5. Sensation Flashcards
(41 cards)
What is sensation?
Sensory organs react to stimuli
What is perception?
Make meaning of the stimuli
What are the 3 basic elements of sensation?
- Reception of incoming stimuli from our environment (Each person has a different sensitivity to the stimuli e.g. oriental women are best at tasting)
- Transduction of those stimuli to electrical stimuli that the brain can read
- Process –> human experience
What is an absolute threshold? Give an example
The smallest amount that we can detect e.g. dog has lower threshold in smell and sound that us
What is a difference threshold?
Detect change: just noticeable difference
What is Weber’s law?
It determine the SMALLEST amount of change we can detect: ORIGINAL STIMULA X CONSTANT
Name weber’s constant for…
a) saltiness of food
b) pressure on skin
c) loudness of sounds
d) Odor
c) heaviness of weights
A) 1/5 B) 1/7 C) 1/10 D) 1/20 E) 1/50
A stone weighing 100g is placed in your hand. How much would a second stone need to weigh for you to know it was lighter?
2 g
o Your dad asks you to turn DOWN the volume of your television. The television is presently set at 80 db. You lower the volume to 75 db. Will dad be satisfied?
No (need 1/10)
What does signal detection depend on? (3)
The stimuli itself
Background “noise” (what is interfering (e.g. where’s waldo)
Biological and physiological state of the receiver
What is sensory adaptation? Give examples
Sensory adaptation is the process in which changes in the sensitivity of sensory receptors occur in relation to the stimulus. All senses are believed to experience sensory adaptation.
you never notice the music at the grocery store until it stops playing
You go into the hot bath, hurts at the beginning but then you accommodate to it
What is transduction? Give an example
the conversion of physical energy we tale in… into ELECTRICAL input that the brain can interpret
E.g. sound waves (pressure) enter our auditory system and must be converted into electrical impulses
Where does transduction occur for vision?
o the conversion of light waves into electrical impulses occurs in the RETINA at the back of the eye
o Light sensitive cells (receptors – rods and cones) are activated and release chemicals… these chemicals convert the light energy into ELECTRICAL IMPULSES
Where are electrical impulses relayed for vision after transduction occurs?
Impulses are relayed to GANGLIONIC cells whose axons form the OPTIC NERVE
Optic nerve –> Lateral Geniculate Nucleus (LGN) of the thalamus –> Visual cortex
Visual cortex has FEATURE DETECTORS: Specialized cells
Builds “picture” ——- and moved forward to understand what has been seen
What do rods do?
Rods can give us vision in light but cannot read wavelengths
What is the blind spot?
blind spot: optic nerve attached to retina (no rods or cones there). If the light hits there –> blind spot
What in the eye is needed for color vision?
color vision: RODS and CONES in the retina: only the cones ‘read’ wavelength, but NEED LIGHT in order to fire
What are the 2 theories of color processing? Explain them.
- Trichromatic Theory: Colour is a MIX of: Red, Blue, Green
- Opponent Process Theory: Cells fire to signal color – causes a decrease in the firing rate of its opposite colour:
a. RED —-> Green
b. BLUE —> YELLOW
What is color based on? Give examples
the characteristics of the waves Short, frequent waves: Bluish colour Long, low frequency waves: Red colour High waves: Bright colors Low, flat waves: Dull colors
What determines the sense we hear?
Characteristics of the sound waves.
Height of wave: LOUDNESS
Frequency of wave: PITCH
What are the 3 stages of hearing?
OUTER EAR
MIDDLE EAR
INNER EAR
What is included in the outer ear?
Eardrum
What is included in the middle ear?
Hammer
Anvil
Stirrup
What is included in the inner ear?
Cochlea
