Neuroscience

How the brain learns new skills

The human brain is "plastic": it can adapt and rewire itself, often more easily when learning new things related to familiar skills. For example, it is probably easier for a professional tennis player to learn to play badminton ...

Psychology & Psychiatry

Imagine: Our attitudes can change solely by the power of imagination

Sometimes in life there are special places that seem to stand out to us—a school playground, perhaps an old church, or that inconspicuous street corner where you were kissed for the first time. Before the kiss you had never ...

Alzheimer's disease & dementia

Artificial intelligence tool vastly scales up Alzheimer's research

Researchers at UC Davis and UC San Francisco have found a way to teach a computer to precisely detect one of the hallmarks of Alzheimer's disease in human brain tissue, delivering a proof of concept for a machine-learning ...

Neuroscience

Dataset bridges human vision and machine learning

Neuroscientists and computer vision scientists say a new dataset of unprecedented size—comprising brain scans of four volunteers who each viewed 5,000 images—will help researchers better understand how the brain processes ...

Psychology & Psychiatry

Researchers study sexual objectification in brain processes

What happens in the human brain when a woman is put on a par with an object? A study addressing this question was conducted at the Department of Psychology and Cognitive Science and the Center for Mind/Brain Sciences (CiMEC) ...

Neuroscience

Unexplored neural circuit modulates memory strength

Learning to avoid negative experiences requires an interplay of two distinct brain circuits, one to interpret "Yikes!" and drive learning, and the other, unexpectedly, to dial in the strength of that memory, a new fruit fly ...

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Human brain

The human brain is the center of the human nervous system and is a highly complex organ. Enclosed in the cranium, it has the same general structure as the brains of other mammals, but is over three times as large as the brain of a mammal with an equivalent body size. Most of the expansion comes from the cerebral cortex, a convoluted layer of neural tissue that covers the surface of the forebrain. Especially expanded are the frontal lobes, which are involved in executive functions such as self-control, planning, reasoning, and abstract thought. The portion of the brain devoted to vision is also greatly enlarged in humans.

Brain evolution, from the earliest shrewlike mammals through primates to hominids, is marked by a steady increase in encephalization, or the ratio of brain to body size. The human brain has been estimated to contain 50–100 billion (1011) neurons[citation needed], of which about 10 billion (1010) are cortical pyramidal cells.[citation needed] These cells pass signals to each other via approximately 100 trillion (1014)[citation needed] synaptic connections.

In spite of the fact that it is protected by the thick bones of the skull, suspended in cerebrospinal fluid, and isolated from the bloodstream by the blood-brain barrier, the delicate nature of the human brain makes it susceptible to many types of damage and disease. The most common forms of physical damage are closed head injuries such as a blow to the head, a stroke, or poisoning by a wide variety of chemicals that can act as neurotoxins. Infection of the brain is rare because of the barriers that protect it, but is very serious when it occurs. More common are genetically based diseases[citation needed], such as Parkinson's disease, multiple sclerosis, and many others. A number of psychiatric conditions, such as schizophrenia and depression, are widely thought to be caused at least partially by brain dysfunctions, although the nature of such brain anomalies is not well understood.

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