PSY2001 Flashcards
What happens when you see an object?
Light reflected from the object strikes your eyes
The optic nerve comes from what type or types of cells?
Ganglion cells
Where do the rods and cones of the retina send their input?
To bipolar cells within the eyeball
Where do the bipolar cells of the retina send their input?
To ganglion cells
Where does light from the right side of the world go?
To the left half of each retina
What causes the blind spot of the retina?
The optic nerve exits the eye at that point
What is one reason why you don’t notice the blind spot of the eye in everyday life?
Anything in the blind spot of one eye is visible to the other eye
What is the fovea?
The center of the retina
In which of these ways is a hawk’s eye specialized?
It has more receptors on the top half of the retina than the bottom
Why is vision less detailed in the periphery?
In the periphery, many receptors converge onto each bipolar cell
Why does vision in the periphery have high sensitivity to faint light?
Toward the periphery, the retina has more convergence of input
What are the effects from having so many receptors converge their inputs onto the bipolar cells in the periphery of the eye?
Good perception of faint lights, but poor perception of detail
In which of these ways does foveal vision differ from peripheral vision?
Foveal vision has better acuity but less sensitivity to dim light
According to the trichromatic theory, or Young-Helmholtz theory, how do we perceive color?
Each wavelength elicits a unique ratio of responses by three kinds of cones
What is color constancy?
The ability to recognize an object’s color after a change in lighting
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
What function does lateral inhibition serve in the visual system?
It sharpens contrast at borders
Why do ganglion cells have larger receptive fields than bipolar cells do?
Ganglion cells receive input from several bipolar cells
Where is the primary visual cortex?
Occipital cortex
What do people lose after damage to area V1?
All conscious vision
When you close your eyes and imagine a visual scene, where does the activity start?
In the memory and language areas of the cortex
Which of these is another term for the ventral stream in the visual system?
The “what” pathway
The inferior temporal cortex is especially important for which of the following?
Recognizing familiar objects
What might cause someone to be unable to perceive visual motion?
Damage to brain area MT
The fusiform gyrus responds most strongly to which of the following?
Faces
The ganglion cells in the human fovea, each connected to just one cone, are called _____ ganglion cells.
midget
The type of visual receptor found in the fovea is a _____.
cone
The Young-Helmholtz theory of color vision is also known as the _____ theory.
trichromatic
The theory devised to explain color constancy is the _____ theory.
retinex
The type of neuron that inhibits bipolar cells to produce lateral inhibition is a _____ cell.
horizontal
The “what” pathway and the “where” or “how” pathways for vision are called the _____ stream and the _____ stream.
ventral; dorsal
Damage to area MT (also called V5) causes _____ blindness.
motion
Explain how we see images from the external world.
When we see a tree, for example, our perception is not in the tree. It is in our brain. We see something only when light from it alters our brain activity. Even if we did send out rays from our eyes—and we don’t—when they struck some object, we wouldn’t know about it, unless they bounced back and returned to our eyes.
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. Why?
When you look slightly to the side, the light falls on an area of the retina with more rods and more convergence of inputs. The result is greater sensitivity to faint light.
Describe the route for visual information, from the retinal receptors to the cortex.
Receptors connect to bipolar cells, which connect to ganglion cells, whose axons form the optic nerve. The optic nerves from the two eyes cross at the optic chiasm. Most of each optic nerve goes to the thalamus, which sends information to the visual cortex.
According to the trichromatic theory, how do we perceive color?
The retina has three types of cones, sensitive to short-, medium-, and long-wavelength light. The relative rate of response by the three types determines the color.
Explain lateral inhibition.
When light shines on a group of receptors, they excite bipolar cells, but they also excite horizontal cells. Horizontal cells inhibit all the bipolar cells around them, regardless of whether those cells had been excited or not. A bipolar cell that is stimulated by light but surrounded by other stimulated cells will have its response somewhat reduced. A bipolar cell that is next to stimulated cells on only one side will be inhibited less. A bipolar cell that is not stimulated, but is next to stimulated cells, is inhibited without being excited. The result is to enhance the contrast at edges.
What is blindsight, and what is a probable explanation?
