SENSES
I. All input to the brain is action potentials!
It is not important to detect the environment accurately;
It is only important to respond to the environment appropriately.
A. How can the brain 'know' that the lights are on, that someone is touching your ear, that the food one is eating is an orange and not a pear, ... if all of this information is in the form of action potentials (of all approximately equal size and shape)!??
1. Wiring - a particular neuron goes to a particular area of the brain. When that area receives signals you know (presume) that that particular neuron was stimulated.
2. Different areas will process the information differently. For example the optic lobe of the brain is particularly good at putting together images.
B. How can the brain 'know' that the lights are bright, that someone is pinching your ear versus caressing it, that the coke is warm, ... if all of this information is in the form of all-or-none action potentials!??
1. Wiring- stronger threshold sensory cells go to a different location than weaker ones.
2. Frequency. A cell that is stimulated more will generate more action potentials per unit time.
II. Signals are often modified before the actual sensor turns the signal into an action potential.
A. Ear- tympanic membrane, bone vibration, cochlea, before actual hairs are vibrated to generate action potentials.
B. Photodetection.
1. Pupil modifies the amount of light that hits the retina so that the signal input is not linear.
2. The image is focused onto the retina saving the brain a lot of effort from deciphering unfocused images.
APPLE DISK 111: Color Perception 5 5 86
Use "Paddle Check" to make sure the photoresistors are working. (PDL(0) is not connected).
Use colored cellophane from Edmunds.Using room lights is all that is needed. Set the colored cellophane right on the surface of the sensors.
I used channel 34. Hooked in through UHF. I circumvented the game box and used a banana clip directly onto one UHF terminal. (Use Gony setup if you have problems)
Run color perception 5 5 86. Block off all light and press return when it says to.
Press space bar when ever it is introduced to a new color.