Robert Galbraith Heath (May 9, 1915 – September 21, 1999) was an American psychiatrist. He followed the theory of biological psychiatry that organic defects were the sole source of mental illness, and that consequently mental problems were treatable by physical means. He published 425 papers and three books. One of his first papers is dated 1946.
Heath founded the Department of Psychiatry and Neurology at Tulane University, New Orleans, in 1949 and remained its chairman until 1980.He performed many experiments there involving electrical stimulation of the brain via surgically implanted electrodes. He placed deep brain stimulation (DBS) electrodes into the brains of more than 54 patients. It has been suggested that this work was financed in part by the CIA and US military. In 1972, he claimed to have converted a homosexual man to heterosexuality using DBS.
Heath also experimented with the drug bulbocapnine to induce stupor, and LSD,using prisoners in the Louisiana State Penitentiary as experimental subjects. He worked on schizophrenia patients, which he regarded as an illness with a physical basis.
Today Heath's work is considered highly controversial and is only rarely used as reference material.
Heath was experimenting in 1953 on inducing paroxysms through brain stimulation.During the course of his experiments in deep brain stimulation, Heath experimented with gay conversion therapy, and claimed to have successfully converted a homosexual patient, labeled in his paper as Patient B-19. The patient, who had been arrested for marijuana possession, was implanted with electrodes into the septal region (associated with feelings of pleasure), and many other parts of his brain. The septal electrodes were then stimulated while he was shown heterosexual pornographic material. The patient was later encouraged to have intercourse with a prostitute recruited for the study. As a result, Heath claimed the patient was successfully converted to heterosexuality. This research would be deemed unethical today for a variety of reasons. The patient was recruited for the study while under legal duress, and further implications for the patient's well-being, including indications that electrode stimulation was addictive, were not considered.
Heath conducted a study on two rhesus macaques trained to smoke "the equivalent of one marijuana cigarette a day, five days a week for six months"and concluded that cannabis causes permanent changes in the brain. Nonetheless, he supported cannabis decriminalization. He later conducted a National Institutes of Health-funded study on 13 rhesus monkeys, with one rotating group representing "heavy smokers" whose cannabis dosage was believed to be comparable to three marijuana cigarettes smoked daily, a "moderate" group that was given the equivalent of one joint a day, and a third group that puffed inactive cannabis. He concluded, "Alcohol is a simple drug with a temporary effect. Marijuana is complex with a persisting effect." According to the BBC, "His findings of permanent brain damage have been dismissed by similar, independently conducted studies. But other scientists have argued these methods of animal research are inconclusive." According to NORML, Heath's "work was never replicated and has since been discredited by a pair of better controlled, much larger monkey studies, one by Dr. William Slikker of the National Center for Toxicological Research and the other by Charles Rebert and Gordon Pryor of SRI International."
Deep brain stimulation (DBS) is a neurosurgical procedure involving the placement of a medical device called a neurostimulator, which sends electrical impulses, through implanted electrodes, to specific targets in the brain for the treatment of movement disorders, including Parkinson's disease, essential tremor, dystonia, and other conditions such as obsessive-compulsive disorder and epilepsy. While its underlying principles and mechanisms are not fully understood, DBS directly changes brain activity in a controlled manner.
A phosphene is the phenomenon of seeing light without light entering the eye. The word phosphene comes from the Greek words phos (light) and phainein. Phosphenes that are induced by movement or sound may be associated with optic neuritis.
Neurotechnology encompasses any method or device in which electronics interface with the nervous system to monitor or modulate neural activity.
In the anatomy of the brain, the centromedian nucleus, also known as the centrum medianum, is a part of the intralaminar nucleus (ILN) of the thalamus. There are two centromedian nuclei arranged bilaterally.
Stereotactic surgery is a minimally invasive form of surgical intervention that makes use of a three-dimensional coordinate system to locate small targets inside the body and to perform on them some action such as ablation, biopsy, lesion, injection, stimulation, implantation, radiosurgery (SRS), etc.
Brain implants, often referred to as neural implants, are technological devices that connect directly to a biological subject's brain – usually placed on the surface of the brain, or attached to the brain's cortex. A common purpose of modern brain implants and the focus of much current research is establishing a biomedical prosthesis circumventing areas in the brain that have become dysfunctional after a stroke or other head injuries. This includes sensory substitution, e.g., in vision. Other brain implants are used in animal experiments simply to record brain activity for scientific reasons. Some brain implants involve creating interfaces between neural systems and computer chips. This work is part of a wider research field called brain–computer interfaces.
Corpus callosotomy is a palliative surgical procedure for the treatment of medically refractory epilepsy. In this procedure the corpus callosum is cut through in an effort to limit the spread of epileptic activity between the two halves of the brain.
Theta waves generate the theta rhythm, a neural oscillation in the brain that underlies various aspects of cognition and behavior, including learning, memory, and spatial navigation in many animals. It can be recorded using various electrophysiological methods, such as electroencephalogram (EEG), recorded either from inside the brain or from electrodes attached to the scalp.
Retinal prostheses for restoration of sight to patients blinded by retinal degeneration are being developed by a number of private companies and research institutions worldwide. The system is meant to partially restore useful vision to people who have lost their photoreceptors due to retinal diseases such as retinitis pigmentosa (RP) or age-related macular degeneration (AMD). Three types of retinal implants are currently in clinical trials: epiretinal, subretinal, and suprachoroidal. Retinal implants introduce visual information into the retina by electrically stimulating the surviving retinal neurons. So far, elicited percepts had rather low resolution, and may be suitable for light perception and recognition of simple objects.
