02 SEP 2016 by ideonexus
How Brains Respond to Positive/Negative Feedback in Child...
In children up to eight or nine years old, the dopamine-modulating reward center in the nucleus accumbens reacts strongly to positive feedback (activating the prefrontal cortex) and minimally to negative feedback. In older children, increased activation still occurs in the PFC when dopamine is released in response to positive feedback (particularly in response to correct answers/ predictions). However, the greatest age-related change is the higher reactivity of the NAc to negative feedback an... 1 
notes
notes09 AUG 2014 by ideonexus
Brain Differences Between Sciences and Humanities
The areas of academic interest (sciences or humanities) and area of study have been known to be associated with a number of factors associated with autistic traits. However, despite the vast amount of literature on the psychological and physiological characteristics associated with faculty membership, brain structural characteristics associated with faculty membership have never been investigated directly. In this study, we used voxel-based morphometry to investigate differences in regional g... 1 notes
notes27 DEC 2013 by ideonexus
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 always alert for times we might be threatened. When it does sense danger, it can completely take over, or hijack, the upstairs brain. That’s what allows us to act before we think... 1 notes
notesOur instinctive, more primitive brain overrides our logical, more advanced from time to time. Children are even more prone to it.
24 DEC 2013 by ideonexus
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 bicycle, or swimming) once you’ve learned (easy) and learning to do it in the first place (hard). Understanding exactly how new hidden layers get laid down in neural circuitry is ... 1 notes
notesFrank Wilczek describes one of the great questions of science, how the difficult taks of learning something leads to the learned easy of later doing it.
24 DEC 2013 by ideonexus
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 cell one molecule of ATP—one unit of precious energy. Indeed, cyclic reactions of this kind were initially labeled “futile.” But the adjective is misleading. The additio...Folksonomies: neurology
Folksonomies: neurology
1 notes
notesThe underlying cyclical process of a synapse firing that turns it into a "tunable" device.
24 DEC 2013 by ideonexus
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 synapses in your head is mind-boggling. If I had a dollar for every synapse in your brain, I could support the current economy of the world for ten years. Cortical neurons on ave...Folksonomies: neurology
Folksonomies: neurology
1 notes
notesTerrence Sejnowski on the incredible three-pound universe.
21 JUN 2013 by ideonexus
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 that cell. Thus frequent use of a nerve cell might lower its threshold, i.e. ease the requirements of its stimulation, and the like. If this were true, the memory would reside i... 1 notes
notesNeurons that get used more often become easier to use. He's just speculating, but his description is spot on.
20 JUN 2013 by ideonexus
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: human ovum, 100 µm; cross-section of a skeletal muscle fiber, 10-100 µm; erythrocytes, 8–10 µm; bacteria, 0.1–8 µm; and viruses, 0.15–0.5 µm.
Cell bodies of neurons... 1 notes
notesInteresting to see how they compare to the sizes of other small objects.
18 JUN 2013 by ideonexus
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 actual process for recording brainprints
for identification purposes goes much deeper than
that. It is based on the electrophysiological responses
(event-related potentials) t... 1 notes
notesThe problem is that they must be updated regularly because the brain is always changing.
27 APR 2013 by ideonexus
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!] ... suggest that such divisions may be fundamentally wrong. Rather than separate processes for motor outputs and individual sensory modalities, adaptive action seems to use all the availab...
1 
1 Speaking involves not just motor functions in the brain, but auditory, suggesting sensory inputs for the brain are not segregated.