Some people with damage to area V1 can respond to visual stimuli that they do not perceive consciously, by moving their eyes toward something, reaching for it, imitating an expression, or indicating an object’s shape, color, or direction of movement, while insisting that they are just guessing. In many if not all cases, connections are intact between visual areas of the thalamus and cortical areas outside V1.
What are the specializations of the ventral and dorsal visual streams?
The ventral stream responds to the shape of an object, identifying faces, objects, scenes, and movement. The dorsal stream attends primarily to the location of an object, guiding movement on the basis of visual information.
Under what condition do normal people become briefly motion blind, and what causes this?
While making a voluntary eye movement (a saccade), people become briefly motion-blind because area MT and part of the parietal cortex decrease their activity and receive less than usual blood flow.
The frequency of a sound corresponds to which aspect of perception?
Pitch
Why do different musical instruments sound different when they play the same note?
They differ in timbre
What is the function of the pinna?
It helps us locate the source of a sound
What is the function of the three tiny bones of the inner ear?
They amplify vibrations onto the oval window
What stimulates the auditory receptors (hair cells)?
Vibrations in the fluid in the cochlea
Which of the following limits the applicability of the frequency theory of pitch perception?
The refractory period of axons
According to the place theory, how do you identify the pitch of a sound?
By a traveling wave that peaks at one point on the basilar membrane
The traveling wave that peaks at a particular point along the basilar membrane enables us to perceive which aspect of a sound?
Pitch
What is one way in which areas A1 and V1 differ?
V1 damage causes blindness, but A1 damage doesn’t produce deafness
Legion has experienced damage to area A1, which of the following could Legion still do?
Localize a sound
Most neurons in the primary auditory cortex (A1) respond best to what?
A dominant tone and its harmonics
Most neurons in the secondary auditory cortex respond best to what?
Meaningful sounds, such as music or speech
A difference between your ears in time of arrival of a sound helps you identify what type of sound?
A sound with a sudden onset
A difference between your ears in loudness of a sound helps you identify what type of sound?
A high-frequency sound
A phase difference of a sound between your ears helps you identify what type of sound?
A low-frequency sound
What structure enables us to localize sounds in the up–down axis?
The pinna
What causes conductive deafness?
Impairment of the bones of the middle ear
Which of the following could cause nerve deafness?
Damage to the hair cells
Hearing improves if the listener watches the:
speaker’s face
What does the vestibular system enable you to do?
Read while jiggling your head
Which of the following does your vestibular system tell your brain?
Which direction you are moving
To what extent does the nervous system maintain separate representations of touch, heat, pain, and other aspects of somatic sensation?
Different types remain separate even in the cortex
The anterior cingulate cortex and the insular cortex respond to what aspect of skin sensations?
Pleasantness or unpleasantness
Where are the taste buds in adult humans?
Along the edge of the tongue
The saccule, utricle, and the three semicircular canals produce _____ sensation.
Vestibular
Someone who perceives each letter and number as having a particular color has the condition known as _____.
Synesthesia
What is the frequency theory of pitch perception, and why does it apply to lower frequencies and not to higher frequencies?
According to the frequency theory, the basilar membrane vibrates in synchrony with sound waves, causing the auditory nerve to produce action potentials at that frequency. This theory works for lower frequencies, but people can hear up to 20,000 Hz, and the refractory period of the axon prevents action potentials from approaching that level.
What is a major way in which the primary visual cortex differs from the primary auditory cortex?
After damage to the primary visual cortex, people become blind. Damage to the primary auditory cortex impairs perception of speech, music, and other meaningful sounds, but it does not make one totally deaf.
Why is it harder to read while jiggling a page than while jiggling your head?
When you move your head, the vestibular system monitors the head movements and makes compensatory movements of your eyes. It can’t help when you jiggle the page.
If you had a cut through the left or right half of your spinal cord, why would it affect touch sensations and pain differently?
The axons conveying pain cross immediately to the opposite side of the spinal cord, whereas the axons conveying touch travel up the ipsilateral side of the cord until they reach the medulla. Therefore, a cut through half of the spinal cord would destroy touch information from that side of the body, and pain information from the opposite side.
What factors contribute to individual differences in olfactory sensitivity?
