Achromatopsia: A failure to perceive color (the world
appears in grayscale), not to be confused with color blindness (e.g. in which red and
green cannot be discriminated).
Action potential: A sudden change (depolarization and repolarization) in the
electrical properties of the neuron membrane in an axon.
Activation: An increase in physiological processing in one condition relative to
some other condition(s).
Additive factors method: A general method for dividing reaction times into
different stages devised by Sternberg.
Afferent dysgraphia: Stroke omissions and additions in writing that may be due to
poor use of visual and kinesthetic feedback.
Affordances: Structural properties of objects imply certain usages.
Agrammatism: Halting, “telegraphic” speech production that is devoid of function
words (e.g. of, at, the, and), bound morphemes (e.g. –ing, –s) and often verbs.
Akinetopsia: A failure to perceive visual motion.
Allele: Different versions of the same gene.
Allocentric space: A map of space coding the locations of objects and places
relative to each other.
Allograph: Letters that are specified for shape (e.g. case, print versus script).
Allophones: Different spoken/acoustic renditions of the same phoneme.
Amodal: Not tied to one or more perceptual systems.
Amusia: An auditory agnosia in which music perception is affected more than the
perception of other sounds.
Amygdala: Part of the limbic system; implicated in detecting fearful stimuli.
Aneurysm: Over-elastic region of artery that is prone to rupture.
Anomia: Word-finding difficulties.
Anterior: Towards the front.
Anterograde memory: Memory for events that have occurred after brain damage.
Apperceptive agnosia: A failure to understand the meaning of objects due to a
deficit at the level of object perception.
Apraxia for speech: Difficulties in shaping the vocal tract.
Articulatory loop: A short-term memory store for verbal material that is refreshed
by subvocal articulation.
Articulatory suppression: Silently mouthing words while performing some other
task (typically a memory task).
Asperger syndrome: Autism with no significant delay in early language and
cognitive development.
Associative agnosia: A failure to understand the meaning of objects due to a deficit
at the level of semantic memory.
Associative priming: Reaction times are faster to a stimulus if that stimulus is
preceded by a stimulus of similar meaning (this is also known as semantic priming).
Attention: The process by which certain information is selected for further
processing and other information is discarded.
Attentional dyslexia: An inability to report the constituent letters of words that
can be read (together with intact reading of isolated letters).
Auditory stream segregation: The division of a complex auditory signal into
different sources or auditory objects.
Autism: The presence of markedly abnormal or impaired development in social
interaction and communication and a markedly restricted repertoire of activities
and interests.
Autotopagnosia: An inability to localize body parts on oneself, on pictures or on
others.
Axon: A branching structure that carries information to other neurons and
transmits an action potential.
Balint’s syndrome: A severe difficulty in spatial processing normally following
bilateral lesions of parietal lobe; symptoms include simultanagnosia, optic ataxia
and optic apraxia.
Basal ganglia: Regions of subcortical gray matter involved in aspects of motor
control and skill learning; they consist of structures such as the caudate nucleus,
putamen and globus pallidus.
Basilar membrane: A membrane within the cochlea containing tiny hair cells
linked to neural receptors.
Behavioral genetics: A field concerned with studying the inheritance of behavior
and cognition.
Behavioral neuroscience: Cognitive neuroscience in non-human animals.
Belt region: Part of secondary auditory cortex.
Biological motion: The ability to detect whether a stimulus is animate or not from
movement cues alone.
Blind spot: The point at which the optic nerve leaves the eye. There are no rods and
cones present there.
Blindsight: A symptom in which the patient reports not being able to consciously
see stimuli in a particular region but can nevertheless perform visual
discriminations (e.g. long, short) accurately.
Block design: Stimuli from a given condition are presented consecutively together.
BOLD: Blood oxygen-level-dependent contrast; the signal measured in fMRI that
relates to the concentration of deoxyhemoglobin in the blood.
Broca’s aphasia: A type of aphasia traditionally associated with damage to Broca’s
area and linked to symptoms such as agrammatism and articulatory deficits.
