PSYA01 - VOCABULARY AND DEFINITIONS
Psychology – the scientific study of mind and behaviour
Mind - our private inner experience of perceptions, thoughts, memories, and feelings
Behaviour – Observable actions of human beings and nonhuman animals
Nativism – the philosophical view that certain kinds of knowledge are innate or inborn.
Philosophical empiricism – the philosophical view that all knowledge is acquired through experience
Phrenology – a now defunct theory that specific mental abilities and characteristics, ranging from memory to the capacity for
happiness, are localized in specific regions of the brain.
Physiology – the study of biological processes, especially in the human body.
Stimulus – sensory input from the environment
Reaction time – the amount of time taken to respond to a specific stimulus
Consciousness – a person’s subjective experience of the world and the mind.
Structuralism – the analysis of the basic elements that constitute the mind.
Introspection – the subjective observation of one’s own experience
Functionalism – the study of the purpose mental processes serve in enabling people to adapt to their environment
Natural selection – Charles Darwin’s theory that the features of an organism that help it survive and reproduce are more likely than
other features to be passed on to subsequent generations
Hysteria – a temporary loss of cognitive ore motor functions as a result of emotionally upsetting experiences
Unconscious – the part of the mind that operates outside of conscious awareness but influences conscious thoughts, feelings, and
Psychoanalytic theory – Sigmund Freud’s approach to understanding human behaviour that emphasizes the importance of
unconscious mental processes in shaping feelings, thoughts, and behaviours.
Psychoanalysis – a therapeutic approach that focuses on bringing unconscious material into conscious awareness to better
understand psychological disorders.
Humanistic psychology – an approach to understanding human nature that emphasizes the positive potential of human beings.
Behaviourism – an approach that advocates that psychologists restrict themselves to the scientific study of objectively observable
Response – an action or physiological change elicited by a stimulus
Reinforcement – the consequences of a behaviour that determine whether it will be more likely that the behaviour will occur again.
Illusions – errors of perception, memory, or judgement in which subjective experience differs from objective reality.
Gestalt psychology – a psychological approach that emphasizes that we often perceive the whole rather than the sum of the parts.
Cognitive psychology – the scientific study of mental processes, including perception, thought, memory, and reasoning.
Behavioural neuroscience – an approach to psychology that links psychological processes to activities in the nervous system and
other bodily processes.
Cognitive neuroscience – a field that attempts to understand the links between cognitive processes and brain activity.
Evolutionary psychology – a psychological approach that explains mind and behaviour in terms of the adaptive value of abilities that
are preserved over time by natural selection.
Social psychology – a subfield of psychology that studies the causes and consequences of interpersonal behaviour.
Cultural psychology – the study of how cultures reflect and shape the psychological processes of their members.
Empiricism – the belief that accurate knowledge can be acquired through observation.
Scientific method – a set of principles about the appropriate relationship between ideas and evidence.
Theory – a hypothetical explanation of a natural phenomenon
Hypothesis – a falsifiable prediction made by a theory.
Empirical method – a set of rules and techniques for observation.
Operational definition – a description of a property in concrete, measurable terms.
Measure – a device that can detect the condition to which an operational definition refers
Electromyograph (EMG) – a device that measures muscle contractions under the surface of a person’s skin.
Validity – the extent to which a measurement and a property are conceptually related
Reliability - the tendency for a measure to produce the same measurement whenever it is sued to measure the same thing.
Power – the ability of a measure to detect the concrete conditions specified in the operational definition
Demand characteristics – those aspects of an observational setting that cause people to behave as they think they should
Naturalistic observation – a technique for gathering scientific information by unobtrusively observing people in their natural
Double mind – an observation whose true purpose is hidden from both the observer and the person being observed
Frequency distribution – a graphical representation of measurements arranged by the number of times each measurement was
made. Normal distribution – a mathematically defined frequency distribution in which most measurements are concentrated around the
Mode – the value of the most frequently observed measurement
Mean – the average value of all the measurements
Median – the value that is “in the middle “ – i.e. greater than or equal to half the measurements and less than or equal to half the
Range – the value of the largest measurement in a frequency distribution minus the value of the smallest measurement.
Standard deviation – a statistic that describes the average difference between the measurements in a frequency distribution and
the mean of that distribution.
Variable – a property whose value can vary across individuals or over time.
Correlation – two variables are said to “be correlated” when variations in the value of one variable are synchronized with variations
in the value of the other.
Correlation coefficient – a measure of the direction and strength of a correlation, which is signified by the letter, r.
Natural correlation – a correlation observed in the world around us.
