Unit 5 | Sensation and Perception

• Perception


  The process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.
• Sensation


  The process that allows our brains to take in information through our five senses, which can then be experienced and interpreted by the brain.
• Transduction


  Conversion of one form of energy into another, as when environmental stimuli are transformed into neural signals.
• Bottom-Up Processing

  When the brain processes sensory information and uses clues to understand stimuli. The stimulus itself shapes our understanding of it.

  • Sensation is bottom-up processing
• Top-Down Processing


  How our brains make use of information that has already been brought into the brain by one or more of the sensory systems.

  • Perception is top-down processing
  • The Stroop Effect is top-down processing (automatically recognize the word before using their senses to understand what the color is)
• Trichromatic Theory


  There are three types of cones in the retina that detect blue, red, and green. When combined in different ways that's what makes the colors we see.
• Opponent-Process Theory


  Sensory receptors in the retina are arranged in pairs, red/green, yellow/blue, and black/white. If one sensor is stimulated, its pair is inhibited from firing.
• Absolute Threshold


  The smallest amount of stimulation needed for someone to detect it 50% of the time.
• Figure and Ground


  The tendency of our visual system to place some objects into focus and others into the background
• Vitreus Humor

  Clear gel-like fluid that allows light to pass through the eye.
• Retina


  The surface on the back of the eye that is sensitive to light and contains the photoreceptors required for vision.
• Fovea


  A small depression in the retina where retinal cones are densely located.
• Cones


  Photoreceptors that allow for color vision. They require moderate to bright light, and can have great detail.
• Rods


  Photoreceptors that allow for black, white, and grey vision. They can be activated in lower light but do not have great detail.
• Bipolar Cells


  Cells in the visual system that connect the photoreceptors (rods and cones) to the ganglion cells.
• Ganglion Cells


  Cells in the retina that receive visual information from the photoreceptors and pass the information onto the brain.
• Optic Nerve


  The bundle of ganglion axons that leave the back of the eye and send information to the brain to allow for vision.
• Blind Spot


  A small area in the retina of the eye where there are no photoreceptor cells , resulting in the lack of visual perception.
• Light Wavelength


  The wavelength of a light Wave affects the color/hue of what you see.
• Light Amplitude

  Light Wave amplitude affect the intensity of the color that you see. (Brightness)
• Proximity


  Grouping items close together.

  • People standing together will be percieved as a group.
• Continuity


  Perceiving a continuous line even when it's interrupted. This goes for patterns as well.

  • A teacher's classroom being expected to stay the same.
• Closure


  Gaps are filled to create a whole, complete object.

  • When hearing only a portion of a conversation, we'll try to fill in the gaps.
• Retinal Disparity


  The brain compares images from both of the retinas, and the greater the difference in images, the closer the object.
• Monocular Cues


  Depth cues available only to each eye sepeately.
• Binocular Cues


  Depth cues that depend on both eyes.
• Phi Phenomenon


  The brain perceived continuous movement in a series of rapid slightly varying images.

  • The perception of motion is created by two or more adjacent lights blinking on and off in quick succession.
• Relative Height


  Objects higher in the field of vision appear farther away.
• Relative Motion


  Objects that are stable appear to move when we are.
• Relative Size


  If assumed 2 objects are similar in size, the smaller image is perceived as farther away.
• Linear Perspective


  Parallel lines appear to meet in the distance.
• Interposition


  If one object partially blocks our view of another, we perceived it as closer.
• Light and Shadow


  Shading produces a sense of depth consistent with our assumption that light comes from above.
• Color Constancy


  Objects are perceived as unchanging in color, even if illumination alters the wavelengths reflected by the object, because of our underlying understanding of the object's color.
• Brightness Constancy


  The object is perceived as having a constant brightness even while it's illumination varies.
• Shape Constancy


  The form of familiar objects are constant even while our retinas receive changing images of them.
• Size Constancy


  Objects are perceived as having a constant size, even while our distance from them varies.
• Amplitude of Waves


  A physical characteristic of sound that determines the loudness of sound waves. (Height of Waves)
• Frequency of Sound Waves


  One of the physical characteristics of sound that involves the length of the waves determining the pitch of it.

  • Long waves have low frequency, short waves have high frequency.
• Path of Sound Waves Through the Ear


  1. Outer Ear
  2. Auditory Canal
  3. Eardrum
  4. Middle Ear (three tiny bones)
  5. Basilar Membrane (outer membrane of the cochlea)
  6. Nerve Cells (axons form the auditory nerve)
  7. Hair Cells (Lines the surface of the basilar Membrane)
  8. Auditory Nerve
  9. Auditory Cortex of the temporal lobe