Brodmann’s areas: Regions of cortex defined by the relative distribution of cell
types across cortical layers (cytoarchitecture).
Cancellation task: A variant of the visual search paradigm in which the patient
must search for targets in an array, normally striking them through as they are
found.
Capgras syndrome: People report that their acquaintances (spouse, family, friends
and so on) have been replaced by “body doubles”.
Categorical perception: Continuous changes in input are mapped on to discrete
percepts.
Category specificity: The notion that the brain represents different categories in
different ways (and/or different regions).
Cell body: Part of the neuron containing the nucleus and other organelles.
Central dyslexia: Disruption of reading arising after computation of a visual word
form (e.g. in accessing meaning, or translating to speech).
Cerebellum: Structure attached to the hindbrain; important for dexterity and
smooth execution of movement.
Change blindness: Participants fail to notice the appearance/disappearance of
objects between two alternating images.
Chromosome: An organized package of DNA bound up with proteins; each
chromosome contains many genes.
Co-articulation: The production of one phoneme is influenced by the preceding and
proceeding phonemes.
Cochlea: Part of the inner ear that converts liquid-borne sound into neural
impulses.
Cognition: A variety of higher mental processes such as thinking, perceiving,
imagining, speaking, acting and planning.
Cognitive neuropsychology: The study of brain-damaged patients to inform
theories of normal cognition.
Cognitive neuroscience: Aims to explain cognitive processes in terms of brainbased mechanisms.
Cognitive subtraction: A type of experimental design in functional imaging in
which activity in a control task is subtracted from activity in an experimental task.
Cohort model: In lexical access, a large number of spoken words are initially
considered as candidates but words get eliminated as more evidence accumulates.
Color constancy: The color of a surface is perceived as constant even when
illuminated in different lighting conditions.
Complex cells: In vision, cells that respond to light in a particular orientation but do
not respond to single points of light.
Conditioned taste aversion: A highly durable avoidance of food that has previously
been associated with sickness.
Cone cells: A type of photoreceptor specialized for high levels of light intensity,
such as those found during the day, and specialized for the detection of different
wavelengths.
Confabulation: A memory that is false and sometimes self-contradictory without an
intention to lie.
Consolidation: The process by which moment-to-moment changes in brain activity
are translated into permanent structural changes in the brain.
Constructive memory: The act of remembering construed in terms of making
inferences about the past, based on what is currently known and accessible.
Contention scheduling: The mechanism that selects one particular schema to be
enacted from a host of competing schemas.
Corpus callosum: A large white matter tract that connects the two hemispheres.
Counting: The process of putting each item in a collection in one-to-one
correspondence with a number or some other internal/external tally.
Critical period: A time window in which appropriate environmental input is
essential for learning to take place.
Cross-modal perception: Integrating information across sensory modalities.
Deactivation: A decrease in physiological processing in one condition relative to
some other condition(s).
Deception: A situation in which outward behavior deliberately contradicts inner
knowledge and beliefs.
Declarative memory: Memories that can be consciously accessed.
Deep dyslexia: Real words are read better than non-words and semantic errors are
made in reading.
Deep dysphasia: An inability to repeat non-words and the producion of semantic
errors in word repetition.
Degrees of freedom problem: There are potentially an infinite number of motor
solutions for acting on an object.
Delusions: Fixed beliefs that are false or fanciful (e.g. of being persecuted).
Dendrites: Branching structures that carry information from other neurons.
Diaschisis: A discrete brain lesion can disrupt the functioning of distant brain
regions that are structurally intact.
Diffusion tensor imaging (DTI): Uses MRI to measure white matter connectivity
between brain regions.
Dipole modeling: An attempt to solve the inverse problem in ERP research that
involves assuming how many dipoles (regions of electrical activity) contribute to
the signal recorded at the scalp.
Directed forgetting: Forgetting arising because of a deliberate intention to forget.
Distance effect: It is harder to decide which of two numbers is larger when the
distance between them is small (e.g. 8–9 relative to 2–9).
