Sensation and Perception

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Chapter 8

• Sensation and Perception

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What is Sensation?

• Sensation What occurs when a stimulus activates
  a receptor.
• Perception The organization of sensory
  information into meaningful information.
• Psychophysics The study of the relationships
  between sensory experiences and the physical
  stimuli that cause them.

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Threshold

• Absolute Threshold The weakest amount of a
  stimulus that a person can detect half the time.

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Sensory Differences and Ratios

• Difference Threshold The smallest change in a
  physical stimulus that can be detected between
  two stimuli.
• Webers Law The principle that the larger or
  stronger a stimulus, the larger the change
  required for an observer to notice a difference.

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Sensory Adaptation

• Which line is longer?

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Signal-Detection Theory

• Signal-Detection Theory The study of peoples
  tendencies to make correct judgments in detecting
  the presence of stimuli.

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The Senses
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Vision

• Pupil The opening in the iris that regulates
  the amount of light entering the eye.
• Lens A flexible, transparent structure in the
  eye that changes its shape to focus light on the
  retina.
• Retina The innermost coating of the back of the
  eye, containing the light-sensitive receptor
  cells.
• Optic Nerve The nerve that carries impulses
  from the retina to the brain.

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Light
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Color Deficiency
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Binocular Fusion

• Binocular Fusion The process of combining the
  images received from the two eyes into a single,
  fused image.
• Retinal Disparity The differences between the
  images stimulating each eye.

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Hearing

• Auditory Nerve The nerve that carries impulses
  from the inner ear to the brain, resulting in the
  perception of sound.

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The Pathway of Sound
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Deafness
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Balance

• Vestibular System Three semicircular canals
  that provide the sense of balance, located in the
  inner ear and connected to the brain by a nerve.

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Smell and Taste

• Olfactory Nerve The nerve that carries smell
  impulses from the nose to the brain.

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The Skin Senses
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The Body Senses

• Kinesthesis The sense of movement and body
  position.

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Perception
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Principles of Perceptual Organization

• Gestalt The experience that comes from
  organizing bits and pieces of information into
  meaningful wholes.

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Figure-Ground Perception
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Perceptual Inference
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Learning to Perceive
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Subliminal Perception
Subliminal Messages Brief auditory or visual
messages that are presented below the absolute
threshold.
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Depth Perception
Depth Perception the ability to recognize
distances and three-dimensionality.
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Monocular Depth Cues

• Motion Parallax the apparent movement of
  stationary objects relative to one another that
  occurs when the observer changes positions.

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Constancy

• Constancy The tendency to perceive certain
  objects in the same way regardless of changing
  angle, distance, or lighting.

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Illusions

• Illusions Perceptions that misrepresent
  physical stimuli.

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Extrasensory Perception

• Extrasensory Perception (ESP) An ability to
  gain information by some means other than the
  ordinary senses.