1. The Eye

2. Energy v. Chemical senses
Energy Senses
Chemical Senses

3. Transduction Transduction –
Each sense has its own process of transduction
Information goes from the senses to the thalamus , then to the various areas in the brain.
Example:
Remember Ethan in Sky High. He changes his body to slime. Solid form to liquid form. Change from one form of energy to another. Click the picture to watch power placement.

4. Vision
Our most dominating sense.
Visual Capture

5. Phase One: Gathering Light

6. The Stimulus Input: Light Energy
Wavelength –
Determines hue (color)

7. Phase One: Gathering Light
HUE
Hue -
ROY G BIV
Example:

8. The Physical Property of Waves
Intensity
Intensity –
Height of a wave gives us it’s intensity (brightness).
Example:

9. Phase Two: Getting the light in the eye

10. The Eye Cornea – Pupil – Iris – Lens – Retina –
Dilation of the pupil allows more light to reach the periphery of the retina where the rods are located
Iris –
Lens –
Accomodation - process by which the lens changes shape (curvature and thickness) to focus near or far images on the retina
Retina –

11. Retina Rods - receptor cells Cones – receptor cells
Fovea - central focal point in the retina

12. The Retina
Rods and Cones
Rods
Cones

13. Rods versus Cones

14. Optic Nerve Optic Nerve – Blind Spot – Blind spot = no receptor cells
Example:

15. Phase III: Transduction
Overview:

16. Transduction 2. 3. 4. Bipolar cells are located in the retina
Ganglion cells axon’s form the optic nerve

17. Visual Problems
Farsighted –
Nearsighted –
Astigmatism –

18. Phase IV: In the Brain Thalamus to Occipital lobe to Visual Cortex to…
Feature Detectors –
Example:
Supercell clusters –
Example: Feature Detector cells –

19. Parallel Processing
Parallel Processing –
Example:
Blindsight –

20. Color Vision
Two Major Theories

21. Trichromatic Theory Trichromatic Theory - Three types of cones:
These three types of cones can make millions of combinations of colors.
Does not explain afterimages or color blindness well.

22. Opponent-Process theory
Opponent-Process Theory - The sensory receptors come in pairs.
If one color is stimulated, the other is inhibited.
Example:

23. Afterimages

24. Hearing, Touch, Taste and Smell

25. Hearing
Audition –

26. Frequency of Sound Waves
Amplitude = loudness = brightness
Pitch is determined by the frequency of the sound wave = color

27. Amplitude of Sound Waves

28. Absolute Threshold Absolute Threshold =
10 decibels = 10X increase in sound intensity
Example:
A 30 decibel sound is _____ times louder than a 10 decibel sound
A 40 decibel sound is _____ times louder than a 10 decibel sound

29. Parts of the Ear
Outer Ear – channels sound waves to the eardrum in the Middle Ear
Middle Ear – chamber between the eardrum and cochlea containing three tiny bones that concentrate vibrations of the eardrum on cochlea’s oval window
Inner Ear – the innermost part of the ear containing the cochlea, semicircular canals, and vestibular sacs
Cochlea – fluid filled tube of inner ear which trigger neural impulses

30. Transduction Overview – 1. 2. 3. 4. 5.
Vibrating air to moving piston to fluid waves to electrical impulses to the brain
Basilar membrane is located in the cochlea
The mechanical vibrations triggered by sound waves are transduced into neural impulses by hair cells
Hair cells line the surface of the basilar membrane
Rods and cones are to vision as hair cells are to audition
Cochlea – fluid filled tube in which sound waves trigger neural impulses
eardrum, hammer, anvil, stirrup, cochlea
It is all about the vibrations!!!

31. The structure of the ear
Bones of the middle ear = the hammer, anvil, stirrup which vibrate with the eardrum.

32. The structure of the ear
Movement of hair cells along the basilar membrane initiates transduction of neural messages to the auditory cortex
Hair cells have extreme sensitivity and extreme speed
Mechanical vibrations triggered by sound waves are transduced into neural impulses by _____________?
_____________ do the same job for vision as __________ do for audition

33. Neural impulse to the brain

34. Perceiving Loudness
Damage to Basilar membrane’s hair cells = hearing loss (lose sensation of soft sounds)
# of activated hair cells allows us to perceive loudness
Compression – harder to hear sounds are more amplified than loud sound
Movement of hair cells along the basilar membrane initiates transduction of neural messages to the auditory cortex
Hard of hearing people like sound compressed because they remain sensative to loud sounds – what hearing aids do
Damage to hair cells = most hearing loss
If we can’t talk over a loud noise it is harmful, especially over long periods of time---over 100 decibles