People differ in olfactory sensitivity because of genetics, age, illness, and gender.
For a small animal, seeing a predator can activate mainly the sympathetic or parasympathetic nervous system, depending on what?
Distance to the predator
Other things being equal, which of the following would increase your probability of feeling angry?
Standing instead of lying down
Which of the following increases (slightly) your rating of a cartoon as being funny?
Holding a pen with your teeth
Which of the following would be a test of the facial-feedback hypothesis?
Does holding a pen with your teeth make you feel happier?
Can you identify someone’s emotion by measuring autonomic activities? If so, how?
No, you cannot.
Which of the following is part of the limbic system?
Amygdala
When researchers recorded brain activity during emotions, what conclusion resulted?
The activity evoked by any emotion varies among studies
The insula, an area important for taste, is also especially important for which type of emotion?
Disgust
The behavioral activation system tends to be associated with which emotions?
Happiness and anger
The behavioral activation system tends to be associated with which part of the nervous system?
Left hemisphere
People with greater right-hemisphere than left-hemisphere activity tend to be what?
Withdrawn and cautious
What evidence indicates that some human emotional expressions are partly built-in?
People blind since birth have many expressions like sighted people
Researchers who doubt the idea of six basic emotions prefer what alternative?
Emotions vary along one or more continuous dimensions
The gene that is most widely studied with regard to human violent behavior regulates the production of what chemical?
Monoamine oxidase A
What brain area is most responsible for the danger and safety signals that raise or lower anxiety?
Amygdala
What does amygdala research tell us about the concept of fear?
What we call fear is a combination of independent reactions
Which of the following is true of SM, the woman with damage to her amygdala?
She seldom makes eye contact
Why do people with amygdala damage have trouble recognizing expressions of fear?
They fail to make eye contact
Response of the amygdala correlates most strongly with which of these?
Frequency of laughing
The behavioral activation system is associated mostly with activity of the _____ hemisphere.
left
What type of studies have researchers conducted to test the facial-feedback hypothesis?
They induced a smile by asking people to hold a pen with their teeth, or they prevented a smile by asking people to hold a pen with their lips. Then they asked people to rate how funny certain cartoons were.
Many studies reported that people throughout the world can recognize six facial expressions of emotion. What aspect of those studies led to overestimating people’s accuracy?
People were given the emotion labels and they were asked to match them to six expressions. They did not have the option of saying that an expression matched none of the labels. If they know one of the expressions, such as happiness, they improve their guessing chance for the others. If they know five of the expressions, they get the sixth one for sure by process of elimination.
How does instrumental conditioning differ from classical conditioning?
In instrumental conditioning, the learner’s behavior affects the outcome
According to Pavlov, what happened as a result of classical conditioning?
The animal reacted to the CS as if it were the UCS
Lashley’s search for the engram was an attempt to test whose theory of learning?
Pavlov
Why did Lashley make cuts in rats’ cerebral cortex?
He was trying to interrupt CS-US connections
What evidence led Lashley to draw his conclusions of equipotentiality and mass action?
Impairment of learning depended on the amount of damage rather than the location
In what brain area did Thompson and colleagues localize the engram for conditioned eyeblinks?
Cerebellum
Thompson and colleagues conducted classical conditioning training while one brain area was temporarily inactivated. Which would be evidence that the brain area was necessary for this type of learning?
No responses during training, and later learning equal to untrained animals
When an animal made no responses during training but showed conditioned responses after brain recovery, what conclusion followed?
That brain area relays the response but does not produce the learning
How did Thompson test whether the red nucleus was necessary for learning a conditioned eyelid response?
They suppressed the red nucleus during training and tested the response later
Because Hebb couldn’t imagine a rapid yet stable chemical process in the brain, he proposed what distinction?
Short-term memory vs. long-term memory
How did Hebb propose that we store a short-term memory?
By a reverberating circuit
Why did researchers have to revise the original concept of memory consolidation?
Some long-term memories form much faster than others
Patient H. M. showed memory deficits after damage to what?
His hippocampus
What is meant by anterograde amnesia?
Inability to form new memories
What is meant by retrograde amnesia?
Loss of memory for previous events
What is meant by a semantic memory?
