Psychology Exam 2

Question 1

Define Absolute Threshold

Answer 1

How weak a stimulus can be to be perceived 50% of the time

Question 2

What is Signal Detection Theory

Answer 2

how different two stimuli need to be before we can tell the difference between them. Can you tell the difference between a 40 watt bulb and a 42 watt bulb? Or does it need to be a 40 watt bulb and a 60 watt bulb before you can see the difference?

As it turns out, you decide how different the stimuli need to be. I may need to be absolutely certain before I’m comfortable saying that two stimuli are different. Maybe your decision criteria are less rigid.

Question 3

The Difference Threshold

Answer 3

The difference threshold is the smallest difference between two stimuli that you can detect 50% of the time. This is also called the just noticeable difference.

Question 4

Weber’s Law

Answer 4

two stimuli must differ by a constant minimum percentage before we can detect the difference between the stimuli.

Question 5

Subliminal Stimuli

Answer 5

A subliminal stimulus is a weak or brief stimulus that is picked up by your senses, but doesn’t make it into your conscious awareness.

Do you think that advertisers are able to shape your buying habits through subliminal messages?

The short answer is, ‘very slightly - very rarely.’ Marketers are far better off to blast your senses with bold letters, bright colours and loud sounds than to try and slip their message in under your radar.

Question 6

Cornea

Answer 6

The clear protective structure covering the front of the eye. The curvature of the cornea also bends light as it passes through the eye.

Question 7

Pupil

Answer 7

The hole through which light passes

Question 8

Anatomy of the Eye (5 parts)

Answer 8

Cornea, Pupil, Iris, Lens, Retina

Question 9

Iris

Answer 9

The coloured muscle that adjusts the size of the pupillary opening. In low light, the iris dilates the pupil. In bright light, the iris constricts the pupil.

Question 10

Lens

Answer 10

The primary focusing structure which produces a clear image on the retina. In people who have myopia (nearsightedness - see things well up close), the lens focuses the image in front of the retina (too near the lens). In people who have hyperopia (farsightedness - see things well far away), the lens focuses the image behind the retina (far from the lens).

Question 11

Retina

Answer 11

The layer of neural tissue at the rear of the eyeball

Question 12

Rods

Answer 12

are rod-like or wiener-shaped. They respond to light and dark and perform better in dim light than do cones. There are approximately 120 million rods per eye.

Question 13

Cones

Answer 13

are shaped like pine cones. They respond to colour and fine detail. There are approximately 6 million cones in each eye.

Question 14

What is the information path for the visual process?

Answer 14

Rods and cones synapse with bipolar cells and ganglion cells. The axons from the ganglion cells are bundled together and travel as the optic nerve to the thalamus and primary visual cortex (V1) in the occipital lobes.

Question 15

Horizontal Cells

Answer 15

help the rods and cones talk to the bipolar cells

Question 16

Amacrine cells

Answer 16

help the bipolar cells talk to the ganglion cells.

Question 16

Dark Adaptation

Answer 16

After absorbing light for a time, a rod or cone can become depleted of its photopigment. Dark adaptation is the gradual regeneration of photopigments and, therefore, the gradual improvement of brightness sensitivity under low light. If you’ve been out in the sun for awhile and walk into a dark room, it takes some time (approx 30 minutes) for your eyes to completely adjust - for the rods in particular to be sensitive to low light again.

Question 17

Visual Transduction

Answer 17

Rods and cones contain photopigments (protein molecules) that absorb light. Absorption of light results in a chemical reaction which becomes an electrical signal which, in turn, causes a release of neurotransmitters at the bipolar cell synapse. If an action potential occurs, the information carries on to the ganglion cells and so on up to the cortex. Once the information reaches the visual cortex, specific neurons respond to specific stimuli. For example, some neurons will only respond to bars and slits of light moving in specific orientations. These cells are called feature detectors. Note, however, that you need your whole cerebral cortex to give those bars and slits of light personal meaning, particularly your temporal and parietal lobes.

