Psych Midterm

Split-Brain Studies

Hemispheres cannot exchange data

Roger Sperry studied this in the 1960s and his work was continued later by Michael Gazzaniga

Created a special apparatus

Picture/Word input would only be shown to one side of the brain

Screen blocks objects on table from view

• Each eye has both a left and a right visual field

Information from your left visual field goes to your right hemisphere Information from your right visual field goes to your left hemisphere

• In a person with a severed Corpus Callosum, this information sharing does not take place

• When a word/picture was flashed to the left visual field - right hemisphere, the patient could not

say what they saw

But, they could point to it with their left hand, because that is controlled by the right hemisphere

• When a word/picture was flashed to the right visual field - left hemisphere, the patient could verbally say what they saw

• This is because the left hemisphere is the speaking side of the brain

Gender Differences - Geschwind (Males)

Testosterone enlarges the RIGHT hemisphere, making males more right brain dominant and leaving language exclusively to the left hemisphere

Boys - More left-handers

- Higher % with language disabilities

• Better at spatial relations tasks

• More violent/aggressive behavior patterns expressed

• Higher % of autism - communication disorder

Gender Differences - Geschwind (Females)

Girls tend to be more bilateral and LEFT brain dominant. Corpus Callosum is thicker so more information exchanged between the hemispheres

Can process language in both hemispheres

• Fewer left handers

• More successful with language development in early years

• Early readers, good spellers

• More difficulty with spatial relations tasks

Angular Gyrus

Takes letters/words and makes them sounds within your head

Located near the back of the temporal lobe

• Receives the visual information from the visual cortex and transforms it into the auditory form, which it then sends to Wernicke's Area

Aphasia

Partial or complete inability to articulate ideas or understand language because of brain injury or damage

Broca's Aphasia

A person has trouble formulating words but can still understand speech (can't plan out what he is going to say)

Wernicke's area

Person has a hard time speaking in meaningful ways and understanding speech

Ex. Asked to describe picture of two boys stealing cookies behind a woman's back

"Mother is away her working her work to get her better, but when she's looking the two boys looking the other part. She's working another time."

Plasticity

Brain's ability to reorganize itself

Functional Platiscity

When an area of the brain takes up a new function to replace a damaged

area of the brain

Structural Plasticity

Actual changing of the neuron or actual growing new neurons a.

- Only can occur in the hippocampus

Phantom Limb

If a body part is amputated, the surrounding neurons in the sensory cortex rewire

themselves to other areas of the body

Example: The hand is between the face and arm regions on the sensory cortex thus when stroking the face of someone whose hand was amputated, the person felt the sensation not only on their face but also on their nonexistent "phantom" fingers.

Example: The sense of touch invades the part of the brain normally used for sight in blind people

Individual Differences

Some individuals need more and some less than the typical 8 hours of sleep per night

Insomniacs

has a normal desire for sleep, but is unable to and feels tired during the day

Insomnia

Recurring problems falling asleep or staying asleep

Sleeping pills tend to inhibit or suppress REM sleep - worsens the problem Alcohol suppresses REM sleep, also worsens the problem

Studies show most people overestimate how long it took them to get to sleep

Sleep Apnea

• A sleep disorder characterized by temporary cessations of breathing during sleep and consequent momentary re-awakenings

• Tend to be loud snorers - caused by constricted airways

• Some people use a Continuous Positive Airway Pressure (CAP) machine to help

Narcolepsy

• A sleep disorder characterized by uncontrollable sleep attacks

• Person goes directly into REM sleep

• Nervous system getting aroused tends to trigger the sleep attack

• Narcolepsy has a genetic link and runs in some breeds of dogs

Somnambulism

Formal name for sleepwalking

• Starts in the deep stages of nREM sleep

Person can walk or talk but remembers nothing of the experience

Night Terrors

• Sleep disorder characterized by high arousal and appearance of being terrified

• Happens during deep stages of sleep, mostly in children

• The children rarely remember the event

Bruxism

teeth grinding

Enuresis

bed wetting

Myoclonus

sudden jolt of a body part occurring during stage 1 sleep - everyone has occasional episodes of myoclonus

