PSYCH 210 Lecture 2Outline of Last Lecture I. Which are useful means of preventing cancer?II. How best might you decrease carbon footprint?III. Syllabus OverviewOutline of Current Lecture I. Scientific Methoda. Compare to ‘Everyday Method”b. Stepsc. Experimental DesignII. Observational Studiesa. Case Studiesb. Epidemiological Studiesc. Case Control StudiesIII. Interventionsa. Animal Studiesb. Human Clinical TrialsCurrent LectureI. Scientific Method a. The primary method used in Nutritional Science fieldi. ‘Everyday Method’ 1. Uses Anecdotal EvidenceThese 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.2. Ex) Friend says Vitamin X cures headaches3. Problems with this method (class response):a. Medication interactionb. Different causec. Volunteer Biasd. Coincidencee. Placebo Effectf. Individual Differences (metabolism)g. Nutritional Deficiency4. **Cannot use one person’s experience for generalizing!b. Scientific Method Stepsi. Ask a questionii. Formulate Hypothesisiii. Test Hypothesisiv. Conduct Experimentv. Evaluate Outcomevi. Confirm or Reject Hypothesisvii. If rejected, reformulate hypothesis and start againc. Experimental Designi. Experimental Group >>> receive treatmentii. Control Group >>> No treatment1. Besides treatment, groups should be identicald. Two types of Experimentsi. Intervention1. Experimenter changes somethingii. Observation1. Experimenter just watchesII. Observational Studiesa. Case Studyi. Experimenter observes one specific caseb. Epidemiological Studyi. Def: natural experiment conducted by a population on itself1. In a large enough population, there is usually enough variation in exposureii. Researcher: “Do differences in outcome over time correlate with exposure?”iii. Evaluating Method1. Advantage: No intervention needed (especially if intervention would be harmful)2. Disadvantage: Not enough evidence to definitively conclude or disprove anythinga. Correlation does not prove causality!iv. Ex) 1. Confounders (Confounding Variables) (Class Responses):a. Undiagnosed casesb. Activity levelsc. Overall decreased life expectancyd. Other causes of deathe. Inaccurate reporting on dietf. Environmental exposure (radiation, chemicals)g. Access to fath. Societal Attitudesi. Breast Feeding2. Cancer is a chronic disease, which have multiple causes and make them difficult to study!c. Case Control Studiesi. Def: Match cases with controls1. Cases: someone with a disease (for example)2. Control: someone of almost identical characteristics (height, weight, age, gender, etc.) but without diseaseii. Researcher: “Did cases receive more or less exposure than controls?”III. Interventionsa. Animal Studiesi. Experimental Group >>> Treatmentii. Control Group >>> No Treatment1. Compare Outcomesiii. Ex) One rat group has high-fat diet, one has low-fatb. Human Clinical Trialsi. Many more confounders exist1. Still important to control for things you can (e.g. all non-smokers, exercisers, etc.)ii. RandomizationAgricultural, Less Wealthy Nations (i.e. Africa, AsiaDietary FatIndustrial, Wealthy Nations (i.e. US, UK, Canada, EU)Breast Cancer1. Def: randomly assign individuals to groupsiii. Placebo Control1. Placebo is a fake (sugar) pill2. Double Blinda. Def: neither study subject nor person giving the pill knows if it’s the placebo or real pilliv. Human Lifespan is much longer than animal’s1. Chronic Diseases develop over many yearsa. Must study for many years to obtain a full enough picturev. Humans harder to control than animals (diet, exercise, etc.)vi. **Humans more difficult and more expensive to
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