Exam 2 - Ch 5-9
strabismus
(or strabismic amblyopia or lazy eye) a condition in which the eyes do not point in the same direction
polarization of rods at rest
-30 (the dark current)
Stage 1 sleep
-Light sleep -The brain emits alpha waves--> consistent with a relaxed state of wakefulness
hair follicle receptors
-Location: Hair-covered skin -Responds to Movement of hairs
number of axons in optic nerve
1 million
Anorexia stats
1% of women 0.033% of men
Bulimia stats
1.5% of women 0.5% of men
Percent of astigmatism in 4-year-olds
10
sleep spindle
12 to 14 Hz brain waves in bursts that last at least half a second (part of stage 2 sleep)
number of rods in retina
120 million
Rods outnumber cones
20:1
Mammals have ____or more kinds of bitter receptors, enabling them to detect many types of harmful substances.
30
How many kinds of taste receptors
5 - sweet, sour, bitter, salty, and glutamate (as in MSG) - maybe six, fats (unami)
Number of cones in retina
6 million
Percent of infants with astigmatism
70
Even people with an intact brain experience a brief period of motion blindness beginning about _____ before a voluntary eye movement and continuing during the eye movement.
75 ms
Over the course of about ______ minutes, a sleeper goes through stages 1, 2, and slow-wave sleep and then returns through stage 2 to a stage called REM (rapid eye movement sleep).
90
Cones provide about ________ of the visual input to the brain.
90%
How does light reset the biological clock?
A branch of the optic nerve, the retinohypothalamic path, conveys information about light to the SCN. The axons comprising that path originate from special ganglion cells that respond to light by themselves, even if they do not receive input from rods or cones.
The best way to classify a cell as simple or complex is to present the stimulus in several locations.
A cell that responds to a stimulus in only one location is a simple cell.
For this reason, we should avoid talking about the color of a wavelength of light.
A certain wavelength of light can appear as different colors depending on the background.
What is the shape of a receptive field of a ganglion cell?
A circle, with a surround that responds in the opposite way
Rodrigo is in a sleep lab having data collected via a polysomnograph. What is being collected about his sleep habits?
A combination of an EEG and his eye movements
What is the primary advantage of maintaining a constant high body temperature?
A constant high body temperature keeps an animal ready for rapid, prolonged muscle activity even in cold weather.
melatonin
A hormone manufactured by the pineal gland that produces sleepiness; hormone that influences both circadian and circannual rhythms
What type of cell is a taste receptor?
A modified skin cell
Why do most antihistamines make people drowsy?
A pathway from the hypothalamus uses histamine as its neurotransmitter to increase arousal. Antihistamines that cross the blood-brain barrier block those synapses.
Painful information takes two routes to the brain.
A route leading to the somatosensory cortex conveys the sensory information, including location in the body. A route to the anterior cingulate cortex conveys the emotional aspect.
How light resets the SCN
A small branch of the optic nerve, known as the retinohypothalamic path, from the retina to the SCN, alters the SCN's settings.
The ability to recognize faces correlates with the strength of connections between which brain areas?
Ability to recognize faces correlates with the strength of connections between the occipital face area and the fusiform gyrus.
Percentage of color deficiency
About 8 percent of northern European men (and a smaller percentage of men from other backgrounds) are red-green colorblind, compared with less than 1 percent of women
That principle was probably the first scientific discovery in psychology
About a thousand years ago, the Arab philosopher Ibn al-Haytham (965-1040) observed that when you open your eyes at night, you immediately see the distant stars. He reasoned that if you saw by sending out sight rays, they couldn't get to the stars that fast. Then he demonstrated that light rays bounce off an object in all directions, but you see only those rays that reflect off the object and strike your retina
What evidence suggests that absolute pitch depends on special experiences?
Absolute pitch occurs almost entirely among people who had early musical training and is also more common among people who speak tonal languages, which require greater attention to pitch.
Paul had a dream that he couldn't move. He thinks he had this dream because he couldn't move while he was asleep so his brain attempted to interpret the sensation as a dream about failing to move. According to Paul's logic, which theory best explains why he had this dream?
Activation-synthesis
If a kitten has one eye shut for its first few weeks of life, its visual cortex becomes insensitive to that eye. Why?
Activity from the active eye inhibits synapses from the inactive eye.
In what ways does the lateral hypothalamus facilitate feeding?
Activity of the lateral hypothalamus improves taste, enhances cortical responses to food, and increases secretions of insulin and digestive juices.
Examine Figure 5.9. According to the trichromatic theory, what causes you to perceive red?
Activity of the long-wavelength cone is not sufficient. In fact, notice that the long-wavelength cone responds to what we call yellow more than to what we call red. A perception of red occurs only if the long-wavelength cone has a high ratio of response relative to the other two types of cone.
Would adding salt to the body's extracellular fluids increase or decrease osmotic thirst?
Adding salt to the extracellular fluids would increase osmotic thirst because it would draw water from the cells into the extracellular spaces.
Where do amacrine cells get their information
Additional cells called amacrine cells get information from bipolar cells and send it to other bipolar, amacrine, and ganglion cells.
What evidence suggests that certain types of feature detectors operate in the human visual cortex?
After you stare at a waterfall or other steadily moving display, you see stationary objects as moving in the opposite direction.
Where are the auditory receptors, known as hair cells?
Along the basilar membrane of the cochlea
A sharp decline in odor sensitivity is often an early symptom of
Alzheimer's disease or Parkinson's disease
amacrine cells
Amacrine cells refine the input to ganglion cells, enabling certain ones to respond mainly to particular shapes, directions of movement, changes in lighting, color, and other visual features
Which method of sound localization is more effective for an animal with a small head? Which is more effective for an animal with a large head? Why
An animal with a small head localizes sounds mainly by differences in loudness because the ears are not far enough apart for differences in onset time to be useful. An animal with a large head localizes sounds mainly by differences in onset time because its ears are far apart and well suited to noting differences in phase or onset time.
What are the contributions of angiotensin II and aldosterone?
Angiotensin II constricts the blood vessels, and stimulates neurons that produce hypovolemic thirst. Aldosterone causes the body to retain salt, at times when blood volume is low.
Why did mammals evolve a temperature of instead of some other temperature?
Animals gain an advantage in being as warm as possible and therefore as fast as possible. However, proteins lose stability at temperatures much above .
What evidence indicates that taste is not sufficient for satiety?
Animals that sham-feed chew and taste their food but do not become satiated.
In what way does eating increase after damage in and around the ventromedial hypothalamus? After damage to the paraventricular nucleus?
Animals with damage to the ventromedial hypothalamus eat more frequent meals. Animals with damage to the paraventricular nucleus of the hypothalamus eat larger meals.
How do ibuprofen and other nonsteroidal anti-inflammatory drugs decrease pain?
Anti-inflammatory drugs block the release of chemicals from damaged tissues, which would otherwise magnify the effects of pain receptors.
How is the auditory cortex like the visual cortex?
Any of the following: (a)Both vision and hearing have "what" and "where" pathways. (b)Areas in the superior temporal cortex analyze movement of both visual and auditory stimuli. Damage there can cause motion blindness or motion deafness. (c)The visual cortex is essential for visual imagery, and the primary auditory cortex is essential for auditory imagery. (d)Both the visual and auditory cortices need normal experience early in life to develop normal sensitivities.
What causes astigmatism?
Astigmatism results when the eyeball is not quite spherical. As a result, the person sees one direction of lines more clearly than the other.
Why are you likely to feel thirst just before bedtime? Would you feel just as thirsty if you went to sleep at an unusual time?
At bedtime, your body secretes vasopressin, which helps conserve water and also stimulates thirst. Both responses help you get through the night while you cannot drink. Your circadian rhythm triggers the increased vasopressin, so you would not feel as thirsty before going to sleep at an unusual time.
How do we perceive high-frequency sounds (above 4000 Hz)?
At high frequencies, the sound causes maximum vibration for the hair cells at one location along the basilar membrane.
How do we perceive middle-frequency sounds (100 to 4000 Hz)?
At intermediate frequencies, no single axon fires an action potential for each sound wave, but different axons fire for different waves, and so a volley (group) of axons fires for each wave.
Through which mechanism do we perceive low-frequency sounds (up to about 100 Hz)?
At low frequencies, the basilar membrane vibrates in synchrony with the sound waves, and each responding axon in the auditory nerve sends one action potential per sound wave.
When is melatonin mostly released?
At night, for all species
Where does the optic nerve exit from the retina?
At the blind spot
4 Symptoms of Nacrolepsy
Attacks of sleepiness during the day. Occasional cataplexy—an attack of muscle weakness while the person remains awake. Cataplexy is often triggered by strong emotions, such as anger or great excitement. (One man suddenly collapsed during his wedding ceremony.) Sleep paralysis—an inability to move while falling asleep or waking up. Many people have experienced sleep paralysis at least once or twice, but people with narcolepsy experience it frequently. Hypnagogic hallucinations—dreamlike experiences that the person has trouble distinguishing from reality, often occurring at the onset of sleep.
the ways in which the lateral hypothalamus promotes eating:
Axons from the lateral hypothalamus to the NTS (nucleus of the tractus solitarius), part of the taste pathway, alter the taste sensation and the salivation response to the tastes. When the lateral hypothalamus detects hunger, it sends messages that make the food taste better. Axons from the lateral hypothalamus extend into several parts of the cerebral cortex, facilitating ingestion and swallowing and causing cortical cells to increase their response to the taste, smell, or sight of food (Critchley & Rolls, 1996). The lateral hypothalamus increases the pituitary gland's secretion of hormones that increase insulin secretion. The lateral hypothalamus sends axons to the spinal cord, controlling autonomic responses such as digestive secretions (van den Pol, 1999). An animal with damage to the lateral hypothalamus has trouble digesting foods.
retinotopic organization
Axons from the retina maintain their relationship to one another—what we call their retinotopic organization—throughout their journey from the retina to the lateral geniculate and then from the lateral geniculate to the cortex.
Well over half of the human body's energy is devoted to which of the following?
Basal metabolism
Which species needs the most sleep per day?
Bats
Why can the fovea pick up acute details?
Because blood vessels and ganglion cell axons are almost absent near the fovea, it has nearly unimpeded vision. The tight packing of receptors aids perception of detail...each receptor in the fovea connects to a single bipolar cell, which in turn connects to a single ganglion cell that has an axon to the brain
If someone electrically stimulated the auditory receptors in your ear, what would you perceive?
Because of the law of specific nerve energies, you would perceive it as sound, not as shock. (Of course, a strong enough shock might spread far enough to excite pain receptors also.)
