Sem 2 Weeks 4-8 Flashcards
(177 cards)
Transduction
getting sensory info to the brain
Perception
process of taking neural signal and creating a psychological reality
How do chemicals become smell
Chemicals do not become a smell until they attach to a receptor in the nose, and the nose takes the chemical, generates an action potential, and the brain creates the feeling of the small
Why can humans only see a small portion of the electromagnetic spectrum
Large waves go around objects, small waves go through objects, and visible spectrum waves bounce off objects - this is the “sweet spot” in the electromagnetic spectrum that contains waves that we can see.
What does temperature translate to in the physical world
Kinetic energy
What does colour translate to in the physical world
Wavelength
What does texture translate to in the physical world
vibration
What does aroma translate to in the physical world
Smell
What does pitch translate to in the physical world
Frequency
What does loudness translate to in the physical world
Amplitude
What does pain translate to in the physical world
Tissue damage
Absolute threshold
How low can you go (how quiet, how dim, how soft)
Discrimination threshold
Can you tell the difference (how big does the difference have to be for you to tell that two things are actually different from each other)
Signal Detection Theory
Allows us to separate sensitivity from response bias
Sensitivity
How well can you distinguish between when the stimulus is present or absent. Sensitivity means you have a high hit rate AND a low false alarm rate
Response Bias
Some participants are biassed towards saying either yes or no
Just Noticeable difference
The amount something must be changed in order for a difference to be noticed.
The discrimination threshold increases proportionally to baseline/reference stimulus increases (must be 8% more intense)
How do we translate light into vision
Rod and cone receptors captures photons, which triggers a change in the polarity of its membrane which causes the photoreceptor to generate an action potential (electrical signal that the brain can interpret)
Rods
- Many rods
- Mostly in the periphery.
- Respond to light of all
- High sensitivity (good in dim light, respond to everything)
- Low resolution (fuzzy in the periphery)
Different cone wavelength sensitivity related to colour
- S-cones, short waves, blue
- M-cones, medium waves, green
- L-cones, long waves, red
Cones
- Centred in the middle of the retina (fovea)
- Respond to different wavelengths (red/green/blue)
- High resolution
- Low sensitivity (doesn’t work well in bad lighting - needs a lot of photons to activate)
Why is Peripheral vision colourblind
no cones are in the periphery and rods are colourblind
Trichromatic Theory
Colour perception is mediated by cones which are wavelength specific (therefore colour specific). Your brain perceives colour based on the combination of photoreceptors that are activated at a specific location.
Monochromat vs dichromat
2 types of colour blindness, mono = only 1 type of cone. di = 2 types of cone (more common)