Dual brain theory

The dual brain theory claims that the two cerebral hemispheres 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.[1] 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 retinas (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.

^[1][2]

See also

• Laterality
• Lateralization of brain function
• Handedness^[3][4]
• Right-handed
• Left-handed
• Cross-dominance
• Ambidexterity
• Left brain interpreter
• Eye dominance
• Bicameralism

References

1. ^ 1. Schiffer F, Johnston AL, Ravichandran C, Polcari A, Teicher MH, Webb RH, Hamblin MR. Psychological benefits 2 and 4 weeks after a single treatment with near infrared light to the forehead: a pilot study of 10 patients with major depression and anxiety. Behav Brain Funct. 2009 Dec 8;5:46.
2. ^ 2. Schiffer F, Teicher MH, Anderson C, Tomoda A, Polcari A, Navalta CP, Andersen SL: Determination of hemispheric emotional valence in individual subjects: A new approach with research and therapeutic implications. Behavioral and Brain Functions 2007, 3:13 3. Schiffer F, Glass I, Lord J, Teicher MH: Prediction of clinical outcomes from rTMS in depressed patients with lateral visual field stimulation: a replication. The Journal of Neuropsychiatry and Clinical Neurosciences, 2008 Spring;20(2):194-200 4.
3. ^ Schiffer F, Stinchfield Z, Pascual-Leone A.: Prediction of clinical response to transcranial magnetic stimulation for depression by baseline lateral visual-field stimulation. Neuropsychiatry Neuropsychol Behav Neurol. 2002 Mar;15(1):18-27.
4. ^ 8. Schiffer F, Zaidel E, Bogen J, Chasan-Taber S: Different psychological status in the two hemispheres of two split-brain patients. Neuropsychiatry, Neuropsychology, and Behavioral Neurology 1998;11:151-156 9. Schiffer F: Of Two Minds, New York, The Free Press; 1998