Psychoanalytic Theory

First thought of by Sigmund Freud

Dreams are the fulfillment of wishes

Unacceptable thoughts of sex and aggression are repressed when you are conscious but come forth when you are asleep in the form of dreams

• Dreams are a "royal road to the unconscious" and a "safety valve" that allows for the release of unconscious and unacceptable urges

• Two component of dreams - manifest content and latent content

• Freud believed symbols played a big role in dreams

Any movement in your dreams (running, dancing) represented sex

• Research does not support his theories

manifest content

the actual dream images themselves

latent content

disguised psychological meaning of the dream

Physiological Function Theory

Neural activity during REM sleep provides periodic stimulation of the brain

• There is no meaning to dreams, it is just neurons firing and creating images

Activation-Synthesis Theory

Brain creates random images during dreams (activation)

A person takes those images and creates a story with them (synthesis)

Brain responds to these internally created signals and assigns them meaning using memories, emotions and sensations

• Meaning is found by analyzing the way the dreamer makes sense of the progression of chaotic dream images

Information Processing Theory

• Dreams serve an important memory-related function by sorting and sifting through the day's experiences

• Research suggests REM sleep helps with memory storage

• REM seems to help with procedural memories and improves performance on learned tasks

• Brain areas activated during training of a task actually are reactivated during REM sleep, perhaps stabilizing the neural connections formed during the training

Cognitive Development Theory

Dreams are a reflection of a person's knowledge and understanding of their experiences and are useful for cognitive development

• Erich Fromm believed that dreams served as a way for us to problem-solve

We dream about future events as a way to rehearse them in our minds

• Some psychologists believe dreams are a way for us to express creativity

EEG

Machine that amplifies and records waves of electrical activity that sweep across the brain's surface

• Used as a means to measure the stages of sleep

° Beta Waves = fast irregular waves seen when we are awake and attentive

• Alpha Waves = larger regular waves that are seen when we are awake but not attentive

Onset of Sleep

Awake and alert - brain produces fast, irregular beta waves

As you lie down to sleep, brain activity slows down generating larger, slower alpha waves

• During drowsy, presleep stage, one may experience vivid sensory hallucinations called hypnagogic hallucinations

• Most common one is that of falling, which can produce a myoclonic jerk - involuntary muscle spasm of the whole body that jolts the person completely awake

Stage 1 Sleep

Waves go to Alpha

Breathing is slowed

• Brain waves become irregular

• It is easy to wake the person, who will insist they are not asleep

• Lasts only a few minutes

• Familiar sounds fade away but you can regain alertness if someone interrupts you

Stage 2 Sleep

Brain wave cycle slows - Theta waves

Appearance of sleep spindles - brief bursts of electrical activity

Appearance of K Complex - large high-voltage spike of electrical activity

Brain activity slows considerably and breathing becomes rhythmic

Slight muscle twitches can occur

Deep Sleep (Stage 3 & 4) nREM Stage 3

Increase in delta waves - long, slow waves

• First time through deep sleep is about 30 minutes and it is when our body gets rejuvenated

During our first stage of deep sleep, heart rate, blood pressure and breathing drop to their lowest levels -it is very hard to wake a person up

: Sleepwalking cours here

People can "wake up" during deep sleep and do a simple task and not remember it

REM Sleep

First stages considered non-REM (nREM) sleep

Rapid eye movement (REM) sleep - eyes are darting back and forth

•

Most dreaming occurs in REM sleep muscle activity is suppressed to keep you from acting out

If denied REM sleep, a person may experience a REM REBOUND and will increase their next time in REM by 50% "catching up" on REM sleep

body is completely paralyzed + cannot move

REM Sleep: Paradoxical Sleep

During REM sleep, brain wave patterns are similar to when we are awake Visual and motor neurons fire as if you are awake

BUT, the brainstem blocks all muscle movement to prevent you from acting out your dreams

