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Period after a meal during which glucose is entering the bloodstream after its absorption from the gut.
A neurotransmitter. (Adj. cholinergic.)
Transport processes across membranes that require the expenditure of energy and use specialised transport molecules.
A process to do with sensations of pleasure and displeasure.
Focused on an object in its own right, rather than in relation to oneself.
Brain structure with a primary role in motivation and emotion.
amyloid precursor protein (APP)
A large transmembrane glycoprotein, which has been shown to play a major role in the pathogenesis of Alzheimer’s disease, as well as other related cerebral amyloid diseases. APP is made of 695 amino acids (APP-695). In 1988, three research groups simultaneously reported the isolation of cDNA clones that were shown to contain one or two additional domains compared with original APP-695. One of them showed extensive similarity to the Kunitz family of serine protease inhibitors (KPI) and resulted in a 56 amino acid insertion within the extracellular domain of the precursor protein. Therefore, the APP gene transcript and the corresponding APP protein that contain the nucleotide sequence or amino acid sequence, respectively, encoding this insert are denoted as KPI-APP or APP-751. APP-695 is predominantly expressed in the brain during development. The level of KPI-APP or APP-751 increased during ageing.
Term describing metabolic reactions that result in the synthesis of materials and in which energy is consumed.
Reduction in the intensity of pain.
A means of specifically relieving pain, e.g. injection of morphine, as distinct from an anaesthetic, which reduces all sensations.
The study of a particular non-human animal in such a way as to reveal general properties, e.g. about how a human might function.
The relentless pursuit of thinness through self-starvation, even as far as death.
An inability to remember new information for any length of time.
That which produces, or increases, anxiety.
Tending to reduce anxiety.
American Psychological Association.
General medical term used to describe a disturbance of speech caused by damage to the brain; strictly, an absence of speech.
apolipoprotein E (ApoE)
Amyloid precursor protein.
Something unnatural that arises as a result of an experimental intervention. For example, a structure that is seen when a cell preparation is examined under the microscope may appear to be a natural cell component, but may actually be the result of an alteration in the cell’s structure caused by the procedures used to prepare the specimen for microscopy.
Derived from a history of associations, as in Pavlovian conditioning.
Learning by experience to associate two events that have been paired (e.g. the sight of a needle with the effect of heroin).
Adenosine triphosphate. Each molecule of ATP is made up of a nucleotide base, a sugar unit and a chain of three phosphate groups. ATP is the energy currency of the cell. Energy is stored as ATP in the reaction between ADP (adenosine diphosphate) and Pi (inorganic phosphate):
ADP + Pi ATP
and is made available as required via the breakdown of ATP to ADP and Pi.
Type of disease in which the immune system of an organism attacks the normal healthy body of the same organism. Autoimmunity or immunological reactions caused by antibodies or T lymphocytes can produce severe inflammation or be innocuous, as when directed to intracellular autoantigens. Autoimmunity can develop spontaneously or be induced experimentally by immunisation with autoantigens or with antigens that are cross-reactive with them.
autonomic nervous system (ANS)
Concerned with the theory of value.
basal metabolic rate (BMR)
The metabolic rate of an individual who has not eaten for 12 hours, and is at rest and at a comfortable temperature.
(in nucleotide) Nitrogen-containing, ring-shaped molecules in DNA and RNA. There are four different bases in a nucleic acid: two with a double-ring structure, called adenine (A) and guanine (G); and three with a single-ring structure, cytosine (C) and either thymine (T), in DNA, or uracil (U), in RNA. It is the sequence of bases which determines the information content of the molecule.
The process by which stable chemicals, for example some pesticides, become increasingly concentrated in the tissues of animals as a consequence of their place in a food chain.
The view that every characteristic of an organism’s structure and functioning, including mental and emotional states in humans, is determined by the genes that an individual has inherited.
The gradual changes to the structures and functions of living things which have been occurring from the moment that the earliest life forms appeared on Earth, perhaps 3500–4000 million years ago.
A conglomerate term which seeks to encompass all the influences on individuals and groups from their biological and psychological functioning and social interactions.
A form of vision in which brain-damaged subjects can show evidence of some level of perception (e.g. an ability to point correctly at targets) even though they are unconscious of any such visual stimuli.
A lower than normal heart rate.
brown adipose tissue (BAT)
A chemical agent that causes cancer.
A disturbance to the normal beating of the heart.
A term used to describe insufficient blood flow to the tissues, such that tissue damage occurs.