Pain travels slowly
Because the axons carrying pain information have little or no myelin, they conduct impulses relatively slowly, in the range of 2 to 20 meters per second (m/s)
Suppose light strikes the retina in a circle, surrounded by dark. Which bipolar cells will show the greatest response, and which will show the least?
Bipolars connected to the receptors just inside the circumference of the circle respond most. Those connected to receptors just outside the circumference respond least.
When food distends the duodenum, the duodenum releases the hormone CCK. By what peripheral mechanism (outside the brain) does it increase satiety?
CCK tightens the sphincter muscle between the stomach and the duodenum.
In what way does pain relief by cannabinoids differ from pain relief by opiates?
Cannabinoids act on the periphery, not the brain.
Orexin peptides are released by
Cells in the lateral and posterior nuclei of the hypothalamus
What is distinctive about visual perception in the inferior temporal cortex?
Cells respond to an object regardless of the angle of view.
The preoptic area and anterior hypothalamus (POA/AH) are critical for temperature control.
Cells there monitor both their own temperature and that of the skin and organs. When they receive input indicating an infection, they initiate responses that produce a fever.
The Columnar Organization of the Visual Cortex
Cells with similar properties group together in the visual cortex in columns perpendicular to the surface
Which of these observations provides evidence that we have several types of taste receptor?
Certain chemicals can modify one taste without affecting others.
Sleep often improves memory. How?
Certain synapses become weakened, enabling others to stand out by contrast.
clock proteins
Circadian Locomotor Output Cycles Kaput; trigger production of PER & TIM
In which of these ways do coldness receptors differ from heat receptors?
Coldness receptors respond to a change in temperature, not to the absolute temperature.
Color vision deficiency demonstrates which fundamental point about perception?
Color is in the brain and not in the light itself.
Figure 5.9 shows light at about 510 nm as green. Why should we nevertheless not call it "green light"?
Color perception depends not just on the wavelength of light from a given spot but also the light from surrounding areas. As in Figure 5.13, the context can change the color perception.
Of the following, which shows the LEAST brain activity?
Coma
Foveal Receptors
Cones
If someone has trouble recognizing faces, what pathway in the nervous system is probably deficient?
Connections between the fusiform gyrus and part of the occipital cortex
Sleep spindles in stage 2 sleep appear to be important for which of the following?
Consolidation of memory
An object that reflects all wavelengths equally ordinarily appears gray, but it may appear yellow, blue, or any other color, depending on what?
Contrast with surrounding objects
What early experience, if any, is necessary to maintain binocular input to the neurons of the visual cortex?
Cortical cells must usually receive simultaneous input from the two eyes.
Light on rods and cones
DECREASES their INHIBITORY output
What is one way in which the auditory cortex is not analogous to the visual cortex?
Damage to the primary auditory cortex does not cause deafness.
What is one way in which the auditory and visual cortices differ?
Damage to the primary visual cortex leaves someone blind, but damage to the primary auditory cortex merely impairs perception of complex sounds without making the person deaf.
Alternative hypothesis for REM sleep
David Maurice (1998) proposed that REM just shakes the eyeballs back and forth enough to get sufficient oxygen to the corneas of the eyes. The corneas, unlike the rest of the body, get oxygen directly from the surrounding air.
The ventral stream of the visual system is specialized for which of these?
Detailed identification of objects
To what extent does the nervous system maintain separate representations of touch, heat, pain, and other aspects of somatic sensation?
Different types of sensation remain separate even in the cerebral cortex.
If someone lacks the gene for digesting lactose, which of these outcomes is likely?
Discomfort after drinking milk
Foveal brightness sensitivity
Distinguishes among bright lights; responds poorly to dim light
According to the neurocognitive hypothesis, what are dreams?
Dreams are thinking that occurs under unusual conditions.
What is the most effective way to satisfy hypovolemic thirst?
Drink water containing some salt or other solutes.
Why do you stop drinking before water reaches the cells that need it?
Drinking inhibits neurons responsible for thirst.
Why is it difficult to watch your own eyes move when looking in the mirror?
During saccadic eye movements, activity decreases in area MT.
How do we identify a high-pitched sound?
Each frequency produces a peak response at one point along the basilar membrane.
Foveal convergence of input
Each ganglion cell excited by a single cone
Peripheral convergence of input
Each ganglion cell excited by many receptors
What is meant by a "tonotopic map"?
Each location in the auditory cortex responds to a preferred tone.
Why is vision most acute at the fovea?
Each receptor in the fovea has a direct line to the brain
Edward and his mother love the smell of freshly cut grass. However, recently Edward's mother has noticed that she cannot smell the grass as well as Edward can. What is the best explanation for this difference between the two?
Edward's mother is getting older
What is the shape of a receptive field of a simple cell in the primary visual cortex?
Either a bar or an edge, in a fixed position
visible light
Electromagnetic radiation that can be seen with the unaided eye; Visible light consists of electromagnetic radiation within the range from less than 400 nm (nanometer, or m) to more than 700 nm.
Why do opiates relieve dull pain but not sharp pain?
Endorphins block messages from the thinnest pain fibers, conveying dull pain, but not from thicker fibers, carrying sharp pain.
How can an investigator determine whether a sleeper is in REM sleep?
Examine EEG pattern and eye movements.
suvorexant
FDA approved sleep aid that blocks orexin receptors
Which of the following is the most correct description of a fever?
Fever is one way in which the body fights against bacteria.
How could a researcher determine whether a given neuron in the visual cortex is simple or complex?
First identify a stimulus, such as a horizontal line, that stimulates the cell. Then present the stimulus in several locations. If the cell responds strongly in only one location, it is a simple cell. If it responds in several locations, it is a complex cell.
Orexin's role(s) in feeding
First, it increases animals' persistence in seeking food . Second, orexin increases activity and motivation in general
Why do we not notice the bl
First, the brain fill sin the gap. Second, anything in the blind spot of one eye is visible to the other eye.
What was Ibn al-Haytham's evidence that we see only because light enters the eyes, not by sending out sight rays?
First, you can see distant objects such as stars far faster than we could imagine any sight rays reaching them. Second, when light strikes an object, we see only the light rays that reflect off the object and into the eyes.
saccule and utricle
Fluid-filled sacs of the vestibular organ that inform the brain about the body's orientation.
In most cases, blindsight apparently depends on what connection?
From the thalamus to the temporal cortex
Foveal sensitivity to detail
Good detail vision because each cone's own ganglion cell sends a message to the brain
In humans, what crosses to the contralateral hemisphere at the optic chiasm?
Half of each optic nerve, the part representing the nasal half of the retina
Carlos is being changed to an overnight shift at work. What would be the best conditions for him so that he adjusts?
He needs to buy dark curtains for the daytime and work under bright lights.
If researchers could find a safe drug that stimulates melanocortin receptors, what would be the probable benefit?
Helping people lose weight
After the proteins TIM and PER reach a high level during the day, what causes their level to decrease at night?
High levels of the proteins inhibit the genes that produce these proteins.
How does the idea of allostasis differ from homeostasis?
Homeostasis keeps certain body variables within a fixed range by reacting to changes. Allostasis acts in advance to prevent or minimize changes.
Certain drugs that relieve pain also relieve which of the following?
Hurt feelings
In what ways are hurt feelings similar to physical pain?
Hurt feelings activate the cingulate cortex, just as physical pain does. Also, acetaminophen decreases hurt feelings (as well as pleasant feelings).
What evidence shows that stomach distension is sufficient for satiety?
If a cuff is attached to the junction between the stomach and duodenum so that food cannot leave the stomach, an animal becomes satiated when the stomach is full.
What is the effect of closing one eye early in life? What is the effect of closing both eyes?
If one eye is closed during early development, the cortex becomes unresponsive to it. If both eyes are closed, cortical cells remain somewhat responsive for several weeks and then gradually become sluggish and unselective in their responses.
What early experience would cause a kitten or human child to lose stereoscopic depth perception?
If the eye muscles cannot keep both eyes focused in the same direction, the developing brain loses the ability for any neuron in the visual cortex to respond to input from both eyes. Instead, each neuron responds to one eye or the other. Stereoscopic depth perception requires cells that compare the input from the two eyes.
What results in increased hunger?
If the insulin level stays constantly high, the body continues moving blood glucose into the cells, including the liver cells and fat cells, long after a meal. Before too long, blood glucose drops, because glucose is leaving the blood without any new glucose entering
People who are blind because of cortical damage can still synchronize their circadian rhythm to the local pattern of day and night. Why?
If the retina is intact, melanopsin-containing ganglion cells can still send messages to the SCN, resetting its rhythm.
If rats are limited to eating for one hour a day, what determines whether or not they will lose weight?
If the room is cool and the rats have access to a running wheel, they will exercise enough to keep warm, which is also enough to force them to lose weight.
If you lacked vasopressin, would you drink like a beaver or like a gerbil? Why?
If you lacked vasopressin, you would have to drink more like a beaver. You would excrete much fluid, so you would need to drink an equal amount to replace it.
You sometimes find that you can see a faint star on a dark night better if you look slightly to the side of the star instead of straight at it. Why?
If you look slightly to the side, the light falls on an area of the retina with more rods and more convergence of input.
According to the opponent-process theory, under what circumstance would you perceive a white object as blue?
If you stared at a bright yellow object for a minute or so and then looked at a white object, it would appear blue.
What is an example of an unconscious response to visual information?
In blindsight, someone can point toward an object or move the eyes toward the object, despite insisting that he or she sees nothing.
peripheral vision
In short, foveal vision has better acuity (sensitivity to detail), and peripheral vision has better sensitivity to dim light
Why do many older people have trouble hearing speech in spite of wearing hearing aids?
In some cases the language areas of the cortex have become less responsive. Also, auditory areas of the brain have decreased levels of inhibitory neurotransmitters, and the result is decreased ability to focus attention on one speaker in a noisy environment.
Examine Figure 5.17. You should see grayish diamonds at the crossroads among the black squares. Explain why.
In the parts of your retina that look at the long white arms, each neuron is inhibited by white input on two of its sides (either above and below or left and right). In the crossroads, each neuron is inhibited by input on all four sides. Therefore, the response in the crossroads is decreased compared to that in the arms.
bipolar cells
In the retina, the specialized neurons that connect the rods and cones with the ganglion cells.
Path of visual
In the vertebrate retina, however, messages go from the receptors at the back of the eye to bipolar cells, located closer to the center of the eye (see Figure 5.2). The bipolar cells send their messages to ganglion cells, located still closer to the center of the eye. The ganglion cells' axons join together and travel back to the brain
Temperature regulation is a likely explanation for which aspect of anorexia?
Increased exercise
What would happen as a result of adding salt to the body's extracellular fluids?
Increased osmotic thirst
Of the following groups, which one tends to spend the highest percentage of sleep in the REM stage?
