Sight, Hearing, Taste, Smell, and Touch.

(p 190)

It explains how different senses can exist. According to the doctrine, different sensory signals are sent through appropriate nerve pathways leading to different areas of the brain.

(p 191)

The answer is in the names.

Anatomical (root word-anatomy) describes the physical layout and individual parts, especially of the brain.

Functional (root word-function) describes the purpose and function of individual parts, especially in the brain.

(p ???) 

Senses can be measured with Absolute Thresholds and Difference Thresholds.

In an Absolute Threshold, the subject is shown a series of signals, and are then asked which signals they could detect. 

Ex: Flashing a light in a room and varying intensity--from very dim to very intense, asking the subject which he can detect. 

In a Difference Threshold, the subject is given two or more signals; the signals will either be varying or identical in intensity. The subject is asked in each instance whether he notices any difference in the intensity, weight, brightness, etc.

Ex: Giving a person two weighted blocks, saltiness of two liquids, the saturation of two hues, etc.

(p 192-193) 

Absolute Threshold refers to the smallest amount of energy that a person can detect.

 Difference Threshold refers to the smallest difference in stimulation that a person can detect.

(p 193) 

What is the Signal Detection Theory?

Why is it used instead of the absolute threshold and the difference threshold? 

The Signal Detection Theory states that: an observer's response in a detection task can be divided into a sensory process (which depends on the intensity of the stimulus), and a decision process (which is influenced by the observer's response bias).

The Signal Detection Theory acknowledges that in many sensory tests, the subject will confirm detectionof a signal more often than not, even when he cannot detect the signal (response bias).

Tests that utilize the SDT allow four possible responses:

Signal present : Subject confims "presence"

"HIT" 

Signal present : Subject confirms "absence" 

 "MISS"

Signal absent : Subject confirms "presence"

"FALSE ALARM"

Signal absent : Subject confirms "absence"

" CORRECT REJECTION" 

(p 194) 

When a stimulus is unchanging or repetitious, sensation often fades or disappears. This is because sensory receptors get "tired" and fire signals less frequently. The sensory receptors' "boredom" is known as sensory adaptation.

(p 194) 

Sensory Deprivation refers to the absence of normal levels of sensory stimulation.

The "cocktail party phenomenon" refers to an overload in sensory stimulation, resulting in the blockiing of unimportant stimuli.

What are the basic characteristics of a wave?

(when referring to light)

The basic characteristics of light waves are:

Wavelength

Intensitiy (Amplitude)

Complexity 

Wavelength-the distance between the crests of a light wave.

 Determines HUE.

Short distance between wave crests are violet or blue.

Long distance between wave crests are red or orange.

Amplitude-maximum height of a light wave.

Determines BRIGHTNESS.

Tall waves are bright.

Short waves are dim.

Complexity-how wide or narrow the range of wavelengths is. 

Determines SATURATION.

 Great variety in wavelengths results in less saturation.

Single type of wavelength results in pure light

(p 197) 

The stuctures in charge of incoming light:

 
Cornea: front, transparent covering of the eye. It bends light toward the Lens, located behind it.

Lens: Located behind the cornea, in the front of the eye. It becomes more or less curved to focus light from objects that are close by or far away.

Iris: The colored ring around the center of the front of the eye.  Located directly above the Lens of the eye. Controls how much light gets into the eye by contracting and expanding.

Pupil: Surrounded by the iris, in the front part of the eye. The pupil is the actual opening in the eye whose size is determined by the iris.

(p 198) 

What are the receptors in the eye?

Where are they located? 

Rods: sensitive to light.

Cones: sensitve to color.

 They are located in the back of the eye, on the Retina, which also contains special cells that communicate information about light and dark to the brain area that regulates biological rhythms.

What nerve carries the visual information from the eye to the visual cortex?

What is glaucoma? 

1) Proximity

2) Closure

3) Similarity

4) Continuity

(p 204) 

What does the Gestalt Principle 
define as Proximity?

Things that are near each other tend to be grouped together.

(p 204) 

The brain tends to fill in gaps in order to perceive complete forms.

(p 204) 

Things that are alike in some way (color, shape, size) tend to be perceived as belonging together.

 (p 204)

Lines and patterns tend to be perceived as continuing in time or space.

(p 204) 

What is Gestalt Psychology? 

Gestalt Psychology is the study of how people tend to perceive the world around them.

(p 203) 

Convergence is defined as the turning of the eyes inward, which occurs when they focus on a nearby object. As the angle of convergence changes, the corresponding muscular changes provide information to the brain about distance.

(p 205) 

Retinal disparity is the slight difference in lateral separation between two objects as seen by the right eye and left eye. The brain can use this to infer depth and calculate distance.

(p 205) 

Shape

Location

Size

Brightness

Color

(p 207) 

Monocular Cues:

What is Shape Constancy?

