Week 3 - Research Methods

Question 1

Experimental research design

Answer 1

Independent variable - variable that is manipulate in a study
Dependent variable - variable that is measured in a study
Experimental control

Question 2

Experimental between-subjects design

Answer 2

experiments are conducted with 2 or more different groups
- interested in the difference between the means of these groups

example: group A given a new drug; group B given CBT

Question 3

Advantages of between groups

Answer 3

• easier and more time efficient to run
• allows observation of variables that are not stable

Question 4

Disadvantages of between groups

Answer 4

• many variables are unable to be controlled
• results are presented in terms of group differences; masks changes within the individual
• method of allocating to groups

Question 5

Experimental within-subjects design

repeated measures

Answer 5

same participants involved in every level of the experiment
- usually interested in difference in the mean of the 2+ testing occassions

eg. participants tested for attention span before & after taking drug

Question 6

Advantages of repeated measures

Answer 6

• requires fewer participants
• each participant acts as their own control

Question 7

Disadvantages of repeated measures

Answer 7

• not amenable to measurement of unstable variables
• time & money
• may need alternate forms to assess DV to counteract practice effect
• may need to counteract cross-over effects

Question 8

Placebo controls

Answer 8

a placebo control condition will be similar to the experimental condition, except rather than receiving the drug they receive a substance containing no active ingredients
- placebo controls are extremely useful for investigating whether any benefits derived from a drug are due to placebo effects

Question 8

Three-groups design

Answer 8

1. given a new drug
2. given a proven drug
3. given a placebo

Question 8

Control groups/conditions

Answer 8

• used to ensure the effect observed is due to the variable we manipulated & not some other variable
• especially important in between-subjects designs
• control group will be identical to the groups being tested, except for the manipulation

Question 9

what do three-groups designs allow for

Answer 9

• comparison between new drug & placebo
• comparison between new & established drugs
• experimenter to see if measure are sensitive enough to detect change

Question 10

what are the alternate combinations of groups that could be used to answer alternate questions

Answer 10

• effectiveness of drugs vs non-pharmacological interventions
• specificity of drug effectson different mental illnesses
• cross-sectional and longitudinal

Question 11

Sources of bias

Answer 11

• systematic errors in measurement or prediction
• experimenter and participant expectations/bias
• selection bias

Question 12

Research methods

Answer 12

• introspection
• naturalistic observation
• case history
• survey
• test
• correlation
• experiment

Question 13

Potential variables

Answer 13

• arousal
• cognition
• perception
• motor function
• mood
• side effect/biochemical or physiological drug effect

Question 14

The more measures used creates

Answer 14

• a more comprehensive assessment
• a more costly experiment
• a greater need to consider ecperimental controls & logistics

Question 15

Measuring performance

Answer 15

assessing change/differences in performance across performance domains (arousal, cognition etc) tells us something about how the drug works, and the effects it produces

Question 16

Arousal levels

Answer 16

• arousal levels change naturally throughout the day, but can also be affected by a number of things.
• drugs are thought of as either stimulants or depressants when given in large doses.
• uppers and downers imply a relationship between arousal and mood
• high arousal does not equal high activity

Question 17

Measuring arousal

Answer 17

• EEG
• introspection; unstructured introspection, systematic introspection
• ask an observer

Question 18

Levels of arousal

Answer 18

• death
• coma
  **- sleep
• drowsy
• normal
• aroused
• highly excited**
• mania
• convulsions
• death

** = normal range of arousal

Question 18

Measures of mood

Answer 18

Studied: experimentally or between groups design
Measured: self-report, doctor’s assessment, informant report, questionnaire, tests of biological markers of depression

Question 19

Measures of perception

Answer 19

visual and auditory perception are most often studied, and is investigated by the changes in the sensitivity of a person’s perception brought about by changes in the internal or external environment

Question 20

Sensitivity thresholds

Answer 20

• absolute threshold - lowest value of stimulus detactable by an organ
• difference threshold - organ detects a change in level of stimulation

Question 21

Absolute thresholds detected 50% of the time

Answer 21

vision: candle flame on a dark straight road at 60km/h
smell: 1 drop of perfume in a 6 room apartment
hearing: watch tick 6m away
taste: 1tsp sugar in 8L water
touch: wing of a fly falling on your cheek from 1cm

Question 22

Difference thresholds

Answer 22

measure the ability of an individual to detect a change in a stimulus - critical frequency at fusion (CFF) sensitive to drug effects

Question 23

Cognitive performance

Answer 23

ability to process, store and retrieve information; can also include higher-level processes such as planning, set-shifting & response inhibition

Question 24

how is cognitive performance manipulated?