The principle, based on the theory of René Descartes, that mind and matter are qualitatively different, and that because the mind does not operate within the laws of physics it cannot be investigated scientifically. Descartes also postulated that the mind (or soul) was unique to humans.
Term describing metabolic reactions that result in the breakdown of materials and the release of energy.
A substance that speeds up a reaction without itself undergoing any overall change in the process.
A causal explanation is one given in terms of the mechanisms that underlie behaviour in a given individual at a particular point in time. It should be distinguished from a functional explanation.
The nature of relationships between events in the environment, e.g. that a bell predicts food, or that a lever-press is followed by delivery of food.
The unit of which all living things are composed.
A variety of types of intercellular connections which may also allow cells to communicate with each other. Tight junctions (e.g. between epithelial cells) connect cells together to form a fluid-tight seal. Anchoring junctions, in which the cell’s cytoskeleton joins cells to one another, are found in tissues that are subject to friction and stretching (e.g. muscle tissue in the heart). In the third type, gap junctions, the adjacent cell membranes come extremely close to each other but do not actually touch. At gap junctions, pores in the cell membranes allow the transfer of material from cell to cell.
central nervous system (CNS)
The part of the nervous system that consists of the brain and spinal cord.
Concerning the brain, or mediated via the brain.
The term cerebrum is often used as a collective name for the left and right cerebral hemispheres of the brain.
A property of some objects that is responsible for electrostatic interactions (i.e. attraction or repulsion) between them. There are two types: positive and negative. Like charges repel and unlike charges attract each other. A stream of moving negative charges (electrons) through an electrical conductor produces an electric current.
A long-standing illness for which there is no known cure. It is not immediately life-threatening but can give rise to unpleasant and painful symptoms.
Facts about the world that can be utilised flexibly in behaviour, e.g. food is by the window.
Term describing a process of information storage and retrieval, which can be utilised flexibly in behaviour. In humans, ‘cognitive’ relates to mental operations sometimes termed thought processes, e.g. reasoning, calculation and planning.
A branch of psychology that is concerned with intelligence and thought processes. It tries to understand the complexity of the relationship between an individual’s thought and action.
A generation of people (or animals) all born during the same period of time.
A substance made up of two or more types of atom.
compression of morbidity thesis
This claims that disease and decay have largely been eliminated until the very last few years of the lifespan.
A gradient that exists when there is a difference in concentration of a particular substance, which results in the net movement of the substance from the region of high concentration to the one of lower concentration.
The extent to which halves of a twin pair correlate in some quality, e.g. height or IQ.
conditional/conditioned stimulus (CS)
An arrangement such that one event is arranged or programmed to follow another. For example, a classical contingency is where a neutral stimulus is arranged to occur just before an unconditional stimulus. In an instrumental contingency, it is arranged that an event (e.g. food presentation) occurs immediately after a response by the animal (e.g. lever-pressing).
An animal is said to be contraprepared to learn something when it has a bias against learning it. For example, whereas rats are easily able to learn an association between a taste and gastrointestinal upset, it is difficult to teach them an association between a sound and gastrointestinal upset.See also prepared.
The outer layer of grey matter of the brain.
A nerve conveying information between the brain and regions of the head, e.g. the optic nerve.
Folds of the inner mitochondrial membrane.
An experimental method which involves making comparisons between groups of people from different sections of the population made at the same point in time.
The gradual changes to the customs, beliefs, values, knowledge and actions of human societies, which have been occurring for perhaps the last million years.
Technical name for the method (cell or tissue culture) used to study biological phenomena in the cell population that was, first, isolated from the animal of interest. A technique that allows living cells to be grown outside the body. Depending on the cell type, they might survive for a few days only, or they might differentiate and proliferate and continue the cell line for many years.
The fluid contents of the cell.
See explicit memory.
An intermediate in androgen and oestrogen biosynthesis.
A group of mental disorders characterised by progressive loss of cognitive and other intellectual functions associated with pathological ageing.
A period in the 1930s in Western economies that was characterised by very high levels of unemployment and poverty.
A region of the body that is associated with a particular spinal nerve.
diabetes mellitus (types I and II)
Clinical condition in which either insulin is absent (type I, insulindependent) or in which insulin responsiveness is lost (type II, non-insulin-dependent). Characterized by the copious production of sweet urine.
Listening to two different inputs simultaneously. This is a paradigm used very often to study attention where subjects listen to a series of two different things at the same time. Subjects are subsequently asked to repeat words previously presented.
differential gene expression
Term describing cells that have become specialised into particular types.
