unit 5: sensation & perception vision and hearing
TRANSCRIPT
Unit 5: Sensation & PerceptionVision and Hearing
Transduction
• Transduction- (transform) changing one form of energy into another– All Senses
• 1) receive sensory information through receptor cells• 2) transform it into neural information• 3) deliver that information to the brain
I. VisionThe Stimulus Input: Light Energy• Wavelength the peak to peak
distance in a sound or light wave• Relationship to frequency…
– Hue the color we experience due to the dominant wavelength of a light
• Amplitude height of the wave– Intensity (brightness)
Electromagnetic Energy Spectrum
The Physical Property of Waves
The Eye• Cornea
• Pupil
• Iris
• Lens– Accommodation- the process by which the eye’s lens changes
shape to focus near or far objects on the retina.
• Retina– Optic nerve– Blindspot– Fovea
The Structure of the Eye
The Structure of the Eye
Describe the function of each part listed.
The EyeThe Retina
• Rods and Cones
RodsCones
Which is which?
• retinal receptors that detect black, white, and gray
• necessary for peripheral and twilight vision, when cones don’t respond
• retinal receptor cells that are concentrated near the center of the retina
• that function in daylight or in well-lit conditions
• detect fine detail and give rise to color sensations.
Rods versus Cones
The Retina’s Reaction to Light
The EyeThe Retina
• Optic nerve
• Blind spot
• Fovea
Visual Information ProcessingVisual Cortex
Pathways from the eyes to the visual cortex
Visual Information ProcessingFeature Detection
• Feature detectors– Hubel and Weisel
Visual Information ProcessingParallel Processing
• Parallel processing–Blind sight (a strange phenomenon)
Visual information processing
Visual information processing
Visual information processing
Visual information processing
Visual information processing
Color Vision
• Color Blindness– Gender differences?
–Monochromatic vision
–Dichromatic vision
How do we perceive color?
Young-Helmholz (trichromatic) Theory
• the retina contains three different color receptors which, when stimulated in combination can produce the perception of any color– 3 color receptors =
• one most sensitive to red
• one to green
• one to blue
Opponent-Processing Theory• opposing retinal
processes) enable color vision– red-green– yellow-blue– white-black
• For example, some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green.
After image
This slide is intentionally left blank.
Hearing
The Stimulus Input: Sound Waves
• Audition
• Amplitude–loudness
• Frequency– Pitch- a tone’s experienced highness or
lowness
The structure of the ear
The ear is divided into the outer, middle and inner ear.
Outer Ear
• Outer ear–Pinna
–Auditory canal
–Ear drum
Outer Ear: Eardrum
Eardrum
Middle Ear
Bones of the middle ear = the hammer, anvil, stirrup which vibrate with the eardrum
Oval window = where the stirrup connects to the cochlea
Inner Ear
Cochlea = a coiled, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses.
The Ear
• Inner ear– Oval window
–Cochlea• Basilar membrane
–Auditory nerve
–Auditory cortex
The structure of the ear
Review what each structure does
Neural impulse to the brain
The EarPerceiving Loudness
• Basilar membrane’s hair cells–Compressed sound
Cochlea and loud sounds
The EarPerceiving Pitch
Place theory- theory that links the pitch we hear with the place where the cochlea’s membrane is stimulated – High pitched sounds
• Frequency theory- theory that the rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, thus enabling us to sense its pitch– Low pitched sounds
• Volley principle
The EarLocating Sounds
• Stereophonic hearing
• Localization of sounds–Intensity
–Speed of the sound
Hearing Loss and Deaf Culture
• Hearing loss–Conduction hearing loss
• Damage to structures (bones, eardrum)
–Sensorineural hearing loss• Damage to hair cells
–Cochlea implant
• Signing– Deaf Culture controversies
Other Senses: Touch, Taste, Smell
Touch
• Types of touch–Pressure
–Warmth
–Cold
–Pain• Sensation of hot
Touch
• Rubber hand illusion
Touch
• Kinesthesis- the system for sensing the position and movement of individual body parts
• Vestibular sense- the sense of body movement and position, including the sense of balance– Semicircular canals
Semicircular Canals
PainUnderstanding Pain
• Biological Influences– Noiceptors– Gate-control theory
• theory that the spinal cord contains a neurological “gate” that blocks pain signals or allows them to pass on to the brain.
– “gate” is opened by the activity of pain signals traveling up small nerve fibers– is closed by activity in larger fibers or by information coming from the brain.
– Endorphins– Phantom limb sensations– Tinnitus
The pain circuit
PainUnderstanding Pain
• Psychological Influences– Rubber-hand illusion– Memories of pain
• Social-Cultural Influences
Biopsychosocial approach to pain
PainControlling Pain
• Physical methods
• Psychological methods
Taste
• Sweet, sour, salty and bitter–Umami
• Taste buds–Chemical sense
• Age and taste
TasteSensory Interaction
• Sensory interaction- the principle that one sense may influence another, as when the smell of food influences its taste.
• Interaction of smell and taste– McGurk Effect
• Interaction of other senses
Smell
• Olfaction–Chemical sense
–Odor molecules
–Olfactory bulb
–Olfactory nerve
Smell (olfaction)
Smell and age