Sensation+Perception (Module 2 Ch 4) Flashcards
Memorize by October 10th (100 cards)
Psychophysics
The study of sensation and perception
Sensation
The interaction between your environment and your sense organs
External, objective, occurs first
Perception
Your brain processing, organizing, and interpreting sense information
Internal, subjective, occurs second
Transduction
The time from when the sense information leaves the sensory organ until it reaches the brain
The conversion of physical stimuli into neural impulses or info
Just Noticeable Difference
The smallest change in a stimulus for you to be able to notice that the stimulus has changed
Weber’s Law
The just noticeable difference isn’t fixed, so a stronger stimulus requires a stronger change
Absolute Threshold
How much of a stimulus is required for you to say that the stimulus exists
Differs from person to person
Introverts and people with autism and/or depression tend to be more sensitive (lower absolute threshold)
What is the difference between Just Noticeable Difference and Absolute Threshold?
Looking for change vs looking for existence
Sensory Adaptation
Our sensitivity diminishes when we have constant stimulation
This ensures we notice changes in stimulation more than stimulation itself
What does stimulus detection theory involve?
Stimulus intensity/strength, noise/distraction, and response criteria (how confident you have to be to say yes)
What are the four different responses to a stimulus?
Hit: stimulus + say it exists
Correct Rejection: no stimulus + say there’s no stimulus
False Alarm: no stimulus + say there is
Miss: stimulus + you say there isn’t
What does Liberal vs Conservative mean in terms of response criteria?
More likely to say it exists than doesn’t exists, leading to more false alarms vs more likely likely to say a stimulus doesn’t exists even if it does, leading to more misses
Bottom-Up Processing
Starts at the sensory receptors and works up to higher levels of processing (starting with the data and working up to the knowledge)
Requires more cognitive resources, but tends to be more accurate
Top-Down Processing
Starts at our knowledge or expectations, which influences how we process or perceive the data
Easier but is more likely to be wrong
What is the strongest, most dominant sense in humans?
Vision
Light vs Color
The physical stimulus for vision (which hits us in waves) vs the subjective experience of vision
Wavelength
The distance from one point on a wave to the same point on the next wave
Vision: shorter = cooler, longer = warmer
Frequency
The amount of waves in a given period
Sound: higher frequency = higher pitch
Amplitude
The height of the tallest point of the wave to the lowest point of the wave
Vision: lower = pastels, higher = darker
Sound: lower = quieter, higher = louder
Cornea
The external layer of the eye, whose main purpose is protection
Pupil
The black hole at the center of the eye, where no light reaches
Iris
A muscle in the eye designed to change the shape/size of the pupil, making it larger in low conditions and smaller in bright conditions
Lens
The circular object behind the pupil that focuses the light through the fluid of the eye and onto the retina
Accommodation (in vision)
When the shape of the lens changes depending on where you want to focus your vision