Domain-specificity: The idea that a cognitive process (or brain region) is dedicated
solely to one particular type of information (e.g. colors, faces, words).
Dopamine: A neurotransmitter with important roles, including in reward,
motivation, attention and learning.
Dorsal: Towards the top.
Double dissociation: Two single dissociations that have a complementary profile of
abilities.
Dual-aspect theory: The belief that mind and brain are two levels of description of
the same thing.
Dualism: The belief that mind and brain are made up of different kinds of
substance.
Dual-task interference: If there is a decrement in performance associated with
doing two things at once, it suggests that these two tasks share cognitive processes.
Duchenne lines: Wrinkles around the eyes associated with a sincere smile.
Dysarthria: Impaired muscular contractions of the articulatory apparatus.
Dyscalculia: Difficulties in understanding numbers; calculation difficulties.
Dysgraphia: Difficulties in spelling and writing.
DZ twins (dizygotic): Twins who share half of their genes, caused when two eggs
are fertilized by two different sperm.
Early selection: A theory of attention in which information is selected according to
perceptual attributes.
Ecological validity: The extent to which a task relates to everyday situations
outside of the laboratory.
efMRI: Event-related functional magnetic resonance imaging.
Egocentric space: A map of space coded relative to the position of the body.
Emotion: States/processes that prepare the organism for certain behaviors,
particularly those with survival value.
Empathy: The ability to appreciate others’ points of view and share their
experiences.
Empiricism: In philosophy, the view that the newborn mind is a blank slate.
Encoding specificity hypothesis: Events are easier to remember when the context
at retrieval is similar to the context at encoding.
Endogenous: Related to properties of the task.
Endogenous orienting: Attention is guided by the goals of the perceiver.
Episodic memory: Memory of specific events in one’s own life.
Error-related negativity: An electrical potential (“error potential”) that can be
detected at the scalp when an error is made.
Event-related design: Stimuli from two or more conditions are presented
randomly or interleaved.
Excitation: An increase of the activity of a brain region (or a cognitive process),
triggered by activity in another region/process.
Executive functions: Control processes that enable an individual to optimize
performance in situations requiring the operation and coordination of several more
basic cognitive processes.
Exogenous: Related to properties of the stimulus.
Exogenous orienting: Attention that is externally guided by a stimulus.
Explicit memory: See declarative memory.
Extinction: When presented with two stimuli at the same time (one in each
hemispace), then the stimulus on the opposite side of the lesion is not consciously
perceived.
Face recognition units (FRUs): Stored knowledge of the three-dimensional structure of familiar faces.
False belief: A belief that differs from one’s own belief and that differs from the true state of the world.
False memory: A memory that is either partly or wholly inaccurate but is accepted as a real memory by the
person doing the remembering.
Familiarity: Context-free memory in which the recognized item just feels familiar.
Figure–ground segregation: The process of segmenting a visual display into objects versus background
surfaces.
Filial imprinting: The process by which a young animal comes to recognize the parent.
Finger agnosia: An inability to identify individual fingers by touch.
Fixation: A stationary pause between eye movements.
Formants: Horizontal stripes on the spectrogram produced with a relative free flow of air (e.g. by vowels).
Forward model: A representation of the motor command (a so-called “efference copy”) is used to predict
the sensory consequences of an action.
Freudian slip: The substitution of one word for another that is sometimes thought to reflect the hidden
intentions of the speaker.
Frontal apraxia: Failure in tasks of routine activity that involve setting up and maintaining different
subgoals, but with no basic deficits in object recognition or gesturing the use of isolated objects (also called
action disorganization syndrome).
Frontal eye fields: Responsible for voluntary movement of the eyes.
Functional imaging: Measures temporary changes in brain physiology associated with cognitive
processing; the most common methods of PET and fMRI are based on a hemodynamic measure.
Functional integration: The way in which different regions communicate with each other.
Functional specialization: Different regions of the brain are specialized for different functions.
Fundamental frequency: The lowest frequency component of a complex sound that determines the
perceived pitch.