Memory of factual information
The delayed matching-to-sample task assesses what type of memory in laboratory animals?
Declarative memory
How does the hippocampus contribute to the contextual aspect of episodic memory?
It coordinates representations in cortical areas, in order
As time passes after an event, how does an episodic memory change?
It becomes more “gist”-like, and it depends more on the cerebral cortex
As time passes after an event, how does representation of an episodic memory change?
Representation in the hippocampus fades, and the cortical representation remains
How does memory storage in the hippocampus relate to memory storage in the cortex?
They develop in parallel from the start
What is a general way to describe hippocampal function?
It encodes ordered sequences
What brain area is most specialized for probabilistic learning? —i.e., learning what will probably happen when the outcome is not certain?
Striatum
The striatum is primarily responsible for which type of learning?
Gradually learning habits
Strengthening a memory and making it a long-term memory is called ____________________.
consolidation
What does endogenous mean?
Self-produced
How do migratory birds know when to fly north for the spring?
They have an endogenous circannual rhythm.
When an animal awakens at almost the same time every day in an unchanging environment, it provides evidence for which of the following?
Endogenous circadian rhythms
Workers on submarines with 18-hour cycles, what happens to their circadian rhythms?
It continues to average a bit more than 24 hours
Who would have the greatest difficulty keeping their alertness in phase with the clock?
Persons who are blind
What is the disruption of circadian rhythms after crossing time zones known as?
Jet lag
What does the suprachiasmatic nucleus (SCN) do?
It generates the circadian rhythm
What evidence strongly indicates that the SCN produces the circadian rhythm itself?
SCN cells produce a circadian rhythm of activity after being isolated from the body
What is unusual about the visual input to the SCN?
It does not depend on rods or cones
What information about light does the SCN record?
The average amount of light over time
What hormone does the pineal gland release?
Melatonin
What is characteristic of a minimally conscious state?
Brief periods of purposeful actions and limited speech comprehension
What is characteristic of brain death?
No brain activity at all
What do alpha waves (8–12 per second) on an EEG indicate?
Relaxation
Sleep spindles are associated with which of the following?
Memory consolidation
What do large, slow waves on an EEG indicate?
A low level of brain activity
Which would indicate that neuronal activity is highly synchronized?
Large, slow waves on the EEG
Paradoxical sleep is synonymous with what?
REM sleep
What does the EEG show during REM sleep?
Irregular, low-voltage fast waves
In terms of brain activity, REM sleep is most similar to what?
Stage 1 sleep
In what way might REM sleep be considered “deep” sleep?
Inhibited postural movements
Why are postural muscles least active during REM sleep?
Inhibition from the pons and medulla
The onset of increased REM depends mainly on what?
The time
Which part of the reticular formation contributes to cortical arousal?
Pontomesencephalon
When is the locus coeruleus most active?
During memorable or stressful events
What does the neurotransmitter histamine do?
It increases arousal and alertness
The transmitter orexin is important for which function?
Staying awake
What happens to someone who lacks orexin?
Alternation between brief periods of waking and sleeping
Why are we unconscious during sleep?
GABA inhibits synaptic spread of information
What happens to people’s body temperature during sleep?
It decreases by 1 or 2 degrees
When is the best time to memorize something?
Right before sleep
What process occurs during sleep to strengthen a memory?
The hippocampus replays a pattern that occurred during learning
Knowledge storage depends on highly synchronized _____?
Sharp wave ripples
What is one important way that memories strengthen during sleep?
The brain weakens or removes ineffective synapses
During REM sleep, where does brain activity increase?
Areas important for emotional processing
During REM sleep, postural muscles are inhibited by cells in the _____?
Pons and medulla
Axons from the locus coeruleus release what neurotransmitter?
Norepinephrine
PGO waves are an abbreviation for _____?
Pons-geniculate-occipital
During sleep, synaptic activity spread is blocked by increased release of _____?
GABA
What evidence indicates humans have an internal biological clock?
People who live 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 a 24-hour basis. People working on a submarine with an 18-hour work schedule are one example.
Why do people in east Germany prefer to wake up and go to sleep earlier than west Germany?
