1. Sensation & Perception
How do we construct our representations of the external world?

2. Sensation & Perception
Sensation: the process of receiving information from the environment.
Perception: the process of assembling and organizing sensory information to make it meaningful.

4. Thresholds
Absolute Threshold: Minimum stimulation needed to detect a particular stimulus 50% of the time.
Proportion of “Yes” Responses
Stimulus Intensity (lumens)

6. Vision
Dominates the senses. We believe what we see first and then secondarily accept information from other senses.
Dominating other senses: video of man saying something

7. Hearing
How strong a sound is and when it arrives at one ear is contrasted by the brain with the strength and arrival time at the other ear.
The difference between them helps us locate where the sound is coming from.
Hearing: bolts
How does your brain help you figure out where the sound is coming from?

8. Touch: Cutaneous Sense
Three Cutaneous receptors
Records pressure
Records changes in temperature
Remains active continuously to record an injury or poison.
Activity with pennies in ice water.
Which Cutaneous receptors are being used in this experiment?

9. Olfaction: Smell
Most critical use for sense of smell is information about food heading towards the mouth.
Smell is more important in eating than taste.

10. Taste There are four types of taste receptors: Salt Sweet Sour Bitter
Skittles Test
What taste receptors are you using?
Is it harder to tell which skittle your eating when you plug your nose? Is this because smell and taste are interrelated?

11. Perceptional Organization
We often interpret things the way we think they should be, not the way they actually are.
Three principles:
Closure: process of filling in missing details.
Similarity: grouping like things together
Proximity: grouping together things that are near each other

12. Closure

13. Similarity

14. Proximity

15. Perceptual Adaptation
Your brain is able to adapt and adjust to abnormal situations.

16. Illusions Occur when we perceive something inaccurately.
Reversible figure: illusion in which the same object is seen as two alternating figures-first one, then the other.
The eye-brain mechanism keeps “changing its mind”

17. What do you see?