Intro To Physiology Of Perception Flashcards
What did Aristotle state?
The heart was at the seat of the mind and soul
What was Galen’s pov?
He saw human health, thoughts, and emotions as being determined by four different spirits flowing from the ventricles
What are ventricles?
Cavities in the center of the brain
Rene Descartes accepted the flowing spirits but specified what?
The pineal gland as the seat of the soul
What did Thomas Willis conclude?
The brain was responsible for mental functioning and different functions were located in different regions of the brain
Two opposing ideas about the nervous system
Reticular theory: nervous system consisted of a large network of fused nerve cells
Neuron theory: the nervous system consisted of distinct cells
What is staining?
Technique that caused nerve cells to become colored and stand out from tissue
Camille Golgi’s technique
Thin slice of brain tissues dipped into silver nitrate created pictures
Johannes Mueller proposed what?
The doctrine of specific nerve energies
What is the doctrine of specific nerve energies?
perceptions depend on “nerve energies” reaching the brain and that the specific quality we experience depends on which nerves are stimulated
Edgar Adrian did what
Recorder electrical signal from single sensory neurons
What is the cerebral cortex?
A 2mm outermost layer that covers the surface of the brain. It is responsible for perception, thinking, language, memory, reasoning, etc.
What is modular organization?
Specific functions are served by specific areas of the cortex
The senses are organized into primary receiving areas which are?
The first areas in the cerebral cortex to receive signals initiated by each sense’s receptors
What are the receiving areas for the occipital, frontal, parietal and temporal lobe?
Area for vision is in the occipital lobe, area for hearing in the parietal lobe, area for touch in the temporal lobe, and the frontal lobe receives signals for all senses.
List two purposes of neurons mentioned in this chapter
- They respond to stimuli and transduce the stimuli into electrical signals
- They communicate with other neurons
Describe the structure of neurons
The cell body contains mechanisms to keep the cell alive ; dendrites are tree like with branch endings that receive electrical signals from other neurons ; axons (aka fibers) have fluids that conduct electrical signals
Receptors are
Neurons that respond to environmental stimuli and are important for perception
What are nerves
They consist of the axons (or nerve fibers) of many neurons
__ are small shaft of glass or metal used to record signals from single neurons
Microelectrodes
When the nerve fiber is at rest what is the difference in potential? What is this known as
-70 mV; aka the resting potential because the neuron is 70mV negative compared to the outside
What happens when the neurons receptor is stimulated and a signal is transmitted down the axon?
The charge inside the neuron rises to +40 mV compared to the outside
When the signal passes the electrode what happens? What is the signal known as?
The fiber reverses course and starts becoming negative again. The signal is called the action potential.
Neurons are surrounded by which solution?
Ions, molecules that carry an electrical charge.
Describe the solution of a axon?
The outside of an axon is rich in (+) sodium ions & the inside is rich in (+) potassium ions
What do Na+ and K+ ions do to cause an action potential?
Sodium flows into the cell and potassium flows out
What property of a the cell membrane allows for sodium and potassium to flow?
A cell’s permeability, which refers to the ease in which a molecule can pass through the membrane
What is selective permeability?
Occurs when a membrane is highly permeable to one specific type of molecule
What is a propagated response? (Hint: it’s an important property of an action potential)
Once the response is triggered it travels all the way down the axon without decreasing in size
What is another property of an action potential? (Has to do with size?)
The size stay the same no matter how intense the stimuli is
What does changing the stimulus of the action potential affect?
The rate of firing
Why does the upper limit occur?
The upper limit happens because of the refractory period
What is the refractory period?
The interval between the time when one nerve impulse occurs & next one can be generated in the axon
What is a third important property of an action potential?
Spontaneous activity which are action potentials that occur in the absence of environmental stimuli
What is the synapse? 
The gap between neurons
Where are neurotransmitters stored?
Structures called synaptic vessels
What are receptor sites?
They are small areas in the receiving neuron sensitive to specific neurotransmitters
What happens when the neurotransmitter makes contact with the receptor site matching its shape?
It activates the receptor site and triggers a voltage change in the receiving neuron
What do excitatory receptors do?
They cause the inside of the neuron to become more positive, this process is called depolarization
What happens if enough excitatory neurotransmitters are released
It will increase the depolarization and an action potential will be triggered causing an excitatory response
What causes the inside of a neuron to become more negative?
Inhibitory transmitters, they cause the process of hyperpolarization
What response does hypopolarization cause?
An inhibitory response because it prevents the neuron from reaching the level of depolarization needed for an action potential
What are neural circuits?
They are a group of interconnected neurons that can range from a few to hundreds or thousands 
What is convergence?
The synapsing of more than one neuron onto single neuron
What is the receptive field of a neuron?
Is the area on the receptors that influences the firing rate of the neuron
What is a center surround receptive field?
The areas of the receptive field are arranged in a center region
Define excitatory- center-inhibitory-surround receptive field
Stimulating the center increases firing and stimulating the surround decreases firing
Define inhibitory-center-excitatory-surround receptive fields
Stimulating the center decreases firing and stimulating the surround increases firing
Since the center and the surround of the receptive field respond in opposite ways it causes an effect called
Center surround antagonism
What is specificity coding
The representation of particular objects in the environment by the firing of neurons that are tuned to respond specifically to the object
Konorski and Lettvin proposed
The concept of a grandmother cell
What is a grandmother cell
A neuron that responds only to a specific stimulus
What did Quiroga and coworkers (2005) do?
They implanted electrodes into the hippocampus or medial temporal lobe of patients
What did Quiroga and coworkers find?
They found some neurons responded to the number of different views of just one person or building
Did Quiroga and coworkers Find these neurons to be grandmother cells? Why?
No. It would be difficult to find specific neurons in the hundreds of millions in the structure &  some neurons might be able to respond to other pictures or concepts but they didn’t have to continue showing pictures
What is distributed coding?
The representation of a particular object by the pattern of firing of groups of neurons
What is sparse coding?
A particular object is represented by the firing of a relatively small number of neurons
What is the mind-body problem?
How do physical processes become transformed into perceptual experience?
What is a neural correlate of consciousness?
Where consciousness can be roughly defined as our experiences
What is the easy problem of consciousness?
Discovering the NCC because it is possible to discover connections between neural firings and experience
What is the hard problem of consciousness?
How do certain processes become perceptions ( seeing a person’s face or the color red?)