Third-variable correlation – the fact that two variables are correlated only because each is casually related to a third variable
Matched samples – a technique whereby the participants in two groups are identical in terms of a third variable.
Matched pairs – a technique whereby each participant is identical to one other participant in terms of a third variable.
Third-variable problem – the fact that a causal relationship between two variables cannot be inferred from the naturally occurring
correlations between them because of the ever-present possibility of third-variable correlation.
Experiment – a technique for establishing the causal relationship between variables.
Manipulation – the creation of an artificial pattern of variation in a variable in order to determine its causal powers.
Independent variable – the variable that is manipulated in an experiment
Experimental group – the group of people who are treated in a particular way, as compared to the control group, in an experiment.
Control group – the group of people who are not treated in the particular way that the experimental group is treated in an
Dependent variable – the variable that is measured in a study
Self-selection – a problem that occurs when anything about a person determines whether he or she will be included in the
experimental or control group.
Random assignment – a procedure that uses a random event to assign people to the experimental or control group.
Internal validity – the characteristic of an experiment that establishes the causal relationship between variables
External validity – a property of an experiment in which the variables have been operationally defined in a normal, typical, or
Population – the complete collection of participants who might possibly be measured.
Sample – the partial collection of people drawn from a population
Case method – a method of gathering scientific knowledge by studying a single individual.
Random sampling – a technique for choosing participants that ensures that every member of a population has an equal chance of
being included in the sample
Informed consent – a written agreement to participate in a study made by an adult who has been informed of all the risks that
participation may entail.
Debriefing – a verbal description of the true nature and purpose of a study.
Neurons – cells in the nervous system that communicate with one another to perform information-processing tasks
Cell body – the part of a neuron that coordinates information-processing tasks and keeps the cell alive
Dendrite – the part of a neuron that receives information from other neurons and relays it to the cell body.
Axon – the part of a neuron that transmits information to other neurons, muscles, or glands.
Myelin sheath – an insulating layer of fatty material
Glial cells – support cells found in the nervous system.
Synapse – the junction or region between the axon of one neuron and the dendrites of cell body of another.
Sensory neurons – neurons that receive information form the external world and convey this information to the brain via the spinal
Motor neurons – neurons that carry signals form the spinal cord to the muscles to produce movement
Interneurons – neurons that connect sensory neurons, motor neurons, or other interneurons.
Resting potential – the difference in electric charge between the inside and outside of a neuron’s cell membrane
Acting potential – an electric signal that is conducted along a neuron’s axon to a synapse
Refractory period – the time following an action potential during which a new action potential cannot be initiated
Terminal buttons – knoblike structures that branch out from an axon
Neurotransmitters – chemicals that transmit information across the synapse to a receiving neuron’s dendrites
Receptors – parts of the cell membrane that receive the neurotransmitter and initiate or prevent a new electric signal Acetylcholine (Ach) – a neurotransmitter involved in a number of functions, including voluntary motor control.
Dopamine – a neurotransmitter that regulates motor behaviour, motivation, pleasure, and emotional arousal.
Glutamate – a major excitatory neurotransmitter involved in information transmission throughout the brain
GABA (gamma-aminobutryic acid) – the primary inhibitory neurotransmitter in the brain
Norepinephrine – a neurotransmitter that influences mood and arousal
Serotonin – a neurotransmitter that is involved in the regulation of sleep and wakefulness, eating, and aggressive behaviour.
Endorphins - chemicals that act within the pain pathways and emotion centers of the brain.
Agonists – drugs that increase the action of a neurotransmitter
Antagonists – drugs that block the function of a neurotransmitter.
Nervous system – an interacting network of neurons that conveys electrochemical information throughout the body.
Central nervous system (CNS) – the part of the nervous system that is composed of the brain and spinal cord
Peripheral nervous system (PNS) – the part of the nervous system that connects the central nervous system to the body’s organs
Somatic nervous system – a set of nerves that conveys information into and out of the central nervous system
Sympathetic nervous system – a set of nerves that prepares the body for action in threatening situations.
Parasympathetic nervous system – a set of nerves that helps the body return to a normal resting state.
Spinal reflexes – simple pathways in the nervous system that rapidly generate muscle contractions.
Hindbrain – an area of the brain that coordinates information coming into and out of the spinal cord.
Medulla – an extension of the spinal cord into the skull that coordinates heart rate, circulation, and respiration.
Reticular formation – a brain structure that regulates sleep, wakefulness, and levels of arousal.
Cerebellum – a large structure of the hindbrain that controls fine motor skills.
Pons – a brain structure that relays information from the cerebellum to the rest of the brain.
Tectum – a part of the midbrain that orients an organism in the environment.
