Chapter 2 Flashcards
define cognitive neuroscience
the study of the physiological basis of cognition
levels of analysis
the idea that a topic can be studied in many different ways, with each approach contributing its dimension to our understanding
levels of analysis when studying physiological cognition
we can study it at levels ranging from the whole brain to structures within the brain, to chemicals that create electrical signals within these structures.
action potential
- temporary reversal of a neuron’s interior polarity
- negative to positive charge
- the opening of voltage-sensitive sodium ion channels, allows positively charged sodium ions inside the neuron
- travel to the axon terminal buttons and trigger synaptic vesicles containing neurotransmitters to release the neurotransmitters across the synapse
nerve net
- a network of continuously interconnected nerve fibers (as contrasted with neural networks, in which fibers are connected by synapses)
- a complex pathway for conducting signals uninterrupted through the network
neuron doctrine
- the idea that individual cells transmit signals in the nervous system
- these cells are not continuous with other cells
cell body
the metabolic center of the neuron that contains mechanisms to keep the cell alive
dendrites
receive signals from other neurons
axon
- usually long processes that transmit signals to other neurons from the cell body to the synapse at the end of the axon
- Aka nerve fibres
synapse
space between the end of an axon and the cell body or dendrite and the next axon
neural circuits
group of interconnected neurons that are responsible for neural processing
resting potential
- inside the neuron has a charge of -70 mV
- at rest
nerve impulse
- neuron is stimulated and reverses the interior polarity of the neuron to 40 mV
- the reversal is action potential
microelectrodes
- a device that measures electrical signals
- small wires that record electrical signals from single neurons
- can measure action potential
- 2 points of reference
2 points of reference for microelectrodes
- inside the neuron: recording electrode
- outside the neuron: reference electrode
neurotransmitters
- chemical messengers that cross the synapse and bind to the dendrites of a nearby neuron
- e.g. GABA, endorphins, dopamine, etc
principle of neural representation
states that everything a person experiences is based on representations in the person’s nervous system
neuron firing
- many neurons at higher levels of the visual system fire to complex stimuli like geometrical patterns and faces
- a specific stimulus causes neural firing that is distributed across many areas of the cortex
- e.g. it was discovered that memory is not determined by a single “memory area,” because there are many areas involved in creating memories and remembering them later.
feature detectors - Hubel and Wiesel
- they called these neurons feature detectors because they responded to specific stimulus features such as orientation, movement, size and length
- each neuron in the visual area of the cortex responded to a specific type of stimulation presented to a small area of the retina.
what do neurons in the visual cortex respond to
neurons in the visual cortex respond to oriented bars