The sun rises about half an hour earlier at the eastern edge of Germany than at the western edge. Even when people try to follow the same work schedule, the sun continues to influence the timing of the circadian rhythm.
How does light reset the timing of the circadian rhythm in the SCN?
Light excites a special population of ganglion cells that have their own photopigment, enabling them to respond to light even if they receive no input from rods or cones. These ganglion cells respond slowly and decline slowly when light ceases, and therefore, they provide information about the average amount of light over a period of time, rather than instantaneous changes.
The left hemisphere of the brain sees which of the following?
The right side of the visual field
For which type of sensation does the left hemisphere receive input from both sides of the body equally?
Taste
What is an example to illustrate that sleep can be local within the brain?
1) In sleepwalking, the motor cortex and a few other areas are aroused while the rest of the brain is asleep. 2) During lucid dreaming, activity is high enough in the frontal and temporal cortex to enable conscious monitoring of dreams. 3) Sometimes people wake up but find they are temporarily unable to move their limbs due to cells in the pons remaining in REM sleep state.
What does the corpus callosum do?
It passes information between the hemispheres
Why don’t rabbits and humans have the same eye-hemisphere connections?
Both human eyes face forward
Where do half the axons from the eye cross to the opposite hemisphere?
Optic chiasm
What does the right hemisphere see?
The left visual field, by means of the right half of each retina
The split-brain operation was performed to relieve what condition?
Epilepsy
What can a split-brain person do that others cannot?
Move the hands at different speeds at the same time
What would be difficult/impossible for a split-brain person?
Pointing with the right hand to what the right hemisphere saw
Can a split-brain person name objects felt with hands?
Only with the right hand
What did Gazzaniga mean by the “interpreter”?
The way the left hemisphere invents explanations for actions
Increased right-hemisphere activity is associated with what emotion?
Depression
What happened when the right hemisphere was temporarily inactivated?
They described their past experiences without emotion
Why was the discovery of Broca’s area important?
It showed that a brain area could have a distinct function
People with Broca’s aphasia are most impaired with which words?
Prepositions and conjunctions
What characterizes Wernicke’s aphasia?
Difficulty remembering the names of objects
How is the speech of people with Wernicke’s aphasia?
Speech is fluent and grammatical, but it omits most nouns
How did researchers demonstrate consciousness in unresponsive people?
By using fMRI after asking people to imagine playing tennis
How did posterior parietal cortex cells respond to click counting?
One set counted the clicks on the left, and another counted clicks on the right
How did prefrontal cortex cells respond to click counting?
One set responded when the left side was ahead, and another when the right side was ahead
How does the ventromedial prefrontal cortex function in learning choices?
It learns about new information quickly
How do the basal ganglia function in learning choices?
They gradually learn over many trials which choice is usually better
What brain area isn’t working if someone bets the same regardless of probability?
Prefrontal cortex
What brain area isn’t working if someone changes bets based only on last outcome?
Basal ganglia
How would prefrontal cortex damage affect decision-making?
Decisions based on habits more than current information
Looking at pictures of loved ones activates same brain areas as what?
Addictive drugs
Which hormones intensify love relationships?
Oxytocin and vasopressin
How did split-brain patients answer questions about left visual field?
The left (speaking) hemisphere took a guess, either yes or no. The right hemisphere, which knew the correct answer, frowned if the guess was wrong. The left hemisphere felt the frown and corrected the guess. Both hemispheres can control and feel the facial muscles.
In most left-handed people, speech production depends on which hemisphere?
Left hemisphere
What is Gazzaniga’s concept for left hemisphere’s tendency to explain actions?
Interpreter
Understanding emotional tone depends mainly on which hemisphere?
Right hemisphere
Which cortex acts as scorekeeper for click counting?
Prefrontal cortex
Which cortex updates decisions with new information?
Prefrontal or ventromedial prefrontal cortex
What does right hemisphere contribute to language?
More responsive to emotional tone of communication, expressed by gestures or tone of voice
How did researchers infer consciousness in unresponsive people?
In response to an instruction to imagine playing tennis, these people activated the same areas that other people activate when imagining the same activity. When told to imagine walking through the house, a different set of brain areas became active, which were again the same ones active for other people imagining a walk through the house.
