Sensation and Perception

• What are the main components of visual sensation?

  • Sense organs
  • Light
  • The eye
  • The retina
• What do specialized sense organs do?

  They process sensations from different stimuli.
• How does the eye respond to stimuli?

  The eye responds to light.
• What is transduction in the context of sensation?

  It is the transformation of environmental stimuli into neural impulses.
• What is the range of visible light that humans can see?

  Approximately 400 to 700 nanometres.
• How are changes in wavelength of light perceived?

  As changes in colour.
• What part of the eye focuses light onto the retina?

  The cornea.
• What is the function of the retina?

  It processes visual stimuli and contains specialized neurons.
• What are the two types of photoreceptor cells in the retina?

  Rods and cones.
• What is the primary function of rods in the visual system?

  They work best in dim light and are primarily responsible for black and white vision.
• Where are cones primarily located in the retina?

  In the central retina, particularly at the fovea.
• What is the difference between the responses of photoreceptors and ganglion cells?

  Photoreceptors produce graded responses, while ganglion cells produce action potentials.
• What is the role of neurotransmitters in photoreceptors?

  They alter the release in response to changes in light energy.
• What is the fovea?

  A dent in the retina where cones are concentrated.
• What does trichromatic theory suggest about human colour vision?

  It suggests there are three separate colour processing channels for red, green, and blue.
• What is the opponent process theory?

  It proposes that colours are processed in antagonistic pairs.
• How does modern understanding of colour vision integrate both theories?

  It supports both theories with biological evidence and explains colour perception through cone outputs.
• What is the absolute threshold in psychophysics?

  The smallest amount of a stimulus that can be detected at least half the time.
• What is the just noticeable difference (JND)?

  The smallest change in a stimulus that can be detected at least half the time.
• What does Weber's law state?

  The ability to perceive a change in a stimulus is proportional to the original stimulus.
• What is the Weber fraction?

  A calculation that quantifies human ability to discriminate within different sense modalities.
• What does signal detection theory account for?

  It accounts for perceptual sensitivity and variations in decision criteria.
• What are the four possible outcomes in a signal detection experiment?

  Hit, miss, false alarm, and correct rejection.
• How is perceptual sensitivity measured in signal detection theory?

  Using the ratio of correct responses (hits/correct rejections) to incorrect responses (misses/false alarms).
• What is the problem of depth perception?

  It is the ability to perceive stimuli in 3D despite receiving 2D information from the retina.
• What are the four categories of depth cues?

  • Oculomotor cues
  • Binocular cues
  • Kinetic depth cues
  • Pictorial depth cues
• What are oculomotor cues?

  They refer to movements within the muscles of the eyes.
• What is accommodation in depth perception?

  It is when the lens changes shape to focus on close objects.
• What is the role of the brain in depth perception?

  • Interprets 2D information from the retina
  • Creates perception of depth
  • Uses cues to enhance depth perception
• What is the relationship between sensation and perception?

  • Sensation: Detection and conversion of stimuli into neural signals
  • Perception: Organization and interpretation of sensory input
• What is convergence in depth perception?

  It is the inward movement of the eyes when focusing on a close object.
• What is the problem in explaining depth perception?

  It involves perceiving a 3D form from 2D sense data.
• What does cue theory suggest about depth perception?

  It suggests that the brain interprets 2D information to create a perception of depth.
• What are the four categories of depth cues?

  • Oculomotor cues
  • Binocular cues
  • Kinetic (movement) cues
  • Monocular static cues
• What are oculomotor cues related to?

  They refer to movement within the muscles of the eyes.
• What is accommodation in terms of depth perception?

  It is the change in shape of the lens to focus on objects at different distances.
• What does convergence refer to in depth perception?

  It is the inward movement of both eyes to focus on a nearby object.
• What is retinal disparity?

  It is the difference in images received by each eye due to their horizontal separation.
• What is stereopsis?

  It is the perception of depth that arises from the fusion of two slightly different retinal images.
• What can affect the development of stereopsis in childhood?

  Conditions like squinting or cataracts.