SENSATION

• Sensation


  Transduction and Sensory Organs
• Sensory organs


  • Act as transducers, converting different forms of energy into electrical signals for the brain
  • Damage to sensory organs can lead to sensory impairments, but advancements in technology offer solutions like bypassing damaged organs
• Example


  • Using miniature cameras to transmit signals directly to the brain, helping blind individuals "see" objects
• Psychophysics


  Studies how physical stimuli relate to our perceptual experiences
• Absolute threshold


  The minimum intensity needed for us to perceive a stimulus, varying between individuals and species
• Difference threshold


  The minimum change needed for us to notice a difference between two stimuli
• Ways our senses select information

  • Lack of Specific Transducers
  • Restricted Range of Transducers
  • Sensory Adaptation
  • Feature Detection
• Visible spectrum


  Range of colors based on the wavelengths of light that our eyes can perceive
• Accommodation


  Changes in the curvature of the cornea and lens to bend light rays onto the retina
• Photoreceptors


  Rods and cones in the retina responsible for transduction
• Cones


  • Sensitive to bright light, producing color and fine details
  • Concentrated in the fovea, providing high-resolution color vision and sharp details
• Rods


  • Responsible for vision in low light conditions and peripheral vision
  • Highly sensitive to movement and function effectively in dim lighting
  • Contribute to dark adaptation
• Color blindness


  Lack or dysfunction of cones in the eyes
• Transduction in the ear

  Conversion of sound waves into electrical signals for the brain
• Types of hearing loss

  • Conductive
  • Sensorineural
  • Noise-induced
• Smell


  Smell receptors in our noses detect airborne chemical molecules, initiating nerve signals to the brain
• Taste


  Receptors on our tongues detecting chemical molecules in food
• Touch


  Receptors in the skin detecting sensations like pressure, temperature, and pain
• Selective attention


  Helps us focus on specific sensory input by filtering out distractions
• Multitasking isn't as effective as we believe; it often leads to errors and accidents because attentional resources are limited
• Factors influencing selective attention


  • Intensity
  • Contrast
  • Personal importance
  • Goals
• Examples of factors influencing selective attention


  • A loud explosion or a bright flash of light
  • Noticing our own name being mentioned in a crowded room
• Mind-wandering


  When our attention shifts from external stimuli to our internal thoughts and fantasies
• Perception


  The brain's way of organizing and understanding the information it receives from our senses
• Illusions


  When our brain interprets sensory information in a way that doesn't match reality
• Hallucinations


  Extreme illusions, where we perceive things that aren't there at all
• Synesthesia


  When sensory impressions, like sounds or tastes, trigger sensations in different senses
• Bottom-up processing


  Starts with raw sensory information and builds it into a complete perception
• Top-down processing


  Uses our past experiences and knowledge to quickly interpret what we see without focusing on every detail
• Our perceptions can be influenced by differences in our sensory organs and our past experiences
• Example


  • The dress was a 2015 online viral phenomenon centred on a photograph of a dress. Viewers disagreed on whether the dress was blue and black, or white and gold
• Role of perception in psychology

  • Understanding behavior
  • Cognitive processes
  • Clinical psychology
  • Applied psychology
  • Perception and therapy