So, your brain is acting as if it is awake, but your body is paralyzed

Stages of Sleep

Upon reaching deep sleep, our sleep then lightens and we start heading back towards a light sleep

Instead of going back to Stage 1, we go to REM Sleep

Sleep cycle goes 1-2-3-4-3-2-REM

Full sleep cycle takes about 90 minutes

Four or five sleep cycles occur in one night

• As the night goes on, the amount of deep sleep decreases and the amount of REM sleep increases

Dream Facts

25% of your night's sleep, or about 2 hours, is spent dreaming

• Sleep Thinking - vague, uncreative, bland thoughts about real life events that take place in nREM sleep - these occur more than dreams

• Dreams occur in both nREM and REM sleep, however, they are more frequent and last longer in

REM

People usually have 4-5 episodes of dreaming a night

: Dreams happen in real time

Dream Characteristics

Dreams have 5 basic characteristics:

1. Emotions can be intense

2. Content & organization are usually illogical

3. Sensations are sometimes bizarre

4. Bizarre details are uncritically accepted

5. Dream images are difficult to remember

Phallic symbols

Dreaming about something like a pencil or tree represented male genitalia

Yonic symbols

Dreaming about something like a tunnel or a house represented female genitalia

Nonsomniacs

sleep far less than most, but do not feel tired during the day

Brain during REM Sleep

• EEG reveals brain wave activity is similar in REM to when you are awake

• PET scans however, reveal that brain activity is much different in REM sleep to when you awake

• Frontal Lobe and Primary Visual Cortex are essentially shut down during REM meaning you are shut out from the external world and rational thought, so you accept your dreams no matter how bizarre they are

• Amygdala and Hippocampus, which deal with emotion and memory, are highly active

what 2 parts of the brain are highly active during REM sleep?

Frontal lobe and primary visual contex

What do we dream about?

• Most dreams are about everyday life

• Some themes are found across cultures

• Aggression is more common than friendliness in dreams

• Environmental cues during dreaming may be incorporated into the dream

Why Don't We Remember Our Dreams?

• Areas of the brain used in forming memories are shut down during REM sleep and neurotransmitters that are used to make memories are greatly reduced

• Most likely to remember a dream if you wake up in the middle of it

• Visual encoders tend to be better at remembering dreams

• Vivid dreams are more likely to be recalled

• Brain seems programmed to forget most of what occurs during sleep

Types of Dreams

True dream, sleep thought, lucid dream

True dream

vivid, detailed dreams consisting of sensory and motor sensations experienced during REM

Sleep thought

lacks vivid sensory and motor sensations, is more similar to daytime thinking and occurs during nREM sleep

Lucid dream

dreamer controls what happens in the dream

Cell Body

Contains the cell's nucleus

Round, centrally located structure

Contains DNA

Controls protein manufacturing

Directs metabolism

No role in neural signaling

Dendrites

Information collectors/receivers

• Receive inputs or signals from neighboring neurons

Inputs may number in thousands

• If enough inputs, the cell's AXON may generate an electrical output

Dendrite Growth -> how we learn

Mature neurons generally cannot divide

But new dendrites can grow

Provides room for more connections to other neurons

New connections are basis for learning

Studies show people with higher education have more dendritic connections than someone who is a high school dropout

axon

Where all the action is

Action Potential takes place here - electrical charge is sent down the axon

One axon per cell with two distinct parts

- Tube-like structure

- Branches at the end (axon terminals) that branch out to dendrites of other cells

Axon Terminals

This is where the message is sent at the end of the axon to the dendrite of the neighboring neuron The electrical impulse trigger synaptic transmission to the dendrites of the receiving neuron

Myelin Sheath

• White fatty casing on an axon

• Acts as an electrical insulator - but not present on all cells

• When present, helps increase the speed of neural signals down the axon allowing the action potential to "jump" at each Node of Ranvier

• If this degenerates, you can get multiple sclerosis (MS) and you can't control your muscles

node of ranvier

Gap in between

Glial Cells

• Non-neural white fatty cells that are interspersed among neurons in the brain to give it support and supply nutrients - considered the "janitor" of the neuron

• They also cover the axon to create the myelin sheath

• Tumor in brain is made of glial cells, not neurons

Brain has approximately 10 billion to 1 trillion neurons

• Brain has approximately 100 billion to 10 trillion glial cells

10:1 ratio

• Makes up myelin sheath

• Suround dil of the nevrons, protecting it

Consciousness

Your immediate awareness of thoughts, sensations, memories, and the world around you.

