Senses Notes

Senses

• Vision
• Our most dominating sense
• The height of a wave gives us its intensity (brightness)
• The length of the wave gives us its hue (color)
• The longer the wave the more red
• The shorter the wavelength the more violet
• Transduction
• Transforming signals into neural impulses
• Information goes from the senses to the thalamus, then to the various areas in the brain
• Young-Helmholtz Trichromatic (three color) Theory
• Three Types of Cones: Red, Blue, Green
• These three types of cones can make millions of combinations of colors
• Most color blind people simply lack cone receptor cells for one or more of these primary colors
• Opponent-Process theory
• The sensory receptors come in pairs
• Red/Green
• Yellow/Blue
• Black/White
• If one color is stimulated, the other is inhibited
• Hearing
• We hear sound waves
• The height of the wave gives us the amplitude of the sound
• The frequency of the wave gives us the pitch of the sound
• Shorter wavelength equals higher pitch
• Longer wavelength equals lower pitch
• Transduction in the ear
• Sound waves hit the eardrum then anvil then hammer then stirrup then oval window
• Everything is just vibrating
• Then the cochlea vibrates
• The cochlea is lined with mucus called basilar membrane
• When hair cells vibrate they turn vibrations into neural impulses which are called organ of Corti
• Sent then to thalamus up auditory nerve
• Place Theory
• Different hairs vibrate in the cochlea when there are different pitches
• So some hairs vibrate when they hear high pitches; after vibrate when they hear low
• Frequency Theory
• All the hairs vibrate but at different speeds
• Deafness
• Conduction Deafness
• Something goes wrong with the sound and the vibration on the way to the cochlea
• You can replace the bones or get a hearing aid to help
• Nerve (sensorineural) Deafness
• The hair cells in the cochlea get damaged
• Loud noises can cause this type of deafness
• No way to replace the hairs
• Cochlea implant is possible
• Smell & Taste
• Sensory Interaction: The principle that one sense may influence another
• Taste
• We have bumps on our tongue called papillae
• Taste buds are located on the papillae (they are actually all over the mouth)
• Types of Taste
• Sweet: Tip of the tongue
• Salty: Front sides of the tongue
• Sour: The back of the tongue
• Bitter: Base of the tongue
• Umami: Flavorful Taste, stays on the tongue
• Touch
• Receptors located in our skin
• Gate Control Theory of Pain
• When the spinal cord contains a neurological gate that blocks pain signals or allows them to pass on to the brain
• Vestibular Sense
• Tells us where our body is oriented in space
• Our sense of balance
• Located in our semicircular canals in our ears
• Kinesthetic Sense
• Tells us where our body parts are
• Receptors located in our muscles and joints
• Always has to do with motion
• Perception
• Process of organizing and interpreting information, enabling us to recognize meaningful objects and events
• Gestalt Philosophy
• The whole is greater than the sum of its parts
• Figure-Ground Relationship
• The organization of the visual field into objects (figures) that stand out from their surroundings (ground)
• Grouping
• The perceptual tendency to organize stimuli into groups that we understand
• Based on: Proximity, Similarity, Continuity, Connectedness
• Depth Perception
• The ability to see objects in three dimensions although the images that strike the retina are two dimensional
• Allows us to judge distance
• Visual Cliff
• Babies can’t tell depth
• Binocular Cues
• Retinal Disparity: A binocular cue for seeing depth
• The closer an object comes to you the greater the disparity is between the two images