Infants
The amygdala and related areas send two kinds of input to the lateral hypothalamus.
Inhibiting eating when ill, stimulating eating highly tasty foods (even when not hungry)
Why are people unconscious during slow-wave sleep?
Inhibitory transmitters block the spread of activity in the cortex.
Name three hormones that increase satiety and one that increases hunger.
Insulin, CCK, and leptin increase satiety. Ghrelin increases hunger.
Workers on certain submarines work 6 hours, relax 6 hours, and then sleep 6 hours. After weeks on this schedule, what happens to their circadian rhythm?
It continues producing the usual 24-hour rhythm.
What does vasopressin do?
It decreases urination and increases thirst.
When a new olfactory receptor forms to replace one that died, does it connect to the same site in the olfactory bulb as the previous receptor? If so, how?
It finds the correct site by chemical attraction.
Which of these does insulin do?
It helps glucose enter cells.
What is the role of orexin with regard to wakefulness and sleep?
It helps someone stay awake.
What is a feature detector?
It is a neuron that detects the presence of a particular aspect of an object, such as a shape or a direction of movement.
Why is REM sleep also known as paradoxical sleep?
It is deep sleep in some ways and light in others.
After light enters through the pupil,
It is focused by the lens (adjustable) and cornea (not adjustable) and projected onto the retina, the rear surface of the eye, which is lined with visual receptors.
What is the primary advantage of maintaining a constant high body temperature?
It keeps the muscles ready for rapid, prolonged activity even in cold weather.
If light strikes only one receptor, what is the net effect (excitatory or inhibitory) on the nearest bipolar cell that is directly connected to that receptor? What is the effect on bipolar cells to the sides? What causes that effect?
It produces more excitation than inhibition for the nearest bipolar cell. For surrounding bipolar cells, it produces only inhibition. The reason is that the receptor excites a horizontal cell, which inhibits all bipolar cells in the area.
The POA/AH integrates several types of information
It receives input from temperature receptors in the skin, in the organs, and in the hypothalamus. also receives input from the immune system, which reacts to an infection by sending prostaglandins and histamines to the POA/AH
What does the anterior cingulate cortex contribute to both the sense of touch and the sense of pain?
It responds to the emotional aspect of the sensation.
Where does the optic nerve start and where does it end?
It starts with the ganglion cells in the retina. Most of its axons go to the lateral geniculate nucleus of the thalamus, but some go to the hypothalamus and superior colliculus.
How do jalapeños produce a hot sensation?
Jalapeños and other hot peppers contain capsaicin, which stimulates receptors that are sensitive to painful heat.
Why do many older people have trouble understanding speech despite using hearing aids?
Lack of inhibitory transmission in the auditory cortex
_________ intestine absorbs water and minerals and lubricates the remaining materials to excrete them.
Large
What do large, slow waves on an EEG indicate?
Large, slow waves indicate a low level of activity, with much synchrony of response among neurons.
Most dominant zeitgeber for land animals
Light
11-cis retinal, all-trans retinal
Light converts 11-cis-retinal to all-trans-retinal, thus releasing energy that activates second messengers within the cell
Inversion of images
Light from the left side of the world strikes the right half of the retina, and vice versa. Light from above strikes the bottom half of the retina, and light from below strikes the top half.
Suppose you perceive something as red. According to the trichromatic theory, what is the explanation?
Light from the object has excited your long-wavelength cones more strongly than your other cones.
What happens when you see something?
Light rays reflect off the object and strike your retina.
In what way do olfactory receptors resemble metabotropic neurotransmitter receptors?
Like metabotropic neurotransmitter receptors, an olfactory receptor acts through a G protein that triggers further events within the cell.
Ruffini endings
Location: Any skin area Responds to: skin stretch
Merkel's disks
Location: Any skin area Responds to: static touch
Pacinian corpuscles
Location: Any skin area Responds to: sudden touch (deep pressure) and vibration
Krause end bulbs
Location: Mostly hairless areas Responds to: uncertain
Simple Cells
Location: V1 Binocular input: Y Size of receptive field: smallest Shape of receptive field:Bar- or edge-shaped, with fixed excitatory and inhibitory zones
Complex cells
Location: V1 & V2 Binocular Input: Y Size of Receptive Cell:Medium Shape of Receptive Cell:Bar- or edge-shaped, but responding equally throughout a large receptive field
End-stopped Cells
Location: V1 & V2 Binocular Input: Y Size of Receptive Field: Largest Shape fo Receptive Field: Same as complex cell, but with a strong inhibitory zone at one end
Free nerve ending
Location: any skin area Responds to: pain & temperature
Meissner's corpuscles
Location: hairless areas Responds to: movement across skin
Which of the following do scientists accept as an advantage of a high body temperature?
Mammals with a high body temperature can stay constantly ready for vigorous activity.
What tends to activate the locus coeruleus?
Meaningful information
Which neuropeptide from the arcuate nucleus to the paraventricular nucleus is most important for satiety?
Melanocortin
The receptors for sweet, bitter, and umami tastes all resemble which of these?
Metabotropic synaptic receptors
For most young adults, what happens to mood as a function of time of day?
Mood tends to be most pleasant in late afternoon or early evening.
Why do most Southeast Asian adults avoid drinking much milk?
Most Southeast Asian adults lack the genes that help digest lactose, the main sugar in milk.
If you awaken but find you temporarily cannot move your arms or legs, what is happening?
Most of your brain is awake, but part of your pons and medulla remain in REM sleep.
What is the mean life span of an olfactory receptor?
Most olfactory receptors survive a little more than a month before dying and being replaced.
Damage to the MT and MST would result in which condition?
Motion blindness
What happens after damage limited to area MT?
Motion blindness
What kinds of individuals get more REM sleep than others? (Think in terms of age, species, and long versus short sleepers.)
Much REM sleep is more typical of the young than the old, and of those who get much sleep than those who get little.
In 1838, Johannes Müller described this insight as the law of specific nerve energies.
Müller held that whatever excites a particular nerve establishes a special kind of energy unique to that nerve. In modern terms, the brain somehow interprets the action potentials from the auditory nerve as sounds, those from the olfactory nerve as odors, and so forth.
Amy has only been asleep a few minutes. She is likely in _____ sleep.
NREM
Which type of hearing loss—conductive deafness or nerve deafness—would be more common among members of rock bands and why?
Nerve deafness is common among rock band members because their frequent exposure to loud noises causes damage to the cells of the ear.
When you move your eyes, why does it not seem as if the world is moving?
Neurons in areas MT and MST respond strongly when an object moves relative to the background, and not when the object and background move in the same direction and speed.
What are the differences between the parvocellular and magnocellular systems?
Neurons of the parvocellular system have small cell bodies with small receptive fields, are located mostly in and near the fovea, and are specialized for detailed and color vision. Neurons of the magnocellular system have large cell bodies with large receptive fields, are located in all parts of the retina, and are specialized for perception of large patterns and movement.
In adult humans, the VNO is tiny and has no receptors
Nevertheless, part of the human olfactory mucosa contains receptors that resemble other species' pheromone receptors
Do placebos relieve pain just by relaxation? And what is the evidence?
No. A placebo can relieve pain in one body part without affecting another.
At which time, if any, is slow-wave sleep most common?
Not immediately, but during the early part of the night's sleep
Note that acetylcholine is important for both wakefulness and REM sleep, states of brain arousal. Serotonin and norepinephrine interrupt REM sleep
Note that acetylcholine is important for both wakefulness and REM sleep, states of brain arousal. Serotonin and norepinephrine interrupt REM sleep
What is a major difference between olfactory receptors and those of the vomeronasal organ?
Olfactory receptors adapt quickly to a continuous odor, whereas receptors of the vomeronasal organ continue to respond. Also, vomeronasal sensations are apparently capable of influencing behavior even without being consciously perceived.
In what way is chronic pain like memory?
One mechanism for memory is that repeated stimulation at a synapse increases its later response to the same type of stimulation. Similarly, repeated pain messages increase a synapse's response to similar stimuli, and therefore the result is chronic pain.
Do opiates increase or decrease itch sensations?
Opiates increase itch by blocking pain sensations. (Pain decreases itch.)
If you stare at a white circle surrounded by a green background, and then look at a white surface, you perceive a green circle surrounded by a red background. What does this observation imply about the opponent-process theory?
Opponent-process color perception depends on the visual cortex, not just the cells in the retina.
Narcolepsy is linked to a deficit of which neurotransmitter?
Orexin
What is the relationship between orexin and narcolepsy?
Orexin is important for staying awake. Therefore, people or animals lacking either orexin or the receptors for orexin develop narcolepsy, characterized by bouts of sleepiness during the day.
REM sleep begins with ____ _______, which are waves of brain activity transmitted from the pons to the lateral geniculate to the occipital lobe.
PGO waves
Suppose you suffer a cut through the spinal cord on the left side only. For the part of the body below that cut, you will lose pain sensation on the right side of the body and touch sensation on the left side. Why?
Pain axons cross the spinal cord at once, but touch fibers do not.
pain begins
Pain sensation begins with the least specialized of all receptors, a bare nerve ending
Information about touch is sent from the body to the primary somatosensory cortex located in the _____ cortex.
Parietal
If someone can identify objects, but does not seem to know where they are, what location of brain damage is likely?
Parietal cortex
dorsal visual stream
Pathway that originates in the occipital cortex and projects to the parietal cortex. The "how" pathway (how action is to be guided toward objects)
ventral visual stream
Pathway that originates in the occipital cortex and projects to the temporal cortex. The "what" pathway (identifies what an object is)
How does sleep enhance memory?
Patterns that occurred during sleep resembled those that had occurred during learning, except that they were more rapid during sleep. Furthermore, the amount of hippocampal activity during sleep correlated highly with the subsequent improvement in performance
What evidence suggests that the somatosensory cortex is essential for the conscious perception of touch?
People are conscious of only those touch stimuli that produce sufficient arousal in the primary somatosensory cortex. Also, cells in the somatosensory cortex respond to what someone experiences, even if it is an illusion.
Under what circumstance does someone with an intact brain become motion blind, and what accounts for the motion blindness?
People become motion blind shortly before and during a saccade (voluntary eye movement), because of suppressed activity in area MT.
What factors contribute to individual differences in olfactory sensitivity?
People differ in olfactory sensitivity because of genetics, age, and gender.
Someone who has just awakened sometimes speaks in a loose, unconnected, illogical way. How could you explain this finding?
People often awaken from a REM period, because REM is abundant toward morning when people usually awaken. Different brain areas don't wake up all at once. Shortly after awakening, certain brain areas may still be in a REM-like state, and thinking may have an illogical, dreamlike quality.
What evidence indicates that humans have an internal biological clock?
