Module 3 Lesson 1 - Sensations Flashcards
1
Q
Sensation
A
A process in which sensory receptors (and the nervous system) receive and represent stimulus energies from an environment.
2
Q
Transduction
A
Conversion of one form of energy into another.
In sensation, this transformation of stimulus energy (sights, sounds, smells) into neural impulses allows the brain to properly interpret them.
3
Q
Absolute Threshold
A
The minimum stimulation required in order to detect a specific stimulus 50% of the time
4
Q
Signal Detection Theory
A
A theory which predicts how and when a faint stimulus (signal) is detected amid background stimulation (noise). This assumes there is no single absolute threshold, and detection depends partly on a person’s experience, expectations, motivation, and alertness.
5
Q
Subliminal Threshold
A
Below one’s absolute threshold for conscious awareness.
6
Q
Difference Threshold
A
The minimal difference required between stimuli for detection 50% of the time. We experience this as a just noticeable difference (or jnd).
7
Q
Sensory Adaptation
A
Diminished sensitivity due to constant stimulation.
8
Q
Wavelength
A
The distance from the peak of one light or sound wave to the next. Electromagnetic wavelengths vary from short blips of cosmic rays to the long pulses of radio transmission.
9
Q
Hue
A
The dimension of color is determined by the wavelength of light; we know these as color names (blue, green, etc…)
10
Q
Olfactory Nerve
A
The first cranial nerve (CN1) and relays sensory information about smell to the brain. The shortest cranial nerve, it is the only cranial nerve with one trunk instead of two.
11
Q
Pupil
A
The adjustable opening at the center of the eye; this is where light enters.
12
Q
Iris
A
A ring of muscle tissue that forms the colored portion of the eye around the pupil, it is responsible for controlling the size of the pupil opening.
13
Q
Lens
A
The transparent structure behind the pupil that changes shape to help focus images on the retina.
14
Q
Retina
A
The light-sensitive inner surface of the eye, containing the receptor rods and cones, as well as layers of neurons that start with the processing of visual information.
15
Q
Accommodation (lens)
A
A process in which the eye’s lens changes shape to focus near or far objects on the retina.
16
Q
Rods
A
Retinal receptors that detect black, white, and gray; this is needed for peripheral and twilight vision, when cones do not respond.
17
Q
Cones
A
Retinal receptor cells that are concentrated near the center of the retina, they function in daylight or well-lit conditions.
18
Q
Optic Nerve
A
The nerve that carries neural impulses from the eye to the brain.
19
Q
Blind Spot
A
The point at which the optic nerve leaves the eye to create a “blind spot.” This is because no receptor cells are located there.
20
Q
Feature Detectors
A
Nerve cells in the brain respond to specific features of the stimulus, like shape, angle, or movement.
21
Q
Depth Perception
A
The ability to see objects in 3 dimensions although the images that strike the retina are two-dimensional: allows us to judge distance.
22
Q
Cornea
A
The see-thru area of the outer lining of the eyeball, through which light initially passes.
23
Q
Convergence
A
The rotation of both eyeballs inward in the direction of light so the visual lies on correlating spots on the foveas. This lets the minutely variant visuals of an item viewed by each eyeball to join one another and shape one visual.
24
Q
Farsighted
A
Medically known as hyperopia or hypermetropia, this is a condition that results from the eye’s physical inability to focus an image correctly on the retina at the back of the eye.
This is the result of the eyeball being too short, and/or the lens of the eye not being flexible enough, for proper focus to occur.
25
Foveal Vision
The fovea is the central focal point on the retina in the eye around where the cones cluster. In fact, the fovea has only cones around it for detecting fine detail better.
26
Ganglion Cells (Retinal Ganglion Cells)
Neurons in the retina that send visual stimulation signals to the brain.
27
Nearsighted
An eye condition where one cannot see objects clearly from afar.
28
Fovea
The central focal point in the retina around which the eye’s cones cluster.
29
Young-Helmholtz Theory
The theory that the retina contains three different color receptors - each of them most sensitive to either red, green, or blue - which, when stimulated in combination, can produce the perception of any color.
