Sensation and Perception
We construct our perception and assemble information to give us our perception. Perception is also
important for understanding creativity and art.
We put our creativity into a simple picture and see it in multiple ways.
We create ideas in our head. Perception is a creative act. Perception is assembled.
Perception is activity and is input of sensory information. All perception is an act.
(Fechner) Some days the subject would see the light of a candle right away and the other days, they
wouldn’t see it right away and the candle would have to be brighter for the subject to see.
Individuals fluctuated and changed a lot. No absolute threshold. 50% of the time the subject would see
Thresholds in psychophysics are defined as the probability of a subject responding.
Weber found that regardless of which senses you were stimulating, there was a constant finding. People
would notice the difference between 2 stimuli being different if they were 1 1/30 or greater different
from each other. This is called Weber’s Law.
Fechner’s law: States that if you have a completely dark room and if you turn on a 60W light bulb, there
will a major difference in brightness. If you keep turning on another bulb, there will not be a huge
difference in brightness. The further you are away from an absolute threshold, the less there will be a
Signal Detection Theory: In terms of perception being governed by intelligence and involves decision
making. There are four possibilities in SDT. Hit (really there and you see it), False alarm (if you say it’s
there but it’s not there), Miss (you say it’s not there but it is there), and finally there is Correct Rejection
(You say it’s not there and it isn’t there. You can raise your criteria if it is important or not to you. If you
order a pizza and are hungry, you will hear the doorbell. If you are not hungry, you might not hear the
Perception without Awareness (Subliminal Perception): Perceiving things without being aware of it.
Example: “EAT POPCORN!” message flashing during intermission of movies. People tend to buy popcorn
even though they are not aware of the message
Sensory Adaptation: People tend to ignore sounds such as ventilation sounds and lights buzzing. When
you stop noticing the noise, you can say you adapt to not listening to it. You’re body gets used to not
listening to it and you ignore it.
Visual System: Eyes and brain react to an energy source such as light. The light hits our retina, and it
turns into neuro impulses. If you something right side up, it will be viewed as upside down at the back of your eye because you’re eye is concavely shaped. You’re perception allows you to reconstruct the image
as it would be right side up.
When you stare at something, you’re eye has tiny little motions that keep the image in front of you
moving to keep the image in front of you visible.
Retina: Absorbs light, processes images, and sends visual information.
The optic disk is a spot in the eye that has no neurons that re