Question 18

The Opponent-Process Theory

Answer 18

(Red - Green, Blue - Yellow, Black - White)

In 1870, Hering agreed that there were 3 types of cones, but he felt that each cone was capable of responding to 2 different (opposing) wavelengths. He identified a red-green cone, a blue-yellow cone, and a black-white cone.

Hering’s theory has since been modified (Sometimes now referred to as the Dual Process Theory). In fact, it’s not the cones that respond to opposing wavelengths, it’s the ganglion cells and visual thalamic cells that do. When red-sensitive ganglion cells are turned on, green-sensitive ganglion cells are turned off and vice versa. When red is no longer perceived (as in when you look at a white wall), a rebound effect occurs. Suddenly, the previously inhibited cells that fire during the perception of green are free to fire, whereas the previously activated cells related to red no longer do so. The same relationship occurs for yellow and blue, as well as for black and white.

Question 19

The Trichromatic Theory

Answer 19

In the 1800s, Young and von Helmholtz felt that there were 3 types of cones - cones sensitive to either blue, green, or red. They believed that any combination of these 3 wavelengths could produce all the visible colours of the spectrum.

Question 20

Dichromat

Answer 20

sensitive to two colour systems. Individuals usually lose the ability to detect red/green (see both red and green as yellowish brown).

Question 21

Monochromat

Answer 21

sensitive only to black and white (colour blind)

Question 22

What is Perception?

Answer 22

What is it? Where is it? What is it doing?

Question 23

Bottom-Up Processing

Answer 23

Information from sensory receptors (rods, cones, hair cells, taste buds, free nerve endings in the skin, etc…) goes to the brain for translation. We start with small sensory features and build upward to a complete perception.

• You’re doing a jigsaw puzzle for the first time without the lid. Pure sensation – no expectations.
• You are walking in the community forest. You feel the sun on your face, hear the leaves rustling, and see something large and dark brown lumbering towards you.

Question 24

Top-Down Processing

Answer 24

Pre-existing knowledge, past experiences memories, and expectations are used to rapidly organize the features of the environment into a meaningful whole. You already have a mindset and assumptions that you use to interpret what you are seeing, hearing, feeling, etc… You use schemas (standard ideas or images) to help interpret sensations. Your brain is like a filing cabinet. You have files on everything that you see, hear, taste, smell, etc… You have a file for bears (big, black, clawed, smelly, dangerous, huntable beasts). When you encounter an animal that you think might be a bear, you compare its features to what you have on file. If it’s similar, you’ll perceive the animal as a bear. The file will expand and change depending on your experience and your willingness to modify the file. Kids with little experience and few schemas will call all four legged furry animals ‘kitties’.

You are doing a favourite jigsaw puzzle that you’ve done many times before and are having no difficulty with it.

You’ve heard the reports about grizzly attacks and come to the conclusion that a bear is approaching you, rather than a large dog.

Check out the rat man.

Question 25

The Figure-Ground Principle

Answer 25

For some reason, our brain likes to see a figure and a ground - a foreground and a background.

Question 26

The Proximity Principle

Answer 26

Stimuli that are close together are usually grouped together by our brains. Do you see three shapes as opposed to random dots?

Question 27

The Similarity Principle

Answer 27

If parts of a stimulus are similar, we perceive them as being together. Do you see alternating rows of red and white objects or do you see alternating columns of circles and squares?

Question 28

Binocular Disparity

Answer 28

Because your eyes are separated, each one receives a slightly different view of objects. Put your finger in front of your nose and alternate viewing it with each eye - you should see it from different perspectives. If you could stretch your arm out about 15 meters, the view from each eye would be the same. The brain detects these different views (disparity) and calculates distance. The greater the disparity, the closer the object.

Question 29

Convergence

Answer 29

The closer the object is to you (use your finger again), the more muscle tension is required to focus (cross-eyed). The further away the object, the less eye convergence. Again, your brain uses this information to calculate distance.

