Neuro Exam 2
advantages of within subjects design
-participants in the group are equivalent (it is the same person undergoing all conditions) -increased power (due to reduction of variability in the sample) -requires fewer participants
factors that need to be met to establish causation
1 covariance- variables changing together 2 temporal precedence- IV manipulation comes before changes in DV 3 internal validity (reduction of the possible third variable problem)- observed results representing the truth
Conditions that need to be met for random assignment
1 each participant has to have an equal chance of being assigned to each group 2 each assignment is independent of other assignments
disadvantages of within subjects design
1 fatigue, context, carryover effects,practice effects aka: Order effects in general, 2 sometimes it isn't practical to test each subject in each condition (like if you needed to measure protein expression following treatments) 3 demand characteristics (participants pick up on cues that might allude them to know the hypothesis)
belmont report
1. Respect for persons informed consent and acknowledgment of autonomy 2. Beneficence doing everything to protect humans from harm 3. Justice fairness in distribution of benefits and burdens of research
Institutional Review Board (IRB)
A committee at each institution where research is conducted to review every experiment for ethics and methodology.
counterbalancing
A method of controlling for order effects in a repeated measure design by either including all orders of treatment or by randomly determining the order for each subject -there is full and partial
between subjects design
A research design in which different groups of participants are randomly assigned to experimental conditions or to control conditions. Each subject is only tested in one condition, the one their group receives
one-group pretest-posttest design
An experiment in which a researcher recruits one group of participants; measures them on a pretest; exposes them to a treatment, intervention, or change; and then measures them on a posttest.
summaries, predictions
Correlations are used for (summaries/predictions) and regressions are used for (summaries/predictions)
control groups
Groups of participants in a research experiment who do not receive the experimental treatment (placebo, vehicle, sham surgery)
third
One of the two reasons why correlation is not the same as causation is because of the ___ variable problem. The other reason is the reason of temporal precedence
strength and direction
Pearson's R (aka correlation coefficient) informs us of the ___ and ___ of a relationship between variables
Tuskegee Syphilis Study
Research study conducted by a branch of the U.S. government, lasting for roughly 50 years (ending in the 1970s), in which a sample of African American men diagnosed with syphilis were deliberately left untreated, without their knowledge, to learn about the lifetime course of the disease.
forced swim test
Technique used to measure depression in animals by placing them in a cylinder of water from which they cannot escape and recording the time it takes for them to abandon attempts to escape.
research ethics
The responsibility of researchers to be honest and respectful to all individuals who may be affected by their research studies or their reports of the studies' results
False, Causation establishes this (also called causality)- one variable happening before another
True or false: correlation helps us to determine/identify temporal precedence
True
True or false: correlations often set ground work for an experimental design
history maturation testing regression to the mean
What are some alternative explanations for the results of quasi experiments?
tentative rigorously evaluated self-correcting replicable
What are the characteristics of what scientific results should be?
partial counterbalancing
a method of counterbalancing in which some, but not all, of the possible condition orders are represented generally speaking, if there are four places for a condition to go partial would be testing each condition in each possible place
one-group posttest-only design
a quasi-experimental design that has no control group and no pretest comparison; a very poor design in terms of internal validity WEAKEST
blocked randomization
a randomization method used in between subjects design in which subjects are split into equal groups and a pattern of assignment of treatments happens within each of these blocks -this assignment would be dependent on other assignments -maintains equal group sizes
Nuremberg Code
a set of research ethics principles for human experimentation set as a result of the subsequent Nuremberg trials at the end of the Second World War.
replicability
a study about a phenomenon produces similar results from a previous study of the same phenomenon
conceptual replication
a type of replication of research using different procedures for manipulating or measuring the variables but is studying the same phenomenon
direct replication
an experiment that uses the same procedures as a previous experiment but with a new sample
within subjects design
an experimental design in which the same subjects are tested under each condition in other words: each participant is tested under all possible conditions
matched groups
an experimental design technique in which participants who are similar on some measured variable are grouped into sets; the members of each matched set are then randomly assigned to different experimental conditions (one goes to one treatment and the other goes to the other)
placebo
an inert substance given to the control group in an experiment
Institutional Animal Care and Use Committee (IACUC)
animal version of the IRB reviews protocol for experimentation on animals one of the people is a veterinarian
multiple regression
assessing how multiple variables predict a certain outcome there are 2+ predictor variables in the regression equation in effort to improve predictions of y
ways to minimize experimenter effects
consistency in everything, standardization of procedure, using same tools each time
induced pluripotent stem cells
creation of neurons and other cell types without the direct sampling from animals or humans allows study of disease progression
pretest post test for between subject design
dependent variable is measured before and after independent variable manipulation -ex: emotional intelligence is DV, you have all subjects take a survey before, then one group attends one workshop and the other group attends another and then you would compare how the DV changed between the pre and post test
Coefficient of determination
determines proportion of variance in Y that can be accounted for by the x variable
vehicle
exposed to a treatment that lacks the actual drug a good example is injecting a control group of rats with saline while the other gets a drug being tested for reduction of anxiety behavior
sham surgery
faked surgical intervention that omits the step thought to be therapeutically necessary
coefficient of multiple determination (R^2)
for multiple regression, the proportion of variance in Y that can be attributed to the linear combination of all other variables
treatment groups
groups of participants that receive the IV manipulation (drug, surgical, behavioral, genetic treatments are all examples)
environmental enrichment
method of social, physical, mental stimulation of rodent environment
Nonequivalent groups posttest design
one group exposed to treatment, other is not. Both groups take a post test and results are compared
Nazi Human Experimentation
prisoners forced to participate in medical experiments -twin studies -immunization studies -wound treatment -freezing
reasons for replication failures
problems with the replication attempt (context changed/underpower) problems with the original study (QRP's were used)
Characteristics of experimental research that quasi experiments lack
random assignment counterbalancing (sometimes) control groups
three r's of animal research
replacement, refinement, reduction
two key features of experimental research
researchers systematically vary IV (levels are called conditions) researchers build in controls in effort to hold extraneous variables constant
wild type
standard for experiment (like a rat group that didn't go through a genetic knockout)
regression
statistical method for establishing relationships between variables in which the equation of a line is generated
reproducibility
the ability of an entire experiment or study to be duplicated, either by the same researcher or by someone else working independently
learned helplessness
the hopelessness and passive resignation an animal or human learns when unable to avoid repeated aversive events
research fraud
three parts: falsification of data, fabrication of data, or plagiarism
nonequivalent control group pretest-posttest design
treatment group with a pretest treatment and potest and then there is a control group with a pretest no treatment and then post test
true
true or false: correlation quantifies relationship between variables and regression expresses relationship in the form of an equation
experimenter effects
unintended changes in subjects' behavior due to cues inadvertently given by the experimenter
moral principles associated with research
weighing of risks and benefits acting responsibly and with integrity respecting people's dignity and rights seeking justice