30
Opponent-Process Theory
The theory that opposing retinal processes (red - green, yellow - blue, white - black) enables color vision. For ex: Some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green.
31
Audition
The sense or act of hearing
32
Middle Ear
The chamber between the eardrum and cochlea that contains three tiny bones (hammer, anvil, and stirrup) that concentrate the vibrations of the eardrum on the cochlea’s oval window.
33
Inner Ear
The innermost part of the ear that contains the cochlea, semicircular canals, and vestibular sacs.
34
Cochlea
A coiled, bony, fluid-filled tube in the inner ear; sound waves travel through the cochlear fluid trigger nerve impulses.
35
Conduction Hearing Loss
Hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea.
36
Sensorineural Hearing Loss
Hearing loss caused by damage to the cochlea’s receptor cells or to the auditory nerves; also called nerve deafness.
37
Cochlear Implant
A device for converting sounds into electrical signals and stimulating the auditory nerve through electrodes threaded into the cochlea.
38
Place Theory
In hearing, the theory that links the pitch we hear with the place where the cochlea’s membrane is stimulated.
39
Frequency Theory
In hearing, the theory that the rate of nerve impulses that travel up the auditory nerve matches the frequency of a tone, which enables us to sense its pitch.
40
Auditory Nerve
The portion of the eighth cranial nerve that deals exclusively with the sense of hearing. The nerve originates in the cochlea, where nerve fibers pass through several layers of nuclei in the brainstem and terminate in the auditory cortex. This is also known as the acoustic nerve-cochlear nerve.
41
Basilar Membrane
Structurally refers to a layer in the inner ear that separates the two fluid-filled tubes of the cochlea.
42
Gate-Control Theory
The theory that the spinal cord contains a neurological “gate” that blocks pain signals or allows them to pass on to the brain. The “gate” is opened by the activity of pain signals traveling up small nerve fibers and is closed by activity in larger fibers or by information coming from the brain.
43
Sensory Interaction
The principle that one sense may influence another, like when the smell of food influences the taste.
44
Kinesthesis
The system for sensing the position and movement of individual body parts.
45
Vestibular Sense
The sense of body movement and position, including the sense of balance.
46
Amplitude
The size of a stimulant or reaction.
47
Bipolar Cells (Retinal Bipolar Cells)
Cells that exist between photoreceptors and ganglion cells that act to transmit signals from the photoreceptors to the ganglion cells.
48
Equilibrium
The state of mental or physical balance or stability
49
Sound Localization (auditory localization)
The ability to identify both the position and changes in position of sound sources based on solely acoustic information.
50
Taste Sensations (Taste Transduction)
The sequence of events that convert chemical signals into taste sensations. As you take something in your mouth, the sensory receptors on the tongue catch the taste and send signals to the brain to identify how is it.
51
Texture Gradient
Applying to the progressively finer appearance of textures and surface grains of objects as the viewer moves away from them. Touch sensation is the sensation produced by receptors in the skin.
52
What are the seven senses and what do they do?
- Sight
- Smell
- Hearing
- Taste
- Touch
- Vestibular
- Kinesthetic
They all help us understand our environment. The senses relay information to the brain for analysis and a response.
53
Action potentials are always…
The same size, but there can be more or less in a given amount of period of time. More if it’s associated with more alertness.
54
Hearing. What does it use?
It does not use electromagnetic radiation, it is using compressional sound waves that are passed through the air. This vibrates the air to move into the ear.
55
What is the cochlea responsible for?
The fluid vibrates within the cochlea. Depending on the pitch, the vibration occurs at a different area. For ex. If a cochlea is very big, low-frequency sounds could be picked up.
Action potentials go to parts of the brain.
56
What energies do our vision and hearing process? What is this called?
Our vision processes light energy.
Our hearing processes sound waves.
This is called transduction.
Our brain uses the converted energy.
57
What are the three steps to convert energy into a different form?
1. Our senses receive the input.
2. Our senses transform or change this to process it.
3. The information is delivered to our brains.
58
What did Gustav Fechner study?
He studied how we hear, see, smell, etc… and at what rates. Absolute Threshold was his brainchild.
