Psychology as Science

•Psychology is the study of human thought and behavior, and the application of the gained knowledge.

•Areas of Study:• Basic Research: Tries to acquire knowledge. Includes

neuroscience, developmental, social, cognitive, and personality psychology.• Applied Psychology: Uses acquired knowledge. Includes

clinical and industrial/organizational psychology.

The scientific method

•Construct a theory: an explanation of a phenomenon using an integrated set of principles that organizes observations and predicts behavior.

•A good theory should produce testable predictions called hypotheses.

Hypotheses

•Hypotheses are predictions of particular outcomes. • Always hypothesize a difference.• Hypotheses must be testable.• You should include directionality in the hypothesis.• Viewing more TV will increase anxiety.

• A hypothesis is usually formulated after careful observation.

To test a hypothesis, we conduct an experiment.

Research Methods

• Experiments: Researchers directly manipulate one variable (Independent Variable) and measure the resulting effects on another variable (Dependent Variable) while keeping all other variables constant.

• Confounding Variables: • Placebo effects- changes in state due to receiving a

treatment when the treatment itself has no biological effects.• Subject variables- variables that human subjects bring in

with them, such as age, sex, occupation, etc.

• Random assignment: participants are randomly assigned to a treatment condition, so all participants have an equal chance of being assigned to every condition. Solves subject variable confounds.

Research Methods Cont.

• Correlational Research: Indicates the extent to which two variables vary together. (Use scatterplots to see trends)

• Does NOT imply causation. • These methods are used when experiments are either impractical or

ethically impossible.• If you know one variable you can then predict the other.

• Positive Correlation: as one variable increases so does the other.• Negative Correlation: as one variable increases, the other variable decreases.

Correlation coefficient (r):Ranges from -1 to +1.0 = zero correlation

Behavioral Neuroscience

Collect

Transform

Transmit

Layout of nervous system

Nervous system

Peripheral

Autonomic (self-regulated action of internal organs

and glands)

Sympathetic (arousal)

Parasympathetic

(relaxation)

Somatic (voluntary movement of

skeletal muscles)

Central

Brain (further divisions coming!) Spinal Cord

Neuron structure Signal:Action Potential

Neuron Resting State

•Neuronal membrane is fatty and won’t let ions in. Ions can only go through special gates and pumps.• Lots of potassium (K+) inside the cell• Lots of sodium (Na+) and chloride (Cl-) outside the cell•Overall, inside of the cell is more negative, outside is more

positive.• Gates and pumps work to keep the right amounts of ions

inside/outside the cell.

Action Potential

• Depolarization happens when Na+ rushes into the neuron, making it more positive.• If this brings the voltage to the

threshold potential, an action potential happens.• Runaway cascade of Na+ entry.

• Cell repolarizes as K+ reactively rushes out of the cell.• Pumps and gates work to

reachieve resting state.• Cell cannot fire during this

period – refractory period.

Neurotransmitters•Neurons “talk” to each other using chemical

neurotransmitters.•Fast acting: •Glutamate (excitatory), GABA (inhibitory), &

Acetylcholine (movement)•Slow acting:•Dopamine (pleasure), Serotonin (mood), Substance

P (runners high)

Synaptic Events1) Action potential reaches axon terminal.2) Vesicles containing neurotransmitter release their

contents into the synaptic cleft.3) Neurotransmitters bind with receptors on receiving

neuron, causing change in its potential.4) Neurotransmitters release from receptors and then

1) Are destroyed by enzymes in the synaptic cleft2) Or are reabsorbed back into the presynaptic axon terminal

(“reuptake”)

Major Structures• Hindbrain:• Medulla: respiration/BP, vomiting• Cerebellum & Pons: coordinated movement

• Midbrain:• Reticular Formation: arousal, alertness• Inferior Colliculus: auditory localization• Superior Colliculus: visual localization

• Forebrain:• Hypothalamus: homeostasis• Thalamus: relay station• Limbic System: emotion & memory• Amygdala: emotion• Nucleus Accumbens: rewards• Hippocampus: memory

• Cortex: higher order cognition

What to remember when making an educated guess:

1. Older & lower brain structures are for more survival based functions like breathing, seeing and moving.

2. Higher/newer structures are for more advanced functions such as cognition and language.

Pp. 64-68

The Brain

The Four Lobes of the Cortex

Cortex & Specialization of Function

Brain Plasticity•Describes the brain’s capacity for remodeling itself,

brain is amazingly plastic in early life•Case of hydrocephalus

• Limits of Plasticity•Fetal Alcohol Syndrome disrupts genetically

preprogrammed neuron birth and migration

Human Development

Domains of Change During Development

•Biological: physical development.•Cognitive: development of thought and mind.•Social: development of patterns of interaction with others.•Moral/Ethical: development of a sense of right and wrong and personal responsibility.

Cognitive Development

•Piaget hypothesized the following: • Thinking and reasoning develop in stages• Each stage is genetically preprogrammed, so the environment

can only change the speed that we pass through the stages.•Schema: framework for understanding the world around

us.•Assimilation: fitting new information into an existing

schema.•Accommodation: modifying or creating a new schema to

represent new information.

Piaget’s Four Stage Theory•Sensorimotor: Child understands through sensing and

acting. Ages 0-2• Limitations: Cannot distinguish past & future, no object

permanence, cannot think symbolically•Milestone: object permanence, stranger anxiety

•Preoperational: Ages 2-6• Limitations: Poor reasoning (conservation tasks)•Milestone: symbolic thought, language

•Concrete Operational: Ages 6-11• Limitations: Poor reasoning about the abstract•Milestone: logical reasoning for observable things (can do

conservation tasks)•Formal Operational: Ages 11-adulthood•Milestone: logical reasoning for unobservable or abstract

events/things (calculus)

Social Development:Attachment

•Harlow’s Monkeys• Preferred the “warm fuzzy” surrogate mother to the food

providing mother•As adults, monkeys showed erratic behavior in groups. They

were also poor mothers at first, but with time, learned to engage in responsive parenting.

•Effects of Daycare•Attachment isn’t affected as long as you don’t have an

insensitive, unresponsive mother and low quality daycare (NIH, 1996)