The brain of Albert Einstein has been a subject of much research and speculation. Albert Einstein's brain was removed within seven and a half hours of his death. His apparent regularities or irregularities in the brain have been used to support various ideas about correlations in neuroanatomy with general or mathematical intelligence. Studies have suggested an increased number of glial cells in Einstein's brain. [1] [2]
Einstein's autopsy was conducted in the lab of Thomas Stoltz Harvey. Shortly after Einstein's death in 1955, Harvey removed and weighed the brain at 1230g. [3] Harvey then took the brain to a lab at the University of Pennsylvania where he dissected it into several pieces. He kept some of the pieces to himself while others were given to leading pathologists. He hoped that cytoarchitectonics, the study of brain cells under a microscope, would reveal useful information. [4] Harvey injected 50% formalin through the internal carotid arteries and afterward suspended the intact brain in 10% formalin. He also photographed the brain from many angles.
Harvey dissected the brain into about 240 blocks (each about 1 cm3) and encased the segments in a plastic-like material called collodion. [5] [6] Harvey also removed Einstein's eyes. He gave them to Henry Abrams, Einstein's ophthalmologist. [4]
Whether or not Einstein's brain was preserved with his prior consent is a matter of dispute. Ronald Clark's 1979 biography of Einstein states "he had insisted that his brain should be used for research and that he be cremated." More recent research has suggested that the brain was removed and preserved without the permission of either Einstein or his close relatives. [7] Hans Albert Einstein, the physicist's elder son, endorsed the removal after the event. However, he insisted that his father's brain should be used only for research to be published in scientific journals of high standing. [4]
In 1978, Einstein's brain was rediscovered in Harvey's possession by journalist Steven Levy. [8] Its sections had been preserved in alcohol in two large mason jars within a cider box for over 20 years.
The brain was driven across many U.S. states and to Hamilton, Ontario, [9] accompanied by Harvey. Journalist and chauffeur Michael Paterniti wrote about some of the journeying that took place in 1997. [10] [11]
In 2010, Harvey's heirs transferred all of his holdings constituting the remains of Einstein's brain to the National Museum of Health and Medicine. This included 14 photographs of the whole brain prior to sectioning, never before revealed to the public. [12] [13]
More recently, 46 small portions of Einstein's brain were acquired by the Mütter Museum in Philadelphia. In 2013, segments of the brain went on exhibit in the museum's permanent galleries. The exhibit featured thin slices of Einstein's brain, mounted on microscope slides. [14]
Harvey had reported that Einstein had no parietal operculum in either hemisphere, [15] but this finding has been disputed. [16] Photographs of the brain show an enlarged Sylvian fissure. In 1999, further analysis by a team at McMaster University in Hamilton, Ontario revealed that his parietal operculum region in the inferior frontal gyrus in the frontal lobe of the brain was vacant. Also absent was part of a bordering region called the lateral sulcus (Sylvian fissure). Researchers at McMaster University speculated that the vacancy may have enabled neurons in this part of his brain to communicate better. "This unusual brain anatomy...[missing part of the Sylvian fissure]... may explain why Einstein thought the way he did," said Professor Sandra Witelson who led the research published in The Lancet . This study was based on photographs of the whole brain made at autopsy in 1955 by Harvey and not a direct examination of the brain. Einstein himself claimed that he thought visually rather than verbally. Professor Laurie Hall of Cambridge University, commenting on the study, said, "To say there is a definite link is one bridge too far, at the moment. So far, the case isn't proven. But magnetic resonance and other new technologies are allowing us to start to probe those very questions." [17]
In the 1980s, University of California, Berkeley professor Marian Diamond received four sections of the cortical association regions of the superior prefrontal and inferior parietal lobes in the right and left hemispheres of Albert Einstein's brain from Thomas Harvey. In 1984, Marian Diamond and her associates were the first ever to publish research on the brain of Albert Einstein. [18] She compared the ratio of glial cells in Einstein's brain with that of the preserved brains of 11 other males. (Glial cells provide support and nutrition in the brain, form myelin, and participate in signal transmission, and are the other integral component of the brain, besides the neurons.) Dr. Diamond's laboratory made thin sections of Einstein's brain, each 6 micrometers thick. They then used a microscope to count the cells.
