THE SENSESBy: Abi Lundstrom, Aric Dvorak, & Kourtney Lothspeich

Vision- Anatomy

Pupil- opening in iris that regulates amount of light entering the eye

Lens- flexible, elastic, transparent structure in eye that changes shape to focus light on the retina

Retina- innermost coating of the back of the eye containing light sensitive receptor cells (rods and cones)

Optic Nerve- nerve that carries impulses from the retina to the brain

Optic Disk (blind spot)- point where the optic nerve exists lacking photoreceptors leading to no vision

Eyes- globular organs used to see by vertebrae animals

Rods- photoreceptor cells sensitive to much lower levels of light allowing them only to detect black and white and are the basis for night vision. (75 to 150 million of them)

Cones- photoreceptor cells that require more light than rods to respond and detect color

Rods and Cones are located in the retina (back of the eye)

We see only a portion of the electromagnetic spectrum. We see particular colors because objects absorb all colors and we see the colors that are not absorbed. For

example, a banana is yellow because it absorbs all colors except

yellow.

Color deficiency, also know as color blindness, affects about 8 % of American men and less than 1 % of American women. This is a genetic condition usually passed from women (xx) to their sons (xy)

Green and red are typically confused with each other and/or blue and yellow are typically confused by color deficient people. Some people have no sense of color and rely only on their rods, seeing black and white

What color we can and can’t see

Binocular fusion- a composite of the two images we receive from

each eye.

Retinal disparity- the different viewpoint each eye has in the retina. This is crucial for our depth perception

A large retinal disparity (difference between the

left and right eye) means that the object is

close. A small retinal disparity means the

object is far.

• 20/20= perfect eyeball objects focused on retina

• Near sighted= elongated eye objects are focused in front of the retina

• Far sighted= to short of an eyeball and objects focused behind the retina

“Find a space with total darkness and slowly move your hand from side to side in front of your face. What do you see?

If the answer is a shadowy shape moving past, you're probably not imagining things. Using computerized eye trackers, a new cognitive science study finds that at least 50% of people can see the movement of their own hand even in the absence of all light.

Through five separate experiments involving 129 individuals, researchers found that this eerie ability to see our hand in the dark suggests that our brain combines information from different senses to create our perceptions.” (Seeing in Total Darkness).

Hearing- Anatomy

Auditory Nerve- neuronal signals travel through this nerve to the brain.

This finally arrives at the cerebral cortex where it is interpreted.

Sound Waves- Vibrations of the air.

The Pinna (earflap) funnels the sound down the Auditory (ear) Canal and causes it to vibrate which in turn vibrates the Eardrum.

Then passing from the Eardrum to the Hammer, Anvil, and Stirrup. These are tiny bones in the middle ear that vibrate with the Eardrum and move the vibrations to the Cochlea.

The Cochlea makes up the inner ear and contains fluids and neurons that move with vibration. This in turn forces tiny hair-like cells to move and produce neuronal signals.

Differences in Sounds

•Decibels- The measurement of loudness of sound, amplitude, or height of sound waves.

Decibels range from 0 to about 140 Decibels. Any sounds over 110 or persistent sounds over 80 can be damaging to hearing.

When hearing two separate frequencies at the same time, you can still detect both distinct pitches. Ex. Striking two keys on the piano at the same time.

•Pitch- The measurement of rate of vibration (Sound Waves).

When you hear a sound, how can you locate where it came from? This is possible because if a sound is produced on your right, it reaches your right ear a moment sooner and is slightly louder, signifying the direction that the sound came from.

The Doppler effect is the apparent change in frequency and wavelength of a wave that is perceived by an observer moving relative to the source of the waves (New World Encyclopedia).

Its why something moving towards us sounds different than the same sound moving away from us at the same length.

Conduction Deafness- Caused by anything hindering the physical motion before the inner ear or the bones of the middle ear being rigid.

Sensorineural Deafness- Caused by damage to the cochlea, hair-like cells, or auditory neuron.

BalanceVestibular system- regulates the body’s sense of balance, the vestibular system is located in the inner ear

Inertia: causes the fluid in the canals to resist changes in motion

Overstimulation: spinning, falling, and tilting your body or head can result in dizziness and motion sickness

Sense of balance: although you are usually unaware of your balance without the vestibule system you would be unable to stand or walk without falling.

Smell and TasteOlfactory nerve: the nerve that sends messages to the brain from the smell receptors in the nasal passage

4 Primary sensory experiences of taste: • Sour Bitter• Salty Sweet

Flavor: the combination of taste, smell, and tactile sensations

Smell and Taste: They are known as chemical senses because their receptors are sensitive to chemical molecules

Scientists say the human nose can detect about 10,000 different scents. Sometimes, we're not even consciously aware of those odors. Lab studies have found that people can tell the difference between the scents of friends and strangers as well as between those of men and women (Sense and Sensibility).

Relationship between smell and taste: much of what is referred to as taste is actually produced by the sense of smell. For example when you have a cold your food seems to taste bland.

Skin SensesReceptors: receptors in the skin provide the brain with four kinds of information about the environment:• Pressure• Warmth• Cold • Pain

Types of pains sensation: • Sharp localized pain you feel

immediately after the injury • Dull generalized pain that you

may feel later.

Gate control theory of pain: the theory that we can lessen pain by shifting our attention away from the impulses or by sending other signals to compete with the pain signals

Senses difference in environment in relation to the skin. For example, if you put your hand in hot water on a hot day, you sense little or no heat.

Body SensesKinesthesis is the sense of movement and body position.

Sensations come from receptors near the muscles, tendons, and joints.

Along with Visual senses, it helps assist Vestibular system in balance and posture.

Without Kinesthetic sensations, movements would be uncoordinated and jerky. Thus making complex physical activities (surgery, piano playing, and acrobatics) impossible.Kinesthetic aftereffect (n).

Any illusion involving the kinesthetic sense in which one kinesthetic experience influences the next. For example, after lifting a very heavy weight you lift a lighter, yet still heavy, weight that now feels much lighter (APA Dictionary of Psychology).

Sources Kasschau, R. A. (2003). Sensation and Perception. In

Understanding Psychology. Columbus, Ohio: Glencoe/McGraw-Hill.

Doppler effect. (2006). In New World Encyclopedia. Retrieved March 3, 2014, from http://www.newworldencyclopedia.org/entry/Doppler_effect

Tadin, D. (2014). Seeing in Total Darkness. Science Teacher, 81(1).

Weir, K. (2010). Sense and Sensibility. Current Health Teens. Gary, V. (2007). APA Dictionary of Psychology. Washington,

DC: American Psychological Association.