People who have lived in an environment with a light-dark schedule much different from 24 hours fail to follow that schedule and instead become wakeful and sleepy on about a 24-hour basis.
What evidence suggests that human concepts rely on activation of the relevant sensory or motor areas of the cortex?
People with damage to the auditory cortex regard many sound-related words, such as "thunder," as if they were nonwords.
Absolute pitch is more common among what type of people?
People with extensive musical training beginning in early childhood
A circuit including the fusiform gyrus of the temporal cortex is specialized for recognizing faces.
People with impairments in this circuit experience prosopagnosia, a difficulty in recognizing faces despite nearly normal vision in other regards.
What causes narcolepsy?
People with narcolepsy lack the hypothalamic cells that produce and release orexin Possibly auto-immune
What behavioral evidence indicates that synesthesia is real, and not just something that people claim to experience?
People with synesthesia can find a 2 among 5s, or a 6 among 8s, faster than usual if they have different synesthetic colors, and slower if they have the same color.
In short, humans localize low frequencies by _____ differences, and high frequencies by _____ differences.
Phase; loudness
he vomeronasal organ responds to what stimuli?
Pheromones
Which aspect of pain is most responsive to relief by placebos?
Placebos primarily relieve the emotional aspect of pain.
Pain relief with placebo
Placebos reduce pain but they produce an even greater effect on the emotional response to pain, as recorded in the cingulate cortex
Peripheral sensitivity to detail
Poor detail vision because many receptors converge their input onto a given ganglion cell
What kind of animal tends to get more than the average amount of sleep?
Predators get much sleep, and so do species that are unlikely to be attacked during their sleep (such as armadillos).
_______ somatosensory cortex is essential for touch experiences
Primary
What is meant by allostasis?
Processes that anticipate future needs
Peripheral receptors
Proportion of rods increases toward periphery
Edwin Land
Proposed Retinex Theory
midget ganglion cells
Provide 70% of the input to the brain
During which part of a night's sleep is REM most common?
REM becomes most common toward the end of the night's sleep.
What evidence from rats suggests that bulimia resembles an addiction?
Rats that alternate between food deprivation and a very sweet diet gradually eat more and more, and they react to deprivation of the sweet diet with head shaking and teeth chattering, like the symptoms of morphine withdrawal.
What is the route from retinal receptors to the brain?
Receptors connect to bipolars, which connect to ganglion cells, which send axons to the brain.
The fusiform gyrus is specialized for which of the following?
Recognizing faces and other highly familiar objects
Melatonin
Released mostly at night In diurnal animals like humans, it increases sleepiness. In nocturnal animals, it increases wakefulness.
If you were in a darkened room and researchers wanted to "read your mind" just enough to know whether you were having visual fantasies, what could they do?
Researchers could use fMRI, EEG, or other recording methods to see whether activity increased in your primary visual cortex.
Peripheral brightness sensitivity
Responds to dim light; poor for distinguishing among bright lights
What evidence most strongly indicates that the SCN produces the circadian rhythm itself?
SCN cells isolated from the body continue to produce a circadian rhythm.
What evidence strongly indicates that the SCN produces the circadian rhythm itself?
SCN cells produce a circadian rhythm of activity even if they are kept in cell culture isolated from the rest of the body. Also, when hamsters received transplanted SCN neurons, their circadian rhythm followed the pattern of the donor animals.
Lateral Inhibition in the Retina
Sharpens contrasts to emphasize the borders of objects The reduction of activity in one neuron by activity in neighboring neurons The response of cells in the visual system depends upon the net result of excitatory and inhibitory messages it receives
What light resets the circadian rhythm
Short-wavelength (bluish) light helps to reset the circadian rhythm better than long-wavelength light does
If you want to get to sleep on time, what should you avoid?
Short-wavelength light late in the evening
What kinds of people are most likely to develop sleep apnea?
Sleep apnea is most common among people with a genetic predisposition, old people, and overweight middle-aged men.
Which of the following is an ectothermic animal?
Snake
What evidence indicates that people learn their synesthetic associations, at least in some cases?
Some people have letter-color synesthesia that matches the colors of refrigerator magnets they played with in childhood.
Why are some people more sensitive than others are to low concentrations of taste or smell?
Some people have more taste receptors or odor receptors than others do
If someone reports seeing a particular letter in color, in what way is it different from a real color?
Someone who perceives a letter as yellow (when it is actually in black ink) can nevertheless see it on a yellow page.
Who would drink more pure water—someone with osmotic thirst or someone with hypovolemic thirst?
Someone with osmotic thirst would drink more water. Someone with hypovolemic thirst would drink more of a solution containing salts.
What would happen to the sleep-wake schedule of someone who lacked orexin?
Someone without orexin would alternate between brief periods of waking and sleeping.
What type of sound do we localize by comparing the time of arrival at the two ears?
Sudden sounds
For someone who is trying to lose weight, why would it be a good idea to cut down on sweets altogether?
Sugars provide many calories. Although fructose provides fewer calories for a given amount of sweet taste, it is less effective at triggering a sense of satiety. People who try to satisfy their sweet cravings with artificial sweeteners do not generally cut down on total calories. Furthermore, artificial sweeteners promote the types of intestinal bacteria that are associated with type 2 diabetes.
What do the high-amplitude slow waves of slow-wave sleep indicate?
Synchrony among neurons
Why do many high school students get worse test grades in the morning than in the afternoon?
Teenagers tend to stay up late and awaken late.
Homeostasis is a tendency to maintain a body variable near a set point.
Temperature, hunger, and thirst are almost homeostatic, but the set point changes in varying circumstances.
Of the following, which one is not associated with an increased probability of sleep apnea?
The Answer is B a) Having a relative with sleep apnea b) Being female c) Being overweight d) Being middle-aged
What are the sources of input to the POA/AH?
The POA/AH receives input from temperatures in the skin, the organs, and the hypothalamus. It also receives prostaglandins and histamines when the immune system detects an infection.
Light can reset the SCN's rhythm even after damage to all rods and cones. Why?
The SCN receives input from ganglion cells that respond to light.
Marina is staring at an optical illusion where she sees a version of the American flag that is colored green, yellow, and black. When the flag is removed and she stares at a blank screen, she sees an afterimage of the flag that is red, white, and blue. Which theory best explains this illusion?
The answer is A a. Opponent-process b. Dichromatic c. Trichromatic d. Retinex
Which of the following is NOT an important function of lateral inhibition?
The answer is A a. Stimulation allows you to see colors compared to black and white. b. A strong stimulus can suppress the response to another one that follows slightly after it. c. Stimulation of one spot on the skin weakens the response to stimulation of a neighboring spot. d. You can "filter out" irrelevant noise and focus on a person's speech.
Which of the following is the correct order for the visual pathway in the eye?
The answer is B a. Bipolar cells, receptors, retinal ganglion cells b. Receptors, bipolar cells, retinal ganglion cells c. Receptors, horizontal cells, retinal ganglion cells d. Receptors, retinal ganglion cells, horizontal cells
Peter is outside watching birds. Suddenly, he hears what sounds like a rare yellow warbler in a tree to his left. Which of the following did NOT help Peter to be able to locate the bird?
The answer is C a. Phase difference b. Time of arrival c. Pitch difference d. Sound shadow
Which of the following is NOT a theory of the function of sleep?
The answer is D a. Sleep is a time for conserving energy. b. Sleep is needed to perform cellular maintenance in neurons. c. Sleep is needed for reorganizing synapses and strengthening memories. d. Sleep is needed because our sensory systems (for example, vision) don't function as well at night.
Which of the following is true?
The answer is D a) High intake of sugar leads to hyperactive behavior. b) Turkey contains large amounts of chemicals that lead to sleepiness. c) Artificial sweeteners help to satisfy a craving for sweet tastes. d) Fish oils are beneficial for brain functioning.
How, then, do we remain unconscious in spite of sustained neuronal activity?
The answer is GABA-mediated inhibition.
Which part of the brain is generally considered the master area for control of appetite?
The arcuate nucleus
When a television set is off, its screen appears gray. When you watch a program, parts of the screen appear black, even though more light is actually showing on the screen than when the set was off. What accounts for the black perception?
The black experience arises by contrast with the brighter areas around it.
What evidence indicates that fever is an adaptation to fight illness?
The body will shiver or sweat to maintain its elevated temperature at a nearly constant level. Also, fish, reptiles, and immature mammals with infections use behavioral means to raise their temperature to a feverish level. Furthermore, a moderate fever inhibits bacterial growth and increases the probability of surviving a bacterial infection.
How does the brain code information?
The brain codes information largely in terms of which neurons are active, and how active they are at any moment. Impulses in certain neurons indicate light, whereas impulses in others indicate sound, touch, or other sensations.
Why do many people suffer chronic pain long after an injury has healed?
The brain has learned to increase its pain perception.
If someone injected into your tongue a chemical that blocks the release of second messengers, how would it affect your taste experiences?
The chemical would block your experiences of sweet, bitter, and umami but should not prevent you from tasting salty and sour.
f an infant is born with dense cataracts on both eyes and they are surgically removed years later, how well does the child see at first?
The child sees well enough to identify whether two objects are the same or different, but the child doesn't understand what the visual information means. In particular, the child cannot answer which visual display matches something the child touches. However, understanding of vision improves with practice.
Sensory information is coded so that the brain can process it.
The coded information bears no physical similarity to the stimuli it describes.
What might one predict about the sleep of fish that live deep in the ocean?
The deep ocean, like a cave, has no light and no difference between day and night. These fish might not need to sleep because they are equally efficient at all times of day and have no reason to conserve energy at one time more than another.
Downfall of Frequency Theory
The downfall of this theory in its simplest form is that the refractory period of a neuron, though variable among neurons, is typically about 1/1000 second, so the maximum firing rate of a neuron is about 1000 Hz, far short of the highest frequencies we hear.
Downfall of place theory
The downfall of this theory is that the various parts of the basilar membrane are bound together too tightly for any part to resonate like a piano string.
Which part of the body secretes CCK?
The duodenum
Certain animal species have evolved to sleep very little under which of these circumstances?
The environment is about the same 24 hours a day.
When you have an infection, what causes the fever?
The immune system delivers prostaglandins and histamine to the hypothalamus.
Suppose someone can describe an object in detail but stumbles and fumbles when trying to walk toward it and pick it up. Which is probably damaged, the dorsal path or the ventral path?
The inability to guide movement based on vision implies damage to the dorsal path
If someone is born with dense cataracts on both eyes, and the cataracts are removed years later, what happens?
The person gains some vision, but remains impaired on object recognition, motion vision, and depth perception.
How has the prevalence of obesity changed since the availability of high-fructose corn syrup and artificially sweetened diet beverages?
The prevalence of obesity has increased after the availability of both of these.