Einstein's brain had more glial cells relative to neurons in all areas studied, but only in the left inferior parietal area was the difference statistically significant. This area is part of the association cortex, regions of the brain responsible for incorporating and synthesizing information from multiple other brain regions. A stimulating environment can increase the proportion of glial cells and the high ratio could possibly result from Einstein's life studying stimulating scientific problems. [19] [20]
The limitation that Diamond admits in her study is that she had only one Einstein to compare with 11 brains of normal intelligence individuals. S. S. Kantha of the Osaka Bioscience Institute criticized Diamond's study, as did Terence Hines of Pace University. [4] Other issues related to Diamond's study point out glial cells continue dividing as a person ages and although Einstein's brain was 76, it was compared to brains that averaged 64 in age (eleven male brains, 47–80 years of age). Diamond in her landmark study "On the Brain of a Scientist: Albert Einstein" noted that the 11 male individuals whose brains were used in her control base had died from nonneurologically related diseases. She also noted that "Chronological age is not necessarily a useful indicator in measuring biological systems. Environmental factors also play a strong role in modifying the conditions of the organism. One major problem in dealing with human specimens is that they do not come from controlled environments." [21]
Dr. Dahlia Zaidel of the University of California, Los Angeles, examined two slices of Albert Einstein's brain containing the hippocampus in 2001. The hippocampus is a subcortical brain structure that plays an important role in learning and memory. The neurons on the left side of the hippocampus were found to be significantly larger than those on the right, and when compared with normal brain slices of the same area in ordinary people, there was only minimal, inconsistent asymmetry in this area. "The larger neurons in the left hippocampus, Zaidel noted, imply that Einstein's left brain may have had stronger nerve cell connections between the hippocampus and another part of the brain called the neocortex than his right. The neocortex is where detailed, logical, analytical and innovative thinking takes place, Zaidel noted in a prepared statement." [22] [23]
A study published in the journal Brain [24] in September 2013 analyzed Einstein's corpus callosum —a large bundle of fibers that connects the two cerebral hemispheres and facilitates interhemispheric communication in the brain—using a novel technique that allowed for a higher resolution measurement of the fiber thickness. Einstein's corpus callosum was compared to two sample groups: 15 brains of elderly people and 52 brains from people aged 26. Einstein was 26 in 1905, his Annus Mirabilis (Miracle Year). The findings show that Einstein had more extensive connections between certain parts of his cerebral hemispheres compared to both younger and older control group brains. [25]
A study, "The cerebral cortex of Albert Einstein: a description and preliminary analysis of unpublished photographs", [16] was published on November 16, 2012, in the journal Brain . Dean Falk, an evolutionary anthropologist at Florida State University, led the study - which analyzed 14 recently discovered photographs - and described the brain: "Although the overall size and asymmetrical shape of Einstein's brain were normal, the prefrontal, somatosensory, primary motor, parietal, temporal and occipital cortices were extraordinary." [26] There was a fourth ridge (apart from the three normal people have) in Einstein's mid-frontal lobe involved in making plans and working memory. The parietal lobes were markedly asymmetrical and a feature in Einstein's primary motor cortex may have been associated with his musical ability. [19]
Another study led by Shanghai-based East China Normal University's Department of Physics, "The Corpus Callosum of Albert Einstein's Brain: Another Clue to His High Intelligence", published in the journal Brain on September 24, 2013, showed a new technique to conduct the study, which is the first to detail Einstein's corpus callosum, the brain's largest bundle of fibers that connects the two cerebral hemispheres and facilitates interhemispheric communication. [27] Einstein's corpus callosum was thicker than those in control groups, possibly indicating better cooperation between the hemispheres. Scientists currently cannot tell how far the unusual features above were innate or how far they were due to Einstein's devoting his life to higher thought.
