AP Psychology - Unit 1 (Part 2)

Cognitive Neuroscience

the study of the brain activity linked with cognition, including language, perception, memory, and thinking

Levels of Consciousness

1. Conscious level

2. Nonconscious level

3. Preconscious level

4. Subconscious level

5. Unconscious level

Conscious Level

the information about yourself and your environment you are currently aware of

Nonconscious Level

bodily processes controlled by your mind that we are not usually (or ever) aware of

Preconscious Level

information about yourself or your environment that you are not currently thinking about but could be.

→ for example, if I asked you to remember your favorite toy as a child, you could bring that preconscious memory to your conscious level.

Subconscious Level

information that we are not consciously aware of, but we know must exist due to behavior

→ for example, behaviors demonstrated in the mere-exposure effect suggest that some information is accessible to our subconscious level but not our conscious level

Unconscious Level

some events and feelings are unacceptable to our conscious mind and are repressed into the unconscious mind

Altered States of Consciousness

• Spontaneous State of Consciousness

• Physiological State of Consciousness

• Psychological State of Consciousness

Spontaneous State of Consciousness

• occur naturally without any intentional effort or external chemical influence

• example: dreaming

Physiological State of Consciousness

• triggered by biological or "physical" changes in the body’s chemistry

• example: hallucinations

Psychological State of Consciousness

• induced by mental techniques or social influence.

• example: hypnosis

Dual Processing

the concept that the brain processes information consciously and coconsciously

→ example: when seeing a bird, you’ll be consciously aware of which type of bird it is but unconsciously be taking in information about its color, size, movement, etc.

Parallel Processing

the ability to simultaneously process multiple pieces of information or stimuli at the same time

Sequential Processing

the processing of one aspect of a problem at a time; it is used for processing new information or solving difficult problems

Blindsight

the ability to respond to visual information without consciously seeing it; it explains how blind people can sense objects in their environment

Circadian Rhythm

our biological clock that regulates our mood, temperature, and arousal through a 24-hour cycle

Describe the changes the circadian rhythm causes to our body during a 24-hour period

As morning approaches, our body temperatures rise and we begin to wake up. Our temperature and arousal peak around midday, then start to dip as we approach dusk

Why do most people prefer to sleep in colder temperatures?

Because our circadian rhythm causes our temperatures to decrease at night, colder temperatures help with that process, signaling it’s time to sleep and thus promoting faster and deeper sleep.

Other Biological Rhythms

• 90-minute sleep cycle

• 28-day menstrual cycle

• annual hibernation/migration

• mating seasons

Sleep

• A state of marked by relatively low levels of physical activity and reduced sensory awareness that is distinct from periods of rest that occur during wakefulness.

• a periodic, natural loss of consciousness

Why do we sleep?

• Protection

• Recuperation

• Restore/rebuild memory

• Feeds creative thinking

• Growth

Restoration Theory

• Sleep:

  • helps restore, repair & supports growth (muscles & brain tissues)

  • restores (reenergize) hormones, neurotransmitters, & energy

  • helps restore & builds our memories

  • helps the brain "flush out" metabolic waste (toxins) that built up during the day.

• most of these functions of sleep occur during REM sleep

• sleep-deprived individuals struggle physically and cognitively

Memory Consolidation Theory

the idea that sleep plays a crucial role in the process of converting short-term memories into long-term memories by strengthening neural connections

Energy Conservation Theory

• based on the evolutionary perspective

• The primary function of sleep is to minimize energy consumption when the body is at rest, allowing the body to redirect some energy towards restorative processes, such as tissue repair, immune function, and memory consolidation

  • during sleep, the body and body enter a state of reduced energy expenditure in order to conserve resources and maintain optimal functioning

  • during sleep, the body’s metabolic rate decreases, leading to a reduction in energy consumption and heat production

Wakefulness

Characterized by high levels of sensory awareness, thought, and behavior

Sleep Cycle

• 90-120 min. cycle

• consists of four stages

• Each stage involves different brainwaves pattern, physiological changes & psychological phenomena

Stages of Sleep

1. NREM Stage 1 (NREM-1)

2. NREM Stage 2 (NREM-2)

3. NREM Stage 3 (NREM-3)

4. NREM-2

5. REM

NREM Sleep (stage 1-3)

• stands for: non-rapid eye movement

• Decreases in length as night sleep progresses

• Vague, partial images and stories

• Night terrors (NREM 3) & Sleepwalking and talking (NREM 3)

• Essential part of sleep for the body

Sleep Onset

• process of transitioning from wakefulness into sleep

• a person might experience mild hallucinations during this stage

• hypnagogic sensations can be experienced in late sleep onset

NREM-1

• light sleep, easily woken

• EEG shows theta waves with high-frequency and low-amplitude

• can experience hallucinations and hypnagogic sensations

Hypnagogic Sensations

bizarre experiences such as jerking with a sensation of falling

NREM-2

• fully asleep, but still light sleep (but deeper than NREM-1)

• EEG shows theta waves with sleep spindles and K-complexes

• theta waves are a bit slower (low frequency) and higher in amplitude compared to NREM-1

Sleep Spindles

random short bursts of rapid brain waves

K-complexes

random tall bursts of activity

NREM-3

• deep sleep

• also called delta sleep (or deep or slow-wave sleep)

• EEG shows delta waves (lowest frequency and highest amplitude)

• a person in NREM-3 is hard to wake up and is very disoriented and groggy if awakened

• slower wave (lower frequency) → deeper sleep → less aware a person is of environment

Purpose of NREM-3

very important in:

• releasing growth hormones in children

• fortifying immunity

• restoration of resources used while we are awake and active

How does increasing exercise affect our sleep and why?