Question 30

Monocular Cues

Answer 30

If you had only one eye you should still be able to make judgments of distance using these cues:

Interposition or overlap
Aerial perspective
Shading/Lighting
Elevation/Height in Plane
Linear Perspective
Texture
Relative Size

Question 31

Accommodation

Answer 31

As the lens changes its curvature to focus on an object, muscles attached to the lens relay information to the brain about distance.

Question 32

Relative Displacement Over Time

Answer 32

When I see you at place ‘A’ at time ‘1’ and then I see you at place ‘B’ at time ‘2’, I assume that you or I have moved.

Question 33

Stroboscopic Movement (Apparent Motion)

Answer 33

When slightly different stimuli are presented close together in time and space, movement will be perceived. In the motion picture industry, 24 still photos per second separated by black spaces gives the illusion of movement (also known as the beta effect). A related effect, the phi phenomenon, occurs when we perceive motion due to the appearance and disappearance of objects that are near each other.

Question 34

Motion-Detecting Neurons

Answer 34

There is evidence that we have specialized cells in the visual parts of the brain that are sensitive to movement cues. Neurons fire when movement occurs.

Question 35

Sleep Stages (5)

Answer 35

Awake, Stage 1 (NREM -1),Stage 2 (NREM-2),Stage 3 (NREM-3), Rapid Eye Movement (REM):

Question 36

Awake Stage

Answer 36

When we are awake, the EEG shows us small, fast desynchronized (erratic) waves called beta waves (13-45 cycles per second/Hertz). The eyes move all over the place and muscle tension is high. When we are relaxed, but still awake, alpha waves appear (8-12 Hz), our eyes stop moving around so much, and our muscle tension eases off a bit. This state of relaxed wakefulness is often the product of meditation.

Question 37

Stage 1 (NREM -1)

Answer 37

As we drift off to sleep, alpha waves begin to disappear and slower, saw-toothed theta waves appear (4-7 Hz). The eyes begin to slowly roll back and forth, and muscle tension continues to decrease.

Question 38

Stage 2 (NREM-2)

Answer 38

Sleep spindles (12-14 Hz) and K-Complexes (large spikes) appear. The eyes stop moving and the muscle tension remains low.

Question 39

Stage 3 (NREM-3)

Answer 39

This is your slow wave sleep or deep restorative sleep. Large, slow delta waves (1-2 Hz) begin to appear and then dominate the sleep recording. The eyes are quiet and muscle tension is low. When in the later part of Stage 3 (what used to be referred to as Stage 4), it’s really hard to awaken. Sleep walking, sleep talking, bed wetting, and night terrors may emerge as well.

Question 40

Rapid Eye Movement (REM)

Answer 40

This stage looks a lot like wakefulness. What distinguishes REM from wakefulness is the fact that the eyes begin to dart back and forth beneath the closed eyelids, and the muscle tension drops off to zero. The resulting paralysis renders you unable to act out your dreams. This is a good thing.

Question 41

Describe Sleep Architecture

Answer 41

Contrary to what you might think, we don’t fall deeper and deeper into sleep and gradually move to a lighter sleep at dawn.

In the first 90 minutes of sleep, we typically move from Stage 1 to Stage 2 and then to Stage 3. We then cycle back up through Stage 2. Instead of going into Stage 1 again, we enter our first REM period which lasts about 5-10 minutes.

We then cycle back down through Stages 2 and 3 before moving back up through Stage 2 to our second REM period. This time we spend more time in REM - perhaps 20 minutes.

From then on, we cycle between Stages 2 and REM until we awaken. By the morning, our REM periods can be 30-60 minutes in length. The number of REM periods that we have depends on how much time we spend asleep. Most of us have about 4 or 5 REM periods per night.

You may find the hypnogram below helpful for visualizing the sleep cycle.

Question 42

Why Do We Sleep?

Answer 42

It’s a good question without a definite answer.

We all know how lousy we feel after losing a night of sleep, but there is no proof that humans would die without sleep (apart from those who suffer from a very rare genetic condition called Fatal Familial Insomnia). Part of the problem is that we can’t find any volunteers who are willing to go without sleep until they die smile

Question 43

The Cyclic Nature of Sleep and Wakefulness

Answer 43

Not only do the stages of sleep cycle through the night, so do feelings of sleepiness and alertness throughout the day. Most of us are on a 24-hour sleep-wake cycle (circadian = about a day) with 7-8 hours spent asleep and 16-17 hours spent awake.