Publication bias may have influenced published results, which means that results showing differences between Einstein's brain and other brains tend to get published while results showing that in many respects Einstein's brain was like other brains tend to be neglected. Researchers knew which brain was Einstein's and which were controls, allowing possible conscious or unconscious bias and preventing impartial research.[ citation needed ]
Neurologist Terence Hines of Pace University is strongly critical of the studies and has stated that they are flawed. Hines maintains that all human brains are unique and different from others in some ways. Therefore, assuming unique features in Einstein's brain were connected with his genius, in Hines' opinion, goes beyond the evidence. He argues further that correlating unusual brain features with any characteristic requires studying many brains with those features, and says that scanning the brains of many very capable scientists would be better research than investigating the brains of just one or two geniuses. [19] [28]
Preserving the brains of geniuses was not a new phenomenon—another brain to be preserved and discussed in a similar manner was that of the German mathematician Carl Friedrich Gauss almost a hundred years earlier. His brain was studied by Rudolf Wagner who found its weight to be 1,492 grams and the cerebral area equal to 219,588 square millimeters. [29] Also found were highly developed convolutions, which was suggested as the explanation of his genius. [30] Other brains that were removed and studied include those of Vladimir Lenin, [31] the mathematician Sofia Kovalevskaya, [32] and the Native American Ishi. The brain of Edward H. Rulloff, a noted philologist and criminal, was removed after his death in 1871; in 1972, it was still the second largest brain on record. [33]
The story of Harvey's theft of Einstein's brain and its subsequent study was explained in an episode of the Science Channel show Dark Matters: Twisted But True (a series which explores the darker side of scientific discovery and experimentation) that September 7, 2011. The program segment "The Secrets of Einstein's Brain" reran on the History Channel on June 4, 2016. [34]
The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all parts of the bodies of bilaterally symmetric and triploblastic animals—that is, all multicellular animals except sponges and diploblasts. It is a structure composed of nervous tissue positioned along the rostral to caudal axis of the body and may have an enlarged section at the rostral end which is a brain. Only arthropods, cephalopods and vertebrates have a true brain, though precursor structures exist in onychophorans, gastropods and lancelets.
The cerebral cortex, also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain in humans and other mammals. It is the largest site of neural integration in the central nervous system, and plays a key role in attention, perception, awareness, thought, memory, language, and consciousness. The cerebral cortex is the part of the brain responsible for cognition.
The corpus callosum, also callosal commissure, is a wide, thick nerve tract, consisting of a flat bundle of commissural fibers, beneath the cerebral cortex in the brain. The corpus callosum is only found in placental mammals. It spans part of the longitudinal fissure, connecting the left and right cerebral hemispheres, enabling communication between them. It is the largest white matter structure in the human brain, about 10 in (250 mm) in length and consisting of 200–300 million axonal projections.
The vertebrate cerebrum (brain) is formed by two cerebral hemispheres that are separated by a groove, the longitudinal fissure. 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, the cerebral cortex, that is supported by an inner layer of white matter. In eutherian (placental) mammals, the hemispheres are linked by the corpus callosum, a very large bundle of nerve fibers. Smaller commissures, including the anterior commissure, the posterior commissure and the fornix, also join the hemispheres and these are also present in other vertebrates. These commissures transfer information between the two hemispheres to coordinate localized functions.
The cingulate cortex is a part of the brain situated in the medial aspect of the cerebral cortex. The cingulate cortex includes the entire cingulate gyrus, which lies immediately above the corpus callosum, and the continuation of this in the cingulate sulcus. The cingulate cortex is usually considered part of the limbic lobe.
The cerebrum, telencephalon or endbrain is the largest part of the brain, containing the cerebral cortex as well as several subcortical structures, including the hippocampus, basal ganglia, and olfactory bulb. In the human brain, the cerebrum is the uppermost region of the central nervous system. The cerebrum develops prenatally from the forebrain (prosencephalon). In mammals, the dorsal telencephalon, or pallium, develops into the cerebral cortex, and the ventral telencephalon, or subpallium, becomes the basal ganglia. The cerebrum is also divided into approximately symmetric left and right cerebral hemispheres.
Split-brain or callosal syndrome is a type of disconnection syndrome when the corpus callosum connecting the two hemispheres of the brain is severed to some degree. It is an association of symptoms produced by disruption of, or interference with, the connection between the hemispheres of the brain. The surgical operation to produce this condition involves transection of the corpus callosum, and is usually a last resort to treat refractory epilepsy. Initially, partial callosotomies are performed; if this operation does not succeed, a complete callosotomy is performed to mitigate the risk of accidental physical injury by reducing the severity and violence of epileptic seizures. Before using callosotomies, epilepsy is instead treated through pharmaceutical means. After surgery, neuropsychological assessments are often performed.