59
What is the Absolute Threshold?
It is the minimum stimulation needed to detect stimuli.
Ex. At a hearing test, the audiologist marks down where you hear stimuli 50% of the time.
60
What is the Difference Threshold?
It is the minimum difference between two stimuli needed to detect differences between the stimuli.
61
What is the JND and who discovered it?
Ernst Weber found that to detect differences between two stimuli, the difference must be proportional. This is referred to as the “Just Noticeable Difference (JND)” or “Weber’s Law.”
Ex. If you change the font size from 11 to 12, your teacher may fail to notice. But if you change it to 24, she would since it’d be obvious.
62
What is Signal Detection?
Signal Detection is when you process a weak stimulus that someone else may not. The Signal Detection Theory says that prior experiences influence the signals that can be detected by each person.
Ex. A waitress hears the rattling of ice in cups as a signal to fill the cups, while another person who does not work that same job may not pick up on this.
Ex. A soldier who has patrolled in a dangerous country hears every snap as he walks, so when he comes home, he hears movement much more readily than a civilian.
63
What is Sensory Adaptation?
Sensory Adaptation happens with diminished sensitivity to a constant stimulus. When the body is first exposed to a stimulus, neurons fire more often for you to detect the stimuli, however, as time goes on, the body adapts to the sense as neurons fire less and less.
Ex. You feel that the water is cold at first when you go to a swimming pool, but after being in it, you feel normal.
64
How does vision work?
The light hits the retina and the information is processed in the occipital lobe of the brain. Light travels in waves.
65
What is hue and what determines hue?
Hue is the color we see.The wavelength (distance from one peak to the next) determines hue.
66
What determines the intensity and brightness of the color?
The light wave’s amplitude.
67
Retina
Light-sensitive; contains the receptors for vision detection.
68
Cornea
A clear layer that covers the pupil and iris. It’s job is to protect the eye.
69
Lens
Once light passes through the pupil, it hits the lens, which works to project light rays into an image onto the back of the retina. The lens actually changes shape through a process known as accommodation, to focus the image onto the retina.
70
Pupil and Iris
The pupil is the black hole in the eye, and the Iris is the muscle that surrounds the pupil. They work together to control the amount of light that enters the eye.
People have different colored Iris’.
71
Rods
Rods are the neural receptors on the retina. Rods detect black and white, night-time vision, and peripheral vision.
72
Cones
Cones are the neural receptors on the retina. Cones detect color and detail.
73
Fovea
The spot on the retina directly behind the lens has a concentration of cones.This is the central focus and has the most clarity.
74
What happens after rods and cones are signaled?
They cause the bipolar cells to activate the ganglion cells, which continue the signal down the optic nerve through the thalamus to the visual cortex in the occipital lobe.
75
A blind spot is…
The point where the optic nerve leaves the eye, where there are no rods or cones.
76
According to Hubel and Wiesel, our brain activates what to break down what we see?
The brain activates feature detectors, nerve cells in the occipital lobe, to determine the edges, lines, shapes, angles, or movements that we see. It can detect motion, color, form, and depth.
77
Match the sense to one of its characteristics.
Vision - processed in occipital lobe
Hearing - dependent on cochlea
Smell - olfactory bulb sends signals to brain
Taste - gustatory cells are processors
Touch - is the largest sense
Vestibular - is processed in the ear
Movement - also called kinesthesis
78
Audition
Refers to hearing
79
How does sound travel?
In waves
80
What do wavelengths determine in hearing?
The sound frequency
81
What is frequency in hearing?
It is the pitch of the sound.
82
What defines the loudness of the sound?
Wave amplitude, height, determines the loudness of the sound.
83
Middle Ear
Sound waves travel to the middle ear, where they hit the tympanic membrane (ear drum), amplifying the waves and causing the 3 tiny bones in the ear - the malleus (Hammer), Incus (Anvil), and Stapes (Stirrup) - to send vibrations to the inner ear.
84
Inner Ear
Contains the semicircular canals and the cochlea, the sound waves travel into the cochlea. The cochlea’s lining is called the basilar membrane. Lined with tiny hair cells that move to trigger impulses to travel down the auditory nerve, through the thalamus, to the auditory cortex in the temporal lobe where the sound will be perceived.
