Chapter 2 Abnormal Psych Brooke Bennett Clemson

Psychology as a science

Psychology is a science because it uses the scientific method.

Scientific method: identify the problem

First step: define a question or problem that can be investigated empirically.

Scientific method: background research

Develop an understanding of what is already known about the problem.

Scientific method: formulate a hypothesis

Create a statement that can be supported or not supported by evidence.

Scientific method: test the hypothesis

Use an empirical test; experiments provide especially strong tests of hypotheses.

Scientific method: analyze results

Use statistical analysis to determine what the data show.

Scientific method after results

If results support the hypothesis, report them; if not, formulate a new hypothesis and test again.

Translational research

Scientific approach that connects basic science, clinical research, and improved health through two-way translation.

Critical thinking

Processing information by examining assumptions, evaluating evidence, looking for hidden agendas, and assessing conclusions.

Critical thinking step 1

Consider underlying motives for making a claim.

Critical thinking step 2

Evaluate the quality of evidence supporting the claim.

Critical thinking step 3

Generate alternative explanations for the results.

Critical thinking step 4

Avoid relying on emotions or personal experiences when evaluating a claim.

Belmont Report

Source of core ethical principles for research discussed in the slides.

Respect for people

Belmont principle requiring respect for participants as persons and their autonomy.

Beneficence

Belmont principle emphasizing benefits and protection from harm.

Justice

Belmont principle emphasizing fairness in the distribution of research burdens and benefits.

IRB

Institutional Review Board; provides oversight for research with human participants.

IACUC

Institutional Animal Care and Use Committee; provides oversight for research with animal subjects.

Informed consent

Process ensuring participants understand the study, participate voluntarily, know foreseeable risks/benefits, and are selected fairly.

Central nervous system (CNS)

Brain and spinal cord.

Peripheral nervous system (PNS)

Nervous system outside the CNS; includes sensory-somatic and autonomic systems.

Sensory-somatic nervous system

Part of the PNS involved in sensation and muscle movement.

Autonomic nervous system

Part of the PNS regulating involuntary bodily functions.

Sympathetic nervous system

Autonomic division that activates a state of physical readiness.

Parasympathetic nervous system

Autonomic division that returns the body toward a resting state.

Neuron

Nerve cell; basic unit of nervous-system communication.

Soma

Cell body of a neuron; contains the nucleus and structures that support the neuron.

Dendrites

Branch-like structures that receive signals from nearby neurons.

Axon

Cable-like extension that carries a neural signal away from the soma.

Axon terminals / terminal buttons

Structures at the ends of axon branches that release chemicals into the space between neurons.

Synapse

The junction or space across which neurons communicate chemically.

Myelin sheath

Fatty insulation around an axon that improves the strength and speed of neural signaling.

Brain stem

Controls many fundamental biological functions necessary for living.

Medulla

Hindbrain structure involved in basic survival functions such as breathing.

Pons

Connects lower and upper parts of the brain and is involved in consciousness and sleep.

Cerebellum

Important for movement, balance, and coordination.

Midbrain

Coordinates sensory information and movement.

Thalamus

The brain's sensory relay station.

Hypothalamus

Helps regulate bodily functions and internal homeostasis and oversees the pituitary gland.

Forebrain

Includes major higher-order structures such as the limbic system, basal ganglia, and cerebral cortex.

Limbic system

System including the amygdala, cingulate gyrus, and hippocampus; deals mainly with emotions and impulses.

Amygdala

Limbic structure involved in emotion and memory.

Cingulate gyrus

Structure listed as part of the limbic system.

Hippocampus

Limbic structure involved in memory.

Basal ganglia

Structures that inhibit movement.

Cerebral cortex

Largest part of the forebrain; supports reasoning, abstract thought, time perception, creativity, and other higher abilities.

Four cerebral lobes

Frontal, parietal, temporal, and occipital lobes.

Reticular formation

Brain structure labeled in the slides as controlling alertness.

Optic tract

Pathway labeled in the slides as involved in vision.

Pituitary gland

“Master gland” that regulates many endocrine functions and is overseen by the hypothalamus.

Endocrine system

System that regulates bodily functions using hormones produced by glands.

Hormones

Chemical messengers released into the bloodstream to influence target cells.

Peripheral endocrine glands

Examples in the slides include the adrenal glands, pancreas, thyroid, and gonads.

