Dual brain theory
Encyclopedia
The dual brain theory claims that the two cerebral hemisphere
s of the brain may sense and react to the environment independently from one another and that as a result of traumatic experience, one half may dominate the other in order to reduce the traumatized hemisphere's exposure to harm.
This theory
is an extension of split-brain studies of epileptic
patients having the corpus callosum
severed in order to reduce seizures. These studies indicated the existence of two intact, autonomous minds.
Studies of healthy people with intact corpus callosums also indicate differing abilities or emotional responses associated with the two hemispheres. Studies using the Wada test
and others are cited. In addition the theory draws upon research by Werner Wittling, Stuart Dimond, Roger Drake, Patrizio Tessoldi, Edward Fouty and Stephen E. Levick.
Dr. Fredric Schiffer claims to have experimented with lateralizing glasses which restrict patients to one side of the visual field or the other, in turn stimulating the associated hemisphere. Schiffer claims this allowed some patients to experience the world through the more submissive or immature self and to compare differing experiences and changes in emotional moods, simply by switching between glasses. The glasses are fabricated simply by taping over the right or left halves of both lenses of typical safety glasses. The glasses function according the properties of the optic tract
, whereby the right halves of both retina
s (which see the left side of the field of view) are each connected to the right hemisphere, and the left halves (which see the right side of the field of view) are each connected to the left hemisphere, via optic nerves, which partially cross at the optic chiasm
. Theoretically, the patient could then relativize experience and escape from a single viewpoint or life experience. In this manner a patient, through counseling, might begin a rapport between hemispheres in order to lead a more balanced and fruitful life.
Cerebral hemisphere
A cerebral hemisphere is one of the two regions of the eutherian brain that are delineated by the median plane, . The brain can thus be described as being divided into left and right cerebral hemispheres. Each of these hemispheres has an outer layer of grey matter called the cerebral cortex that is...
s of the brain may sense and react to the environment independently from one another and that as a result of traumatic experience, one half may dominate the other in order to reduce the traumatized hemisphere's exposure to harm.
This theory
Theory
The English word theory was derived from a technical term in Ancient Greek philosophy. The word theoria, , meant "a looking at, viewing, beholding", and referring to contemplation or speculation, as opposed to action...
is an extension of split-brain studies of epileptic
Epilepsy
Epilepsy is a common chronic neurological disorder characterized by seizures. These seizures are transient signs and/or symptoms of abnormal, excessive or hypersynchronous neuronal activity in the brain.About 50 million people worldwide have epilepsy, and nearly two out of every three new cases...
patients having the corpus callosum
Corpus callosum
The corpus callosum , also known as the colossal commissure, is a wide, flat bundle of neural fibers beneath the cortex in the eutherian brain at the longitudinal fissure. It connects the left and right cerebral hemispheres and facilitates interhemispheric communication...
severed in order to reduce seizures. These studies indicated the existence of two intact, autonomous minds.
Studies of healthy people with intact corpus callosums also indicate differing abilities or emotional responses associated with the two hemispheres. Studies using the Wada test
Wada test
The Wada test, named after Canadian neurologist and epileptologist Juhn Atsushi Wada, also known as the "intracarotid sodium amobarbital procedure" , is used to establish cerebral language and memory representation of each hemisphere.-Method:...
and others are cited. In addition the theory draws upon research by Werner Wittling, Stuart Dimond, Roger Drake, Patrizio Tessoldi, Edward Fouty and Stephen E. Levick.
Dr. Fredric Schiffer claims to have experimented with lateralizing glasses which restrict patients to one side of the visual field or the other, in turn stimulating the associated hemisphere. Schiffer claims this allowed some patients to experience the world through the more submissive or immature self and to compare differing experiences and changes in emotional moods, simply by switching between glasses. The glasses are fabricated simply by taping over the right or left halves of both lenses of typical safety glasses. The glasses function according the properties of the optic tract
Optic tract
The optic tract is a part of the visual system in the brain.It is a continuation of the optic nerve and runs from the optic chiasm to the lateral geniculate nucleus....
, whereby the right halves of both retina
Retina
The vertebrate retina is a light-sensitive tissue lining the inner surface of the eye. The optics of the eye create an image of the visual world on the retina, which serves much the same function as the film in a camera. Light striking the retina initiates a cascade of chemical and electrical...
s (which see the left side of the field of view) are each connected to the right hemisphere, and the left halves (which see the right side of the field of view) are each connected to the left hemisphere, via optic nerves, which partially cross at the optic chiasm
Optic chiasm
The optic chiasm or optic chiasma is the part of the brain where the optic nerves partially cross...
. Theoretically, the patient could then relativize experience and escape from a single viewpoint or life experience. In this manner a patient, through counseling, might begin a rapport between hemispheres in order to lead a more balanced and fruitful life.
See also
- LateralityLateralityLaterality is the preference that most humans show for one side of their body over the other. Examples include right-handedness or left-footedness. It may also apply to other animals, or to plants.- Human laterality :...
- Lateralization of brain functionLateralization of brain functionA longitudinal fissure separates the human brain into two distinct cerebral hemispheres, connected by the corpus callosum. The sides resemble each other and each hemisphere's structure is generally mirrored by the other side. Yet despite the strong anatomical similarities, the functions of each...
- HandednessHandednessHandedness is a human attribute defined by unequal distribution of fine motor skills between the left and right hands. An individual who is more dexterous with the right hand is called right-handed and one who is more skilled with the left is said to be left-handed...
- Right-handed
- Left-handedLeft-handedLeft-handedness is the preference for the left hand over the right for everyday activities such as writing. In ancient times it was seen as a sign of the devil, and was abhorred in many cultures...
- Cross-dominanceCross-dominanceCross-dominance, also known as mixed-handedness, mixed dominance, or hand-confusion, is a motor skill manifestation where a person favors one hand for some tasks and the other hand for others. For example, a cross-dominant person might write with the left hand but throw primarily with the right...
- AmbidexterityAmbidexterityAmbidexterity is the state of being equally adept in the use of both left and right appendages . It is one of the most famous varieties of cross-dominance. People that are naturally ambidextrous are rare, with only one out of one hundred people being naturally ambidextrous...
- Left brain interpreterLeft brain interpreterIn neuropsychology the left brain interpreter refers to the construction of explanations by the left brain in order to make sense of the world by reconciling new information with what was known before...
- Eye dominance
- BicameralismBicameralism (psychology)Bicameralism is a hypothesis in psychology that argues that the human brain once assumed a state in which cognitive functions were divided between one part of the brain which appears to be "speaking", and a second part which listens and obeys—a bicameral mind...