Glia, also called glial cells (gliocytes) or neuroglia, are non-neuronal cells in the central nervous system and the peripheral nervous system that do not produce electrical impulses. The neuroglia make up more than one half the volume of neural tissue in the human body. They maintain homeostasis, form myelin in the peripheral nervous system, and provide support and protection for neurons. In the central nervous system, glial cells include oligodendrocytes, astrocytes, ependymal cells and microglia, and in the peripheral nervous system they include Schwann cells and satellite cells.
The longitudinal fissure is the deep groove that separates the two cerebral hemispheres of the vertebrate brain. Lying within it is a continuation of the dura mater called the falx cerebri. The inner surfaces of the two hemispheres are convoluted by gyri and sulci just as is the outer surface of the brain.
The lobes of the brain are the major identifiable zones of the human cerebral cortex, and they comprise the surface of each hemisphere of the cerebrum. The two hemispheres are roughly symmetrical in structure, and are connected by the corpus callosum. They traditionally have been divided into four lobes, but are today considered as having six lobes each. The lobes are large areas that are anatomically distinguishable, and are also functionally distinct to some degree. Each lobe of the brain has numerous ridges, or gyri, and furrows, the sulci that constitute further subzones of the cortex. The expression "lobes of the brain" usually refers only to those of the cerebrum, not to the distinct areas of the cerebellum.
Thomas Stoltz Harvey was an American pathologist who conducted the autopsy on Albert Einstein in 1955. Harvey afterwards preserved Einstein's brain on the condition that it would be studied for scientific purposes.
The lateralization of brain function is the tendency for some neural functions or cognitive processes to be specialized to one side of the brain or the other. The median longitudinal fissure separates the human brain into two distinct cerebral hemispheres, connected by the corpus callosum. Although the macrostructure of the two hemispheres appears to be almost identical, different composition of neuronal networks allows for specialized function that is different in each hemisphere.
In human brain anatomy, an operculum, may refer to the frontal, temporal, or parietal operculum, which together cover the insula as the opercula of insula. It can also refer to the occipital operculum, part of the occipital lobe.
The commissural fibers or transverse fibers are axons that connect the two hemispheres of the brain. Huge numbers of commissural fibers make up the commissural tracts in the brain, the largest of which is the corpus callosum.
Dean Falk is an American academic neuroanthropologist who specializes in the evolution of the brain and cognition in higher primates. She is the Hale G. Smith Professor of Anthropology and a Distinguished Research Professor at Florida State University.
In human neuroanatomy, brain asymmetry can refer to at least two quite distinct findings:
Environmental enrichment is the stimulation of the brain by its physical and social surroundings. Brains in richer, more stimulating environments have higher rates of synaptogenesis and more complex dendrite arbors, leading to increased brain activity. This effect takes place primarily during neurodevelopment, but also during adulthood to a lesser degree. With extra synapses there is also increased synapse activity, leading to an increased size and number of glial energy-support cells. Environmental enrichment also enhances capillary vasculation, providing the neurons and glial cells with extra energy. The neuropil expands, thickening the cortex. Research on rodent brains suggests that environmental enrichment may also lead to an increased rate of neurogenesis.
Marian Cleeves Diamond was an American neuroscientist. She and her team were the first to publish evidence that the brain can change with experience and improve with enrichment, what is now called neuroplasticity. She was a professor of anatomy at the University of California, Berkeley.
Sandra Freedman Witelson is a Canadian neuroscientist best known for her analysis of specimens from Albert Einstein's brain, as well as exploring anatomic and functional differences regarding male and female brains, handedness, and sexual orientation. She and her colleagues maintain the world's largest collection of "cognitively normal" brains at McMaster University in Hamilton, Ontario.
Francisco Aboitiz is a Chilean neuroscientist, academic, and author. He is a professor at the Medical School and the Director of the Interdisciplinary Center for Neuroscience NeuroUC at Pontificia Universidad Católica (PUC) de Chile.
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