The passive (i.e. non-energy-requiring) movement of a substance from a region where it is at a high concentration to a region where it is at a lower concentration.
A two-ring sugar, e.g. sucrose, lactose.
A stimulus that is paired with either reward (i.e. reinforcer) availability (+) or its lack (−). An animal’s operant behaviour can be brought under the control of a discriminative stimulus such that it responds only in the presence of the reinforcer. In other words, discrimination training involves the association of a discriminative stimulus with a reinforcer.
This theory suggests that older people voluntarily withdraw from society in preparation for death, and in order that society can continue to function.
disposable soma theory
A theory of the evolution of ageing and death, which suggests that organisms derive little benefit from investing resources in maintaining and repairing body tissues and thereby increasing their lifespan beyond a certain point. To do so would be inefficient as death is inevitable and resources that could have been put into reproduction would have been wasted.
diurnal (circadian) rhythm
Non-identical twins. Two individuals that develop in one uterus from separately fertilised eggs. Also called fraternal twins.
Short for deoxyribonucleic acid. DNA is a macromolecule made up of individual units called nucleotides, and is found in all living cells and some viruses. The DNA molecule exists as a complex of two chains in an intertwined double helix. It is the carrier of genetic information that is passed on from generation to generation by replication of the DNA molecule.
The idea that mental events and brain events are two aspects of the same underlying reality.
The situation where a lesion at site A produces a disturbance in function X but not Y, and a lesion at site B produces a disturbance in function Y but not X.
Diagnostic and Statistical Manual (of mental disorder). An American-based reference text; the ‘Bible’ of classification of psychological disorders. DSM I was first published in 1952 and has been updated several times since then. (The number, i.e. I, II, etc., denotes the edition.)
The idea that brain events and mind events are two distinct categories of existence. According to this, the mind can exist even in the absence of a physical brain.
Negative mood, e.g. depression; the opposite of euphoria. (Adjective: dysphoric.)
The scientific investigation of animals, plants and microbes in relation to their natural surroundings, both animate and inanimate.
A behaviour is described as elastic if its performance changes as a function of effort, e.g. if the demands made to gain access to a drug are increased and consumption falls. It is inelastic if, as the demands increase, consumption remains the same.
Concerned with the electrical properties of the skin. Electrical resistance changes with different emotions.
A technique in which electrodes are attached to the head, thus enabling the activity of populations of the brain’s neurons to be monitored. The record of such activity is called an electroencephalogram (also abbreviated to EEG).
electron transport chain
Chain of molecules (electron carriers) in the inner mitochondrial membrane which are involved in oxidative phosphorylation. Electrons are transferred from NADH and FADH2 to these molecules, then from molecule to molecule along the chain, and are finally accepted by oxygen. ATP formation is coupled to this electron transfer.
A substance made up of only one type of atom.
embedded figures test
A test that measures a subject’s ability to distinguish figures from their context, e.g. a human face that is set in a number of disguising lines.
Properties are said to emerge at different levels of organization, i.e. they are emergent properties.
endoplasmic reticulum (ER)
enteric nervous system
A term used in this module to encompass geography, climate and physical surroundings, together with social circumstances, housing, diet, culture, politics, legislation, technology, religion, science, the media and so on – in fact, anything that could be considered as having an influence on health.
The study of how a condition is distributed within a population and how it changes over time, undertaken in order to understand the factors that contribute to the development of the condition.
epidermal proliferative unit
A philosophically loaded term that is difficult to define; usually a mental state that is assumed to have no influence on behaviour or the brain. (Its mere postulation raises complex and highly controversial philosophical issues.)
Relating to knowledge and the theory of how knowledge is acquired.
The bases and nature of knowledge that is employed in a branch of science. What constitutes its terms and preconceptions.
epithelial tissue (epithelium)
Name of one of the enzyme systems for repairing damaged DNA molecules. DNA repair occurs in several stages, each mediated by a specific enzyme: a specific endonuclease recognises the damaged region, cutting the relevant polynucleotide strand; an exonuclease digests away the nucleotides next to the cut; DNA polymerase binds 5′-nucleoside triphosphates to the resulting single-stranded region and, finally, the two ends of the strand are joined by the polynucleotide ligase.
Someone who believes that individuals are free to choose what they are, rather than having to follow a predetermined blueprint. The most famous existentialist, Jean-Paul Sartre, declared that for the existentialist ‘existence preceded essence’, by which he means that we invent ourselves through our actions, our ‘essence’ is not given.
