lecture four
Sensation and Perception
💡 sensation: how we take energy from the environment and turn it into
information we taste, see, hear, touch, etc.
Psychophysics -
sensation is the stimulation of sense organs
exception - synesthesia
same for everyone
perception is the selection, organization, and interpretation of sensory
input
uniquely subjective
qualia: understanding how one person subjectively sees the world
based on experiences, memories, and what we tell ourselves
our unconscious chooses what we select
organization is based on unconscious (dreams) experiences and
conscious experiences
interpretation occur naturally
Thresholds:
each sensory receptor is tuned to a particular form of energy
ie: auditory receptors in the ear code for sound changes but not light (light
is for visual receptors)
sensory systems require a minimum amount of energy to be activated -
absolute threshold
lecture four 1
, different for each person - some are very similar for everyone
JND - just-noticeable difference: (Weber) notes that the JND is a factor of
the original stimulus intensity - there’s a fraction of the amount of energy
you must add to notice a difference
sound: 1/10th
Each Weber fraction is different for each sense
the JND is the minimum difference in stimulation that is just noticeable
The Visual System
The Eye
eyes detect the electromagnetic radiation
light
all on a spectrum
the visible spectrum (white light)
technology is used to view light outside of the white light spectrum
allows for viewing colors represented by the waves - ROY G. BIV
cones in the eyes detect the colors due to their size
located in the center of the retina (fovea)
long - ROY
medium - G
short - BIV
wavelength (color) is measured from one peak to the other (hue)
amplitude measures the intensity of the color (brightness of light)
vision allows for the detection of movement and color
light detection (vision) is useful because:
light travels rapidly (faster than hearing)
lecture four 2
Sensation and Perception
💡 sensation: how we take energy from the environment and turn it into
information we taste, see, hear, touch, etc.
Psychophysics -
sensation is the stimulation of sense organs
exception - synesthesia
same for everyone
perception is the selection, organization, and interpretation of sensory
input
uniquely subjective
qualia: understanding how one person subjectively sees the world
based on experiences, memories, and what we tell ourselves
our unconscious chooses what we select
organization is based on unconscious (dreams) experiences and
conscious experiences
interpretation occur naturally
Thresholds:
each sensory receptor is tuned to a particular form of energy
ie: auditory receptors in the ear code for sound changes but not light (light
is for visual receptors)
sensory systems require a minimum amount of energy to be activated -
absolute threshold
lecture four 1
, different for each person - some are very similar for everyone
JND - just-noticeable difference: (Weber) notes that the JND is a factor of
the original stimulus intensity - there’s a fraction of the amount of energy
you must add to notice a difference
sound: 1/10th
Each Weber fraction is different for each sense
the JND is the minimum difference in stimulation that is just noticeable
The Visual System
The Eye
eyes detect the electromagnetic radiation
light
all on a spectrum
the visible spectrum (white light)
technology is used to view light outside of the white light spectrum
allows for viewing colors represented by the waves - ROY G. BIV
cones in the eyes detect the colors due to their size
located in the center of the retina (fovea)
long - ROY
medium - G
short - BIV
wavelength (color) is measured from one peak to the other (hue)
amplitude measures the intensity of the color (brightness of light)
vision allows for the detection of movement and color
light detection (vision) is useful because:
light travels rapidly (faster than hearing)
lecture four 2
