Psych FINAL

Hindsight bias

the tendency to believe, after learning an outcome, that one would have foreseen it. (Also known as the I-knew-it-all-along phenomenon.)

Confirmation bias

a tendency to search for information that supports our preconceptions and to ignore or distort contradictory evidence

Overconfidence

the tendency to be more confident than correct—to overestimate the accuracy of our beliefs and judgments.

Quantitative research

using numerical measures

Qualitative research

complex textual responses

Hypothesis

a testable prediction, often implied by a theory

Dependent variable

in an experiment, the outcome that is measured; the variable that may change when the independent variable is manipulated.

Independent variable

in an experiment, the factor that is manipulated; the variable whose effect is being studied

Falsifiable

a hypothesis or theory that can be potentially proven false through experimentation or observation

Operational definitions

a carefully worded statement of the exact procedures (operations) used in a research study. For example, human intelligence may be operationally defined as what an intelligence test measures.

Replicated

repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding can be reproduced

Sample

the group of participants

Population

all those in a group being studied, from which samples may be drawn. (Note: Except for national studies, this does not refer to a country’s whole population.)a sample that fairly represents a population because each member has an equal chance of inclusion.

Representative sample

a sample that’s representative of a larger population

Random sampling

a sample that fairly represents a population because each member has an equal chance of inclusion.

Convenience sampling

collecting data from a group of people who are easily accessible to you (friends/family)

Generalize

the tendency, once a response has been conditioned, for stimuli similar to the conditioned stimulus to elicit similar responses. (In operant conditioning, generalization occurs when responses learned in one situation occur in other, similar situations.)

Stratified sampling

a process that allows a researcher to ensure that the sample represents the population on some criteria

sampling technique in which the population is first divided into distinct, non-overlapping strata based on a specific characteristic, such as age, income level, or education

Confounding variables

a factor other than the factor being studied that might influence a study’s results.

Random assignment

assigning participants to experimental and control groups by chance, thus minimizing preexisting differences between the different groups.

Experimenter bias

situation-relevant confounding variable

unconscious tendency for researchers to treat members of the experimental and control groups differently to increase the chance of confirming the researchers' hypothesis

Experimenter bias can be eliminated by using a double-blind procedure

Double-blind study

an experimental procedure in which both the research participants and the research staff are ignorant (blind) about whether the research participants have received the treatment or a placebo. Commonly used in drug-evaluation studies

Single-blind study

only the participants do not know to which group they have been assigned; this strategy minimizes the effect of demand characteristics as well as certain kinds of response or participant bias.

Social desirability bias

tendency to try to give answers that reflect well upon oneself

Experimental group

in an experiment, the group exposed to the treatment, that is, to one version of the independent variable

Control group

in an experiment, the group not exposed to the treatment; contrasts with the experimental group and serves as a comparison for evaluating the effect of the treatment.

Placebo method

experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition, which the recipient assumes is an active agent

Placebo effect

experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition, which the recipient assumes is an active agent.

Positive correlation

one thing increases the occurrence of the other thing +1

Negative correlation

the presence of one thing predicts the absence of the other -1

Study

a detailed investigation and analysis of a subject or situation.

Likert scales

pose a statement and ask people to express their level of agreement/disagreement with the statement

Directionality problem

The inability to tell which of the variables came first (also known as temporal precedence)

Third variable

can be a confounding variable, the true cause of something

Naturalistic observation

a descriptive technique of observing and recording behavior in naturally occurring situations without trying to manipulate or control the situation.

Structured interview

like a survey in that there are fixed number of questions asked in a set order.

A structured interview can even be completely quantitative if the questions all have a prescribed set of answer choices.

Case study

a descriptive technique in which one individual or group is studied in depth in the hope of revealing universal principles.

Central tendency

Measures of central tendency attempt to mark the center of a distribution.

(mean median mode)

Mean

the arithmetic average of a distribution, obtained by adding the scores and then dividing by the number of scores.

Median

the middle score in a distribution; half the scores are above it and half are below it

Mode

the most frequently occurring score(s) in a distribution.

Bimodal

if two scores appear equally frequently and more frequently than any other score.

Positively skewed

When a distribution includes an extreme score (or group of scores) that is very high

Negatively skewed

When the skew is caused by a particularly low score (or group of scores)

Range

the difference between the highest and lowest scores in a distribution.

Variance

n. Measures of variability attempt to depict the diversity of the distribution

(range, variance, standard deviation)

Standard deviation

a computed measure of how much scores vary around the mean score

Normal curve

(normal distribution) a symmetrical, bellshaped curve that describes the distribution of many types of data; most scores fall near the mean (about 68 percent fall within one standard deviation of it) and fewer and fewer near the extremes.