Answer 24

experimentally

Question 25

measuring motor performance

Answer 25

- simple or choice reaction time - tapping - pursuit rotor

Question 26

measuring side effects/physiological effects

Answer 26

- questionnaire - biochemical assay - doctor's checkup/physical exam - informant report

Question 27

general questions of identifying good research design

Answer 27

- what is the research question: does the chosen design allow that question to be answered - what are the strengths and limitations of the measures used to assess effects - what experimental controls have been put in place - effect size: how meaningful is the change observed in terms of everyday functioning?

Question 28

factors to consider with drug studies

Answer 28

- washout effect - deprivation study designs - level of drug administered - dose of drug used - inclusion of biochemical assays - controls for routine/habitual or other drug use - non-specific treatment effects - special group selection factors (mild, moderate, sever depression) - timeframe for assessing effect - reporting of adverse events/non-compliance/attrition

Question 29

factors to consider with drug studies cont.

Answer 29

- if in-vitro cellular trials are used: how generalisable are results to intact living systems? - if animal trials are used: how similar is the species, apparatus, domain of function being tested

Question 30

Research ethics

Answer 30

- APS code of ethis - NHMRC guidelines

Question 31

drug development

Answer 31

- development, testing, manufacturing & eventual marketing of any drug is time-consuming & expensive - companies can evaluate 1000s of different chemicals before finding one that is successful in all phases of testing

Question 32

Major considerations in drug development

Answer 32

1. medical need 2. commercial potential 3. feasibility for mass production "orphan drugs"

Question 33

FDA approval processes

Answer 33

1. preclinical investigation (animal studies) 2. clinical investigation (human volunteers) 3. review of NDA 4. postmarketing studies

Question 34

Specifc limitations of animal studies

Answer 34

cats: markedly different sleep-wake cycles monkeys: develop obvious behavioural abnormalities from confinement rabbits: different enzymes from humans

Question 35

Stage 1: step 1 of animal testing

Answer 35

Determing toxicity - acute toxicity (for single doses) - subacute toxicity (short-term use of drug) - chronic toxicity (longer-term drug use) - special toxicity (carcinogenic, teratogenic)

Question 36

Stage 1: step 2 of animal testing

Answer 36

pharmacological studies (direct and indirect) direct: to locate direct measures of changes induced by drugs via tools indirect: to identify markers of signs of effect rather than evidence of the effect itself or to observe effects on behaviours that are induced in animals

Question 37

Direct pharmacological studies - conditioning: General principles

Answer 37

Stimulant substances: rapid learning/acquisition of conditioned response, poor discrimination/ready generalisation, slow termination/extinction Depressant substance: slow acquisition/learning, poor generalisation/easy discrimination, rapid extinction

Question 38

Schedules of reinforcement

Answer 38

pattern that determines when reinforcements are to be given - ratio schedules - interval schedules - avoidance-escape take - punishment

Question 39

Stimulus properties of drugs

Answer 39

ability to act as a discriminative stimulus in discrimination learning taks

Question 40

Reinforcing properties of drugs

Answer 40

- rate of responding - progressive ratio - breaking point - choice - 2 levers; one has consequences - conditioned place preference - animal will spend time in area of reinforcement

Question 41

Phase 1 of human testing | pharmacokinetic & safety testing

Answer 41

human testing to determine toxicity & side effects in healthy human volunteers

Question 42

Phase 2 of human testing | small scale and effectiveness testing

Answer 42

human testing in clinical samples to assess potential therapeutic effect (adverse)

Question 43

Phase 3 of human testing | large scale effectiveness testing

Answer 43

expanded clinical trials using basic 3-group design (approval or rejection of new drug for licensing & marketing

Question 44

Phase 4 of human testing

Answer 44

accumulation of data on drug effects

Question 45

Postmarketing studies | phase 4

Answer 45

- after NDA review completed & approved - lasts on average, 15 years - new drug placed on the market - surveillance: check for new harmful effects in larger group of humans - drug removed from market if seroius problems occur