PSYC 2390 Lecture : methods, refractory period, psychophysics(part)
17 Jan 2012
School
Department
Course
Professor
Document Summary
Refractory period: means a delay between one action potential and the next. Sets upper limit of ap/second (500-800 action potentials/ second. Graded response: not enough stimulation to reach action potential. For a small amount of time, sodium is let into the axon. Graded potentials can be big or small, action potentials are always the same. Spontaneous activity: action potentials that occur without stimulation. When an action potential travels down the axon, it reaches the synaptic vesicle (which holds neurotransmitters) where it then jumps the synaptic gap and reaches the receiving neuron. Excitatory effect -increases probability that receiving neuron will have an action potential (after jumping synapse) In a living organism, there is already spontaneous activity. Found in the brain and areas of the body, used in-between areas of nerves and musclces. When it is picked up by a receiving neuron, it increases rate of ap per second.
