Chapter 3 - The Brain Flashcards
Won't be on tests... but know it anyway (144 cards)
action potential
The all-or-none firing of a neuron that leads to the release of neurotransmitters.
activation function (as in neural networks)
A function that takes in the weighted sum of the previous layer’s inputs and returns the activation level of the node.
activation level (as in neural networks)
The numerical value of a node in a neural network.
aphasia
The loss of language comprehension or expression due to brain damage.
artificial neural network (ANN)
A type of machine-learning models based loosely on the brain consisting of layers of nodes connected by modifiable weights that determine their activations.
association neurons
Neurons that receive their inputs and send outputs to other neurons.
autonomic nervous system
A portion of the peripheral nervous system that connects to most organs in the body and regulates certain unconscious bodily functions.
axon
A projection of the neuronal cell body along which action potentials are propagated, terminating in the release of neurotransmitters
backpropagation
A technique for gradually changing the weights of a neural network in order to reduce the error
brainstem
A stalk-like structure at the base of the brain that connects it to the spinal cord and regulates involuntary functions like heart rate and breathing.
Broca’s aphasia
A form of aphasia typically due to damage to the inferior frontal gyrus that leads to slow and labored speech production.
central nervous system
A portion of the nervous system consisting of the brain and spinal chord.
cerebral cortex
A folded, layered structure that is the largest single structure and the most superficial portion of the human brain
cerebrum
The largest portion of the human brain, sitting at the top of the brain and consisting of the cerebral cortex and related structures.
cognitive neuroscience
A subfield of neuroscience that uses multiple tools to measure and analyze active brain processing in awake and (typically) healthy individual.
corpus callosum
A band of fibers that connect the right and left hemispheres of the cerebrum
contralateral
A spatial relationship between brain and body observed in vertebrates in which one side of the brain controls or receives input from the opposite side of the body.
dendrites
Branch-like projections that protrude from the cell body of a neuron and contain receptor sites to which neurotransmitters can bind.
distributed/population encoding:
A theory of neural representation in which complex patterns or objects are represented by the distribution of activation across many neurons.
electroencephalography (EEG)
A method that measures electrical activity due to neural or other processing at the surface of the scalp.
encephalization quotient (EQ)
A measure of actual brain size relative to the size that would be predicted based on body size alone. It is strongly correlated with intelligence.
error/loss (as in a neural network)
The difference between the observed output and the correct output of an ANN, used as a measure of its performance and minimized during training.
event-related potential (ERP)
Rapid changes in electrical potential, as measured by EEG, due to the onset of a stimulus.
excitatory
When the firing of a neuron causes a receiving neuron to fire more frequently.