In a classification of depression, refers to that caused by an external factor, e.g. divorce.
A term meaning that an animal (e.g. a rat) has some knowledge of what is at the goal and acts as if it expects to receive this.
A term used in behavioural studies to describe both a procedure and a result. It is the procedure whereby the strengthening agent is omitted in a conditioning situation (CS). For example, after an animal has been classically conditioned to respond to a bell by salivating, extinction consists of omitting the food but still presenting the bell. As a result, extinction is seen when the animal ceases to respond to the CS. Similarly, in instrumental conditioning, an extinction procedure consists of omitting the food. Extinction is observed when the animal ceases to respond.
Federal Drugs Administration. The US drugs policy and control organisation.
The number of fertilised eggs that a sexually reproducing organism produces.
A sustained increase in body temperature above normal. It is usually the result of infection but can be due to physical trauma.
The dutifulness that a son or daughter displays to his or her parents.
Ability of an organism to survive and produce offspring that can themselves produce viable offspring. The term should not be confused with the common use, which refers specifically to physical bodily fitness.
flavin adenine dinucleotide (FAD)
A hydrogencarrying coenzyme derived from vitamin B2 (riboflavin).
Atoms or group of atoms that contain unpaired electrons and are therefore unstable and highly reactive. They are produced both via metabolism and by exposure to harmful substances. Free radicals acquire electrons from other molecules around them, thus creating another unpaired electron in that molecule, and so on, resulting in a chain reaction. This chain reaction can cause considerable damage to living material. Free radicals can be inactivated by antioxidants.
An enzyme that breaks down lactose.
gastric inhibitory peptide (GIP)
The unit of genetic information. Most genes code for the production of proteins.
Technical name for the scientific study of the elderly.
Structure from which substances are secreted by the body. Glands can be endorine, secreting hormones into the bloodstrean, or exocrine, secreting (for example) digestive juices into the gut or sweat onto the surface of the skin.
glia (glial cells)
Cells in the nervous system, found in close physical association with neurons. They are not directly involved in transmission of information along neurons, but have a supporting role. Their functions are both metabolic, e.g. regulating the chemical composition of the nervous system, and structural – they are often wrapped tightly around neurons, where their fatty membranes, called myelin, act as electrical insulation.
The new synthesis of glucose from other small molecules (e.g. lactate, pyruvate, glycerol).
glutathione peroxidase (GPx)
An enzyme that catalyses the oxidation of two molecules of glutathione, a tripeptide made of three amino acids (γ-glutamyl-cysteinyl-glycine) by hydrogen peroxide, to form oxidised glutathione and two molecules of water. This enzyme is very important in protection of haemoglobin from oxidative breakdown.
Breakdown of glycogen to release glucose.
Lipid with covalently attached sugar chains.
First stage in the catabolism of glucose. The end-product of glycolysis is pyruvate.
Protein with covalently attached sugar chains.
(1) broad (H2): the proportion of total phenotypic variation in a particular trait at the population level that is attributable to variation in the 10 genotype;
(2) narrow (h2): the proportion of phenotypic variation that can be attributed to additive genetic variation, and which can be used to predict the response of the population to natural selection or selective breeding.
high density lipoproteins (HDL)
Molecular aggregates in the bloodstream consisting of about equal proportions of protein and lipid (i.e. 50 per cent protein and 50 per cent lipid, of which about two-fifths is cholesterol). HDL returns cholesterol to the liver where it is broken down to waste products that are excreted in bile. The proportion of HDL in the circulation is increased by the consumption of unsaturated fatty acids.
(noun: holism) A type of approach to describing or analysing a complex phenomenon, which takes account of all possible levels of explanation and their interactions; the phenomenon itself is considered as a ‘whole’ which is more than the sum of its component parts or influences.
The process of maintaining the stability of important internal variables and the instigation of corrective action when these deviate from optimum.
A chemical that is secreted into a blood vessel at one location and carried in the blood to effect action at some other site, which may be a large distance away.
A branch of psychology which emphasises that humans are free agents in possession of consciousness and able to influence events in the world.
Literally, ‘water-loving’, i.e. having a tendency to associate with (polar) water molecules.
Literally, ‘water-hating’, i.e. having a tendency to associate with non-polar molecules (such as each other) and away from water.
Excessive pain sensitivity to a given noxious stimulus. (Adjective: hyperalgesic.)
Elevated concentration of glucose in the circulation (above about 140 mg ml-1).
The state of the body resulting from elevated temperature. Fever is the usual index of hyperthermia but there can also be heat exhaustion and heat stroke.
