Biological Approach to Understanding Behaviour Vocabulary List Terminology related to research Bidirectional ambiguity A problem with correlational research. We cannot be sure whether variable A causes a change in variable B or vice versa. It could also be that there is not cause and effect relationship in either direction, but that it is interactive or caused by another, underdetermined "third variable." Cross-sectional design Comparing two or more groups on a particular variable at a specific time. The opposite is a longitudinal design where the researcher measures change in an individual over time. Double-blind testing An experimental procedure in which neither the researcher doing the study nor the participants know the specific type of treatment each participant receives until after the experiment is over; a double-blind procedure is used to guard against both experimenter bias and placebo effects. Longitudinal study Research over a period of time using observations, interviews or psychometric testing. Meta-Analysis Pooling data from multiple studies of the same research question to arrive at one combined answer. Placebo Effect A beneficial effect produced by a placebo drug or treatment, which cannot be attributed to the properties of the placebo itself, and must, therefore, be due to the patient's belief in that treatment. Prospective research A study that attempts to find a correlation between two variables by collecting data early in the life of participants and then continuing to test them over a period of time to measure change and development. Reductionist Approach analyzes a complex behaviour by studying the simplest, most basic mechanisms that are believed to be responsible for the behaviour. Retrospective research A study of an individual after an important change or development. For example, the study of a person after a stroke. This requires the research to "reconstruct" the life of the individual prior to the event. Single-blind testing An experiment in which the researchers know which participants are receiving treatment and which are not; however, the participants do not know which condition they are in. Triangulation Using multiple data sources, multiple researchers or multiple research methods in an investigation to reach a richer understanding of a behaviour or cognitive process. Adoption Studies Adopted children and their adopted families are observed for whether a behaviour has genetic or environmental roots. Not representative. - (+) Allows for nature vs nurture to be studied - (--) Non-representative, a focus on the birth-mother Twin Studies Studies with both monozygotic and dizygotic twins where the genetic similarity between the two is used to determine genetic roots of behaviours. - (+) Controls for environment to study gene inheritance, - (--) Non-representative - (--) Twin registries are based in the developed world, Biological concepts and terminology Acetylcholine The most common neurotransmitter. Acetylcholine receptor sites are found in the hippocampus. It appears that acetylcholine plays a key role in memory consolidation from STM to LTM. Adrenaline Also called epinephrine, adrenaline is secreted by the adrenal glands and stimulates the sympathetic nervous system and prepares the body for fight or flight. Agonist A chemical or a drug that binds to receptors in the brain and causes a reaction. Agonists can occur naturally in the body as hormones and neurotransmitters (endogenous agonists) or come from exterior sources like drugs and toxins (exogenous agonists). Antagonist A chemical or drug that binds to receptors in the brain and prevents a neurotransmitter or hormone from having an effect on behaviour. For example, scopolamine is an antagonist for acetylcholine. Amygdala Part of the limbic system, this part of the brain is believed to play a key role in emotion and memory. In addition, there is evidence that it plays a role in aggression, sexual orientation, trust, and alcoholism. Concordance Rate The probability that the same trait will be present in both members of a pair of twins. Cortisol A stress hormone that is secreted by the adrenal cortex. Responsible for the breakdown of glucose in the fight or flight response. Appears to be linked to hippocampal cell loss and memory dysfunction. Diathesis Stress Model Attempts to explain a disorder as the result of an interaction between a predisposition and stress caused by life experiences. Dizygotic Twins The clinical term for fraternal twins; this occurs when two fertilized eggs are implanted in the uterus wall at the same time. When two eggs are independently fertilized by two different sperm cells, fraternal twins result. The genetic similarity is the same as any other siblings. Dopamine A neurotransmitter that helps control the brain's reward and pleasure centers. Dopamine also helps regulate emotional responses. Dopamine deficiency results in Parkinson's Disease and people with a lower number of dopamine receptor sites may be more prone to addiction. Epigenetics A branch of genetics that focuses on "gene expression" - that is, how environmental factors may "activate" genes. Equal Environment fallacy Environmental similarity between twins does not have much of an impact on trait similarity. Excitatory function When a neurotransmitter increases the likelihood that the neuron will fire an action potential. This depends on the receptor site. Many neurotransmitters are excitatory when they act on some receptor sites, and inhibitory when they act on others. For example, serotonin is an excitatory neurotransmitter that regulates sleep and wakefulness and is found in neurons in the pons and upper brain stem - but it is inhibitory in mood and emotion. Family/kinship Studies Researchers trace a phenotype over several generations in a family tree to determine the likelihood that a behaviour is inherited. Fight/Flight Response A physiological reaction that occurs in response to perceived harm or threat to survival. It is triggered by the sympathetic nervous system activation that innervates the adrenal medulla, producing a hormonal cascade