Neurotransmitters

Chemicals that relay signals between neurons.

Neurotransmission sequence

An electrical signal reaches the presynaptic terminal, neurotransmitters are released, cross the synapse, bind postsynaptic receptors, and initiate a signal in the next neuron.

Psychiatry and neurotransmitters

The slides note that psychiatry studies drug treatments that act on specific neurotransmitter systems.

DNA

Deoxyribonucleic acid; described in the slides as a basic building block of life.

Genes

Units of heredity; the slides state that each person has approximately 30,000 genes.

Chromosome pairs

The slides state that humans have 23 pairs of chromosomes.

Chromosome patterns listed in the slides

The course slide lists X, XX, XXY, XY, XYY, and XXXY under biological sex.

Behavioral genetics research

Uses methods such as family, twin, and adoption studies to examine genetic and environmental influences.

Family pedigree study

Examines whether family members of a person with a disorder are more likely to have that disorder.

Proband

The family member with the disorder who serves as the starting point in a family study.

Shared environmental factors

Environmental factors that are shared by members of a family.

Adoption study

Compares an adopted child with biological parents and adoptive parents to separate genetic and environmental similarities.

Adoption study genetic inference

Similarity between biological parents and adopted-away offspring is treated as evidence consistent with genetic influence.

Adoption study environmental inference

Similarity between an adopted child and adoptive parents is treated as evidence consistent with environmental influence.

Monozygotic (MZ) twins

Identical twins; comparisons involving MZ twins can help researchers study genetic and environmental influences.

Dizygotic (DZ) twins

Fraternal twins used as a comparison group in twin research.

Nonshared environmental factors

Environmental experiences that differ between family members; MZ twins reared apart can help researchers examine these influences.

Molecular genetics

Research on how specific genes or genetic regions are related to a disorder.

Genome-wide linkage analysis

Examines family members with a disorder to narrow down genetic regions associated with that disorder.

Candidate gene association study (CGAS)

Compares selected genes in groups with and without a disorder.

Genome-wide association study (GWAS)

Tests genetic variations across the genome against matched controls.

Gene-environment interaction

When environmental factors change the expression or impact of a genotype; the slide example is childhood nutrition affecting adult height.

Gene-environment correlation

When a person's genotype influences the environments they experience or select; the slide example is an introverted person selecting more solitary activities.

Case study

Comprehensive description of an individual or group, providing detailed narratives of behavior and treatment.

Case study strengths

Can examine rare phenomena, generate hypotheses, and illustrate important clinical issues.

Case study limitations

Data may vary, results are hard to standardize or generalize, and case studies do not establish causes.

Single-case design

Experimental study with an individual who serves in both experimental and control conditions.

Single-case design strengths

Can support causal inference, uses fewer resources, and focuses on individual patterns of change.

Single-case design limitations

Limited generalizability, limited ability to address individual differences, and treatment reversal may be unethical or impractical.

ABAB / reversal design

Single-case design that alternates baseline (A) and intervention (B) phases to see whether behavior changes with treatment.

Multiple baseline design

Single-case strategy that introduces treatment at different times across participants, behaviors, or settings rather than withdrawing an effective treatment.

Correlation method

Examines the relationship between variables or conditions without manipulating them.

Correlation coefficient

Number indicating the direction and strength of a relationship; ranges from -1.0 to +1.0.

Positive correlation

As one variable increases, the other tends to increase; the variables move in the same direction.

Negative correlation

As one variable increases, the other tends to decrease; the variables move in opposite directions.

Correlation is not causation

A relationship between two variables does not by itself show that one variable caused the other.

Experimental group

Group exposed to the treatment or manipulated condition.

Control group

Comparison group used to evaluate the effect of the treatment.

Independent variable

Variable controlled or manipulated by the researcher.

Dependent variable

Outcome measure that is assessed.

Random assignment

Each participant has an equal chance of being assigned to a study group.

Analogue sample

A research sample used to approximate a clinical condition rather than consisting only of diagnosed clinical patients.

Clinical sample

A sample made up of people who have the clinical condition or diagnosis of interest.

Internal validity

How confidently a study supports a conclusion that the manipulated factor caused the observed outcome.

External validity

How well findings generalize beyond the study to other people, settings, or situations.

Efficacy research

Tests whether a treatment works under controlled, ideal research conditions.