How do the proteins TIM and PER relate to sleepiness in Drosophila?
The proteins TIM and PER remain low during most of the day and begin to increase toward evening. They reach high levels at night, promoting sleep. They also feed back to inhibit the genes that produce them, so that their level declines toward morning.
When light strikes a receptor, does the receptor excite or inhibit the bipolar cells? What effect does it have on horizontal cells? What effect does the horizontal cell have on bipolar cells?
The receptor excites both the bipolar cells and the horizontal cell. The horizontal cell inhibits the same bipolar cell that was excited plus additional bipolar cells in the surround.
vestibular organ
The sensory structures in the inner ear that provide the brain with information about orientation and movement.
How do the responses to skin sensations differ between the somatosensory cortex and the insular cortex or the anterior cingulate cortex?
The somatosensory cortex is necessary for conscious perception of the location and type of skin sensation. The insular cortex and anterior cingulate cortex respond to the pleasantness.
Why do people at the eastern edge of a time zone awaken earlier than those at the western edge on their weekends and holidays?
The sun rises earlier at the eastern edge than at the western edge. Evidently, the sun controls waking-sleeping schedules even when people follow the same clock time for their work schedule.
Why do people in eastern Germany awaken earlier, on average, than those in western Germany?
The sun rises earlier in eastern Germany.
The brain has no specialized areas for perceiving flowers, clothes, or food. For what items does it have specialized areas?
The temporal cortex has specialized areas for perceiving places, faces, and bodies, including bodies in motion.
Sharp pain
The thicker and faster axons convey sharp pain. The thinner ones convey duller pain, such as postsurgical pain.
People with damage to the vestibular system have trouble reading street signs while walking. Why?
The vestibular system enables the brain to shift eye movements to compensate for changes in head position. Without feedback about head position, a person would not be able to correct the eye movements, and the experience would be like watching a jiggling book page.
area V1 (striate cortex)
The visual receiving area of the occipital lobe where signals from the retina and LGN reach the cortex and whose name indicates that it is the first visual area in the cortex
How do we identify a low-pitched sound?
The whole basilar membrane vibrates in synchrony with the sound frequency.
Why do people in Antarctica during the winter often find it difficult to work together?
Their circadian rhythms drift out of phase with one another.
As we progress from bipolar cells to ganglion cells to later cells in the visual system, are receptive fields ordinarily larger, smaller, or the same size? Why?
They become larger because each cell's receptive field is made by inputs converging at an earlier level.
According to a study by Kelly et al. (1999), naval personnel on submarines were asked to function on 18-hour "shifts": 6 hours of work, 6 hours of recreation, and 6 hours of sleep. What happened to their circadian rhythms?
They had a hard time deviating from the 24-hour schedule.
Why do some people have greater than average sensitivity to brief, faint, or rapidly changing visual stimuli?
They have more axons from the retina to the brain.
Why are supertasters more sensitive to tastes than other people are?
They have more taste buds.
How do taste and ghrelin promote eating and arousal?
They increase inhibition from the arcuate nucleus to the paraventricular nucleus, an area that inhibits the lateral hypothalamus.
What do horizontal cells in the retina do?
They inhibit bipolar cells.
How do ectothermic animals regulate their body temperature, if at all?
They move to a location with a more favorable temperature.
What do cells within a column of the visual cortex have in common?
They respond best to lines in the same orientation. Also, they are similar in their preference for one eye or the other, or both equally.
Why did the Pima begin gaining weight in the mid-1900s?
They shifted from a diet of local plants that were seasonally available to a calorie-rich diet that is available throughout the year.
How do whales and dolphins get oxygen at night?
They sleep in just one hemisphere at a time.
When frigate birds spend weeks at sea, what do they do about sleep?
They sleep only in brief episodes, and not much overall.
Why are leptin injections less helpful for most overweight people than for mice with a mutation in the leptin gene?
Those mice fail to produce leptin. Nearly all overweight people produce enough leptin, and extra leptin only weakly suppresses appetite.
People vary in their number of axons from the retina to the brain.
Those with more axons show a greater ability to detect brief, faint, or rapidly changing stimuli.
Why do people with very low insulin levels eat so much? Why do people with constantly high levels eat so much?
Those with very low levels, as in type 1 diabetes, cannot get glucose to enter their cells, and therefore, they are constantly hungry. They pass much of their nutrition in the urine and feces. Those with constantly high levels deposit much of their glucose into fat and glycogen, so within a short time after a meal, the supply of blood glucose drops.
Most dominant zeitgeber for marine animals
Tides
When ancient fish evolved into land animals, why did they need to evolve the elaborate mechanisms of the middle ear and inner ear?
To amplify sounds
What is the function of lateral inhibition in the retina?
To sharpen borders
Vision in the periphery of the retina has poor sensitivity to detail but great sensitivity to faint light. Why?
Toward the periphery, the retina has more convergence of input.
Thomas Young and Hermann von Helmholtz
Tri-chromatic theory/tri-color/component theory; theory that color is perceived through the relative rates of response by three kinds of cones, each one maximally sensitive to a different set of wavelengths
Suppose someone suffers from constant itching. What kinds of drugs might help relieve it?
Two kinds of drugs might help—histamines or capsaicin—depending on the source of the itch.
How do the pain-relieving effects of cannabinoids differ from those of opiates?
Unlike opiates, cannabinoids exert most of their pain-relieving effects in the peripheral nervous system, not the CNS.
Jeff was hit in the back of the head during a sporting match. Following the injury, he was unable to report conscious vision, visual imagery, and visual images in his dreams. The doctor thinks he suffered damage to his ____.
V1
Humans also respond somewhat to pheromones, although our receptors are in the olfactory mucosa, not the _______
VNO.
Why is color vision deficiency a better term than color blindness?
Very few people see the world entirely in black and white. The more common condition is difficulty discriminating red from green.
Understanding what you see requires much more than just adding up points and lines.
Vision is an active process based partly on expectations.
Which of these happens after you eat something salty?
Water flows out of the cells.
Why is it possible for us to taste a wide variety of chemicals as bitter?
We have 30 or more types of bitter receptors.
How do we manage to smell a wide variety of chemicals?
We have hundreds of types of olfactory receptors.
In what way is somatosensation several senses instead of one?
We have several types of receptors, sensitive to touch, heat, and so forth, and different parts of the somatosensory cortex respond to different kinds of skin stimulation.
According to the neurocognitive hypothesis, why do we have visual imagery during dreams? Why do dreams sometimes make an incoherent or illogical story?
We have visual imagery because areas of the visual cortex other than the primary visual cortex become active, without any input from the eyes. Dreams are sometimes incoherent or illogical because low activity in the prefrontal cortex means poor memory for what has just happened.
If you found a species with a high ratio of cones to rods in its retina, what would you predict about its way of life?
We should expect this species to be highly active during the day and seldom active at night.
How does weakening synapses during sleep improve memory?
Weakening the less active synapses enables the strengthened ones to stand out by contrast.
Most people find it easier to adjust to crossing time zones going _______than east.
West
If we want to predict how many hours a day some species sleeps, which of these questions would be most helpful in making that prediction?
What does the animal eat?
What would happen to someone's appetite if insulin levels and glucagon levels were both high?
When glucagon levels rise, stored glycogen is converted to glucose, which enters the blood. If insulin levels are high also, the glucose entering the blood is free to enter all the cells. So the result would be decreased appetite.
Blind spot interruptions
When the blind spot interrupts a straight line or other regular pattern, your brain fills in the gap.
What are two mechanisms by which CCK increases satiety?
When the duodenum is distended, it releases CCK, which closes the sphincter muscle between the stomach and duodenum. CCK therefore increases the rate at which the stomach distends. Also, neural signals from the intestines cause certain cells in the hypothalamus to release CCK as a neurotransmitter, and at its receptors, it triggers decreased feeding.
Under which of these circumstances would the semicircular canals respond most vigorously?
When you are moving and changing speed
Dale Purves
Whenever we see anything, we make an inference. That is, visual perception requires reasoning and inference, not just retinal stimulation.
What is the best-documented example of an effect of pheromones on humans?
Women who spend much time together tend to synchronize their menstrual cycles.
The vestibular system is responsible for which of these observations about behavior?
You can read a page better while shaking your head than while shaking the page.
Suppose you find a new, unusual-tasting food. How could you determine whether we have a special receptor for that food or whether we taste it with a combination of the other known taste receptors?
You could test for cross-adaptation. If the new taste cross-adapts with others, then it uses the same receptors. If it does not cross-adapt, it may have a receptor of its own. Another possibility would be to find some procedure that blocks this taste without blocking other tastes.
Why do you feel tired at the end of the day?
You feel tired at the end of the day because inhibitory processes in your brain force you to become less aroused and less alert
How do you see light
You see because light strikes your retina, causing it to send a message to your brain. You send no sight rays out to the object.
When you see a tree, for example, your perception is not in the tree. It is in your brain.
You see something only when light from the object alters your brain activity.
Suppose you suffer a cut through the spinal cord on the right side only. For the part of the body below that cut, will you lose pain sensation on the left side or the right side? Will you lose touch sensation on the left side or the right side?
You will lose pain sensation on the left side of the body because pain information crosses the spinal cord at once. You will lose touch sensation on the right side because touch pathways remain on the ipsilateral side until they reach the medulla.
If you had damage to your POA/AH, what would happen to your body temperature?
You would be much less able to shiver, sweat, or control other physiological mechanisms that control body temperature. However, you could still try to find a place in the environment that keeps you close to your normal temperature.
What would happen to sleeping and waking if you took a drug that blocked GABA?
You would remain awake, or at least somewhat conscious. (Tranquilizers put people to sleep by facilitating GABA.)
If we inserted a probe into your POA/AH and heated it, what would happen?
You would sweat.
If it were possible to flip your entire brain upside down, without breaking any of the connections to sense organs or muscles, what would happen to your perceptions of what you see, hear, and so forth?
Your perceptions would not change. The way visual or auditory information is coded in the brain does not depend on the physical location within the brain. Seeing something as "on top" or "to the left" depends on which neurons are active but does not depend on the physical location of those neurons.
olfactory bulb
a brain structure located above the nasal cavity beneath the frontal lobes
chorda tympani
a branch of the seventh cranial nerve (the facial nerve); Information from the receptors in the anterior two-thirds of the tongue travels to the brain along it
Receptive Fields follow
a chain of command (e.g., block manager reports to street manager reports to neighborhood manager reports to city manager...)