that results in the secretion of glucocorticoids. The animal is then readying for fighting or fleeing. This response is recognized as the first stage of Seyle's General Adaptation Syndrome. Genes Genes are made of DNA providing the blueprint for the structure and function of the human body, including behaviour. Genetic similarity Studying genetic similarity (twins, siblings, parents, adopted children) for one behaviour. Genetic similarity is referred to as relatedness. The greater the genetic similarities between two individuals or a group of individuals the higher the degree of relatedness. Genetic vulnerability An underlying inherited susceptibility - that is, the theory that you may have genes that may make you more likely to have certain traits if those genes are exposed to the appropriate environmental stressors. Genome-wide association studies (GWAS) An examination of a genome-wide set of genetic variants in a large sample of individuals to see if any variant is associated with a trait. Hippocampus Part of the limbic system, this part of the brain appears to play a key role in the consolidation of memory from short-term to long-term, as well as play a role in spatial navigation. There are several acetylcholine receptor sites in the hippocampus. Hippocampal cell loss plays a role in dementia, including Alzheimer's Disease. Hormone A chemical released by a gland directly into the bloodstream which has an effect on behaviour. HPA Axis A complex set of interactions between two parts of the brain—the hypothalamus and the pituitary glands—and the adrenal glands that are located at the top of each kidney. This is the basis of the human stress response. Human Genome Project The international, collaborative research program whose goal was the complete mapping and understanding of all the genes of human beings. All our genes together are known as our "genome." Inhibitory function When a neurotransmitter decreases the likelihood that the neuron will fire an action potential. This depends on the receptor site. Many neurotransmitters are inhibitory when they act on some receptor sites, and excitatory when they act on others. For example, serotonin is an inhibitory neurotransmitter when it is involved in emotion and mood, but excitatory in sleep and wakefulness. Linkage analysis Matching genetic variations (polymorphisms) with the frequency of a behaviour Localisation of function The theory that specific behaviours may have their origin in specific parts of the brain. Melatonin Secreted by the pineal gland, melatonin forms part of the system that regulates the sleep-wake cycle by chemically causing drowsiness and lowering the body temperature. Monozygotic twins The clinical term for identical twins; they share 100% of their DNA. Natural Selection The process whereby organisms better adapted to their environment tend to survive and produce more offspring Neural network Usually called a neural circuit, a group of neurons interconnected by synapses to carry out a specific function when activated. Neural pruning Usually referred to as synaptic pruning refers to the process by which extra neurons and synaptic connections are eliminated in order to increase the efficiency of neuronal transmissions. Neuroplasticity The brain’s ability to alter its own structure following changes within the body or in the external environment. Neurotransmitters A neurotransmitter is a chemical messenger that carries signals between neurons. Neurotransmitters are released from the terminal buttons at the end of an axon after the action potential has sent an electrical charge down the neuron. The neurotransmitter then crosses the synaptic gap to reach the receptor site on another neuron. Oxytocin Secreted by the pituitary gland, oxytocin plays a role in social recognition, pair bonding, and maternal attachment. For this reason, it is sometimes referred to as the "love hormone". There is some evidence that oxytocin promotes trust and empathy of in-groups. Permissive effect When the mere presence of the hormone allows for a behaviour, rather than the amount of the hormone. In the case of testosterone, Sapolsky argues that it not how much testosterone an animal has that determines whether it is aggressive, it is whether they have testosterone. Pheromone A chemical substance produced and released into the environment by an animal affecting the behaviour or physiology of others of its own species. Polymorphism A genetic variation (mutation) resulting in the occurrence of several different forms or types of individuals among the members of a single species. Reuptake The reabsorption of a neurotransmitter by the terminal buttons of the presynaptic neuron after it has performed its function of transmitting a neural impulse. This prevents further activity of the neurotransmitter. Prozac is an SSRI - that is, a selective serotonin reuptake inhibitor, allowing more serotonin to remain in the synaptic gap. Selective Placement A limitation of adoption studies in which children are placed with families that are very similar to the original family. Serotonin A neurotransmitter that works to regulate mood, appetite, and sleep. Low levels of serotonin have been linked to Clinical Unipolar depression and high levels of aggression. High levels of serotonin have been linked to hallucinations. Sexual selection Natural selection arising through preference by one sex for certain characteristics in individuals of the other sex. Testosterone The male sex hormone. Secreted by the testes in males and the ovaries in females. Transgenic Mice A mouse that has had a single gene changed or removed. Twin studies Interactionist Approach Uses different approaches: biological, cognitive and sociocultural, to get a richer understanding of behaviour. Reductionist Approach Analyzes a complex behaviour by studying the simplest, most basic mechanisms that are believed to be responsible for the behaviour. Electroencephalogra Used to show brain activity in certain psychological states, such as alertness or phy (EEG) drowsiness. Useful in the diagnosis of seizures and other medical problems