PSYCH 147 REVIEWER axon or nerve fiber- transmits signals to other neurons.
CHAPTER 2: COGNITIVE NEUROSCIENCE *Thus, the neuron has a receiving end and a transmitting end,
cognitive neuroscience- the study of the physiological basis and its role, as visualized by Cajal, was to transmit signals.
of cognition receptors- neurons that pick up information from the
neurons- the building blocks and transmission lines of the environment, such as the neurons in the skin, eye, and ear,
nervous system similar to brain neurons in that they have a cell body and axon,
NEURONS: THE BUILDING BLOCKS OF THE NERVOUS but they have specialized receptors that pick up information
SYSTEM from the environment.
Brain- a static tissue that weighs 3.5 pounds and has no synapse- a small gap between the end of the neuron’s axon
moving parts and doesn’t expand or contract and the dendrites or cell body of another neuron
The Microstructure of the Brain: Neurons Neural circuits- neurons that are connected together, Neurons
Nerve net- continuous, like a highway system in which one are not connected indiscriminately to other neurons, but form
street connects directly to another, but without stop signs or connections only to specific neurons.
traffic lights; provided a complex pathway for conducting The Signals that Travel in Neurons
signals uninterrupted through the network Edgar Adrian- was able to record electrical signals from single
Camillo Golgi- developed a staining technique that involved sensory neurons, an achievement for which he was awarded
immersing a thin slice of brain tissue in a solution of silver the Nobel Prize in 1932
nitrate. This technique created pictures like the one in Figure *Adrian recorded electrical signals from single neurons using
2.2b, in which individual cells were randomly stained microelectrodes—small shafts of hollow glass filled with a
Ramon y Cajal- a Spanish physiologist who was interested in conductive salt solution that can pick up electrical signals at
investigating the nature of the nerve net. First he used the Golgi the electrode tip and conduct these signals back to a recording
stain, which stained only some of the cells in a slice of brain device.
tissue. Second, he decided to study tissue from the brains of Recording electrode- electrode is lowered into tissue until the
newborn animals, because the density of cells in the newborn tip of the electrode is positioned near a neuron, connected to a
brain is small compared to the density in the adult brain. This recording device and to another electrode, called the reference
property of the newborn brain, combined with the fact that the electrode, which is located outside of the tissue
Golgi stain affects less than 1 percent of the neurons, made it -The key principle for understanding how electrical signals are
possible for Cajal to clearly see that the Golgi-stained cells recorded from neurons is that we are always measuring the
difference in charge between the recording and reference
electrodes.
oscilloscope- which indicates the difference in charge by the
vertical position of a small dot that creates a line as it moves
across the screen
nerve impulse or action potential- electrical signal, is
transmitted down the axon, the dot is de ected up (as the
neuron becomes more positive) and then back down (as the
charge returns to its original level), all within 1 millisecond
(1/1,000 second)
-Adrian also found that each action potential travels all the way
down the axon without changing its size. This property makes
action potentials ideal for sending signals over a distance,
because it means that once an action potential is started at one
end of an axon, the signal is still the same size when it reaches
the other end.
neurotransmitter- imakes it possible for the signal to be
transmitted across the synaptic gap that separates the end of
the axon from the dendrite or cell body of another neuron
-Adrian studied the relation between nerve firing and sensory
were individual units
experience by measurng how the firing of a neuron from a
-Cajal’s discovery that individual units called neurons were the
receptor in the skin changed as he applied more pressure to
basic building blocks of the brain was the centerpiece of
the skin. What he found was that the shape and height of the
neuron doctrine—the idea that individual cells transmit signals
action potential remained the same as he increased the
in the nervous system, and that these cells are not continuous
pressure, but the rate of nerve ring—that is, the number of
with other cells as proposed by nerve net theory.
action potentials that travel down the axon per second—
CHAPTER 2: COGNITIVE NEUROSCIENCE *Thus, the neuron has a receiving end and a transmitting end,
cognitive neuroscience- the study of the physiological basis and its role, as visualized by Cajal, was to transmit signals.
of cognition receptors- neurons that pick up information from the
neurons- the building blocks and transmission lines of the environment, such as the neurons in the skin, eye, and ear,
nervous system similar to brain neurons in that they have a cell body and axon,
NEURONS: THE BUILDING BLOCKS OF THE NERVOUS but they have specialized receptors that pick up information
SYSTEM from the environment.
Brain- a static tissue that weighs 3.5 pounds and has no synapse- a small gap between the end of the neuron’s axon
moving parts and doesn’t expand or contract and the dendrites or cell body of another neuron
The Microstructure of the Brain: Neurons Neural circuits- neurons that are connected together, Neurons
Nerve net- continuous, like a highway system in which one are not connected indiscriminately to other neurons, but form
street connects directly to another, but without stop signs or connections only to specific neurons.
traffic lights; provided a complex pathway for conducting The Signals that Travel in Neurons
signals uninterrupted through the network Edgar Adrian- was able to record electrical signals from single
Camillo Golgi- developed a staining technique that involved sensory neurons, an achievement for which he was awarded
immersing a thin slice of brain tissue in a solution of silver the Nobel Prize in 1932
nitrate. This technique created pictures like the one in Figure *Adrian recorded electrical signals from single neurons using
2.2b, in which individual cells were randomly stained microelectrodes—small shafts of hollow glass filled with a
Ramon y Cajal- a Spanish physiologist who was interested in conductive salt solution that can pick up electrical signals at
investigating the nature of the nerve net. First he used the Golgi the electrode tip and conduct these signals back to a recording
stain, which stained only some of the cells in a slice of brain device.
tissue. Second, he decided to study tissue from the brains of Recording electrode- electrode is lowered into tissue until the
newborn animals, because the density of cells in the newborn tip of the electrode is positioned near a neuron, connected to a
brain is small compared to the density in the adult brain. This recording device and to another electrode, called the reference
property of the newborn brain, combined with the fact that the electrode, which is located outside of the tissue
Golgi stain affects less than 1 percent of the neurons, made it -The key principle for understanding how electrical signals are
possible for Cajal to clearly see that the Golgi-stained cells recorded from neurons is that we are always measuring the
difference in charge between the recording and reference
electrodes.
oscilloscope- which indicates the difference in charge by the
vertical position of a small dot that creates a line as it moves
across the screen
nerve impulse or action potential- electrical signal, is
transmitted down the axon, the dot is de ected up (as the
neuron becomes more positive) and then back down (as the
charge returns to its original level), all within 1 millisecond
(1/1,000 second)
-Adrian also found that each action potential travels all the way
down the axon without changing its size. This property makes
action potentials ideal for sending signals over a distance,
because it means that once an action potential is started at one
end of an axon, the signal is still the same size when it reaches
the other end.
neurotransmitter- imakes it possible for the signal to be
transmitted across the synaptic gap that separates the end of
the axon from the dendrite or cell body of another neuron
-Adrian studied the relation between nerve firing and sensory
were individual units
experience by measurng how the firing of a neuron from a
-Cajal’s discovery that individual units called neurons were the
receptor in the skin changed as he applied more pressure to
basic building blocks of the brain was the centerpiece of
the skin. What he found was that the shape and height of the
neuron doctrine—the idea that individual cells transmit signals
action potential remained the same as he increased the
in the nervous system, and that these cells are not continuous
pressure, but the rate of nerve ring—that is, the number of
with other cells as proposed by nerve net theory.
action potentials that travel down the axon per second—
