1. Sensation and Perception

2. Sensory Involves everything we are exposed to
Our brains are designed to recognize and translate what we are used to
Our brain adapts to the environment around us (adaptation)

3. Sensory
Absolute Threshold: The amount of a stimulation needed for our brain to register its action
Sensation: The process of receiving info
Perception: Process of organizing the info

4. Sensation
Vision
- This is the most dominate of the senses that we posses
This is determined by the amount of white light that hits an object
- The “color” we see is the wavelength of the object AFTER the white light hits it.

5. Parts of the Eye
Cornea
- Covering in the front of the eye that contains fluid
Iris
- Colored part of the eye
- This is the muscle that allows the pupil to expand and contract, depending on how much light comes in through the

7. Parts of the Eye
Lens
- This helps focus the light as it comes into the eye
- If it is not in focus, then glasses
Retina
- This is the back of the eye
- This is where the rods and cones of the eye exist

9. Oh there are more parts of the eye to learn
Pupil
- This is the opening that appears black
- This can have light added to it, and you can see into the eyes
- Dr. Exam
- Redeye is caused because the light flashes into the eye, and then is reflected back

10. And More parts…
Rods
- This is what we use to see black and white in objects
Cones
- Used for colors and for sharpness
- If there is a deficiency in the cones, this is what causes color-blindness

11. The colors you see… All colors we see are made up of three colors
- Red, blue, and green
- They mix together to show us shades and colors
- The wavelengths of the object (reflected back at us) is picked up by cones
- Afterimages are an example of how you can saturate the cones in your eyes

12. Hearing Sound is really energy that our ears can detect
- There are several characteristics of sound, and they are…

13. Hearing 1. Pitch: The highs and lows of a sound
2. Timbre: The “texture” of the sound
- Difference between a C on a piano or a guitar
3. Intensity: This is how loud something really is
- Measured in decibels
4. Decibels: The scientific measurement of how loud a sound is
- Too loud, or too close, and the sound can actually kill sound receptors on the ear

14. Hearing
3. Intensity: This is how loud something really is - Measured in decibels 4. Decibels: The scientific measurement of how loud a sound is - Too loud, or too close, and the sound can actually kill sound receptors on the ear

16. Structure of the ear How do we hear?
Hair Cells!
The cells are in the Cochlea.
The Cochlea is also filled with fluid along with the Hair Cells
The Hair Cells have cilia at the end of them
The cilia are tuned to hear specific frequencies
- As the cilia moves, an electrical current is sent to the auditory nerve, in the brain, and the brain interprets what is being heard

17. Hair! The Hair Cells have cilia at the end of them
The cilia are tuned to hear specific frequencies
As the cilia moves, an electrical current is sent to the auditory nerve, in the brain, and the brain interprets what is being heard

19. Psychological effects of hearing
Our brain is used to hearing certain things and develops a conditioned response
E.g. recognizing familiar voices

20. Touch Cutaneous Sense - These receptors are broken into categories
- All of them are wired to the brain so we can tell what is going on
1. Pressure
2. Temperature
3. Pain

21. Smell This is also called olfaction This is purely a chemical reaction
There are cilia in your nasal cavity
- Once an odor attaches itself to the cilia, an electrical signal is sent to the olfactory bulbs which sends a signal to the brain

22. Can you smell that smell
Pheromones
- These are “odors” given out in the animal kingdom that alert animals to sexual desire
- more prevalent in animals

23. Tasty Taste is activated by taste buds on your tongue
- They are divided up into four groups
1. Salt
2. Sweet
3. Sour
4. Bitter

24. Taste
These combine, like the cones in an eye, to tell us what we are eating
The level of all of these tastes differ and change throughout our lives
- Small children do not usually like spicy foods, yet most adults like mustard
- As we get older, taste buds diminish and stronger foods are needed for the full effect of taste

25. Perception
Is the process by how we interpret all of the information that comes to us
- How do you react to situations that you are not used to?
Rely on experience and instant reactions
All of the sensations previously discussed also help with us dealing with our world

26. Perceptions
Size: we are used to seeing sizes and we use this memory to judge how far something away is.
- Ex: The size of a playing card and its distance away from you
Color: The color of something is already known, so we can “guess” the color of that item in different conditions
- Ex: Taking an apple from a bright kitchen to dark room

27. Perceptions
Brightness: The brain knows what it should be seeing, so it compensates when it sees something it does not understand
Shape: Once we know what a shape looks like, we can adjust its angle and still tell what it is.
Book laying down or standing up

28. Perceptions
Space: There are two types of motion, when we discuss space
1. Object motion (Other objects around us move)
2. Self motion (We move within our environment)
When you drive, subtle differences in motion are not always noticed because we combine the two
Major differences are seen, but they often come too late
- Brake lights
- Distractions while driving

29. Depth Perception
Is the ability to judge space between objects and tell how far/close they are
Retinal Disparity
Each eye sees a different image
The brain must combine these images so we can see correctly
If there is a loss of an eye, the brain does not know what to do with the loss of an image, so the brain creates an image

30. Perceptual Organization
Gestalt: A common region of something that we create
We use the similarity of objects to create images we expect to see
Proximity: Sometimes we group things together if they are close to each other
Closure; We can see an image even if the whole picture is not there

31. Illusions
These are pictures that the brain creates to help us understand what we are seeing
They are not mistakes of the brain, but the brain trying to decipher what is actually going on

32. Perceptual organizing
a. Figure + Ground --
1) Figure -- stands out
2) Ground -- it’s behind
What takes importance -- What does take precedent?
b. Grouping -- Gestalt -- Whole
1) Proximity – group near-by fixtures together
2) Similarity – group objects that are similar
3) Continuity – patterns are seen as smooth
4) Closure – fill in the gaps
5) Texture

33. Perceptual Processing
Top-Down – involves perceiving patterns as meaningful wholes (eg recognizing faces of people we know) without having to piece together parts
Based on acquired knowledge and experience with patterns
Bottom-Up – brain assembles specific features of shapes to form patterns that we can compare with stored images

34. Perceptual organizing --
c. Perceptual constancy
1). Consistent --Feature changes
2). visual size -- Closeness or far Retina threshold changes -- lens
(a). shape constancy
(b). bright constancy
III. Sensation/Perception/Consciousness

35. Depth Perception Cues
Binocular - cues provide depth information when viewing a scene with both eyes.
Monocular - cues provide depth information when viewing a scene with one eye. Includes:

36. Monocular Cues relative size - closer bigger
Height -- Horizon is farther
Interpositions -- Blocking = closer
Linear perspectives -- Lines RR
clarity – hazy = farther away
Light + Shadows - Depth texture

37. e. Motion e. Motion -- Structural
1). Accommodation - lens flexes more depth
2). Convergings - Rotation
3). Binocular -- Illusions Motion sickness
4).Motion + movement
(a). Looming - Approaching – faster; away - slow -- expansion of the stimuli -- Somatosensory – Vestibular balance
f. Illusions –
perceptual mistakes
Not a delusion. . . Thot quirk!