that involve an overabundance or lack of activity in certain parts of the brain. Positron Emission Tomography (PET) Measure levels of sugar glucose in the brain in order to illustrate where neural activity is taking place. Magnetic Resonance Imaging (MRI) Uses strong magnetic fields to align spinning atomic nuclei within body tissues, then disturbs the axis of rotation of these nuclei and observes the radio frequency signal generated as the nuclei return to their baseline status. Functional MRI (fMRI) Series of MRIs that measure both the structure and the functional activity of the brain through computer adaptation of multiple images. Specifically, measures signal changes in the brain that are due to changing neural activity through detecting blood flow. Nature vs. Nurture Debate Researchers debated whether human behaviour is the result of biological or environmental factors. Cerebral Cortex The outer layer of the brain, composed of folded gray matter, plays an important role in consciousness.Consists of the frontal lobe, the temporal lobe, the parietal lobe, and the occipital lobe. Frontal Lobe Involved in the control of voluntary muscles, speech, and personality. Temporal Lobe Located just above the ears. Involves the auditory cortex, auditory association cortex, and part of the visual association cortex. Involves hearing, language processing, and memory. Damage can lead to failure to store new information. Parietal Lobe One region involves the integration of sensory information (taste, touch). The second involves a spatial coordinate system (movement). Occipital Lobe Located at the back of the head. Processes visual information. Left Hemisphere Receives sensory information and controls voluntary movements on the right side of the body. Responsible for verbal tasks (speech, reading, comprehension) and logical reasoning (maths, evaluation). Right Hemisphere Receives sensory information and controls voluntary movements on the left side of the body. Responsible for non-verbal tasks and big-picture processing (visualization, spatial, creativity, art, music, emotions). Localisation of Function Is the theory that specific parts of the brain are responsible for specific behaviors or cognitive processes. Basal ganglia Involved in the formation of procedural memories. Utilitarian Argument (Animal Ethics) If experimentation results in the greater good, then it was appropriate. If research can be conducted in any other way and still yield the same results, then animals should not be used. Animal Ethics Guidelines Animal Rights Argument (Animal Ethics) The 3Rs of Animal Ethics - PURPOSE of the research NUMBER of animals used should be minimized COST & BENEFIT must be carefully evaluated DISTRESS of the animals should be minimized ALTERNATIVES to animal research should be used when possible All animals have rights and the utilitarian argument is an example of speciesism, that being human is a good enough reason to ignore the rights the animals hold. - REPLACE the use of animals with alternative techniques, or avoid the use of animals altogether - REDUCE the number of animals used to a minimum REFINE the way experiments are carried out to lessen the suffering of animals Hormones A(nother) class of hormones that affect a wide range of behaviours. Are secreted by glands in the endocrine system directly into the bloodstream and hence, the changes in behaviors take longer to be produced but also lasts longer. Primer Pheromone Causes slow, long-term physiological changes, such as hormonal effects Signalling Pheromone Produces rapid behavioral effects such as mating Neurons Fundamental units of the brain and nervous system, responsible for receiving sensory input from the environment as well as send signals to the body (internal environment). Cell Body (Soma) The cell body of the neuron. Nucleus and other cell structures are present. Collections of the soma produce the greyish appearance of the grey matter of our brain. Axon Body of the neuron in which electrical impulses from the cell body or soma are sent away from and through. Axon Terminals Specialize in the release of neurotransmitters. Release transmitter substances (neurotransmitters) into the synaptic cleft of which then travel across and to the next neuron. Dendrites Membranous free-like projections arising from the body of the neuron with about 5-7 per neuron on average. Usually branch extensively, forming a dendritic tree around the neuron. Myelin Sheath An insulating layer, made usually of protein and fatty substances, around the body of the neuron (nerves), including those in the brain and spinal cord. Allows electrical impulses to be transmitted quickly. Synapse Site of transmission of electric nerve impulses between two nerve cells (neurons). The gap between two neurons. Dendritic Branching Multi-step biological process in which new dendrite trees and branches are formed by neurons to create more synapses. Long-Term Potentiation A persistent strengthening of synapses based on recent patterns of activity (repetition). GABA Gamma Aminobutyric acid, a natural inhibitory neurotransmitter which blocks or inhibits certain brain signals and decreases activity in your nervous system. Humaniquness The unique ability of human beings to create culture. Candidate Genes Genes which along the Manhattan plot are shown to differentiate between the experimental and control group and indicate (are) genes for potential, further research. Manhattan Plot A graph in which along the x-axis resides the chromosome and genes on each chromosome, and on the y-axis, the level of significance for the association of a genetic variation with the behaviour. Gene-Environment Interaction The interaction between the gene and the environment. A specific allele along a specific environmental stressor will have to simultaneously occur to result in a particular behaviour. Gene Expression The process by which the information a gene holds is used (expressed) as a result of environmental or physiological changes, stresses or needs. The process in which the regulation of the on and off of certain genes occur.
