2 Physiology Of Perception Flashcards
Axon
Part of a neuron that conducts the fiber impulses over distances. Also called the nerve fiber.
Action potential
Rapid increase in positive charge in a nerve fiber that travels down the fiber. Also called the nerve impulse.
Cell body
Part of a neuron that contains the neuron’s metabolic machinery and that receives stimulation from other neurons.
Center-surround antagonism
Competition between the center and surrounding regions of the center-surround receptive field, caused by the fact that one is excitatory and the other is inhibitory. Stimulating Center and surrounding areas simultaneously decreases responding of the neuron, compared to stimulating the excitatory area alone.
Center-surround receptive field
Receptive field that consists of a roughly circular excitatory area surrounded by an inhibitory area, or circular inhibitory center surrounded by an excitatory area.
Cerebral cortex
2 mm thick layer that covers the surface of the brain and contains the machinery for creating perception, as well as for other functions, such as language, memory, and thinking.
Convergence
When many neurons synapse onto a single neuron.
Dendrites
Nerve processes on the cell body that receive stimulation from other neurons.
Depolarization
When the inside of a neuron becomes more positive, as occurs during the initial phases of the action potential. Depolarization is often associated with the action of excitatory neurotransmitters.
Distributed coding
Type of neural code in which different perceptions are signaled by the pattern of activity that is distributed across many neurons.
Doctrine of specific nerve energies
Principal proposed by Mueller, which states that our perceptions depend on “nerve energies” reaching the brain and that the specific quality we experience depends on which nerves are stimulated. For example, activating the optic nerve results and see, and activating the auditory nerve results in hearing.
Easy problem of consciousness
Problem of determining the relationship between physiological processes like nerve firing and perceptual experience. Note that this involves determining a relationship, not a cause.
Excitatory area
Area of receptive field that is associated with excitation. Stimulation of this area causes an increase in a rate of nerve firing.
Excitatory response
Response of the nerve fiber in which the firing rate increases.
Excitatory transmitter
Neurotransmitters that causes the inside of a neuron to become more positively charged. Excitatory neurotransmitters increase the probability that an action potential will be generated and are also associated with increases in the rate of nerve firing.
Excitatory-center-inhibitory-surround receptive field
Center-surround receptive field in which stimulation of the center area causes an excitatory response, installation of the surround causes an inhibitory response.
Frontal lobe
Receiving signals from all of the senses, the frontal low plays an important role in perceptions that involved the coordination of information received through two or more senses. It also serves functions such as language, thought, memory, and motor functioning.
Grandmother cell
Hypothesized type of neuron that responds only to a very specific stimulus, such as a person’s grandmother.
Hard problem of consciousness
Problem of determining how physiological processes, such as ion flow across nerve membranes, cause different perceptual experiences.
Hyperpolarization
When the inside of a neuron becomes more negative. Hyperpolarization is often associated with the action of inhibitory transmitters.
Inhibitory area
Area of the receptive field that is associated with inhibition. Stimulation of this area causes a decrease in the rate of nerve firing.
Inhibitory response
Response of a nerve fiber in which the firing rate decreases due to inhibition from another neuron.
Inhibitory transmitter
Neurotransmitters that cause the inside of the neuron to become negatively charged. Inhibitory transmitters decrease the probability that an action potential will be generated and are also associated with decrease in the rate of nerve firing.
Inhibitory-center-excitatory-surround receptive field
Center-surround receptive field in which stimulation of the center causes an inhibitory response and stimulation of the surround causes an excitatory response.
Ions
Charged molecules found floating in the liquid that surrounds nerve fibers.
Microelectrode
Thin piece of wire that is small enough to record electrical signals from a single neuron.
Mind-body problem
One of the most famous problems in science: how do physical processes such as nerve impulses or sodium and potassium molecules flowing across membranes (the body part of the problem) become transformed into the richness of perceptual experience (the mind part of the problem)?
Modular organization
Organization of specific functions into specific brain structures.
Nerve
Group of nerve fibers traveling together.
Nerve fiber
In most sensory neurons, the long part of the neuron that transmits electrical impulses from one point to another.
Neural circuits
Neurons that are connected by synapses.
Correlate of consciousness (NCC)
Connections between the firing of neurons and perceptual experience.
Neuron theory
Idea that the nervous system consists of distinct elements or cells.
Neurotransmitter
Chemicals stored in synaptic vesicles that is released in response to a nerve impulse and excitatory or inhibitory effect on another neuron.
Occipital lobe
Lobe at the back of the cortex that is the site of the cortical receiving area for vision.
Parietal lobe
Lobe at the top of the cortex that is the site of the cortical receiving area for touch and is the termination point of the dorsal (where or how) stream for visual processing.
Permeability
Property of the membrane that refers to the ability of molecules to pass through it. If the permeability to a molecule is high, the molecule can easily pass through the membrane.
Pineal gland
Gland at the base of the brain that Renée Descartes identified as being the seat of the soul.
Primary receiving areas
Areas of the cerebral cortex the first received most of the signals initiated by a sense’s receptors. For example, the occipital cortex is the site of the primary receiving area for vision, in the temporal lobe is the site of the primary receiving area for hearing.
Propagated response
Response, such as a nerve impulse, that travels all the way down the nerve fiber without decreasing in amplitude.
Receptive field
Area on the receptor surface (the (the retina for vision; the skin for touch) that, when stimulated, affects the firing of that neuron.
Receptor sites
Small area on the postsynaptic neuron that is sensitive to specific neurotransmitters.
Receptors
Sensory receptor is a neuron sensitive to environmental energy if that changes this energy into electrical signals in the nervous system.
Refractory period
Time period of about 1/1000th of a second that a nerve fiber needs to recover from conducting a nerve impulse. No new nerve impulses can be generated in the fiber until the refractory period is over.
Resting potential
Difference in charge between the inside and outside of the nerve fiber when the fiber is not conducting electrical signals. Most new fibers have resting potentials about -70 mV, which means the inside of the fiber is negative relative to the outside.
Reticular theory
Early alternative to neuron theory that held that nervous system consisted of large network of fused nerve cells.
Selective permeability
Occurs when a cell membrane is highly permeable to one specific type of molecule, but not to others.
Sparse coding
Idea that particular object is represented by the firing of a relatively small number of neurons.
Specificity coding
Type of neural code in which different perceptions are signaled by activity and specific neurons.
Spontaneous activity
New firing that occurs in the absence of environmental stimulation.
Staining
Technique in which neurons take up dye that makes their structure visible.
Synapse
Small space between the end of one neuron (the presynaptic neuron) and the cell body of another neuron (the postsynaptic neuron).
Temporal lobe
Lobe on the side of the cortex that is the site of the cortical receiving area for hearing and the termination point for the ventral, or what, stream for visual processing. The number of areas in a temper a little, such as the fusiform face area and the extrastriate body area, serve functions related to perceiving and recognizing objects.
Ventricles
Cavities located at the center of the brain that were identified by Galen as the source of “spirits” that determined human health, thoughts, and emotions.