Capsaicin
a chemical, found in hot peppers, that produces a painful burning sensation
polysomnograph
a combination of EEG and eye-movement records
Narcolepsy
a condition characterized by frequent periods of sleepiness during the day
Bulimia nervosa
a condition in which people alternate between binges of overeating and periods of strict dieting
REM behavior disorder
a condition in which people move around vigorously during REM sleep REM sleep. linked to GABA deficiency
astigmatism
a decreased responsiveness to one direction of line or another, caused by an asymmetric curvature of the eyes
jet lag
a disruption of circadian rhythms due to crossing time zones
PGO waves
a distinctive pattern of high-amplitude electrical potentials that occur first in the pons, then in the lateral geniculate, and then in the occipital cortex
Bulemia resembles
a drug addiction (dopamine & opioid response, withdrawal symptoms)
placebo
a drug or other procedure with no pharmacological effects
oval window
a membrane of the inner ear
melanopsin
a photopigment present in ganglion cells in the retina whose axons transmit information to the SCN, the thalamus, and the olivary pretectal nuclei
vomeronasal organ (VNO)
a set of receptors, located near, but separate from, the olfactory receptors Wernicke-Korsakoff syndrome. See Korsakoff's syndrome
K-complex
a sharp brain wave associated with temporary inhibition of neuronal firing (part of stage 2 sleep)
periodic limb movement disorder
a sleep disorder characterized by repeated involuntary movement of the legs and sometimes the arms
locus coeruleus (dark blue place)
a small structure in the pons that emits bursts of impulses in response to meaningful events, especially those that produce emotional arousal
alpha waves
a steady series of brain waves at a frequency of 8 to 12 per second that are characteristic of relaxation
reticular formation
a structure that extends from the medulla into the forebrain; controls motor areas of the spinal cord and selectively increases arousal and attention in various forebrain areas
osmotic thirst
a thirst resulting from eating salty foods
hypovolemic thirst
a thirst resulting from loss of fluids due to bleeding or sweating
Fovea
a tiny area of the retina specialized for acute, detailed vision
set point
a value that the body works to maintain
absolute pitch (perfect pitch)
ability to hear a note and identify it
Prolonged use of morphine
activates immune system increasing pain sensitivity
Bianca is celebrating her birthday by having all of her favorite sweets: cake, ice cream, and soda. However, she notices that after she has eaten some cake, her ice cream doesn't taste as sweet. What might explain this?
adaptation
aldosterone
adrenal hormone that causes the body 9 the kidneys, salivary glands, and sweat glands to retain salt) to retain salt
Olfactory receptors are vulnerable to damage because they are exposed to the
air
Olfaction processes airborne chemicals that do not range
along a single continuum.
People communicate emotion by
alterations in pitch, loudness, and timbre
pineal gland
an endocrine gland located just posterior to the thalamus that releases the hormone melatonin
coma
an extended period of unconsciousness with a low level of brain activity
motion blindness
an impaired ability to perceive movement
Visual agnosia
an inability to recognize objects despite otherwise satisfactory vision
A fever represents
an increased set point for body temperature.
Melanocortin receptors in the paraventricular nucleus are important for limiting food intake,
and anything that damages these receptors leads to overeating
Hypovolemic thirst is triggered by the hormone ______________, which increases when blood pressure falls.
angiotensin II
paradoxical sleep
another name for REM sleep
The subfornical organ initiates thirst in ______________of future need, such as during a meal and shortly before bedtime. It __________________thirst after drinking, long before the ingested water reaches the cells that need it.
anticipation, decreases
The _____ nucleus of the _____ has one set of neurons sensitive to hunger signals and a second set sensitive to satiety signals.
arcuate; hypothalamus
basal forebrain
area anterior and dorsal to the hypothalamus; includes cell clusters that promote wakefulness and sleep
primary auditory cortex (area A1)
area in the superior temporal cortex in which cells respond best to tones of a particular frequency
secondary visual cortex (area V2)
area of the brain that processes information from the primary visual cortex and transmits it to additional areas
periaqueductal gray area
area of the brainstem that is rich in endorphin synapses
primary visual cortex
area of the cortex responsible for the first stage of visual processing
lateral hypothalamus
area of the hypothalamus that controls insulin secretion, alters taste responsiveness, and facilitates feeding in other ways
MT (middle temporal cortex)
area of the middle temporal lobe that is important for perception of visual motion
area V5
area of the middle temporal lobe that is important for perception of visual motion
A decrease in inhibition means net excitation, so to avoid double negatives, let's think of the receptors' output
as excitation of the bipolar cells.
Mammalian species have evolved ways of maintaining body water, ranging from frequent drinking (____________) to extreme conservation of fluids (__________). Humans alter their strategy depending on the availability of acceptable fluids.
beavers,gerbils
René Descartes
believed that the nerves from the eye would send the brain a pattern of impulses arranged like a picture of the perceived object, right side up
Geniculate
bent like a knee
The hardest color for the eye to see
blue; there are not as many short-wavelength cones in the eye
preoptic area/anterior hypothalamus, or POA/AH
brain area important for temperature regulation, thirst, and sexual behavior
fusiform gyrus
brain area of the inferior temporal cortex that recognizes faces
OVLT (organum vasculosum laminae terminalis)
brain area that detects osmotic pressure and salt content of the blood
subfornical organ (SFO)
brain structure adjoining the third ventricle of the brain, where its cells monitor osmotic pressure and sodium concentration
Nerves from the duodenum inform the brain not only about distension,
but also about the type and amount of nutrition
placebo effectiveness
but they often relieve pain, depression, and anxiety
otoliths
calcium carbonate crystals; tells the brain which direction you are moving & the direction of head tilts when one is at rest by pushing against different sets of hair cells
Digestion begins in the mouth, where enzymes in the saliva break down ____________.
carbohydrates
Regarding human digestion, _____ can be broken down in the mouth, whereas _____ must be digested in the stomach.
carbohydrates; proteins
Prolonged use of cannabinoids
cause memory impairment
Prolonged use of capsaicin
causes an excessive buildup of calcium in heat receptors, and damages the mitochondria in those receptors, rendering the cell nonfunctional for a substantial time
After an eye deprived of vision in adults is reopened,
cells gradually return to their previous levels of responsiveness
hunger neurons and satiety neurons receive input from
certain hormones such as insulin and leptin, but also from cells in the amygdala, basal forebrain, and thalamus
ghrelin
chemical released by the stomach during a period of food deprivation; also released as a neurotransmitter in the brain, where it stimulates eating
Theorists believe that the first sensory system of the earliest animals was a
chemical sensitivity
photopigments
chemicals contained in rods and cones that release energy when struck by light
pheromones
chemicals released by an animal that affect the behavior of other members of the same species
According to the trichromatic (or Young-Helmholtz) theory of color vision,
color perception begins with a given wavelength of light stimulating a distinctive ratio of responses by the three types of cones.
flavor
combination of taste and smell
retinex
combination of the words retina and cortex
We perceive the brightness of an object by
comparing it to other objects.
The nervous system determines the color of the light by
comparing the responses of different types of cones.
Determining the direction and distance of a sound requires
comparing the responses of the two ears.
place theory
concept that pitch perception depends on which part of the inner ear has cells with the greatest activity level
frequency theory
concept that the basilar membrane vibrates in synchrony with a sound, causing auditory nerve axons to produce action potentials at the same frequency
retinex theory
concept that the cortex compares information from various parts of the retina to determine the brightness and color for each area
vegetative state
condition in which someone has decreased brain activity and alternates between wakefulness and sleep but shows only limited responsiveness, such as increased heart rate in response to a painful stimulus
minimally conscious state
condition of decreased brain activity with occasional, brief periods of purposeful actions and limited speech comprehension
Brain death
condition with no sign of brain activity and no response to any stimulus
Ectothermic
controlling temperature by relying on external sources of heat or cooling
endothermic
controlling temperature by the body's physiological mechanisms
Prosody
conveying emotional information by tone of voice
As shown in Figure 5.16b, information from the nasal half of each eye (the side closer to the nose)
crosses to the contralateral hemisphere.
Visual agnosia results from
damage to the temporal cortex
adaptation
decreased response to a stimulus as a result of recent exposure to it
Actually, light striking the rods and cones _________their spontaneous output, and the receptors make __________ synapses onto the bipolar cells.
decreases; inhibitory
stereoscopic depth perception
depth perception created by input from both eyes
The inferior temporal cortex
detects objects and recognizes them despite changes in position, size, and so forth.
Area V1
detects spacial frequency, not bars or edges
Anorexia nervosa
disorder characterized by refusal to eat enough to remain healthy
The main signal to end a meal is ______________of the stomach
distension
In the visual system, the _____ stream is the "how" pathway whereas the ____ stream is the "what" pathway.
dorsal; ventral
According to the activation-synthesis hypothesis,
dreams are the brain's attempts to make sense of the information reaching it, based mostly on haphazard input originating in the pons.
According to the neurocognitive hypothesis,
dreams originate mostly from the brain's own motivations, memories, and arousal. The stimulation often produces peculiar results because it does not have to compete with normal visual input and does not get organized by the prefrontal cortex.
Bulimia nervosa has been compared to which of the following?
drug addiction
Greek meaning of Koniocellular
dust celled
Path of sound through the ear
ear canal, ear drum, hammer/anvil/stirrup, oval window, cochlea, auditory nerve
tympanic membrane
eardrum
Cell bodies in the lateral hypothalamus are most important for which of the following?
eating
What benefit of sleep applies to all species, even those with little or no nervous system?
energy conservation
basal metabolism
energy used to maintain a constant body temperature while at rest
histamine
enhances arousal and alertness
Activity in the primary somatosensory cortex corresponds to what someone is experiencing,
even if it is illusory.
Night terrors
experiences of intense anxiety from which a person awakens screaming in terror; more severe than a nightmare
phase advanced
falls asleep easily but awakens early
What produces leptin?
fat cells
Which part of the body secretes leptin?
fat cells
Soft sounds activate
fewer neurons
A pathway in the posterior temporal cortex and the parietal cortex specialized
for locating sounds
Taleesa took a pie out of the oven and let it cool for a while. She wants to test a bite, but before she does, she lightly touches it with her finger to see how hot it is. By touching it, her _____ will be able to let her know that it is now cool enough to eat.
free nerve endings
Sarah is playing the piano. Normally, her dog doesn't respond, but one particular song requires her to play a large number of higher notes. When she plays the high notes, her dog starts to howl because his ears are sensitive to the ____ of the high notes.
frequency
Tinnitus
frequent or constant ringing in the ears
optic nerve
ganglion cell axons that exit through the back of the eye and continue to the brain
midget ganglion cells
ganglion cells in the fovea of humans and other primates
The SCN generates circadian rhythms itself in a ______ controlled manner.
genetically
Information from the temporal half (the side toward the temporal cortex)
goes to the ipsilateral hemisphere.