Tegmentum – a part of the midbrain that is involved in movement and arousal
Cerebral cortex – the outermost layer of the brain, visible to the naked eye and divided into two hemispheres.
Subcortical structures – areas of the forebrain housed under the cerebral cortex near the very center of the brain.
Limbic system – a group of forebrain structures including the hypothalamus, the amygdala, and the hippocampus, which are
involved in motivation, emotion, learning, and memory.
Thalamus – a subcortical structure that relays and filters information from the senses and transmits the information to the cerebral
Hypothalamus – a subcortical structure that regulates body temperature, hunger, thirst and sexual behaviour.
Pituitary gland – the “master gland” of the body’s hormone producing system, which releases hormones that direct the functions of
many other glands in the body.
Hippocampus – a structure critical for creating new memories and integrating them into a network of knowledge so that they can be
stored indefinitely in other parts of the cerebral cortex
Amygdala – a part of the limbic system that plays a central role in many emotional processes, particularly the formation of
Basal ganglia – a set of subcortical structures that directs intentional movements.
Corpus callosum – a thick band of nerve fibers that connects large areas of the cerebral cortex on each side of the brain and
supports communication of information across the hemispheres.
Occipital lobe – a region of the cerebral cortex that processes visual information.
Parietal lobe – a region of the cerebral cortex whose functions include processing information about touch.
Temporal lobe – a region of the cerebral cortex responsible for hearing and language.
Frontal lobe – a region of the cerebral cortex that has specialized areas for movement, abstract thinking, planning, memory, and
Association areas – areas of the cerebral cortex that are composed of neurons that help provide sense and meaning to information
registered in the cortex.
Gene – the unit of hereditary transmission
Chromosomes – stands of DNA wound around each other in a double-helix configurations.
Heritability – a measure of the variability of behavioural traits among individuals that can be accounted for by genetic factors.
Electroencephalograph (EEG) – a device used to record electrical activity in the brain.
Synesthesia – the perceptual experience of one sense that is evoked by another sense
Sensation – simple stimulation of a sense organ
Perception – the organization, identification, and interpretation of a sensation in order to form a mental representation.
Transduction – what takes place when many sensors in the body convert physical signals form the environment into encoded neural
signals send to the central nervous system.
Psychophysics – methods that measure the strength of a stimulus and the observer’s sensitivity to that stimulus. Absolute threshold – the minimal intensity needed to just barely detect a stimulus
Just noticeable difference (JNB) – the minimal change in a stimulus that can just barely be detected.
Weber’s law – the just noticeable difference of a stimulus is a constant proportion despite variations in intensity.
Signal detection theory – an observation that the response to a stimulus depends both on a person’s sensitivity to the stimulus in
the presence of noise and on a person’s response criterion.
Sensory adaptation – sensitivity to prolonged stimulation tends to decline over time as an organism adapts to current conditions.
Visual acuity – the ability to see fine detail.
Retina – light-sensitive tissue lining the back of the eyeball
Accommodation – the process by which the eye maintains a clear image on the retina.
Cones – photoreceptors that detect colour, operate under normal daylight conditions, and allow us to focus on fine detail.
Rods – photoreceptors that become active under low-light conditions for night vision.
Fovea – an area of the retina where vision is the clearest and there are no rods at all
Blind spot – a locations in the visual field that produces no sensation on the retina because the corresponding area of the retina
contains neither rods nor cones and therefore has no mechanism to sense light.
Receptive fields – the region of the sensory surface that, when stimulated, causes a change in the firing rate of that neuron.
Trichromatic colour representation – the pattern of responding across the three types of cones that provides a unique code for each
Colour-opponent system – pairs of visual neurons that work in opposition
Area V1 – the part of the occipital lobe that contains the primary visual cortex.
Visual-form agnosia – the inability to recognize objects by sight.
Binding problem – how features are linked together so that we see unified objects in our visual world rather than free-floating or
Illusory conjunction – a perceptual mistake where features from multiple objects are incorrectly combined.
Feature integration theory – the idea that focused attention is not required to detect the individual features that comprise a
stimulus but is required to bind those individual features together.
Perceptual constancy – a perceptual principle stating that even as aspects of sensory signals change, perception remains consistent.
Template – a mental representation that can be directly compared to a viewed shape in the retinal image.
Monocular depth cues – aspects of a scene that yield information about depth when viewed with only one eye.
Binocular disparity – the difference in the retinal images of the two eyes that provides information about depth.
Apparent motion – the perception of movement as a result of alternating signals appearing in rapid succession in different locations.
Change blindness – when people fail to detect changes to the visual details of a scene.