Psych 202 1st Edition Lecture 7 Research Methods Notes o Can correlations support causal statements Third problem variable o The monoamine deficiency theory of depression states Dopamine DA Norepinephrine NE Serotonin 5 HT Depression is caused by low levels of NT s especially NE and 5 HT High level of NE and 5 HT metabolites lower depression o Directionality problem Direction 1 favored by drug companies the drug causes a chemical change Direction 2 depression creates the biochemical change o Third Variable problem Activity level Lack of sleep Environment Levels of stress Family problems Confounding variables Do hospital s make people die example Activity level is associated with depression and biogenic amine metabolite levels Observed correlations are said to be spurious when compelling confounding 3rd variables can be identified o How can descriptive correlational data help scientific knowledge development Reality most knowledge begins with noticing correlational associations David Hume Multivariate correlational research Has same problems of interpretation Theory development hypothesis testing and experimentation o Experimental methods our best known method for inferring valid causal relationships Core features Independent variables IV s Dependent variables DV s Random sampling from representative populations Almost never happens Random assignment to conditions or treatments Efforts to control extraneous irrelevant factors Ex 1 what affects sexual desirability IV shirt color Method procedure These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute What 2 operationalized DV s were identified What construct was being tested Do color of clothes matter to passion What can be concluded really College men who look at pictures of attractive women are more attracted to one in red shirt Ex 2 antidepressants vs placebos vs cognitive therapy as treatments for major depression The sample depressed people IV 3 levels of treatment Antidepressant Placebo Cognitive therapy Method procedure DV depression level after 3 months Results 60 of antidepressant users and cognitive therapy were no longer depressed 30 of people who had placebo were not depressed What can be concluded really The 2 active treatments are better than placebo at reducing depression for people who volunteered to be in this experiment we don t know if it applies to everyone Is there a control group missing People who aren t getting any medicine at all Ex 3 the seating experiment Where did the research hypothesis come from Physics professor had a theory Who were the research participants What construct was being investigated Is there a relationship between where people sit in room and how well they do in course IV seating spot Method of seating assignment Randomly assigned to seat in 1 of 4 groups Most important DV s Grades Attendance Fraction of A s decreased steadily as the group s original seat location was furthered from the front while fraction of F s increased Davidson et al s experiment on Mindfulness and Brain Function MBSR Sample and context volunteers from a high tech company upper middle class people who said they wanted to do it 8 weeks Big idea the abstract construct being tested Does mindfulness affect health outcomes IV meditation level DV s Decrease in self reported negative affect and anxiety Increase in L sided pre frontal cortical symmetry Left side is happy side Increase in influenza vaccine antibody titers Control group same workgroup but were told they would be on wait list Confound unexamined variable that might alter results In this experiment MBSR had to work and control group also had to work jealous of other group Correlation relates to important insights but not causality