Increasing exercise will increase the amount of time we spend in NREM sleep in order to replenish the resources used.

Predict what would happen to a person deprived of delta sleep

they would be more susceptible to illness and will feel physically tired

REM

• stands for: rapid eye movement

• also known as paradoxical sleep since brain waves appear as active and intense as they do when we are awake but the body is paralyzed

• a period of intense activity, in which eyes dart back and forth and many of our muscles may twitch repeatedly

• dreams (especially vivid dreams) are more likely to occur in this sleep stage

• becomes longer & more frequent as night progresses

• EEG shows beta waves

What affects how much time a person spends in REM sleep?

• Age: as we age, the amount of time spent in REM sleep decreases

• Stress: more stress → longer periods of REM sleep

• REM Deprivation: leads to REM Rebound

REM Rebound

the tendency for REM sleep-deprived individuals to experience more and longer periods of REM sleep the next time they are allowed to sleep normally

What does Sleep Lab research?

• muscle tone

• oxygen level

• heart rate

• brain wave

• temperature

What affects our sleeping?

• Age: as we age, our total need for sleep decreases

• Genetics

• Environment

• Exposure to light

• Brain:

  • Pineal gland: adjust melatonin levels

  • Reticular Formation: monitors sleep and wake cycle

  • Suprachiasmatic Nucleus (SCN)

Suprachiasmatic Nucleus

a pair of cell clusters in the hypothalamus that control circadian rhythm

What happens to our sleep as we get closer to morning (or whenever we naturally wake up)?

we spend more time in NREM stages 1 and 2 and in REM sleep and less in NREM stage 3

Effects of Sleep Deprivation

• diminished attentional focus on memory consolidation

• gain weight

• get sick

• be irritable and/or depressed

• feel old

• increases risk of high bp

• increased ghrelin and decreased leptin

• reduced muscle strength and slower reaction time and motor learning

• increased production of fat cells & greater risk of obesity

• increased inflammation in joints and arthritis

• suppression of immune cell production and increased risk of viral infections

Sleep Disorders

• Insomnia

• Narcolepsy

• Sleep Apnea

• REM Sleep Behavior Disorder

• Night Terrors

• Somnambulism

Insomnia

persistent problems falling or staying

Causes of Insomnia

• stress

• irregular sleep schedule

• pain/illness

• diet/medication

Insomnia Treatment

• reduce intake of caffeine or other stimulants

• exercising at appropriate times (not right before bedtime) during the day

• maintaining a consistent sleep pattern

• stress management

• sleeping pills

  • but only with caution as they disturb sleep patterns during the night and can prevent truly restful sleep

Narcolepsy

• a sleep disorder, characterized by uncontrollable sleep attacks

• sleep episodes are often associated with cataplexy

• symptoms include:

  • cataplexy

  • falling in REM sleep at unpredictable times throughout the day

Cataplexy

a temporary, sudden loss of muscle tone or muscle weakness

Sleep Apnea

• a sleep disorder characterized by temporary cessations of breathing during sleep and repeated momentary awakenings to gasp for air

• robs the person of deep sleep and causes tiredness and possible interference with attention and memory

Types of Sleep Apnea

• obstructive

• central

• complex

Risk Factors of Sleep Apnea

• Weight

• Smoking

• Gender

• Age

• Thick neck

• Narrow airway

• nasal obstruction

Possible Treatments for Sleep Apnea

• lose weight

• surgery

• CPAP machine

Obstructive Sleep Apnea

throat muscles relax & press down on windpipe causing inability to breathe

Central Sleep Apnea

brain doesn’t send proper signals to muscles controlling our breathing, causing breathing to stop

Complex Sleep Apnea

• treatment-emergent

• occurs when both obstruction (as well as) miscommunication between brain & spinal cord & the muscles that allow you to breathe

REM Sleep Behavior Disorder

a rare sleep disorder in which the person is not immobilized during REM sleep, physically “acting out” their dream

Night Terrors

• a sleep disorder characterized by high arousal and an appearance of being terrified

• unlike nightmares, night terrors occur during NREM-3 sleep and are not remembered

• usually affect young children

Somnambulism

• sleepwalking

• occur more commonly in children

• occur during the first few hours of the night in NREM-3

Dreams

• sequences of images, emotions, and thoughts passing through a sleeping person’s mind.

• Although dreams can occur at any stage of sleep, they are most vivid during REM sleep.