Experience of this tends to blend together

William James described it as "a stream or river that is always changing but unified and unbroken

First studied through introspection and then later rejected in favor of studying observable behavior

Body Rhythms

Natural variations we experience daily in our consciousness as part of our sleep-wake cycle (24 hours)

• Most people experience two peaks in mental alertness during the day

- Around 9/10am and 8/9pm

• Most people experience two dips in your mental alertness during the day

- Around 3am and 3pm

As blood levels of melatonin decrease, mental alertness increases

sleep deprivation

Decreases efficiency of immune system functioning

• Raises the level of stress hormone, cortisol, which is linked to damage of the brain cells responsible for memory and learning

• Safety and accident issues

• Contributes to hypertension, impaired concentration, premature aging

• After one night of sleep deprivation, people have episodes of sleep lasting for a few seconds called microsleeps

Why we sleep

Most people need about 8-8.5 hours of sleep to function but most Americans sleep 7-7.5 hours

• Most teenagers need 9 hours and 15 minutes of sleep a night

- Average teenager's biological clock does not prepare them to awaken until 8 or 9am

• Students with most sleep had better grades and scored better on exams

Restoration Theory

Body wears out during the day and sleep is necessary to put it back into shape

nREM sleep

aids in our body resting

REM sleep

aids in cognitive resting

Adaptive Theory

sleep emerged in evolution to preserve energy and to protect during the time of day when there is little value and considerable danger

- Hibernation occurs during the time of year most hazardous to the animal

Improving Sleep Quality

Avoid going to sleep in the "forbidden zone" of wakefulness that usually sometime between 8-10pm

• Set your alarm 15 minutes earlier and make it so that you have to get up to turn it off

Don't go to bed very full or very hungry

• Raise your core body temperature with a warm bath or shower

Acetylcholine

Excitatory neurotransmitter found in neuromuscular junctions

• Involved in muscle contractions

• Involved in learning and memory

• Botulism - blocks ACh receptors - paralysis results

• Nerve gasses and Spider venom - mimics ACh - too much ACh leads to severe muscle spasms and possible death

• Cigarettes - nicotine works on ACh receptors by mimicking ACh

• Can artificially stimulate skeletal muscles, leading to slight trembling movements

Alzheimer's Disease

- Deterioration of memory, reasoning, and language skills

- Low levels of ACh found in those with Alzheimer's Disease

- Symptoms may be due to loss of ACh neurons

Serotonin

Involved in mood, hunger, sleep

• Low levels involved in depression

- Prozac works by keeping serotonin in the synapse longer, giving it more time to exert an effect (reuptake inhibitor)

Norepiniphrine

Arousal, learning and memory

Deals with "fight or flight" response

Low levels found in those with depression

Dopamine

Involved in movement, attention and learning

• Also involved in pleasure and rewarding sensations

• Too much dopamine involved in schizophrenia - drug Thorazine blocks it

Drugs like cocaine and nicotine mimic dopamine

: Loss of dopamine-producing neurons is cause of Parkinson's Disease

Parkinson's disease

Results from loss of dopamine

• Symptoms include:

• Difficulty starting and stopping voluntary movements

• Tremors while at rest

• Stooped posture

• Rigidity

• Poor balance

Treatments

• L-Dopa

• transplants of fetal dopamine

• electrical stimulation of the thalamus

GABA

Slows down brain activity

Influences anxiety when it is in low supply

Anti-anxiety medications Valium and Xanax work by increasing GABA activity, which slows the brain