85
What are the two theories on how pitch is determined?
Place Theory and Frequency Theory
86
What is Place Theory?
A theory stating that we hear different pitches based on where the sound waves hit inside the cochlea. In other words, the “place” the sound waves lands determines the pitch.
87
Frequency Theory
A theory stating that we hear different pitches because the frequency of the soundwave triggers the basilar membrane to vibrate at the same rate as the sound wave.
88
What is Olfaction?
This refers to our sense of smell.
89
How does smell work?
Different molecules in the air travel into our nose
This triggers olfactory receptor cells to trigger the olfactory nerve in the olfactory bulb
This sends the signal directly to the temporal lobe and parts of the limbic system responsible for memory and emotion.
This is why certain smells can trigger a memory and cause us to get emotional.
90
Smell is the only sense that…
Bypasses the thalamus of the brain
91
Taste is also known as …? What are the 5 tastes?
Taste is also known as gustation.
The five main tastes are sweet, salty, sour, bitter, and umami.
92
What is umami?
This was discovered last and is a savory, meaty taste.
93
What is taste strongly linked with?
The nose, but is also processed in the mouth and throat.
94
Taste receptors
The tiny bumps on the tongue, called taste buds. When eating, the saliva breaks down food and triggers the taste buds to send signals to different parts of the brain for interpretation.
95
What is sensory interaction? Example?
Sensory interaction is the notion that senses interact and influence each other, such as smell and taste.
96
What is synesthesia?
When senses go haywire and sensory interactions cross to become extreme. A person with this may smell certain sounds or see words in certain colors, or taste certain smells.
97
What is the largest sense? How sensitive is it?
Touch! This is because our entire skin processes touch. We have touch receptors unevenly distributed all over our body. Areas with higher concentration of touch receptors are more sensitive.
98
What are the three main sensations in touch?
Temperature, pressure, and pain.
99
Where is touching processed in the brain?
The spinal cord and brainstem.
100
What is the Gate-Control theory?
By Melzack, it states that as pain is experienced, a neurotransmitter known as Substance P (for pain) is released that “opens the gate” and allows people to know that there is hurting. The brain releases neurotransmitters such as endorphins and dopamine as a result to “close the gate” to minimize the sensation of pain.
101
What is vestibular and kinesthesis?
The sense of balance is vestibular and the sense of movement is kinesthesis.
102
What is responsible for our vestibular sense?
The semicircular canals in our inner ear are responsible for processing our sense of balance, but information can be taken in from vision and touch receptors too.
103
What does kinesthesis allow for, and where are the receptors for kinesthesis found?
Kinesthesis allows for the sense of body position and movement, and the receptors are found in the muscles, tendons, and joints.
104
What are some vision disorders?
Nearsightedness
Farsightedness
Astigmatism
Color blindness (varying degrees)
105
Young-Helmholtz Trichromatic Theory
A theory stating that we have three types of color receptors that process red, green, and blue. These cones combine to produce many different kinds of colors.
106
Opponent Processing Theory
A theory stating that we see color because color processing works in pairs. There are three pairs of opposing colors which are red-green, blue-yellow, black-white. When one color is stimulated, the opposing pair is inhibited, This explains why we see afterimages after staring at an image and then looking away.
107
What causes color blindness?
It is a genetic situation where the gene responsible for the cause is found on the X chromosome, which helps to explain why more men are colorblind than females.
It is believed that faulty cones are to blame (remember… the three cones are red, green, and blue). When they function correctly, we have trichromacy. When there are two functioning cones instead of three, there is dichromacy colorblindness. The most common type would be red/green. People with no functioning cones have monochromacy, which only sees in shades of black, white, and gray.
108
Trichromacy vs. Dichromacy vs. Monochromacy
+ Trichromacy - Three functioning cones to produce different colors (normal sight)
+ Dichromacy - Two functioning cones, limited color blindness (usually red/green)
+ Monochromacy - No functioning cones; everything is in shades between black and white.
