cognitive neuroscience
involves the study of the physiological basis of cognition.
involves an understanding of both the nervous system as well as the individual units that comprise that system
nerve net/ continuous network
the interconnection of neurons create the appearance of what was referred to as a nerve net.
it was thought that this functions similarly to a highway, with one connecting to another
Golgi staining
introduced the ability to stain/highlight individual neurons. using this technique, discrete units throughout the network were observed, we now know these as neurons.
led to neuron doctrine
neuron doctrine
discovered due to Golgi staining. Individual nerve cells transmit the signals , and are not actually continuous with other nerve cells
neurons
specialized cells that create , receive , and transmit information in the nervous system. They communicate by the way of electrical and chemical signals.
cell body
contains mechanisms to keep cell alive
axon
tube filled with fluid that transmits electrical signal to other neurons
dendrites
multiple branches reaching from the cell body, which receives information from other neurons
action potential
an all or nothing electrical impulse used for signaling purposes. Constitute a primary method of communication within the nervous system. APs travel along the axon of the sending neuron to the dendrites of receiving neurons
microelectrodes
measure action potentials.
pick up electrical signals.
placed near axon. active for 1 second.
size is not measured (size remains consistent; it is all or nothing), but rather firing rate.
low intensities; slow firing
high intensities; fast firing
synapse
space between axon of one neuron and dendrite or cell body of another.
when the action potentials reaches the end of the axon, synaptic vesicles open and release chemical neurotransmitters
neurotransmitters
chemicals that affect the electrical signal of the receiving neuron , cross the synapse and bind with the receiving dendrites.
vision and neurons
the visual cortex plays a critical role , however many neurons outside of the visual cortex are tuned to respond to visual properties. A given visual stimulus may create distributed patterns of activation throughout the cortex.
‘tuned’ neurons
one of the primary way neurons represent ‘stuff’ is by being selectively tuned to respond to a relatively specific property.
feature detectors
neurons that respond best to a specific stimulus. typically associated with some simple physical property.
if the relevant stimuli is not present in the environment then the type of feature detector that would be tuned to respond to that type of property never develops.
hierarchical processing
when we perceive different objects, we do so in specific order that moves from lower to higher areas of the brain.
the ascension from lower to higher areas of the brain corresponds to perceiving objects that move from lower (simple) to higher levels of complexity.
mirror neurons
thought to be specialized for emulating what other people are experiencing.
important implication for various behaviours: empathy, language acquisition, theory of mind, understanding intentions of others, ‘contagious’ behaviours, etc
specific coding
A single neuron is responsible for representing a specific stimulus or concept
population coding
A stimulus is represented by the combined firing patterns of a large population of neurons.
sparse coding
A concept is represented by the firing of a small number of neurons out of a larger population.
localization of function
idea that specific functions are served by particular areas of the brain.
cognitive functioning breaks down in specific (predictable) ways when areas of the brain are damaged
cerebral cortex
3mm thick layer t5hat covers the brain, contains mechanisms responsible for most of our cognitive functions.
occipital lobe
primary receiving area for vision
parietal lobe
primary receiving area for touch, temperature, and pain