Alcohol mimics GABA

Huntington's disease involves loss of neurons that utilize GABA - leads to jerky involuntary movements and mental deterioration

Glutamate

Major excitatory neurotransmitter

• Too much glutamate (and too little GABA) associated with epileptic seizures

Substance P

When we get hurt, Substance P is released

Amplifies the pain signal and contributes to the sensation of acute pain

• If we have too much Substance P, we could experience chronic pain

Endorphins

Control pain and pleasure by blocking the neurotransmitter Substance P which transmits pain messages to the brain

• Released in response to pain

• Morphine and codeine work on endorphin receptors

• Runner's high - feeling of pleasure after a long run is due to heavy endorphin release

Mental awareness

How awake you are

Circadian Rhythm

Rhythmic change that occurs approximately once in a 24-hour cycle

(Sleep/Wake)

Suprachiasmatic Nucleus (SCN)

cluster of neurons in the hypothalamus that governs the timing of circadian rhythms

Regulates melatonib

Melatonin

hormone of the pineal gland that produces sleepiness

When light hits the SCN, it tells the pineal gland to reduce the production of melatonin

Descriptive Research Strategy

Strategies for observing or describing behavior

Experiment Research Strategy

Only way to try and prove cause and effect

Case Study

Use one or a few individuals to study in depth

Studying one person=study in depth

• Pros - often good when you have something new, rare or unusual to study

• Cons - Cannot generalize to population because only one person was studied

Naturalistic Observation

Observe subjects in a natural environment → watching people

Pros - Ethical, See subjects in natural environment

Real behavior in a real situation

Cons - If they know they are being watched, may act differently, might not see everything NO MANIPULATION

not true behavior

Longitudinal Study

study the same people over many years

Pros - better control over subject variables because you are using the same people

Cons -time-consuming, expensive, subjects may leave or drop out

Cross-Sectional Study

Study subjects of different ages all at the same time

Pros - inexpensive, quicker to perform

• Cons - Cannot account for all the different individual variables

Content Analysis

technique that quantifies aspects of various types of communication and media

Pros - Can go back over the years and make comparisons

no people involved

Cons - Problems in consistency in scoring variables and defining them

Ex Post Facto

subjects in this type of study are selected based on a condition or variable they already

have. Usually unethical to manipulate that variable naturally

Pros - allows more topics to be studied

Cons- not as random, "cherry-picking" participants

Meta-Analysis

- a procedure for statistically combining the results of many different research studies

Surveys

Most commonly used descriptive strategy

Research strategy that relies on self-reports, will often use questionnaires, interviews

Pros - quick, cheap, can gather a large amount of data, confidential

Cons - not always filled out, not always done honestly (social desirability), some can have vague or unclear terms, some can lead the subject to answer in a certain way

How do we try to fix the problem of people not finishing/handing back surveys, or people lying on them?

1.Make it short -just one side of the paper usually around 15 questions max

2. Always include sponsorship (how and why you are doing this survey)

3. Make it easy to read - typed and objective

4. Clearly state confidentiality

5. Include a follow-up procedure

Problems with Survey Wording can have the biggest impact on results

Problems with Survey Wording

Sometimes surveys can be confusing with their wording

Wording is important after emotionally charged issues

Responses are influenced by a range of response options - more options is always better!

Order of questions and alternatives

sex

biologically influenced characteristics which people define male, female and intersex, defined by body

gender

the attitudes, feelings and behaviors that a given culture associates with a person’s biological sex, defined by mind

intersex

possessing male and female biological sexual characteristics at birth

aggression

physical or verbal behavior intended to harm emotionally of physically

gender similarities

receive 46 chromosomes, similar biological evolution, ability to survive, reproduce, avoid predators

gender differences (female)

females begin puberty 2 years earlier than males and live ~2 years longer, express emotions more freely, better at spelling and reading, twice the risk of anxiety and depression and 10x likely to get an eating disorder, more likely to gossip and bully, relationship oriented