refers to the process by which sense organs gather information about the environment and transmit it into the brain for initial processing.
refers to the closely related process by which the brain selects, organizes, and interprets sensations.
Psychophysics studies the relationship between
the physical world
psychological experiences
physics and psychology
psychological and physical science
Specialized cells that all sensory systems contain are called .
Sensory cells
respond to environmental stimuli
tell your body that danger is coming because they know what you are seeing and hearing
typically generate action potentials in adjacent sensory neurons
take energy from the environment and turn it into neural impulses that are sent to the brain
Within each sensory modality, the brain codes sensory stimulation for
intensity
perception
quality
emotion
The common features of the senses are that they
must translate physical information into sensory signals
all have thresholds below which a person does not sense anything
require constant decision making (mostly unconscious)
are able to detect changes in the environment
allow the body to adapt to light various noises in the room
tell the body to move when a car is coming
make it easier for you to see in the dark
The absolute threshold refers to the maximum amount of physical energy (stimulation) needed for an observer to notice a stimulus.
❌ A candle flame 30 miles away on a dark, clear night. ❌ A watch ticking 20 feed away in a quite place ❌ A drop of perfume in a six-room house ❌ A teaspoon of sugar in 2 gallons of water ❌ A wing of a fly falling on the chichi from a height of a centimeter
refers to the lowest level of stimulation required to sense that a change in stimulus has occurred.
is the smallest difference in intensity between two stimuli that a person can detect.
JND explained in relation to a stimulus can be shown as
more intense existing stimulus needs a larger change
more intense existing stimulus needs a smaller change
less intense existing stimulus needs no change
more intense existing stimulus needs the same amount of change
This law states that regardless of the magnitude of two stimuli, the second must differ by a constant proportion from the first for it to be perceived as different.
Fechner's Law
Weber's Law
Steven's Power Law
The law of perception
This law holds that the physical magnitude of a stimulus grows logarithmically as the subjective experience of intensity grows arithmetically... So people subjectively experience only a small percentage of actual increases in stimulus intensity.
Fechner's law
The law of sensory perception
This law states that subjective intensity grows as a proportion of the actual intensity raised to some power... So sensation increases in a linear fashion as actual intensity grows exponentially.
The law of adaptation
is the tendency of sensory systems to respond less to stimuli that continue without change.
An example of Weber's law is that if you are holding a 50 lb bag it only takes one pound to be perceived as different. If you are holding a 100 lb bag it only takes 2lb. So 1:50 ratio.
An example of Steven's power law is that if there is more pain, there is less addition intensity required for a JND.
An example of Fechner's law is your ears adapting at a concert or the eyes to the lighting from the sunlight to the lighting in a movie theatre.
The three basic principles that apply across all of the senses are:
No one to one correspondence between physical and psychological reality
They are active, not passive
They are adaptive
They are passive, not active
They have a known correspondence between physical and psychological reality
The process of converting physical energy or stimulus information into neural impulses is called .