Foveal color vision
good (many cones)
Huntington's disease
have widespread damage in the basal ganglia. In addition, most lose neurons in the hypothalamus, including the neurons that make orexin. As a result, they have problems staying awake during the day and difficulty staying asleep at night
conductive deafness or middle-ear deafness
hearing loss that occurs if the bones of the middle ear fail to transmit sound waves properly to the cochlea
Nerve deafness, or inner-ear deafness
hearing loss that results from damage to the cochlea, the hair cells, or the auditory nerve
Sounds higher in frequency are ________ in pitch
higher
Slow waves indicate that neuronal activity is
highly synchronized
Nolan has a fever. His doctor explains to him that a fever is a good thing because _____
his immune system functions better and many bacteria cannot grow well at the slightly higher temperature
negative feedback
homeostatic processes that reduce discrepancies from the set point
leptin
hormone released by fat cells in proportion to their volume; found only in vertebrates
cholecystokinin (ko-leh-SIS-teh-KI-nehn) (CCK)
hormone released from the duodenum that constricts the sphincter muscle between the stomach and duodenum, limiting the meal size
renin
hormone secreted by the kidney; it raises blood pressure by influencing vasoconstriction (narrowing of blood vessels)
angiotensin II
hormone that constricts the blood vessels, compensating for the drop in blood pressure; triggers thirst
antidiuretic hormone (ADH)
hormone that enables the kidneys to reabsorb water from urine; also known as vasopressin
The best gauge of insomnia—inadequate sleep—is
how someone feels the following day.
lateral inhibition
how the nervous system identifies borders between one object and another to begin filtering information
arcuate nucleus
hypothalamic area with sets of neurons for hunger and satiety
The SCN is part of the _________ and generate circadian rhythms for sleep and _____________
hypothalamus, temperature
Jose recently had a stomach virus that resulted in him having severe diarrhea for several days. Although he was constantly trying to drink water, his doctor started to get concerned that he was experiencing ____ and suggested that he drink fluids that would restore his ___ levels along with water levels.
hypovolemic thirst; salt
activation-synthesis hypothesis
idea that a dream represents the brain's effort to make sense of sparse and distorted information
gate theory
idea that stimulation of certain axons can close the "gates" for pain messages
opponent-process theory
idea that we perceive color in terms of opposites
a pathway in the anterior temporal cortex specialized for
identifying sounds
sleep apnea
impaired ability to breathe while sleeping
color vision deficiency
impaired ability to perceive color differences (colorblind)
An _________ in the osmotic pressure of the blood draws water out of cells, causing osmotic thirst.
increase
PER (period) and TIM (timeless) proteins
increase the activity of certain kinds of neurons in the SCN that regulate sleep and waking
sodium-specific hunger
increased preference for salty tastes
The sensitive period depends on
inhibitory neurons
agouti-related peptide (AgRP)
inhibitory transmitter that blocks the satiety actions of the paraventricular nucleus
lactase
intestinal enzyme that metabolizes lactose
Curt Richter (1967)
introduced the concept that the brain generates its own rhythms—a biological clock—and he reported that the biological clock is insensitive to most forms of interference.
The gene causing color vision deficiency
is on the X chromosome
arcuate nucleus of the hypothalamus
is regarded as the master area for controlling appetite
Because the horizontal cell is a local cell, with no axon and no action potentials,
its depolarization decays with distance.
magnocellular neurons
large cell bodies with large receptive fields that are distributed evenly throughout the retina
Morphine is not effective on
large-diameter axons that convey sharp pain. For that reason, morphine is ineffective against the sharp pain of a surgeon's knife. However, morphine does block messages from thinner axons that convey slower, duller pain such as postsurgical pain
Many older people have trouble attending to relevant information and filtering out the distractions,
largely because of the loss of inhibitory neurotransmitters in auditory areas of the brain.
Is it easier for people to follow a cycle slightly monger or shorter than 24 hours?
longer (as when travel WEST through time zones)
The frequency of awakenings correlates with
loss of cells in the hypothalamus, and with a tendency toward cognitive decline loss of cells in the hypothalamus, and with a tendency toward cognitive decline
As a rule, larger animals like elephants hear best at _____ pitches, and small animals like mice hear _____pitches, including a range well above what humans hear.
lower; higher
For high-frequency sounds, with a wavelength shorter than the width of the head, the head creates a sound shadow
making the sound louder for the closer ear.
People with sleep apnea have multiple brain areas that appear to have lost neurons, and consequently,
many of them show deficiencies of learning, reasoning, attention, and impulse control
Fourier analysis
mathematical procedure for breaking down complex waves into their component sine waves
Sleep deprivation impairs
memory, attention, and cognition It also magnifies unpleasant emotional reactions and increases the risk of depression
Receptors send messages to excite nearby bipolar cells (like giving them cookies) and also send .
messages to horizontal cells that slightly inhibit those bipolar cells and the neighbors to their sides (like subtracting cookies)
Sweetness, bitterness, and umami receptors resemble the
metabotropic synapses
The receptors for taste are not true neurons but
modified skin cells
Most of the time, humans drink ____ is needed.
more than
In contrast to parvocellular neurons, magnocellular neurons are more sensitive to _____.
movement
11-cis-retinal
needed for binding with opsin in the photoreceptor rod cells
olfactory cells
neurons responsible for smell, located on the olfactory epithelium in the rear of the nasal air passages
feature detectors
neurons whose responses indicate the presence of a particular feature
orexin or hypocretin
neurotransmitter that increases wakefulness and arousal
Sleep spindles increase in number after ___ ________, and the number of sleep spindles correlates positively with improvements in certain types of _______
new learning; memory
Taste information from the posterior tongue and the throat travels along branches of the
ninth and tenth cranial nerves.
Sleepiness is _____a voluntary or optional act.
not
Color is in the brain
not in the light or the object itself
frequency
number of cycles per second, measured in Hz
Somnambulism (sleepwalking)
occurs when a person arises and walks around while asleep
monogenic obesity
occurs when a single gene leads to obesity without other physical or mental abnormalities. People with a mutation in the gene for the melanocortin receptor (important for satiety) overeat and become obese from childhood onward
A ganglion cell has a receptive field consisting
of a circular center and an antagonistic doughnut-shaped surround.
Although the biological clock continues to operate in constant light or constant darkness, the _______of light resets the clock.
onset
Ewald Hering
opponent-process theory of color vision
Sleep spindles result from
oscillating interactions between cells in the thalamus and the cortex.
When the stirrup vibrates the ____ window, it sets into motion the fluid in the _____.
oval; cochlea
Which type of sensation inhibits itch sensations?
pain
insulin
pancreatic hormone that enables glucose to enter the cells
glucagon
pancreatic hormone that stimulates the liver to convert stored glycogen to glucose
Much of the output from the arcuate nucleus goes to the _______________ of the hypothalamus
paraventricular nucleus (PVN)
paraventricular nucleus (PVN)
part of the hypothalamus in which activity tends to limit meal size and damage leads to excessively large meals
lateral preoptic area
part of the hypothalamus that controls drinking
supraoptic nucleus
part of the hypothalamus that controls the release rate of vasopressin SWS. See Slow-wave sleep
suprachiasmatic (soo-pruh-kie-as-MAT-ik) nucleus, or SCN
part of the hypothalamus; provides the main control of the circadian rhythms; It gets its name from its location just above ("supra") the optic chiasm
pontomesencephalon
part of the reticular formation that contributes to cortical arousal
duodenum
part of the small intestine adjoining the stomach; first digestive site that absorbs nutrients
supertasters
people with a higher than average number of taste buds - tend to dislike strongly flavored foods
neuropeptide Y (NPY)
peptide that blocks the satiety actions of the paraventricular nucleus
opsins
photosensitive pigments in the photoreceptors: e.g., rhodopsin and photopsin
By altering the reflections of sound waves, the _____helps us locate the source of a sound
pinna
parahippocampal cortex responds to pictures of
places
Peripheral color vision
poor (few cones)
amusia results from
poor memory for pitch; auditory cortex is normal but has fewer connections; from either an impairment of the prefrontal cortex, or input to it from the auditory cortex.
inferior temporal cortex
portion of the cortex where neurons are highly sensitive to complex aspects of the shape of visual stimuli within very large receptive fields
What releases Vasopressin?
posterior pituitary
Continuous flash suppression
present a static stimulus to one eye, present 'flashes' of ever changing stimuli to the other eye, most people report not seeing the static stimulus
If you were in a darkened room and researchers wanted to know whether you were having visual fantasies (without asking you), they could measure activity in which brain area?
primary visual cortex
sham-feeding
procedure in which everything that an animal swallows leaks out a tube connected to the esophagus or stomach
How stress impairs memory
prolonged elevations of cortisol damage neurons in the hippocampus, a brain area important for memory.
neurocognitive hypothesis
proposal that dreams represent thinking related to recent memories under conditions of reduced sensory input
Olfactory receptors are ____________, each of them highly responsive to a few related chemicals and unresponsive to others. Vertebrates have hundreds of olfactory receptors, each contributing to the detection of a few related odors.
proteins
Leptin activates
puberty; the sympathetic nervous system and increases blood pressure
Aaron walks out into the bright sun. As he does, his _____ change size in response to the light.
pupils
Vasopressin
raises blood pressure by constricting blood vessels
a variant form of the FTO gene
raises someone's probability of obesity to about two-thirds greater than the average level
saccades
rapid movements of the eyes from one place to another
Each cell in the visual system of the brain has a _____, an area in visual space that excites or inhibits it.
receptive field
taste buds
receptors on the tongue that detect certain chemicals
Thomas Young
recognized that light required a biological explanation; showed that light, like waves, could be diffracted
cross-adaptation
reduced response to one taste after exposure to another CS. See Conditioned stimulus CSF. See Cerebrospinal fluid
ventromedial hypothalamus (VMH) - inhibits feeding
region of the hypothalamus in which damage leads to faster stomach emptying and increased secretion of insulin
polygenic or common obesity,
relates to many genes, each of which slightly increases the probability of obesity
vomeronasal organ (VNO)
respond only to pheromones
Magnocellular neurons
respond to movement & large overall patterns; not color sensitive
mechanical senses
respond to pressure, bending, or other distortions of a receptor
Area A1
responds to imagined sounds as well as real ones
area V1
responsible for visual imagery in thinking and dreams
Cingulate cortex
responsive to the emotional aspects of pain
negative color afterimage
result of staring at a colored object for a prolonged length of time and then looking at a white surface
Bertha was swimming at the beach and accidentally swallowed some seawater. Several minutes later, she realized that she feels really thirsty. This is because the salt in the seawater ______.
resulted in osmotic thirst
syndromal obesity
results when a gene causes a medical problem that includes obesity (overproduction of ghrelin)
cones
retinal receptor cells that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. The cones detect fine detail and give rise to color sensations.
rods
retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision, when cones don't respond
Taste is coded by the relative activity of different kinds of cells but also by the
rhythm of responses within a given cell.
endogenous circadian rhythms
self-generated rhythm that lasts about a day
endogenous circannual rhythm
self-generated rhythm that lasts about a year
After spinning around a bat during a race, Frank tried running in a straight line. However, he was dizzy due to the fluid movement within his ____.
semicircular canals
Everything in psychology starts with
sensations.