Lowered concentration of glucose in the circulation (below about 70 mg ml-1).
hypothalamo-pituitary-adrenal (HPA) axis
The collection of nuclei below the thalamus which, amongst other things, helps to regulate the activities of the hormonal system and the autonomic nervous system.
Reduction of body temperature below the normal range of values (i.e. 36–38 °C).
International Association for the Study of Pain.
An effect that arises as an unwanted consequence of a medical intervention
International Classification of Diseases (10th edition).
Intracranial self-stimulation. Pressing a lever in a Skinner box to deliver electric shocks to the brain via implanted electrodes.
The philosophy that the mind (and spirit) is fundamental to the world and cannot be reduced to a product of the brain.
The idea that brain events and mind events are two different languages for describing the same reality, i.e. mind events do not have an existence apart from brain events.
Concerned with the measurement and analysis of individual differences.
Memory that is revealed when performance on a task is facilitated without conscious recollection (such as when naming an object).
The number of new cases occurring per thousand of the population in any given period.
index of learning
insensible water loss
Passive loss of water by evaporation from the skin and from the lungs during exhalation.
An act that is assumed to occur (or to occur more frequently) because of the positive consequences that arise from it, e.g. euphoria after taking a drug.
insulin-dependent diabetes mellitus (IDDM)
Insensitivity of cells to insulin, which occurs in non-insulin-dependent diabetes mellitus (type II).
intelligence quotient (IQ)
The score that is the result of a standard intelligence test.
Neurons that are neither sensory nor motor but lie somewhere between these.
Arising from within the body, e.g. the stretch of the stomach.
By means of injection into a vein.
The process of reflecting upon the contents of one’s own conscious mind. A tool used in psychological investigation.
Chemical bonding between ions of opposite charge. Also called electrostatic interaction.
A type of excitatory amino acid receptor for which glutamate may be the endogenous ligand. It is named after its specific agonist ligand, kainate. The receptor is coupled to Na+/K+ channels in the cell membrane, which are opened when activated by the agonist. Activation by the agonist is indirect, through the action of G-protein, or guanine nucleotide binding protein, which acts as a transducer of information between the receptor and the ion channel. For more details on the structure and mechanism of signal transduction, see Carlson, Ch. 4; or Oxford Reference Online.
Natural selection operating indirectly on a character by favouring the relatives of the individual having that character. For example, the genes that cause a woman’s reproductive activity to be switched off at a certain stage will be favoured by natural selection if, as a result of her post-reproductive behaviour, her progeny and those of other close relatives are more likely to survive.
(social) Describes some aspect of an individual’s condition such that it becomes a way of defining that individual’s relationship with the rest of the world.
The asymmetrical distribution of function between the two hemispheres of the brain, e.g. localisation of language in the left hemisphere.
A mixture containing opium, which was widely available in Britain in the Victorian period.
law of effect
The law that states that behaviour is strengthened by its consequences.
The process by which a memory of experience is acquired that will modify behaviour.
A graph showing an index of learning as a function of the number of trials over time.
level of explanation
A term applied to explanations for a certain phenomenon which are derived from a coherent body of concepts, hypotheses and knowledge associated with a particular academic discipline or subdiscipline; the term signifies the existence and value of other levels of explanation of the same phenomenon.
The average number of years a person can expect to live from birth.
The length of life of the longest-lived member of a species.
Cells located at the retina of the eye and specialised for the detection of light.
(genetic) The situation in which alleles of different genes do not assort independently; they are held together, or linked. The degree of linkage is greater the closer together the genes are on the chromosome because, the closer they are, the less likely they are to be separated during the process of crossing over.
Breakdown of fats to release fatty acids and glycerol.
An experimental method that involves testing and retesting the same subjects at different ages over a long period of time.
Memory that is stored by the brain for long periods of time.
low density lipoproteins (LDL)
manual social classes
The Registrar General’s social classification of the population is based on occupational status. The manual social classes are made up of people whose work is manual, e.g. building or plumbing work, and are sometimes referred to as blue-collar workers.
mesolimbic/mesotelencephalic dopamine system/ pathway
messenger RNA (mRNA)
A group of sequential metabolic reactions.
The rate at which energy is used by the body. It is usually expressed in kilocalories per hour.
The term refers to when a cancerous tumour spreads out to establish satellite tumours elsewhere.
A substance that is prescribed for heroin addicts. It is believed to have a less-addictive potency than heroin, though in this regard its use is controversial.
