H5, Sensation and perception
Pg 159 tm 166, Pg 173 tm 183, Pg 194 tm 197
How do we sense and perceive the world around us?
What we see, hear, taste, smell, or feel from touch results from brain processes that actively
construction perceptual experiences from sensory information. This constant conversation of
sensation to perception allows us to adapt to the details of our physical environments.
5.1 sensory information is translated into meaningful signals
Sensation: the detection of physical stimuli and the transmission of this information to the brain
Perception: the processing. Organization, and interpretation of sensory signals in the brain.
Perception results in our conscious experience of the world. Whereas the essence of sensation is
detection, the essence of perception is the construction of useful and meaning full information about
a particular sensation.
Sensation and perception are integrated into experience. At the same time, experience guides
sensation and perception. In other words, the processing of sensory information is a two-way street.
Bottom-up processing: perception based on the physical features of the stimulus.
As each sensory aspect of a stimulus is processed, the aspects build up into perception of that
stimulus.
Top-down processing: the interpretation of sensor information based on knowledge, expectations,
and past experiences.
Context affects perception, what we expect to see influences what we perceive.
, • Transduction
Our sensory systems translate the physical properties of stimuli into patterns of neural impulses. The
different features of the physical environment are coded by activity in different neurons.
Transduction: the process by which sensory stimuli are converted to neural signals the brain can
interpret.
Transduction involves specialized cells in the sense organs called sensory receptors. The sensory
receptors receive stimulation, physical stimulation in de case of vision, hearing, and touch and
chemical stimulation in the case of taste and smell.
The sensory receptors than pass the resulting impulses to the brain in the from of neural impulses.
With the exception of smell, most sensory information first goes to the thalamus. This information is
projected from the thalamus to a specific region of the cerebral cortex for each sense.
• Quality versus quantity
To function affectively, the brain needs qualitative and quantitative information about the stimulus
Qualitative information consists of the most basic qualities of a stimulus.
Quantitative information consists of the degree, or magnitude, of those qualities.
If you were approaching a traffic light, qualitative information might include whether the light was
red or green. Regardless of the color, quantitative information would include the brightness of the
light.
Sensation and perception result from a symphony of sensory receptors and the neurons those
receptors communicate with. The receptors and neurons fire in different combinations and at
different rates. The sum of this activity is the huge range of perceptions that make up our experience
of the world.
Pg 159 tm 166, Pg 173 tm 183, Pg 194 tm 197
How do we sense and perceive the world around us?
What we see, hear, taste, smell, or feel from touch results from brain processes that actively
construction perceptual experiences from sensory information. This constant conversation of
sensation to perception allows us to adapt to the details of our physical environments.
5.1 sensory information is translated into meaningful signals
Sensation: the detection of physical stimuli and the transmission of this information to the brain
Perception: the processing. Organization, and interpretation of sensory signals in the brain.
Perception results in our conscious experience of the world. Whereas the essence of sensation is
detection, the essence of perception is the construction of useful and meaning full information about
a particular sensation.
Sensation and perception are integrated into experience. At the same time, experience guides
sensation and perception. In other words, the processing of sensory information is a two-way street.
Bottom-up processing: perception based on the physical features of the stimulus.
As each sensory aspect of a stimulus is processed, the aspects build up into perception of that
stimulus.
Top-down processing: the interpretation of sensor information based on knowledge, expectations,
and past experiences.
Context affects perception, what we expect to see influences what we perceive.
, • Transduction
Our sensory systems translate the physical properties of stimuli into patterns of neural impulses. The
different features of the physical environment are coded by activity in different neurons.
Transduction: the process by which sensory stimuli are converted to neural signals the brain can
interpret.
Transduction involves specialized cells in the sense organs called sensory receptors. The sensory
receptors receive stimulation, physical stimulation in de case of vision, hearing, and touch and
chemical stimulation in the case of taste and smell.
The sensory receptors than pass the resulting impulses to the brain in the from of neural impulses.
With the exception of smell, most sensory information first goes to the thalamus. This information is
projected from the thalamus to a specific region of the cerebral cortex for each sense.
• Quality versus quantity
To function affectively, the brain needs qualitative and quantitative information about the stimulus
Qualitative information consists of the most basic qualities of a stimulus.
Quantitative information consists of the degree, or magnitude, of those qualities.
If you were approaching a traffic light, qualitative information might include whether the light was
red or green. Regardless of the color, quantitative information would include the brightness of the
light.
Sensation and perception result from a symphony of sensory receptors and the neurons those
receptors communicate with. The receptors and neurons fire in different combinations and at
different rates. The sum of this activity is the huge range of perceptions that make up our experience
of the world.