During these periods of wakefulness, we also experience natural periodic dips in alertness. Our biological clock (the suprachiasmatic nuclei in the hypothalamus) dictates when we are drowsy and when we are alert. Typically, adults are most alert and productive at 9-11 am and 7-9 pm. Their sleepiest times occur around 3-5 am and 2-4 in the afternoon. Most industrial and vehicular accidents occur during these two windows.

Having said that, our biological clock changes with age. Teenagers may not feel sleepy until after midnight, whereas elderly people may feel the pressure to get to bed at 8 pm.

The most powerful influence on our biological clock is sunlight, which resets it every day. If you were to go without time cues (e.g., live in an underground cave - like a Chilean miner), your biological clock would begin to free-run on about a 25-hour cycle. That means that you would likely go to bed one hour later each night and wake up one hour later each morning, regardless of the real light/dark cycle.

Keep this idea of the biological clock in mind as it underlies many of the insomnias that we’ll explore.

Question 44

Total Sleep Deprivation Studies

Answer 44

In 1965, Randy Gardner made it into the Guinness World Book of Records for going 264 hours - that’s 11 full days - without sleep! Besides feeling sleepy, Randy had a number of problems. He couldn’t name things by touch alone. He falsely believed that he was an African American football player. He couldn’t manage tongue twisters. He couldn’t remember that he was trying to break a world record. He became uncoordinated. In short, he had problems with thinking. memory, perception, mood, motivation, and motor control. But he lived to tell the tale.

In 2007, Tony Wright took up the challenge and supposedly beat the world record.

Don’t try this at home, though. Note that rats will die from complete system failure after 3-4 weeks of total sleep deprivation.

Question 45

Partial Sleep Deprivation Studies

Answer 45

Fortunately, people will volunteer to be selectively deprived of REM or Non-REM (NREM) sleep. The results of these studies tell us that we need REM sleep for brain development and procedural memory consolidation (memory for skills, actions, and procedures). Recent research also suggests that we need REM sleep for emotional regulation and creativity. We need NREM sleep (Stages 1-3) for cellular repair, general physical restoration, physical growth, and declarative memory consolidation (memory for personal experiences, facts about the world, and language).

The bottom line is that when we are short on sleep, we feel awful and we do stupid things. When we lose sleep, we need to reclaim it. If we don’t, we’ll pay the price. Note that 37% of drivers have admitted to falling asleep at the wheel. Six out of 10 drivers do not pull over when drowsy while driving. Do you?

Question 46

Insomnia

Answer 46

By far the most prevalent sleep disorder is insomnia which is the inability to fall asleep or stay asleep. If you are sleepy in the daytime, it takes you more than 30 minutes to fall asleep, and you get less than 6 hours of sleep per night, you have insomnia. If you suffer from multiple awakenings on a regular basis and are dysfunctional during the day, you are also suffering from insomnia. Approximately 30-50% of the population reports experiencing symptoms of insomnia. Note that many of us report experiencing paradoxical insomnia which is the feeling that we were awake half the night, but in fact slept fairly well. People suffering from paradoxical insomnia likely have high levels of arousal that keep the brain more active during sleep, which makes judgements of wakefulness versus sleep difficult. On average, paradoxical insomniacs get only 25 minutes less sleep per night than good sleepers.

Question 47

Stress- Sleep

Answer 47

For most true insomniacs, stress is the culprit - you just can’t let go of the day’s trials and tribulations. The wheels keep turning and, as a result, you keep tossing and turning. Hyperarousal is the root cause of insomnia in about 50% of the cases. This type of insomnia then may become a learned response where there is a great deal of anxiety and tension around getting ready for bed. This tendency to worry about not being able to fall asleep translates into arousal and the vicious cycle begins.