A representation using chemical symbols for the atoms contained in one molecule of a covalent compound; it gives the types of atoms and the numbers of each present; for example, the molecular formula of water is H2O. (Formulae for ionic compounds are also given using the same shorthand convention, e.g. sodium chloride is NaCl.)
monism / monistic
A philosophical view that there is just one kind of matter in existence, e.g. materialism.
A single-ring sugar, e.g. glucose, fructose, ribose.
Genetically identical twins. Two individuals that developed in one uterus from a singe zygote by separation of the embryo after the two-cell stage.
Occurrence of illness. Specifically, the reported incidence of illness per 1000 of the population.
The tendency of an animal to engage in a particular behaviour, e.g. a feeding motivation or a sexual motivation.
Describes an agent that can cause mutations (e.g. UV radiation and certain chemicals).
An antagonist to opioids. It can cause distress and some signs of withdrawal if injected by heroin users, a so-called naloxone challenge.
An opioid (opiate) drug, e.g. morphine or heroin.
Driving force of evolution as described by Darwin. In the competition for resources between individuals in an environment that cannot support all of a population, a natural process of ‘selection’ occurs in which individuals with the most adaptive characteristics are more likely to survive and reproduce.
negative cognitive set
Tendency to construe the world in negative terms; characteristic of a depressed mood.
(in cell metabolism) Also called end-product inhibition. It is the mechanism by which a metabolic pathway is regulated: when the product of the pathway exceeds a critical concentration, it ‘switches off’ an enzyme early in the pathway, thereby preventing further synthesis of the regulatory end-product.
negative feedback system
A system in which a displacement of a variable from a state causes corrective action such as to return the variable to that state.
Another name for a neuron.
The collection of all of the neurons of the body, in brain, spinal cord and periphery.
Dendrites or axons grown from neurons.
A disorder of behaviour or personality brought about by damage to the brain. Sometimes called an organic disorder.
nicotinamide adenine dinucleotide (NAD+)
Hydrogencarrying coenzyme derived from the vitamin niacin.
N-methyl-D-aspartate (NMDA) receptor
One subtype of glutamate receptor, which binds the amino acid glutamate (a major excitatory neurotransmitter) and mediates its effect in neurotransmission. It is named after the dicarboxylic amino acid N-methyl-D-aspartate (NMDA), an agonist of glutamate used extensively to characterise different isoforms of glutamate receptor.
A neuron that is sensitive to tissue damage at its tip. Normally, the first stage in the process of pain.
non-insulin-dependent diabetes mellitus (NIDDM)
The most common form of diabetes mellitus, in which the responsiveness of cells to insulin is diminished. Thus, although insulin may be present at normal (or near-normal) levels, it is not able to effect its normal regulatory role.See also diabetes mellitus (type II).
non-manual social classes
Those who fall into this social class are from professional and managerial occupations; sometimes called white-collar workers.
norm of reaction
The idea that something is nothing but its component parts and can be explained simply in terms of them, e.g. that humans are ‘nothing but’ a collection of physical components.
The double layer of membranes that surrounds the nucleus.
Term describing behaviour that is freely emitted by an animal and can be reinforced by the experimenter.
A variety of instrumental conditioning in which an animal emits a behaviour at a time it decides and that behaviour is then reinforced by its consequences. For example, an animal might press a lever in a Skinner box to earn a pellet of food. Not all instrumental conditioning can be described as operant. For instance, where an experimenter puts a rat in a maze and then removes it after its choice, is not described as operant since the timing of behaviour is not under the control of the rat.
A class of drug that includes opium, morphine and heroin.
A distinct structure in the body serving a particular function, e.g. brain or kidney.
A group of organs that all work together, e.g. the cardiovascular system, the urinary system, the digestive system. Also sometimes called body system.
The movement of water across a membrane that is freely permeable to water but not to solutes (dissolved substances), from a region of low solute concentration to one where the solute concentration is higher.
A disease of bones. It is brought about when old bone is lost faster than new bone is gained in the remodelling process.
The process coupled to electron transport which is last of the series of reactions in which energy is derived from glucose. It takes place at the inner mitochondrial membrane. Electrons are transferred from NADH and FADH2 (formed by reduction of NAD+ and FAD during glycolysis and the TCA cycle) along a series of electron carrier molecules, and are eventually passed to oxygen. The process generates large quantities of ATP.
See free radicals.
The relief of pain and suffering.
The care of patients with active, progressive, far advanced disease and limited prognosis and for whom the focus of care is the quality of life.
