Sensory Perception

Depth Perception

• Depth perception is the ability to perceive the distance of objects from us.

Binocular Vision

• Binocular vision helps us perceive depth due to the 6.35 cm distance between our two eyes.
• The brain combines images from each eye to create a single image with depth cues.

Monocular Cues

• Monocular cues are depth cues that can be perceived with one eye.
• Examples of monocular cues include:
  • Relative size: larger objects appear closer.
  • Interposition: overlapping objects are perceived at different distances.
  • Atmospheric perspective: farther objects appear lighter and less detailed.
  • Shading and texture: objects appear more three-dimensional with shading and texture.

Motion Parallax

• Motion parallax is a monocular cue that helps us perceive depth.
• Closer objects appear to move faster than farther objects.

Stability

• Stability refers to perceiving objects as remaining the same despite changes in appearance.
• Examples of stability include:
  • Size constancy: objects appear to maintain their size despite distance changes.
  • Shape constancy: objects maintain their shape despite viewing angle changes.
  • Color constancy: objects maintain their color despite lighting changes.

Other Depth Cues

• Other depth cues include:
  • Accommodation: the eye's ability to focus on objects at different distances.
  • Convergence: the eye's ability to converge on objects at different distances.
  • Stereopsis: perceiving depth through the combination of images from each eye.

Sensory Adaptation

• Sensory adaptation occurs when sensory organs change their sensitivity in response to environmental changes.
• It helps to protect sensory organs from damage and enables them to function optimally.

Hearing

• The eardrum adapts to loud sounds by tightening the muscles in the middle ear, reducing sound intensity.
• This adaptation protects the eardrum from damage, but may not be quick enough to prevent damage from extremely loud sounds.

Touch

• Nerve endings in the skin adapt to changes in temperature, becoming less sensitive over time.
• This adaptation is demonstrated when the sensation of coldness decreases after initial exposure to cold water.

Smell

• The sense of smell adapts to changes in the environment, with the sensitivity of nerve endings decreasing over time.
• This is demonstrated when the intensity of a strong odor decreases after initial exposure.

Proprioception

• Proprioception is the sense of body orientation and movement, which can adapt to changes in the environment.
• The brain can adapt to altered proprioception, as demonstrated in an experiment where participants wore glasses that altered their sense of proprioception.

Vision

• The iris adapts to changes in light intensity, constricting in bright light and dilating in dim light.
• The rods and cones in the retina also adapt to changes in light intensity, becoming more sensitive in low light conditions.

Down-Regulation

• Down-regulation is the process of reducing sensory organ sensitivity in response to intense stimuli.
• Examples include the eardrum's adaptation to loud sounds, nerve endings' adaptation to cold temperatures, and the retina's adaptation to bright light.

Up-Regulation

• Up-regulation is the process of increasing sensory organ sensitivity in response to weak stimuli.
• Examples include the retina's adaptation to low light conditions and the olfactory system's adaptation to weak smells.