Sensation与perception的区别
Intro to psychology Chapter 4 -sensation |
Sensation
Sensation与perception的区别
Definition
Psychological
fundamental,raw experiences
Biological
involves the sense organ,the neural pathway
Threshold sensitivity
Absolute threshold
the minimun intensity
detection
Difference threshold
jnd
discrimination
suprathreshold sensation
Signal detect theory
‒Theory of how people detect signals
‒The theory is based on the idea that signals are always embedded in noise, and thus the challenge is to distinguish signal from noise
Signal
important information
Noise
unimportant information
Vision
stimuli is light
electromagnetic energy
Visual system
Form the image
the cornea
The cornea is the transparent front surface of eye:Light enters here, and rays are bent inward by it to begin the formation of the image.
the lens
The lens complete the process of focusing the light on the retina.To focus on objects at different distances, the lens changes shape.(accomodation)
not flat enough
myopic(near-sighted)
not spherical enough
hyperopic(farsighted)
the pupil
The pupil change size in different level of light, thereby helping to ensure that enough light passes through the lens to maintain image quality at different light levels.
largest in dim light
smallest in bright light
Transduction system
Absorption of light by photo pigments in receptors starts transduction process neural impulse travels to brain via neurons.
Rods
For seeing at night
cannot distinguish details
periphery
Cones
For seeing during the day
can distinguish details and work for color vision
fovea
Dark adaptation
Process that leads to increased sensitivity to light after being in the dark.
The pupil changes size
Photochemical changes in the receptors
dark adaptation curve
Seeing color
Color
short wavelength
blue
medium wavelength
green
long wavelength
red
Color mixture
metamers
Color theory
Trichromatic theory
3 types of receptors
short-wavelength cones
medium-wavelength cones
long-wavelength cones
receptor level
explains color deficiencies
Dichromats
Monochromats
Opponent-color theory
2 types of color-sensitive units
red green
blue yellow
neural level
afterimages
color deficiency
red&green
Sensory coding
temporal pattern
number of neurons activated
Audition
Stimuli
air-pressure change
Auditory system
Amplify and transmit the sound to the receptors
Transduce the sound into neural impulse
Theories
Temporal theory
low-frequency tones
time
Place theory
high-frequency tones
basilar membrance