposexuality was the exception, although it was consistent with a discharging lesion altering this emotion-driven behavior."
Grandin and Johnson, in the Notes section of Animals in Translation, point out that "There are at least three different lines of evidence that religion is basic to the human brain: (1) religion is universal to all cultures, (2) identical twins separated at birth have the same degree of religiosity as adults, and (3) there is a 'God part' of the brain in the temporal lobes that makes you feel the presence of God when it's stimulated." The BBC produced a story called God on the Brain which references several scientists and their work in this area.
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