Ch.2- Research Methods in Abnormal Psychology
2.1Describe three core principles of ethics in the scientific study of abnormal behavior.(pg. 40)
One core ethical principle is respect for persons, which means that individuals participating in a study must be capable of making decisions about themselves. A second principle is beneficence, which means that researchers must respect participants’ decisions, protect them from harm, and attempt to secure their well-being. The third ethical principle, justice, emphasizes “fairness in distribution” or “what is deserved.”
2.2Understand important features of informed consent.(pg. 40)
All potential participants must be able to understand the informed consent document and recognize that participation is voluntary. The researcher also needs to consider risks and benefits of participating in the project and ensure that participants are selected fairly. An IRB must review and approve all research conducted on humans.
2.3Identify the two main parts of the nervous system and brain/body components of each.(pg. 42)
The two main parts of the nervous system are the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS consists of the brain and the spinal cord. The PNS includes the sensory-somatic and autonomic nervous systems. The autonomic nervous system includes the sympathetic and parasympathetic systems.
2.4Explain the role of neurotransmitters as they relate to abnormal behavior.(pg. 48)
Neurotransmitters are chemicals that relay electrical signals from one neuron to the next. They travel across the synapse from one neuron to another, triggering the second neuron to release an electrical impulse. Most drug treatments for abnormal behavior affect one or more of the core neurotransmitters.
2.5Recognize new techniques used to study abnormal psychology at the cellular or neuroanatomical level.(pg. 49)
Neuroimaging technology allows us to create detailed images of the brain. Tests such as the CAT (computerized axial tomography) and MRI (magnetic resonance imaging) provide snapshot images of brain structure (structural neuroimaging). PET (positron emission tomography) and fMRI (functional MRI) allow us to see neurotransmitter pathways and changes in blood flow (functional neuroimaging).
2.6Understand the differences between family, adoption, and twin studies (which do not study genes directly) and molecular genetics research (which does directly study genes) and the strengths and limitations of both approaches.(pg. 50)
Family studies examine whether the family members of someone with a particular disorder (proband) are more likely to have that disorder than family members of people without the disorder. Adoption studies allow us to examine genetically related individuals who live in separate families, which helps to separate the potential effects of genetic and environmental factors. Twin studies compare concordance rates between monozygotic (MZ, or identical) and dizygotic (DZ, or fraternal) twin pairs to quantify genetic and environmental contributions to variance in liability to a trait. In candidate gene association studies, scientists compare one or a few specific genes in a large group of individuals who have a specific trait or disorder with a well-matched group of individuals who do not have that trait or disorder. A genome-wide association study (GWAS) is also a case-control design but compares millions of genetic variants across the genome.
2.7Describe the strengths and limitations of case studies.(pg. 56)
Case studies allow the examination of rare phenomena when group-based research would be nearly impossible. They also can be used to generate hypotheses for group studies and illustrate important clinical issues that are not readily apparent in a group-based report. Case studies vary with regard to the amount and type of data included, but they do not allow us to determine causes of symptoms or change following treatment.
2.8Identify two types of single-case designs and the strengths and limitations of each.(pg. 58)
Single-case designs are experimental studies at the individual level (i.e., with a single person). The most common single-case design is the ABAB, or reversal, design. In this design, two phases (A and B) are alternated such that treatment occurs only during the B phase. If behavior changes occur only during B phases, we can conclude that the treatment was effective. This design, however, cannot be used if learning during the B phase cannot be reversed. In these cases, multiple baseline designs may be used to examine separate AB sequences across individuals, settings, or behaviors.
2.9Understand the principles of correlational research and their application to the study of abnormal behavior.(pg. 60)
Correlational research helps us understand abnormal behavior by examining relations between variables or conditions. A correlation coefficient is a statistic that tells us whether the relation between two variables is positive or negative and how strong the relation is. Correlational research, however, tells us nothing about whether one variable causes the other.
2.10Describe the factors that influence outcomes of randomized controlled trials.(pg. 63)
The outcomes of randomized controlled trials are influenced by how participants are selected, the internal validity and external validity of the study (how well controlled the variables are and how representative conditions are to the real world), and assessment strategies (most importantly, whether they are blinded).
2.11Understand the importance of diversity in group-based research in abnormal psychology.(pg. 66)
Generalizability of findings from group-based research is influenced by how diverse the study sample is. For many years, studies of abnormal behavior excluded women, older people, and racial and ethnic minorities. To encourage improved diversity research, the NIH and other funding agencies now require studies to include specific recruitment plans for traditionally underrepresented groups.
2.12Explain the difference between cross-sectional and longitudinal cohorts and the strengths and limitations of each.(pg. 67)
Cross-sectional research allows us to compare groups of people (cohorts) who are assessed at the same point in time. Longitudinal research examines changes in a single group of people over time. Cross-sectional research is efficient and cost-effective, whereas longitudinal designs allow us to examine changes in people over time.
2.13Differentiate incidence and prevalence as these terms relate to understanding abnormal behavior.(pg. 70)
Incidence refers to the number of new cases that emerge in a given population during a specified period of time (e.g., the number of new cases of depression over the past year). Prevalence is the total number of cases of a disorder in a given population at a designated time (e.g., the number of people with depression at any specified point in time or over their lifetime).
2.14Recognize the types of epidemiological research as they relate to understanding abnormal behavior.(pg. 70)
Observational epidemiology documents the presence of psychological disorders in human populations usually by administration of diagnostic interviews. Experimental epidemiology involves documenting the presence of psychological disorders after the researcher manipulates exposure to causal or preventative factors.