Ch. 2, Cognitive Neuroscience Flashcards
Neurons:
create and transmit info about what we experience and know
Nerve Net:
previously believed to be continuous , highway like system that provided a pathway for conducting signals uninterrupted through the network
Golgi:
developed a staining technique in which a thing slice of brain tissue was immersed in a solution of silver nitrate that shows the shape of a few neurons
Neurstructure, Cajal
studied the newborn brain, could see that the nervenet was not continuous but made up of individual units connected together
Neuron Doctrine Cajal: i
idea that individual cells transmit signals in the nervous system, and that these cells are not continuous with other cells as proposed by nerve net theory
Cell Body:
metabolic center of the neuron, contains mechanisms to keep the cell alive
Dendrites:
branch out from the cell body to receive signals from other neurons
Axons:
long processes that transmit signals to other neurons
Synapse:
gap between the end of a neurons axon and the dendrites or cell body of another neuron
Recording vs. reference electrode
Recording Electrode: shown with its recording tip inside the neuron, recording electrical signals
Reference Electrode: located some distance away from the recording electrode, outside axon
MEASURE DIFFERENCE BETWEEN ELECTRICAL CHARGES
What makes action potentials ideal for sending signals over a long distance
Found that each action potential travels all the way down the axon without changing its height or shape: MAKES ACTION POTENTIALS IDEAL FOR SENDING SIGNALS OVER A DISTANCE BECAUSE IT MEANS THAT ONCE AN ACTION POTENTIAL IS STARTED AT ONE END OF THE AXON THE SIGNAL WILL STILL BE THE SAME SIZE WHEN IT REACHES THE OTHER END
Quality across vs. within a sense
Quality Across the Senses: refers to the different experience associated with each of the senses
Quality within a particular sense: such as for vision, color, movement, etc.
Action Potential Process RNAI
Resting Potential: WHEN AXON/NERVE FIBER IS AT REST: –70 MILLIVOLTS
(2) Nerve Impulse: transmitted down the axon when neuron receptor is stimulated
(3) AS IMPULSE PASSES THE RECORDING ELECTRODE, THE CHARGE INSIDE THE AXON IS 40 millilivolts
(4) Impulse continues past the electrode, charge inside the nerve fibers reverses course and starts becoming negative again and returns to the resting potential
What happens when signals reach the end of the axon at the synapse?
NEUROTRANSMITTER IS RELEASED; neurotransmitters make it possible fort the signal to be transmitted across the gap that separates the end of the axon from the dendrtite or cell body of another neuron
Principle of Neural Representation:
NEURAL STATE A= CORRELATES WITH EVENT A IN THE ENVIRONMENT
For example, a researcher may find that a group of neurons fires whenever a mouse sees a predator. Because that particular neural state is correlated to seeing the predator, the researcher may say the neural state represents the predator.
Feature Detectators:
only respond to specific stimulus features such as orientation, movement, and length
Blakemore and Cooper, Experience Dependent Plasticity:
tructure of the brain is changed by experience (kittens exposed only to horizontal or vertical bars only had neurons that responded to one of these depending on the environment)
Hierarchal Processing:
neurons respond to relatively simple stimuli send their axons to higher levels of the visual system, where signals from many neurons combine and interact; neurons at thais higher level which respond to more complex stimuli then send signals to even higher areas, combining and interacting further and creating neurons that respond to even more complex stimuli