Percentiles

a measure of the extent to which two factors vary together, and thus of how well either factor predicts the other

Correlation

a measure of the extent to which two factors vary together, and thus of how well either factor predicts the other.

Correlation coefficient

a statistical index of the relationship between two things (from −1.00 to +1.00).

Scatterplot

a graphed cluster of dots, each of which represents the values of two variables. The slope of the points suggests the direction of the relationship between the two variables. The amount of scatter suggests the strength of the correlation (little scatter indicates high correlation).

Statistically significant

Scientists have decided that a p-value of 0.05 is the cutoff for statistically significant results.

A p-value of 0.05 means that a 5 percent chance exists that the results occurred by chance

A p-value can never equal 0 because we can never be 100 percent certain that results did not happen due to chance.

Effect size

how large an effect is

Replication

repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding can be reproduced.

Meta-analysis

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

Peer review

a paper is read by several others in the field and the is author asked to make revisions in order to ensure high quality publications.

No coercion

Participation should be voluntary.

Informed consent

giving potential participants enough information about a study to enable them to choose whether they wish to participate.

Deception

participant is deceived by the nature of the study

Informed assent

Only adults can consent to be in research; minors should be asked to assent and may also be asked to obtain the consent of their parent or guardian.

Confidentiality

Participants’ privacy must be protected.

Risk

Participants cannot be placed at significant mental or physical risk; they must have protection from harm.

Protection from harm

Participants cannot be placed at significant mental or physical risk; they must have protection from harm.

Debriefing

After the study, participants should be told the purpose of the study and provided with ways to contact the researchers about the results.

Genetic predisposition

the increased chance of developing a specific trait or condition due to our genetic code.

Neurons

a nerve cell; the basic building block of the nervous system.

Multiple sclerosis

the myelin sheath deteriorates around neurons, interfering with neural transmission.

Neural transmission

a neuron transmits a message

Resting potential

resting state of a neuron -70 mV

because mostly negative ions are within the cell and mostly positive ions are surrounding it.

Threshold

if enough neurotransmitters are received by neuron B from neuron A to change the membrane potential ~ +40

Action potential

a neural impulse; a brief electrical charge that travels down an axon.

All-or-none principle

If the dendrites of a neuron receive enough neurotransmitters to push the neuron past its threshold, the neuron will fire completely every time. A neuron cannot fire a little or a lot; the impulse is the same every time.

Depolarization

neural firing (the charge is becoming more positive so the cell is becoming less negative and less polar)

Excitatory

neurotransmitter that excite the next cell into firing

Inhibitory

neurotransmitter that inhibit the next cell from firing.

Dopamine

Motor movement and alertness

Lack of dopamine is associated with Parkinson? s disease; an overabundance is associated with schizophrenia.

Serotonin

Mood control

Lack of serotonin is associated with clinical depression.

Norepinephrine

Alertness, arousal

Lack of norepinephrine is associated with depression.

Glutamate

GABA

Excitatory neurotransmitter, involved in memory

Triggers migraines, seizures.

Endorphins

“morphine within”—natural, opiate-like neurotransmitters linked to pain control and to pleasure

Substance P

Pain perception

Lack of substance P may be associated with a lack of pain perception.

Acetylcholine

Motor movement

Lack of acetylcholine is associated with Alzheimer's disease. Acetylcholine is also involved in the disease Myasthenia gravis, a condition that causes muscle weakness.

Alzheimer's disease

a neurocognitive disorder marked by neural plaques, often with onset after age 80, and entailing a progressive decline in memory and other cognitive abilities.

Myasthenia gravis

a condition that causes muscle weakness.

Sensory neurons

Interneurons

neurons within the brain and spinal cord; they communicate internally and process information between the sensory inputs and motor outputs.

Motor neurons

efferent neurons, take information from the brain to the rest of the body

Central nervous system

the brain and spinal cord.

Peripheral nervous system

the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body

Reflex arcs

humans have reflexes that have differently

pathway that different reflexes take

Somatic nervous system

the division of the peripheral nervous system that controls the body’s skeletal muscles. Also called the skeletal nervous system.

Autonomic nervous system

the part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart). Its sympathetic division arouses; its parasympathetic division calms.

Sympathetic nervous system

the division of the autonomic nervous system that arouses the body, mobilizing its energy.

Parasympathetic nervous system

the division of the autonomic nervous system that calms the body, conserving its energy.

Endocrine system

the body’s “slow” chemical communication system; a set of glands that secrete hormones into the bloodstream.

Hormones

chemicals that carry messages through the bloodstream

Adrenaline

Activated during the fight-or-flight response in stressful situations. Speeds up bodily processes. 

Leptin

Involved in weight regulation. Suppresses hunger (food may be perceived as less appetizing).