Question 48

Aging - Sleep

Answer 48

As we age, our biological clock shifts so that we become more like larks than owls. That means that most of us will fall asleep earlier in the evening (8-9 pm) and awaken in the wee hours of the morning (4-5 am). Many of us will fight this natural tendency and try to stay awake longer and sleep in. It doesn’t work! The sleep drive also weakens which makes it more difficult to stay asleep.

Question 49

Obstructive Sleep Apnea

Answer 49

When a patient suffers from sleep apnea, the muscles at the back of the throat relax and collapse during sleep. This stops the air flow for 10 seconds to 1 minute. The brain panics which causes the person to awaken. Breathing then resumes immediately. This cessation of breathing can occur hundreds of times a night and the sleeper is usually unaware of it. The result is a night of stages 1 and 2 sleep only, followed by dramatic daytime sleepiness. The continuous fall-off of oxygen and build-up of carbon dioxide increases blood pressure and is a definite health risk.

My husband recently went for a sleep assessment and was diagnosed with severe sleep apnea. While sleeping at the lab, he experienced 52 awakenings per hour with zero slow wave sleep (NREM-3). No wonder he’s sleepy in the daytime sleepy

If you suspect someone you know suffers from sleep apnea, it is important to get help right away. Email me if you need contact information. Sleep apnea is a life-threatening sleep disorder!

Question 50

Narcolepsy

Answer 50

1. Unbearable, unrelenting sleepiness with REM-onset sleep attacks
2. Cataplexy: attacks of muscle weakness or collapse brought on by strong emotion (e.g., laughter, surprise, anger, anticipation)
3. Hypnagogic hallucinations: very vivid, frightening visions when falling asleep
4. Sleep paralysis: the inability to move upon awakening

What causes it?

There is a genetic component. However, recent evidence points towards degeneration of the hypothalamic neurons that produce hypocretin/orexin (A neurotransmitter/neuromodulator involved in the regulation of sleep and eating). A spinal tap will likely show a lack of hypocretin in the cerebrospinal fluid.

I did my Ph. D. thesis on narcolepsy, so I could go on forever here. If you have any specific questions, please feel free to ask them and I’ll do my best to answer them. This is also true for any topic that we cover in Introductory Psychology.

Question 51

What is Dreaming?

Answer 51

As most of you know, the stage of sleep typically associated with dreaming is REM sleep. Approximately 80-90% of our REM sleep is occupied by dreaming.

For most of us, dreaming is the bizarre (or not so bizarre) movie that goes on in our heads while we sleep.

Question 52

Why Do We Dream?

Answer 52

Dream Protection/Wish Fulfillment: Freud (and First Nations peoples) would say that dreaming is an indirect expression of unconscious wishes, desires, and impulses.

Memory Consolidation: Others say that dreaming is important for one particular type of long-term memory - procedural memory which is the memory for how to do things. Some say that dreaming helps us manage our emotional memories and to come up with creative solutions to problems. Note that you need NREM sleep to remember facts like these. So don’t pull an all-nighter before your exams.

Activation-Synthesis: Some say that dreaming is simply the brain trying to make sense of the random electrical noise it generates during sleep.

Evolutionary Theory: Dreams allow us to rehearse threatening and non-threatening scenarios so that we are better prepared if the scenario becomes real. The bottom line is that we will live longer and be

Question 53

Drug Tolerance

Answer 53

refers to a decreasing response to a drug over time. This means that the brain adapts its chemistry such that you need to take more and more of a drug to get the same effect. For example, Jax used to snort two lines of cocaine to get high. Now he needs six lines to feel the same effect.

Question 54

Drug Withdrawal

Answer 54

When you take a drug, your brain produces a compensatory (neuroadaptive) response. This means that the brain tries to balance out your system. For example, if you take cocaine (a stimulant), your brain will try to compensate by slowing your body down. If you decide to stop using a drug, the body’s compensatory response is still engaged. As a result, you begin to experience a reaction that is opposite to the effect of the drug. In the cocaine example, you would feel depressed and fatigued. This lingering compensatory response is called withdrawal.

