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Memes tagged “neurology”

1–11 of 11

The Upstairs and Downstairs Brain

Our amygdala (pronounced uh-MIG-duh-luh) is about the size and shape of an almond and is part of the limbic area, which resides in the downstairs brain. The amygdala’s job is to quickly process and express emotions, especially anger and fear. This little mass of gray matter is the watchdog of the brain, remaining…

How Neural Circuitry is Laid Down

In thinking about hidden layers, it’s important to distinguish between the routine efficiency and power of a good network, once that network has been set up, and the difficult issue of how to set it up in the first place. That difference is reflected in the difference between playing the piano (or, say, riding a…

The Signaling Pathway

In a typical signaling pathway, proteins are continually being modified and demodified. Kinases and phosphatases work ceaselessly like ants in a nest, adding phosphate groups to proteins and removing them again. It seems a pointless exercise, especially when you consider that each cycle of addition and removal costs…

The Connections in the Brain

Two neurons can communicate with each other at a synapse, which is the computational unit in the brain. The typical cortical synapse is less than a micron in diameter (10-6 meter), near the resolution limit of the light microscope. If the economy of the world is a stretch for us to contemplate, thinking about all the…

von Neumann Correctly Hypothesizes How Memory Works

The question of the physical embodiment of this memory remains. For this, various authorrs have suggested a variety of solutions. It has beeen proposed to assume that the thresholds—orr, more broadly stated, the stimulation criteria—^f or various nerve cells change with time as functions of the previous history of…

Relative Sizes of Structures in the Brain

Linear measure- ments and dimensions generally are given in microns or micrometers (µm) (1 µm equals one- millionth of a meter) or nanometers (nm) (1 nm or millimicron equals one-billionth of a meter). About 240,000 µm equal one inch. As a reference, the following are the dimen- sions of some non-neural structures…

Brainscans as a Form of Identification

Brainprint scans are considered the definitive method for identifying egos. Contrary to popular misconceptions, the term “brainwave scan” is a misnomer, as this form of identifier is not based on simple electroencephalography (EEG: a reading of the electrical activity created by neurons firing within the brain). The…

Sensations are Related in the Brain

Production of speech is seen as a pure motor act, involving muscles and the neurons controlling them, while perception of speech is seen as purely sensory, involving the ear and the auditory pathway. This parcellation of the systems appear intuitive and clear, but recent studies [beginning with Taine 1870!]…

The BRAIN Initiative

As humans, we can identify galaxies light years away, we can study particles smaller than an atom. But we still haven’t unlocked the mystery of the three pounds of matter that sits between our ears. (Laughter.) But today, scientists possess the capability to study individual neurons and figure out the main functions…