SENSATION AND PERCEPTION

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SENSATION AND PERCEPTION
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KEY POINTS

• Distinguish between sensation and perception
• Psychophysics absolute threshold and difference
  threshold
• Identify each major sensory system, their
  receptors, and type of sensory information each
  receives
• Perception selection, organization and
  interpretation

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Sensation

• Input of sensory information
• Process of receiving, converting, and
  transmitting information from the outside world

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Sensory Systems

• Vision
• Hearing
• Smell (olfaction)
• Taste (gustation)
• Vestibular sense (balance)
• Kinethesis (body movement)
• Touch (pressure, pain, temperature)

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Vision

• Visual receptor cells located on retinarods for
  night vision and cones for color vision
• The eye captures light and focuses it on the
  visual receptors, which convert light energy to
  neural impulses sent to the brain

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Hearing

• Audition (hearing) occurs via sound waves, which
  result from rapid changes in air pressure caused
  by vibrating objects
• Receptors located in the inner ear (cochlea) tiny
  hair cells that convert sound energy to neural
  impulses sent along to brain

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Smell and Taste

• Olfaction (smell) receptors are located at top of
  nasal cavity
• Gustation - (taste) receptors are taste buds on
  tongue. Four basic tastes sweet, salty, sour
  and bitter

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Body Senses

• Vestibular sense (sense of balance) results from
  receptors in inner ear
• Kinethesis - (body posture, orientation, and body
  movement) results from receptors in muscles,
  joint and tendons
• Skin senses detect touch (pressure, temperature
  and pain)

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Processing

• Sensory reduction - filtering and analyzing of
  sensations before messages are sent to the brain
• Transduction - process of converting receptor
  energy into neural impulses the brain can
  understand
• Adaptation- decreased sensory response to
  continuous stimuli

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Psychophysics

• Study of the relationship between the physical
  properties of stimuli and a persons experience
  of them
• Absolute threshold - minimum amount of energy we
  can detect
• Difference threshold - (jnd) the smallest change
  in a stimulus we can detect

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Perception

• a constructive process by which we go beyond
  the stimuli that are presented to us and attempt
  to construct a meaningful situation.

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Perceptual Processing

• Top-down perception is guided by higher-level
  knowledge, experience, expectations, and
  motivations
• Bottom-up perception that consists of
  recognizing and processing information about the
  individual components of the stimuli

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Perception-Key Concepts

1. Selection
2. Organization
3. Interpretation
4. Subliminal perception and ESP

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1. Three Major Factors of Selection

• Selective attention
• Feature detectors
• Habituation

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2. Organization

• Form (Gestalt)
• Constancy(size, shape, color, brightness)
• Depth
• Color

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Gestalt Principles

• Rules that summarize how we tend to organize bits
  and pieces of information into meaningful wholes

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Gestalt Psychology Form

• figure ground
• proximity
• closure
• contiguity
• similarity

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Constancy

• Size constancy
• Shape constancy
• Color constancy
• Brightness constancy

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3. Four Major Factors of Interpretation

• Perceptual adaptation
• Perceptual set
• Individual motivation
• Frame of reference

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Subliminal Perception

• Stimuli that occur below the threshold of our
  conscious awareness but have a weak, if any
  effect on behavior

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4. Extrasensory Perception (ESP)

• Alleged perception in the absence of sensory data
• Types of ESP - telepathy, precognition,
  clairvoyance, and psychokinesis