Lucid Dreams

dreams in which we are aware dreaming and can control the storyline of the dream

Activation-Synthesis Theory

• Developed by Allan Hobson and Robert McCarley.

• dreams are the brain’s interpretations of what is happening physiologically during REM sleep

  • as we are in REM sleep, the limbic system becomes active and randomly fires. Our cerebral cortex tries to interpret random electrical activity we have while sleeping by weaving them into stories

• explains why some dreams make no sense

• weakness: the individual’s brain is weaving the stories, which still tells us something about the dreamer

Information-Processing Theory

• The brain processes the events and the stress of the day and consolidate our memories during REM dreams

• The function of REM may be to integrate the information processed during the day into our memories

• Weakness: why do we dream about things we have not experienced?

According to the Information-Processing Theory, how does stress during the day affect our dreams?

Stress during the day will increase the number and intensity of dreams

According to the information processing theory, how does babies’ sleep differ from that of adults?

Babies may need more REM sleep than adults because they process so much new information every day

Physiological Function Theory of Dreams

• Dreams provide the sleeping brain with periodic stimulation to develop and preserve neural pathways

• Weakness: this theory doesn’t explain why we experience meaningful sleep

According to the Physiological Function Theory of Dreams, why do kids need more sleep?

Neural networks of newborns are quickly developing; therefore, they need more sleep

Cognitive Theory of Dreams

• Dreams are the expression of a person's thoughts

• A dream is conceived as a pictorial representation of the dreamer's conceptions, usually about himself, other people, the world, impulses, prohibitions, penalties, and conflicts

• They reveal the structure of how we envision our lives

• Weakness: does not address the neuroscience of dreams

Wish-Fulfillment Theory

• suggested by Sigmund Freud

• Dreams are simply ways we play out all of the things we want to do subconsciously (hidden wishes) that may be otherwise unacceptable or that we can’t consciously face.

• Dreams consist of manifest & latent content

• Weakness:

  • lacks any scientific support

  • dreams may be interpreted in many different ways

Manifest Content

actual content of the dream

Latent Content

hidden or symbolic meaning of the dream

Sleep Paralysis

• a feeling of being conscious but unable to move

• occurs when a person passes between stages of wakefulness and sleep.

• During these transitions, you may be unable to move or speak for a few seconds up to a few minutes.

Sensation

the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment

Perception

the process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.

Bottom-up Processing

analysis that begins with the sensory receptors and works up to the brain’s integration of sensory information (sensation first)

Top-down Processing

information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experiences and expectations (experience first)

Transduction

process of converting one form of energy to another

→ in sensation, it is the converting of sensory stimulation into neural impulses

Psychophysics

studies the relationships between the physical characteristics of stimuli and our psychological experience of them

Signal Detection Theory

• Detection of a stimulus not only relies on the strength of the stimulus, but also our psychological state - our experience, expectations, motivation, alertness, etc.

• predicts how and when we detect the presence of a faint stimulus amid background stimulation, thus assuming there is no single absolute threshold and that detection depends on the person.

Subliminal Stimuli

Stimuli you cannot consciously detect 50% of the time and are below your absolute threshold

Priming

a phenomenon in which exposure to one stimulus influences how a person responds to a subsequent, related stimulus.

Perceptual Set

a mental predisposition to perceive one thing and not another

Absolute Threshold

• the minimum amount of stimulus energy needed to detect a particular stimulus 50% of the time

• studied by Gustav Fechner

Difference Thresholds

minimum difference between two stimuli required for detection 50% of the time

Weber’s Law

to be perceived as different, two stimuli must differ by a constant percentage rather than a constant amount

Sensory Adaptation

• diminished sensitivity as a consequence of constant stimulation or exposure

• Sensory receptors become less responsive to a constant, unchanging stimulus. Receptors stop firing as frequently

Sensory Habituation

• Reduced perception or response to a repeated, but not necessarily constant, stimulus.

• our perception of sensations is partially due to how focused we are on them

• brain learns to ignore the stimulus

What does the light’s wavelength determine?

the hue (color)

What does the light’s amplitude determine?

the intensity (the amount of energy the wave contains) or brightness

→ higher amplitude = more contained energy = brighter/more intense color

Types of Lights Waves with Wavelengths Longer than Visible Light

• Infrared Waves

• Microwaves

• Radio Waves

Types of Lights Waves with Wavelengths Shorter than Visible Light

• Ultraviolet Waves

• X-rays

Color Hues from Shortest Wavelengths to Longest

• red

• orange

• yellow

• green

• blue

• indigo

• violet

Vision Process

• Light is reflected off objects and gathered by the eye

• Light enters the cornea and then the pupil

• Light is focused by the lens on the retina

• Light activates the neurons in the retina

  • Photoreceptors are activated by light

  • If enough rods and cones fire, bipolar cells become activates

  • If enough bipolar cells fire, ganglion cells fire

• The visual cortex of the brain receives impulses from the cells of the retina, and the impulses activate feature detectors

Cornea

the eye’s clear, protective layer that also plays an important role in focusing the light