Lecture #12: Sensory systems Flashcards
Sensory systems
Focus on intensity and quality
Intensity
How we perceive a low-level stimulus (Ex: soft sound) from a high-level stimulus (Ex: loud sound)
Quality
How we perceive different varieties of stimulation (Ex: different musical notes)
Sensation
Detection of sensory stimuli
Perception
Meaningful interpretation of sensory information
Taste
Chemical (molecules) bind to a taste receptor cell
- causes a DEPOLARIZATION in the taste receptor cell
- causes neurotransmitter to be released which binds to the sensory neuron
- causes the sensory neuron to send (change) nerve impulses sent to brain
- brain processes info –> decision
Receptors
sensory receptor cells receive a stimulus
Transduction
change stimulus energy into nerve impulses
Transmission
Sending the nerve impusles to the brain
Integration (processing)
Decision-making (occurs in CNS)
Motor output
Response
How to increase intensity?
- Increase the rate of firing of individual sensory neurons toward brain
Ex: default rate –> 1/sec —> 3/sec —> 5/sec
no sweetness ——–> sweeter - Increase the number of sensory neurons that increase rate of firing
- Does NOT change the voltage of an individual action potential (all or none)
What is quality?
Flavors
- have 5 basic taste types: sweet, sour, Umami (savory), bitter, salt
1. vary the relative contribution from the basic taste types
2. combine info from taste with input from olfaction
Cornea
outside layer, bends light but is not adjustable
Lens
bends light and is adjustable by use of ciliary bodies
