Columbia Encyclopedia

Search results

277 results found

dream

(Encyclopedia)dream, mental activity associated with the rapid-eye-movement (REM) period of sleep. It is commonly made up of a number of visual images, scenes or thoughts expressed in terms of seeing rather than in...

stroke

(Encyclopedia)stroke, destruction of brain tissue as a result of intracerebral hemorrhage or infarction caused by thrombosis (clotting) or embolus (obstruction in a blood vessel caused by clotted blood or other for...

amyotrophic lateral sclerosis

(Encyclopedia)amyotrophic lateral sclerosis (ALS) āˌmīətrōfˈik, sklĭrōˈsĭs [key] or motor neuron disease, sometimes called Lou Gehrig's disease, degenerative disease that affects motor neurons in the brai...

neural network

(Encyclopedia)neural network or neural computing, computer architecture modeled upon the human brain's interconnected system of neurons. Neural networks imitate the brain's ability to sort out patterns and learn fr...

Braintree, town and district, England

(Encyclopedia)Braintree, town and district, Essex, E England, between the Pant (Blackwater) and Brain river valleys. It has textile, plastic, and metal-product indust...

cybernetics

(Encyclopedia)cybernetics [Gr.,=steersman], term coined by American mathematician Norbert Wiener to refer to the general analysis of control systems and communication systems in living organisms and machines. In cy...

pineal gland

(Encyclopedia)pineal gland pĭnˈeəl [key], small organ (about the size of a pea) situated in the brain. Long considered vestigial in humans, the structure, which is also called the pineal body or the epiphysis, i...

stereoscope

(Encyclopedia)stereoscope stĕrˈēəskōpˌ [key], optical instrument that presents to a viewer two slightly differing pictures, one to each eye, to give the effect of depth. In normal vision the two eyes, being a...

neurotransmitter

(Encyclopedia)neurotransmitter, chemical that transmits information across the junction (synapse) that separates one nerve cell (neuron) from another nerve cell or a muscle. Neurotransmitters are stored in the nerv...

Alzheimer's disease

(Encyclopedia)Alzheimer's disease ălsˈhīˌmərz, ôls– [key], degenerative disease of nerve cells in the cerebral cortex that leads to atrophy of the brain and senile dementia and, ultimately, death. The disea...