Question 55

Depressants

Answer 55

Sedative-hypnotic drugs are classified as depressants. Barbiturates (e.g., Seconal), nonbarbiturates (e.g., Quaaludes), and benzodiazepines (e.g., Valium) are sedative-hypnotics that have a calming and sleep inducing effect. Strong doses produce sleep almost immediately. Excessive doses are lethal because they paralyze the brain’s respiratory centres. Just ask Jimi Hendrix.

Opiates (aka opioids or narcotics) may also be considered as depressants. They provide pain relief and elevate the mood by depressing the central nervous system. Morphine and codeine are opiates that have been extracted from the opium poppy. They are frequently used in the medical world to control pain.

Heroin, on the other hand, is a derivative of morphine which has become a fairly popular recreational drug in some countries. It crosses the blood-brain barrier 100 times faster than morphine resulting in a rush of euphoria (along with nausea and vomiting), followed by lethargy. Unfortunately, tolerance develops easily. Withdrawal is particularly nasty.

Beware of taking Oxycontin (yet another derivative of morphine) for recreational purposes. It’s highly addictive and it depresses the respiratory centres.

Be even more wary of using Fentanyl and W-18, synthetic opiates that are killing all kinds of Canadians.

Note that Indigenous people are 3 times more likely to die from an opioid overdose than are non-indigenous people. Further note that Indigenous communities are prescribed a disproportionate number of opioid prescriptions. In 2017, a study from Alberta reported that 61% of Indigenous people who died from an overdose had filled an opioid prescription within 30 days of their death.

Question 56

Stimulants

Answer 56

in contrast to depressants, increase neuronal firing and arouse the central nervous system. Stimulants (e.g., amphetamines, nicotine, Ecstasy) are typically used to increase alertness, elevate the mood, and reduce appetite.

Question 57

Hallucinogens

Answer 57

or psychedelics, distort sensory images so that the individual senses things in unusual ways. The experience is not always pleasant. The distorted objects and sounds can be threatening and terrifying.

Hallucinogens are typically derived from mother nature herself (e.g., psilocybin, peyote, etc…). Some classify Ecstasy and marijuana as hallucinogens as well. Most are thought to affect the serotonin system, but the method of action is unclear.

Question 58

How do drugs affect your brain?

Answer 58

Drugs affect your brain by:

1. Causing leakage of a neurotransmitter from a synaptic vesicle
2. Preventing release of a neurotransmitter into a synaptic cleft
3. Causing release of a neurotransmitter into a synaptic cleft
4. Preventing re-uptake of a neurotransmitter
5. Blocking the enzyme that breaks down a neurotransmitter
6. Binding to a neurotransmitter’s receptor

Question 59

How does Alcohol Affect your brain?

Answer 59

Alcohol increases GABA (Gamma aminobutyric acid) which is an inhibitory neurotransmitter. It also decreases glutamate which is an excitatory neurotransmitter.

Question 60

How doee Marijuana affect your brain?

Answer 60

Marijuana causes euphoria and affects judgement (distortion of space and time). It binds to receptors meant for anandamide, a naturally occurring neurotransmitter. Heavy use can cause hallucinations, depression, and anxiety.

Question 61

Crystal Methamphetamine

Answer 61

Crystal Meth is a highly addictive man-made stimulant which increases dopamine release. Over time, it also damages the terminal buttons of neurons containing dopamine and serotonin.

Question 62

Ecstasy (Methylenedioxymethamphetamine - MDMA)

Answer 62

Ecstasy causes the release of serotonin, blocks the re-uptake of serotonin, and eventually depletes the serotonin in the brain. Recent research indicates that Ecstasy permanently damages serotonin-containing neurons. Note that you need serotonin to regulate mood and sleep, among other things.

Question 63

Heroin

Answer 63

Heroin causes euphoria and dulls pain by binding to the receptors meant for endorphins (the body’s own natural pain-killing neurotransmitters).

Question 64

Nicotine

Answer 64

Nicotine causes the release of excess dopamine in the brain.