Behaviour that is out of touch with conventional reality. Bizarre behaviour in which the sufferer feels persecuted by others and can be dangerous to others.
parasympathetic nervous system
The conceptualisation of health in terms of disease.
peripheral nervous system
As it appears to the subject who experiences a particular effect.
A psychologist who studies the contents of conscious experience by means of asking subjects to introspect.
The study of one’s conscious experiences of the world, e.g. how it feels to experience addiction.
One of the most important membrane lipids; the polar phosphate ‘head’ groups are on the outside and the fatty acid ‘tails’ cluster together in the membrane interior.
The process whereby characteristics appear as a result of evolution.
Endocytosis of liquid.
A neutral substance that can none-the-less have a specific effect, especially if a subject believes that it will do so, e.g. to reduce pain.
polar covalent bond
This approach to analysing society is concerned with the unequal distribution of wealth.
The introduction into the environment (air, water or land) of contaminants, the quantities, characteristics and duration of which are likely to be injurious to humans, animal, or plant life.
A process in which a deviation from some condition tends to promote further deviation.
A reference to a philosophical position which considers only observable and measurable phenomena (e.g. movement, quantity of saliva produced) to be the basis of science.
Period starting about 4 hours after a meal and continuing until the next meal, during which no glucose is entering the circulation from the gut, and hence during which glucose must be derived from energy stores laid down during the absorptive state.
A term referring to physical life that continues despite serious progressive mental disability. The term is used to describe the state of people with Alzheimer’s disease or other types of neurodegenerative conditions.
An animal is said to be ‘prepared’ to learn something if it has a bias in favour of learning it. For example, animals are prepared to learn relationships between food and gastrointestinal upset. It is easy to teach them such an association.
A family of highly conserved transmembrane proteins with a variety of biological functions. Mutations in presenilin genes are most likely to act as dominant negative gene defects, which may ultimately lead to proteolytic processing of APP and activation of caspases. Mutations in presenilins account for up to 40 per cent of early-onset Alzheimer’s disease.
The number of individuals per thousand of the population actually showing a disease or trait at any given point in time.
Effect observed in investigations of short-term memory. Subjects are presented with a sequence of 15–30 unrelated words. Immediately after the last word, they are asked to recall as many words as they can in any order they wish. Performance on this task shows that the first-presented words are recalled reasonably well – the primacy effect.See also recency effect.
A term with two meanings in behavioural biology:
A biological relative against which comparisons can be made.
Memory that includes knowledge of skills, of ‘knowing how’ (such as swimming, riding a bike, driving a car).
A disorder of behaviour or personality without obvious brain damage. Sometimes called a functional disorder.
Term used by Pavlov to describe secretions of saliva evoked by such stimuli as people entering the room. We would now see these as a type of conditional stimulus.
psychological life-history explanation
Explanation that seeks the origins of a disorder within an individual’s own life history.
The study of the behaviour of humans (and other animal species) and of their mental states.
The link between sensory information and motor reactions made on the basis of it. A process impaired by, for example, alcohol.
A class of drug (including amphetamine), which has the effect of increasing the level of activity in a given situation.
Behaviour that is out of touch with conventional reality. (Adjective: psychotic.)
Describes behaviour directed to obtaining a goal and guided by a representation of the goal.
Effect observed in investigations of short-term memory. Subjects are presented with a sequence of 15–30 unrelated words. Immediately after the last word, they are asked to recall as many words as they can in any order they wish. Performance on this task shows that the last few words are recalled extremely well – the recency effect.See also primacy effect.
The area of sensory surface which, when stimulated, changes the activity of a neuron in a sensory system.
A term with two very different meanings in neurobiology:
A return to drug taking after a period of abstinence.
rectangularisation of mortality
An automatic, predictable and relatively stereotyped reaction to a particular stimulus.
Negative reinforcement encourages a particular behaviour pattern by making that behaviour pattern necessary if the animal is to avoid, or escape from, an unpleasant stimulus.
Positive reinforcement encourages a particular behaviour pattern by the presentation of a pleasant stimulus, such as food, every time the desired behaviour pattern is performed.
The process of making new DNA molecules; each strand serves as a template for the synthesis of another, complementary strand. In this way, two new DNA double helices are formed, each having one strand from the ‘old’ original DNA double helix and one newly synthesised strand, i.e. DNA synthesis is semi-conservative.
The behavioural reaction of an animal to a stimulus.
