Sensation + Perception Flashcards
Define sensation
Gathering sensory information from the environment
Define perception
psychological/mental organisation + interpretation of sensory info
What are the two ways we process sensory info?
- bottom-up processing
2. top-down processing
Describe bottom-up processing
- based on physical features of the stimulus
- as each aspect is processed, our perception builds up
Describe top-down processing
- information processing guided by higher-level mental processes (i.e. what we expect to see)
- based on our past experiences/expectations
What are the 4 elementary tastes?
- sweet
- salty
- sour
- bitter
( and umami )
What are umami receptors and what do they do?
- fat/glutamate receptors
- they enhance the flavours
What is transduction?
changing the physical simulus into a neural signal
Describe the 4 steps in transduction
Physical > receptor organ > receptor > neural signal
How does Taste transduction occur?
By having a food chemical react with a taste bud
Describe the steps leading up to taste transduction
- chemicals dissolve in saliva
- find their way into fungiform papillae
- each F. Papillae contains specialised taste buds
- food enters taste buds = action potentials
For each taste there is a _____?
Different type of taste bud
What is sensory interaction?
When one sense influences another
What is synaesthesia?
when one sense is simultaneously experienced with another.
- normally people experience one
What’s special about non-tasters + supertasters?
non-tasters: have fewer taste buds than normal
super-tasters: have more taste buds than normal
What impacts differences in perception?
- cultural differences
- individual histories differ [ex. food you prefer are probably determined by upbringing]
What is stability provided by?
the vestibular system
Where is the vestibular system located?
In the middle ear
The vestibular system provides us with: _____?
the ability to balance and maintain posture
What are the 5 aspects of visual info processing?
- scene
- retinal processing
- feature detection
- abstraction
- recognition
What is light?
the physical stimulus for vision
What is the eye designed to do?
take incoming light rays + focus them so they hit the retina
describe the Lens [4 points]
- transparent
- flexible
- convex
- performs 20% of refraction
What is accommodation?
process where the ciliary muscles (attaches to lens) changes the shape of the lens
- this brings the image into focus
Describe the retina [3 points]
- light sensitive inner surface
- has 2 types of photoreceptors: rods + cones
- layers of neurons that begin visual info processing
What do rods do?
- greatly increase visual sensitivity
» ability to see in many light levels
» low levels to bright levels
What do cones do?
Detect differences in details
Where are the rods found?
in the sides, NOT FOVEA
Where are cones found?
In the fovea, NOT THE SIDES
What is colour-deficient vision caused by?
- missing 1 type of photo pigment
OR - an atypical proportion of 3 cone types
- genetically based
What is acuity?
- lack of convergence in the cones/fovea
- can distinguish one point from another
What is sensitivity?
the convergence or pooling of info in rods/periphery
What happens when the rods converge?
- can’t discriminate 2 stimuli
What can’t you perceive?
things that aren’t in the real world
What specific features do neurones in the brain respond to? [4]
- shape
- angle
- intersections
- movement
Describe the Nasty Contact Lens study
- Pritchard et al
- stabilised retinal image to fatigue feature detectors
Conclusion from the Nasty Contact Lens study?
- Humans have feature detectors
What are Gestalt Principles?
the idea that the whole is MORE THAN the sum of the parts
What do Gestalt principles help us to do?
make sense of ambiguous inputs
What is perceptual organisation?
the tendncy to integrate pieces of information into meaningful wholes
Define ‘grouping’
the perceptual tendency to organise stimuli into coherent groups
What are the 6 key things for grouping?
- simplicity
- closure
- continuity
- similarity
- proximity
- common fate
What is the symmetry rule?
symmetric shapes = better figures
What is the lower region rule?
regions @ the bottom = better figures
What are the 2 aspects of depth perception?
- monocular rules
- binocular rules
What are the 4 aspects of monocular rules?
- linear perspective: converging lines on horizons points
- texture gradient: fewer, learger units = closer
- interposition: closer in front
relative height: lower objects are closer
What is binocular disparity?
> > space between the eyes - each eye registers a slightly diff view of the world
these differences provides brain w important direct info