35. Place Theory and Frequency Theory
Pitch Theories
Place Theory and Frequency Theory

36. Place Theory or Herman von Helmholtz Theory
Best explains how we sense high pitches

37. Frequency Theory Frequency Theory –
Frequency (speed) of sound wave matches the speed of the neural impulse.
Theory limitations: Can’t explain high pitch sounds (neural impulses can only travel at 1000 impulses per sec.)
Best explains how we hear low pitches
Example:
The rate at which impulses travel up the auditory nerve matches the frequency of the tone being heard

38. Volley Principle Volley Principal –
Can achieve a combined frequency of above 1000 waves/sec
Current Research suggests that both frequency and place theory explain how we hear pitch

39. Locating Sound
Sound waves strike one ear sooner and more intensely in the direction of the sound
Locating sound – activity with person sitting in a chair facing the class. Clap at varing locations around the head. Left, right, front, back top (should have more difficulty locating sound in the 360 degree plane equidistant between the ears – overhead, back, front
Cock head to hear location of sound
Sound waves strike one ear sooner than the other, helps us to locate the direction of the sound
When sound is directly overhead it reaches both ears simultaneously
Time lag between left and right auditory stimulation is important for accuratley locating sound

40. Deafness Conduction Deafness - Nerve (sensorineural) Deafness -
You can replace the bones or get a hearing aid to help.
Example:
Loud noises can cause this type of deafness.
NO WAY to replace the hairs.
Cochlea implant - converts sound waves to into electrical signals.
Example:

41. Touch Receptors located in our skin. Types of touch
– Activity with paper clip and touch
no simple relationship between what we feel at a given spot and the type of specialized nerve endings found there
Pressure receptors have been identified
Other skin sensations are variations of the basic - pressure, warmth, cold, pain
Tickle – stroking adjacent pressure spots
Itching – repeated gentle stroking of a pain spot
Wetness – touching adjacent cold and pressure spots
Hot – stimulating nearby cold and warm spots
Top down processing = rubber hand illusion

42. Kinesthetic Sense Kinesthetic Sense –
Receptors located in our joints, tendons, bones and ears
Example:
– receptor cells have been identified in joints, tendons, bones, and ear.
Detecting whether you are vertical or horizontal
Activity - close eyes and touch mouth, nose chin. It is your kinesthetic sense that enables you to do this. stand with right heal in front of left toes and close your eyes…what happens? you wobble.
Proprioception – loss of kinesthetic sense. Can only move their bodies when they can see them. In the dark, they become limp and collapse
Without the kinesthetic sense you could not touch the button to make copies of your buttocks.

43. Vestibular Sense Vestibular Sense –
Located in our semicircular canals in our ears.
Example:
Demo of spinning around in a chair ?
Elephant balancing on two legs
Riding the corkscrew at Cedar Point – fluid in semicircular canals make us feel dizzy
Fluid in the semicircular canals have fluid which moves when head rotates or tilts – movement stimulates hair-like receptors that send messages to the cerebellum enabling you to sense your body position

44. Pain Biological Influences Psychological influences
Noiceptors –
Gate-control theory*
Endorphins
Phantom limb sensations
Tinnitus
Psychological influences
Distraction
Memory of Pain – peak pain, end pain
Socio Cultural Influences
More pain when others experience pain
Mirror neurons that empathize with others pain
When you burn your finger, noiceptors transmit pain signals to your central nervous system
Phantom limb sensations – misinterpretation of central nervous system activity in absence of normal sensory activity
Tinnitus – phantom sounds with loss of hearing

45. Gate Control Theory Gate Control Theory – Example:
No one theory explains pain
Gate control – theory suggests that large fiber activity in spinal chord can prevent pain messages from reaching the brain

46. Sweet, sour, salty and bitter Taste buds
Umami
Taste buds
Chemical sense
Age and taste

47. Taste Bumps on our tongue are called papillae.
Taste buds are located on the papillae 200+ each containing a pore.
Pore – taste receptor cells that sense food molecules

48. Sensory Interaction Sensory interaction – Examples:
Jello in the shape of a brain looks so unappetizing, it tastes terrible too
McGurk Effect –

49. Smell Olfaction Chemical sense Olfactory receptors -
Olfactory bulb – transmits smell from the nose to the brain
Olfactory nerve – sends neural messages to from the olfactory bulb directly to the olfactory cortex in the brain bypassing the thalamus
Olfactory cortex – receives information from the olfactory bulb
Conscious awareness of odors
Identification of odors
Hotline between olfactory cortex and limbic system (memory and emotion)

52. Smell (olfaction)

53. Smell and age