Parvocellular neurons
sensitive to detail and color because they are located in & near the fovea
somatosensory system
sensory network that monitors the surface of the body and its movements
Janella has been taking calcium supplements to support bone health. She is taking advantage of her body's _____, meaning that if she can get her blood calcium level above 0.16 g/L, she knows that the excess calcium will be stored in her bones.
set point
A saltiness receptor, which detects the presence of sodium,
simply permits sodium ions on the tongue to cross its membrane.
Taste receptors are modified _____ _____ inside taste buds in papillae on the tongue.
skin cells
PER & TIM promote
sleep & inactivity
slow-wave sleep
sleep occupied by slow, large-amplitude brain waves
Stage 2 sleep is characterized by ____________
sleep spindles and K-complexes
rapid eye movement (REM) sleep
sleep stage with rapid eye movements, high brain activity, and relaxation of the large muscles
paradoxical sleep
sleep that is deep in some ways and light in others
Circadian rhythms affect
sleep/wake cycles, and cylces in mood, eating, drinking, urination, hormone secretion, metabolism, sensitivity to drugs
_____________intestine has enzymes that digest proteins, fats, and carbohydrates
small
Stage 2 of sleep cycle
small bursts of activities spindles, nonrem sleep
parvocellular neurons
small cell bodies with small receptive fields in or near the fovea PCP. See Phencyclidine
koniocellular neurons
small ganglion cells that occur throughout the retina; small but variable receptive fields, some are color sensitive
Lucid dreaming
someone is dreaming but aware of being asleep and dreaming.
Only known animal w/o melatonin
sponges
Adapting to a Martian schedule
start work 39 minutes later each day (each day is 24hr39min)
Most common treatment for narcolepsy
stimulant drugs such as methylphenidate (Ritalin), which enhance dopamine and norepinephrine activity.
Acetylcholine
stimulates the basal forebrain cells that promote wakefulness, although those cells release other transmitters to the cortex
zeitgeber
stimulus that resets the circadian rhythm; "time giver"
Which part of the body secretes ghrelin?
stomach
cochlea
structure in the inner ear containing auditory receptors
nucleus of the tractus solitarius (NTS)
structure in the medulla that receives input from taste receptors
semicircular canals
structures located in the vestibular organ, oriented in three planes and lined with hair cells; sensitive to the directional tilt of the head
papillae
structures on a tongue's surface that contain taste buds
Neurons in the OVLT and ______________organ detect changes in osmotic pressure and send information to hypothalamic areas responsible for vasopressin secretion and for drinking.
subfornical
solutes
substance dissolved in a solution
lactose
sugar in milk
A placebo increases activity in parts of the prefrontal cortex,
suggesting that a placebo exerts its effects by top-down control of sensations and emotions
The most potent zeitgeber for land mammals is the _____.
sunlight
Cats, hyenas, seals, and sea lions have no
sweetness receptors
opioid mechanisms
systems that respond to opiate drugs and similar chemicals
Mammalian taste receptors are found inside _____ located in groups of 10 or more in _____ on the surface of the tongue.
taste buds; papillae
MST (medial superior temporal cortex)
temporal cortex area that responds best to the expansion, contraction, or rotation of a visual display
Osmotic pressure
tendency of water to flow across a semipermeable membrane from the area of low solute concentration to the area of high solute concentration
homeostasis
tendency to maintain a variable, such as temperature, within a fixed range
volley principle
tenet that the auditory nerve as a whole produces volleys of impulses for a sound even though no individual axon approaches that frequency
vagus nerve
tenth cranial nerve, which has branches to and from stomach and several other organs
lateral geniculate nucleus (LGN)
thalamic nucleus that receives incoming visual information
histamines
that dilate blood vessels and produce an itching sensation.
color constancy
the ability to recognize colors despite changes in lighting
blindsight
the ability to respond in limited ways to visual information without perceiving it consciously
Output from the locus coeruleus increases
the activity of the most active neurons and decreases the activity of less active neurons. The result is enhanced attention to important information and enhanced memory
allostasis
the adaptive way in which the body changes its set points depending on the situation
Pupil
the adjustable opening in the center of the eye through which light enters
Most human hearing takes place below 4000 Hz,
the approximate limit of the volley principle.
receptive field
the area in visual space that excites or inhibits any neuron
Pitch
the aspect of auditory perception related to the frequency of a sound (how high or low a sound is)
hair cells
the auditory receptors that lie along the basilar membrane in the cochlea
According to the law of specific nerve energies,
the brain interprets any activity of a given sensory neuron as representing a particular type of sensory information.
Hunger depends upon
the contents of your stomach and intestines, the availability of glucose to the cells, and your body's fat supplies, as well as your health and body temperature.
According to the retinex theory,
the cortex compares the responses across the retina to determine brightness and color of each object.
Information from touch receptors in the head enters the central nervous system (CNS) through
the cranial nerves.
Phase difference
the difference in arrival times of sound waves at each of the eardrums
retinal disparity
the discrepancy between what the left and right eyes see
Synesthesia
the experience some people have in which stimulation of one sense evokes a perception of that sense and another one also
prosopagnosia
the inability to recognize faces due to damage of several brain areas
amplitude
the intensity of a sound wave
The axons of the ganglion cells form the optic nerve, which leaves the retina and travels along
the lower surface of the brain.
MT, MST, & area V5 receive input from
the magnocelllular path
In addition to the somatosensory cortex, painful stimuli also activate a path that goes through
the medulla, and then to the thalamus, and then to the amygdala, hippocampus, prefrontal cortex, and anterior cingulate cortex
In addition to sleep, melatonin helps control
the onset of puberty & bodily adjustments to changes of season (hibernation)
pinna
the outer ear structure of flesh and cartilage that sticks out from each side of the head
blind spot
the point at which the optic nerve leaves the eye, creating a "blind" spot because no receptor cells are located there
optic chiasm
the point at which the optic nerves from the inside half of each eye cross over and then project to the opposite half of the brain
During REM, activity increases in
the pons (which triggers the onset of REM), the limbic system, parts of the parietal and temporal cortex
During REM sleep, activity decreased in
the primary visual cortex, the motor cortex, and the dorsolateral prefrontal cortex
timbre
the quality or complexity of a tone, dependent on its harmonics
According to the trichromatic theory, we discriminate among wavelengths by
the ratio of activity across the three types of cones
lateral inhibition
the reduction of activity in one neuron by activity in neighboring neurons
lateral inhibition
the reduction of activity in one neuron by activity in neighboring neurons, i.e., the retina's way of sharpening contrasts to emphasize the borders of objects.
Olfaction
the sense of smell, which is the response to chemicals that contact the membranes inside the nose
ganglion cells
the specialized cells which lie behind the bipolar cells whose axons form the optic nerve which takes the information to the brain
Evidence from a 6,500-year-old piece of chewing gum (Battersby, 1997) suggests that ____.
the urge to chew is strong
Part of the visual input goes to the thalamus and from there to
the visual cortex. Another part goes to the superior colliculus.
People with conductive deafness have a normal cochlea and auditory nerve, they readily hear
their own voices, conducted through the bones of the skull directly to the cochlea, bypassing the middle ear.
If you cannot imagine a sound,
then a word relating to sound seems meaningless
trichromatic theory
theory that color is perceived through the relative rates of response by three kinds of cones, each one maximally sensitive to a different set of wavelengths
The brain areas surrounding the ___________ventricle are in a good position to monitor the contents of the blood, because the blood-brain barrier is weak in this area, enabling chemicals to enter that would not reach neurons elsewhere in the brain.
third
hypovolemic (HI-po-vo-LEE-mik) thirst
thirst provoked by low blood volume
osmotic thirst
thirst triggered by certain neurons that detect the loss of their own water
How many types of heritability for obesity?
three
sensitive period
time early in development when experiences have a particularly strong and enduring influence
amusia
tone deafness (about 4% of people have it)
mechanical senses include
touch, pain, body sensations, & vestibular sensation (position & movement of head)
endorphins
transmitters that attach to the same receptors as morphine
path of somatosensory information
travel through the spinal cord in separate pathways toward the thalamus, which then sends impulses to different areas of the primary somatosensory cortex, located in the parietal lobe. Information about skin sensations also goes to areas such as the anterior portion of the cingulate gyrus (see Figure 3.10) and insular cortex, which respond only to the pleasantness of the sensation, not the sensation itself
Researchers estimate that people can distinguish among more than a ________olfactory stimuli.
trillion
phase delayed
trouble falling sleep
horizontal cells
type of cell that receives input from receptors and delivers inhibitory input to bipolar cells
melanocortins
type of chemical that promotes satiety
complex cells
type of visual cortex cell located in areas V1 and V2 that responds to a pattern of light in a particular orientation anywhere within its large receptive field
simple cell
type of visual cortex cell that has a receptive field with fixed excitatory and inhibitory zones
End-stopped
type of visual cortex cell that resembles complex cells; responds best to stimuli of a precisely limited type, anywhere in a large receptive field, with a strong inhibitory field at one end of its field
shortly before time to go to sleep, the body's circadian rhythm triggers increased secretion of ___________, which inhibits the need to urinate and therefore helps retain water when drinking cannot occur
vasopressin
A path of axons from the _____medulla releasing GABA promotes REM sleep
ventral
Shortest visible wavelength
violet
Although her vision is intact, Karin has an inability to recognize objects. She likely has _____.
visual agnosia
hypercomplex cells
visual cortex cells that respond to a bar-shaped pattern of light in a particular orientation, but only if it does not extend beyond a certain point
dorsal stream
visual path in the parietal cortex that helps the motor system locate objects; the "where" path
ventral stream
visual paths in the temporal cortex that are specialized for identifying and recognizing objects; the "what" path
According to the opponent-process theory of color vision,
visual system neurons beyond the receptors respond with an increase in activity to indicate one color of light and a decrease to indicate the opposite color. The three pairs of opposites are red-green, yellow-blue, and white-black.
semipermeable membrane
water can pass, solutes cannot
Functions of sleep
we rest our muscles, decrease metabolism, perform cellular maintenance in neurons, reorganize synapses, and strengthen memories.
We see white or gray
when all 3 types are cones are equally active
endopiriform cortex
where taste and smell axons converge
GABA,
which inhibits or interrupts behavior and promotes slow-wave sleep
