04/10/14 Hearing and Taste

• Parallel Processing
• Young- Heimholtz Trichromatic Theory
• Three types of cones:
1. Red 
2. Blue 
3. Green
• These three types of cones can make millions of combinations of colors.
• Most colorblind people simply lack cone receptors for one or more of these primary colors. 

• Opponennt- Process Theory
• The sensory receptors come in pairs.
• Red/ Green
• Yellow/ Blue
• Black/ White
• If one color is stimulated, the other is inhibited.
• Hearing- Out Auditory Sense
• The height of the wave gives us the amplitude of the sounds.
• The frequency of the waves gives is the pitch of the sound.
• Transduction in the Ear
• Sound waves hit the eardrum then anvil then hammer then stirrup then oval window. 
• Everything vibrates, then the cochlea vibrates.
• Membrane
• In basilar membrane there are hair cells.
• When hair cells vibrate they turn vibrations into neural impulses which are called organ of Corti. 
• Sent then to thalamus up auditory nerve.
• Place Theory
• Different hairs vibrate in the cochlea when there are different pitches. 
• SO Some hairs vibrate when they hear higher pitches and other vibrate when they hear low pitches. 
• Frequency Theory
• All the hairs vibrate but at different speeds.
• Deafness
1. Conduction Deafness- Something goes wrong with the sound and the vibration on the way up to the cochlea. 
• You can replace the bones or get a hearing aid to help.
• Nerve (Sensorineural) Deafness
• The hair cells in the cochlea gets damaged
• Loud noises can cause this type of deafness.
• No way to replace the hairs.
• Cochlea implant if possible.

• Smell and Taste
• We study both together because of sensory interaction the principle that one sense may influence another.
• Taste
• We have bumps on our tongue called papillae. 
• Taste buds are located on the papillae (they are actually all over the mouth)
• Sweet, salty, bitter, and sour.
• Umami- Flavor, meaty, savory taste.