Acknowledgement that the perceived shape of an object remains the same regardless of a difference in retinal image produced when perspective is changed.

 Ex: A Frisbee is round, even when set on a table. Although perspective changes to an oval rather than a circle, we still recognize the Frisbee to be a circle.

Monocular Cues:

What is Location Constancy?

Acknowledgement that stationary objects remain in the same place even though the retinal image moves about as we move our eyes, heads, and bodies.

Ex: Driving along a highway, looking out the window, you can see the telephone poles flying by--on your retina. But you know that these objects are not actually moving, and you also know that your body is moving.

(p 204) 

Monocular Cues:

What is Size Constancy?

Acknowledgement that objects have a constant size even when their retianl images become smaller or larger.

Ex: Your friend walks toward you, and you watch. He may be getting bigger on your retina, but you know he is not. He is moving toward you, and you are standing still.

(p 206) 

Monocular Cues:

What is Brightness Constancy?

Acknowledgement that objects have a relatively constant brightness, regardless of the amount of light reflected.

Ex: Snow remains white, even on a cloudy day.

(p 206) 

Monocular Cues:

What is Color Constancy?

Acknowledgement that objects maintain their hue, regardless of illumination type.

Ex: You know that an apple is red indoors (in yellowish light) and you also know that same apple is still red outdoors (in bluish light).

(p 207) 

Light and Shadow

Interposition

Motion Parallax

Relative Size

Relative Clarity

Texture Gradients

Linear Perspective 

(p 207) 

Optical illusions are the result of Visual INconstancies.

(p 209)

Both light and sound move in waves.

(p 210) 

Sound

What is Loudness?

How is a sound's loudness created? 

Loudness is the psychological dimension of auditory experience related to the intensity of a wave's pressure.

Intensity coresponds to the amplitude (maximum height) of a wave's pressure.

High amplitude creates loud sounds

Low amplitude creates quiet sounds 

(p 210) 

Sound

What is Pitch?

How is a sound's Pitch created?

Pitch is the dimension of auditory experience related to the frequency of the sound wave and, to some extent, its intensity.

Frequency refers to how rapidly the air vibrates--the number of times per second the wave cycles through a peak and a low point.

High frequency creates high pitch

Low frequency creates low pitch 

(p 210) 

Sound

What is Timbre?

How is a sound's Timbre created? 

Timbre is the distinguishing quality of a sound. It is the dimension of auditory experience related to the complexity of the sound wave--to the relative breadth of the range of frequencies that make up the wave.

The complexity of a sound wave or group of sound waves correlates directly with the distinctiveness of the sound wave or group of sound waves.

An orchestra has a high timbre

A computer's error response sound has a low timbre 

(p 210) 

 Ear

What are the six major structures of the ear?

eardrum

anvil

hammer

stirrup

cochlea

auditory nerve 

(p 211-212) 

Ear

What is the function of the eardrum, anvil, hammer, and stirrup?

The eardrum is the first sound sensory organ at work with a stimulating sound. A sound wave enters the ear and causes the ear drum to vibrate, at the same frequency and amplitude.

The sound passes through the eardrum and the energy is transferred to the anvil, hammer, and stirrup. These three bones work one after another, intensifying the vibration. The stirrup (innermost bone) pushes on on a membrane that opens into the inner ear.

(p 211) 

Ear

What important structure does the Cochlea contain and how does it work?

The Cochlea contains the Organ of Corti. The Organ of Corti serves the same relative purpose in the ear as the retina serves in the eye. It contains tiny hairs that serve as receptor cells for incoming sound waves.

The auditory nerve then transfers the sound to the brain for interpretation. 

(p 211-212) 

Ear 

What is the difference between Mechanical Deafness and Nerve Deafness?

Mechanical Deafness involves damage to the parts of the inner ear, left of the cochlea. The damage is mendable.

Nerve Deafness involves damage to the cochlea and to the right of the cochlea. Currently, there exists only a way to repair the cochlea, but not the organ of corti or the auditory nerve.

(p 212) 

Ear 

What is the function of the tiny hairs in the Cochlea?

The tiny hairs in the Cochlea are called cilia, and they are responsible for reception of sound waves and vibrations.

(p 213) 

Taste

How does taste work? 

Chemicals stimulate thousands of receptors in the mouth. These receptors are located primarily on the tongue, but some are also found in your throat, inside your cheeks, and on the roof of your mouth.

(p 214) 

Taste

What is the purpose of taste? 

Evolutionary reasons involve our ability to decipher what's healthy, protein, or calorie-packed from poisonous.

(p 214) 

 Taste

What are the four basic tastes?

salty

sour

bitter

sweet

(p 214) 

The Gate Control Theory explains that pain impuulses must get past a "gate" in the spinal cord, and then travel to the brain to be recognized as pain.

Another theory, the Neuromatrix Theory, explains that pain can be, and often is, generated by the brain.

(p 218-219)