Amino acids have the same general formula, possessing an amino group, a carboxylic acid group, and a group of atoms that is different for each amino acid; this is called the R group. The shape and properties of a protein, and hence its function, are determined by the R groups of their constituent amino acids.
A test in which subjects are shown ink blots and asked to describe what images they perceive. It is said to give insights into personality.
The abbreviation for reactive oxygen species, such as hydroxy, nitric and superoxide radicals.
A state of loss of motivation as a result of completing a session of a particular behaviour. For example, after food deprivation an animal might be given food and then achieve a state of satiety as a result of free ingestion.
schedules of reinforcement
Regular structure within a polypeptide chain. There are two main types: the α-helix and the β-sheet.
Memory that includes general knowledge of the world acquired through education and experience, including the use of language.
One of the brain’s neurotransmitters.
A procedure whereby an experimenter rewards successive approximations to a desired operant response. For example, if lever-pressing is the desired operant, an experimenter might offer reward for first touching the lever and then for lowering the lever slightly. Finally, reward would be given only for fully lowering the lever.
A term used to describe patients who are treated by others as if they were not there.
Classification of groups in society in terms of social characteristics (e.g. marital status) or economic determinants (e.g. income level).
The study of human interactions and social relationships, their organisation, functions, development and significance.
somatic nervous system
An individual in whom the corpus callosum has been cut. Under certain conditions, such individuals behave as if they had two brains with separate consciousnesses.
Unusual repetitive behaviour such as picking a part of the skin repeatedly.
Something that impinges upon an animal's sense organs.
Sulci (plural) are folds in the cerebral cortex. They serve as landmarks for identifying brain regions.
superoxide dismutase (SOD)
sympathetic nervous system
Overactivity of the part of the nervous system that controls such processes as heart rate, sweating and digestion. A consequence of its overactivity is a higher than normal heart rate.
Junction between cells in the nervous system, and also between such cells and their target organs, e.g. muscles. A synapse consists of a specialised presynaptic membrane from which molecules of neurotransmitter can be released, a gap across which the neurotransmitter diffuses (synaptic cleft) and a postsynaptic membrane that has receptor molecules on it which are specific for and so bind the neurotransmitter.
Process of new synapse formation.
An instrument for very brief measured exposure of objects to the eye.
Abnormally high heart rate.
taste reactivity test
A test in which substances are placed on the tongue of a laboratory animal (e.g. a rat) by means of an implanted tube. The reaction of the animal to the substance (e.g. swallowing, mouth wiping) is usually monitored by video.
Tricarboxylic acid cycle (also citric acid cycle or Krebs cycle.) Second of three consecutive metabolic pathways involved in energy production from glucose. Acetyl CoA, formed from pyruvate in the link reaction, is catabolised via a cyclic series of reactions, in which CO2 and reduced coenzymes are produced. The former is excreted via the lungs and the latter reoxidised via the electron transport chain.
Guided by a goal or end-point. For example, some have suggested that evolution is guided in this way (though this is not a mainstream view).
A term used for the end of the chromosome; simple tandem DNA repeat sequences that make the end of a eukaryotic chromosome.
The presentation of two stimuli (e.g. a conditional and an unconditional stimulus) at the same time.
This describes the state of affairs when the body finally wears out.
The maintenance of body temperature within its normally narrow range (36–38 °C.).
Growing cells that have been isolated from the body, in dishes containing all the nutrients necessary for survival and growth.
A decreasing response to an interventio (e.g. drug injection) as a function of its repeated presentation.
total energy expenditure
Total energy used by the body over a period of time. It is the sum of the heat energy generated plus the external work done plus the energy stored.
Elements that are needed in very small quantities in the diet.
transfer RNA (tRNA)
Term used for factors that exert a nutritive, or trophic, effect on cells.
unconditional response (UCR)
unconditional/unconditioned stimulus (UCS)
A tube passing into a vein through which a drug can be passed into the body.
very low density lipoproteins (VLDL)
The probability that a fertilized egg will go on to develop into an individual that can reproduce.
word completion task
In this test, subjects are presented with a three-letter word-fragment and asked to write down the first word they think of, or that had appeared on the previously presented list. Subsequently, subjects are asked to complete fragments. The score is the number of completed words that were elicited.
Also referred to as amyloid-β (abbreviated to Aβ). It is a peptide derived from the larger amyloid precursor protein (APP) and is the principal component of amyloid fibrils. The specific role of β-amyloid is unclear, but it is thought that amyloid deposits may cause neurons to degenerate. Amyloid deposits also occur in the brains of older Down’s syndrome patients.