The septal area, consisting of the lateral septum and medial septum, is an area in the lower, posterior part of the medial surface of the frontal lobe, and refers to the nearby septum pellucidum.
In neuroscience, single-unit recordings provide a method of measuring the electro-physiological responses of a single neuron using a microelectrode system. When a neuron generates an action potential, the signal propagates down the neuron as a current which flows in and out of the cell through excitable membrane regions in the soma and axon. A microelectrode is inserted into the brain, where it can record the rate of change in voltage with respect to time. These microelectrodes must be fine-tipped, low-impedance conductors; they are primarily glass micro-pipettes, metal microelectrodes made of platinum, tungsten, iridium or even iridium oxide. Microelectrodes can be carefully placed close to the cell membrane, allowing the ability to record extracellularly.
Electrocorticography (ECoG), or intracranial electroencephalography (iEEG), is a type of electrophysiological monitoring that uses electrodes placed directly on the exposed surface of the brain to record electrical activity from the cerebral cortex. In contrast, conventional electroencephalography (EEG) electrodes monitor this activity from outside the skull. ECoG may be performed either in the operating room during surgery or outside of surgery. Because a craniotomy is required to implant the electrode grid, ECoG is an invasive procedure.
Transcranial direct current stimulation (tDCS) is a form of neuromodulation that uses constant, low direct current delivered via electrodes on the head. It was originally developed to help patients with brain injuries or neuropsychiatric conditions such as major depressive disorder. It can be contrasted with cranial electrotherapy stimulation, which generally uses alternating current the same way, as well as transcranial magnetic stimulation.
Brain stimulation reward (BSR) is a pleasurable phenomenon elicited via direct stimulation of specific brain regions, originally discovered by James Olds and Peter Milner. BSR can serve as a robust operant reinforcer. Targeted stimulation activates the reward system circuitry and establishes response habits similar to those established by natural rewards, such as food and sex. Experiments on BSR soon demonstrated that stimulation of the lateral hypothalamus, along with other regions of the brain associated with natural reward, was both rewarding as well as motivation-inducing. Electrical brain stimulation and intracranial drug injections produce robust reward sensation due to a relatively direct activation of the reward circuitry. This activation is considered to be more direct than rewards produced by natural stimuli, as those signals generally travel through the more indirect peripheral nerves. BSR has been found in all vertebrates tested, including humans, and it has provided a useful tool for understanding how natural rewards are processed by specific brain regions and circuits, as well the neurotransmission associated with the reward system.
José Manuel Rodríguez Delgado was a Spanish professor of neurophysiology at Yale University, famed for his research on mind control through electrical stimulation of the brain.
A visual prosthesis, often referred to as a bionic eye, is an experimental visual device intended to restore functional vision in those suffering from partial or total blindness. Many devices have been developed, usually modeled on the cochlear implant or bionic ear devices, a type of neural prosthesis in use since the mid-1980s. The idea of using electrical current to provide sight dates back to the 18th century, discussed by Benjamin Franklin, Tiberius Cavallo, and Charles LeRoy.
Ablative brain surgery is the surgical ablation by various methods of brain tissue to treat neurological or psychological disorders. The word "Ablation" stems from the Latin word Ablatus meaning "carried away". In most cases, however, ablative brain surgery doesn't involve removing brain tissue, but rather destroying tissue and leaving it in place. The lesions it causes are irreversible. There are some target nuclei for ablative surgery and deep brain stimulation. Those nuclei are the motor thalamus, the globus pallidus, and the subthalamic nucleus.
Neurostimulation is the purposeful modulation of the nervous system's activity using invasive or non-invasive means. Neurostimulation usually refers to the electromagnetic approaches to neuromodulation.
Neuromodulation is "the alteration of nerve activity through targeted delivery of a stimulus, such as electrical stimulation or chemical agents, to specific neurological sites in the body". It is carried out to normalize – or modulate – nervous tissue function. Neuromodulation is an evolving therapy that can involve a range of electromagnetic stimuli such as a magnetic field (rTMS), an electric current, or a drug instilled directly in the subdural space. Emerging applications involve targeted introduction of genes or gene regulators and light (optogenetics), and by 2014, these had been at minimum demonstrated in mammalian models, or first-in-human data had been acquired. The most clinical experience has been with electrical stimulation.
A peripheral nerve interface is the bridge between the peripheral nervous system and a computer interface which serves as a bi‐directional information transducer recording and sending signals between the human body and a machine processor. Interfaces to the nervous system usually take the form of electrodes for stimulation and recording, though chemical stimulation and sensing are possible. Research in this area is focused on developing peripheral nerve interfaces for the restoration of function following disease or injury to minimize associated losses. Peripheral nerve interfaces also enable electrical stimulation and recording of the peripheral nervous system to study the form and function of the peripheral nervous system. For example, recent animal studies have demonstrated high accuracy in tracking physiological meaningful measures, like joint angle. Many researchers also focus in the area of neuroprosthesis, linking the human nervous system to bionics in order to mimic natural sensorimotor control and function. Successful implantation of peripheral nerve interfaces depend on a number of factors which include appropriate indication, perioperative testing, differentiated planning, and functional training. Typically microelectrode devices are implanted adjacent to, around or within the nerve trunk to establish contact with the peripheral nervous system. Different approaches may be used depending on the type of signal desired and attainable.