cogs midterm

• Senses


  • Vision (seeing)
  • Audition (hearing)
  • Olfaction (smell)
  • Gustation (taste)
  • Somatosensation (touch)
  • Thermoception (heat)
  • Proprioception (body position)
  • Vestibular (head position)
  • Equilibrioception (being upright)
  • Interoception (internal feelings)
  • Chronoception (passage of time)
• Senses limit reality and how we experience the world
• Sensory substitution


  Organisms have different "doors" to the physical world
• Within our species our door to perception is incomplete
• Umwelt


  The world as it is experienced by a particular organism
• Umwelt examples


  • Color vision is helpful to humans as a species
  • Cat/rat whiskers
  • Chameleons have 360 degree vision
• Underdetermined problems


  A problem that cannot be solved with the information given
• When you see things, light hitting your retina is all the information you have and your brain just has to fill in the rest

  
• Inverse projection problem


  Converting an object to 2d retinal image is straightforward, knowing exactly what caused the 2d image is not
• An infinite number of objects could produce the same retinal image
• Distal stimulus


  The stimuli "out there" in the environment
• Proximal stimulus


  The physical energy from a stimulus as it directly stimulates a sense organ
• The perceptual process involves many transformations of the distal stimulus
• Everything we perceive is based not on direct contact with stimuli but on representations of the stimuli
• Sensory receptors


  Cells specialized to respond to a specific type of environmental energy
• Transduction


  The transformation of one form of energy (here light energy) to another (electrical energy)
• Goal of perception


  • Classic cognitive psychology: to create a representation in the mind
  • Action-specific perception hypothesis: to enable us to interact with the environment
• Action and perception interact

  • Softball players who had just bat well perceive softballs as larger than those who had just bat poorly
  • Tennis players who just won a match perceive the net to be lower than those who just lost
  • People with chronic back/leg pain perceive distances as longer than pain-free people
  • Those expecting to lift a box with another person estimate the box to be lighter than those expecting to lift it alone
• Perception vs recognition


  • Visual form agnosia: inability to recognize common objects even though perception is totally intact
  • We can have conscious experience of the properties of an object without being able to categorize the object
• Knowledge


  Any information that the perceiver brings to the perceptual process
• Bottom up processing


  Processing based on observation
• Top down processing


  Processing based on existing knowledge (ie context clues)
• Qualia


  Subjective experience
• Criterion of falsifiability


  The perspective that for a hypothesis, theory, or enterprise to be regarded as scientific, it must be falsifiable (refutable) on the basis of some physical observation
• Empiricism


  The perspective that knowledge and evidence must be empirically based: depend on that which can be physically observed/measured
• To study something empirically we must be able to measure physical observations
• Theoretical constructs


  Entities/concepts that we are interested in (such as whether someone experiences color) but that are unobservable
• Operational definition


  An external behavior that "stands in" for the construct we are interested in. We cannot measure a construct so we define a behavior that we believe corresponds to the construct
• In cognitive science, operational definitions are important because we use a large variety of measures to infer cognitive processes or brain activity
• Measures used in cognitive science

  • Reaction time -> processing time
  • Blood flow -> brain activity
  • Looking time -> interest/novelty
• Visible light


  The energy within the electromagnetic spectrum that humans can perceive

  
• Short wavelengths are blue, medium ones are green, long ones are red
• Camera obscura


  The pinpoint thing people do to look at the eclipse, causes light to filter by direction and inverts the light going through it
• Camera aperture


  Bigger hole, blurrier image (but more light)
• In order to form a crisp image we need to 1) let enough light into the eye but at the same time 2) represent one and only one point on the distal stimulus (this is the goal of the eye!)

  
• Distal stimulus


  Stimuli "out there" in the environment
• Refraction


  Allows us to refocus the many light rays that pass through the eyes
• Refraction allows us to have a crisp image as bright as a pinhole image

  
• Retina


  A membrane in the back of the eye that contains light sensitive photo receptors
• Retina sends information to the brain via the optic nerve