Garden-path sentences: A sentence in which the early part biases a syntactic interpretation that turns out
to be incorrect.
Gene X–environment interactions: Susceptibility to a trait depends on a particular combination of a gene
and environment.
Gene–environment correlations: Genetic influences in people’s exposure to different environments.
Gerstmann’s syndrome: A set of four deficits believed to be associated with damage to the left parietal
lobe (acalculia, finger agnosia, agraphia and left–right disorientation).
Glia: Support cells of the nervous system involved in tissue repair and in the formation of myelin (amongst
other functions).
Grandmother cell: A hypothetical neuron that just responds to one particular stimulus (e.g. the sight of
one’s grandmother).
Graph: Letters that are specified in terms of stroke order, size and direction.
Grapheme: An abstract description that specifies letter identity.
Graphemic buffer: A short-term memory component that maintains a string of abstract letter identities
while output processes (for writing, typing, etc.) are engaged.
Gray matter: Matter consisting primarily of neuronal cell bodies.
Group studies: In neuropsychology, the performance of different patients is combined to yield a group
average.
Gyri (gyrus = singular): The raised folds of the cortex.
Habituation: In infant studies, old or familiar objects receive less attention.
Hallucinations: Illusory percepts not shared by others (e.g. hearing voices).
Head-related transfer function (HRTF): An internal model of how sounds get distorted by the unique
shape of one’s own ears and head.
Hemianopia: Cortical blindness restricted to one half of the visual field (associated with damage to the
primary visual cortex in one hemisphere).
Hemiplegia: Damage to one side of the primary motor cortex results in a failure to voluntarily move the
other side of the body.
Hemodynamic response function (HRF): Changes in the BOLD signal over time.
Heritability: The proportion of variance in a trait, in a given population, that can be accounted for by
genetic differences amongst individuals.
Homophone: Words that sound the same but have different meanings (and often different spellings); e.g.
ROWS and ROSE.
Homunculus problem: The problem of explaining volitional acts without assuming a cognitive process
that is itself volitional (“a man within a man”).
Huntington’s disease: A genetic disorder affecting the basal ganglia and associated with excessive
movement.
Hypercomplex cells: In vision, cells that respond to particular orientations and particular lengths.
Hyperkinetic: An increase in movement.
Hypokinetic: A reduction in movement.
Hypothalamus: Consists of a variety of nuclei that are specialized for different functions that are primarily
concerned with the body and its regulation.
Ideomotor apraxia: An inability to produce appropriate gestures given an object, word or command.
Illusory conjunctions: A situation in which visual features of two different objects are incorrectly
perceived as being associated with a single object.
Imitation: The ability to reproduce the behavior of another through observation.
Implicit memory: See non-declarative memory.
Inattentional blindness: A failure to consciously see something because attention is directed away from it.
Inferior: Towards the bottom.
Inferior colliculi: A midbrain nucleus that forms part of a subcortical auditory pathway.
Information processing: An approach in which behavior is described in terms of a sequence of cognitive
stages.
Inhibition: A reduction/suppression of the activity of a brain region (or a cognitive process), triggered by
activity in another region/process.
Inhibition of return: A slowing of reaction time associated with going back to a previously attended
location.
Instinct: A behavior that is a product of natural selection.
Insula: A region of cortex buried beneath the temporal lobes; involved in body perception and contains the
primary gustatory cortex; responds to disgust.
Integrative agnosia: A failure to integrate parts into wholes in visual perception.
Interactions: The effect of one variable upon another.
Interactivity: Later stages of processing can begin before earlier stages are complete.
Inverse problem: The difficulty of locating the sources of electrical activity from measurements taken at
the scalp (in ERP research).
James–Lange theory: The self-perception of bodily changes produces emotional experience (e.g. one is
sad because one cries).
Kana: A Japanese writing system in which each character denotes a syllable.
Kanji: A Japanese writing system based on the logographic principle.
Kluver–Bucy syndrome: In monkeys after bilateral amygdala and temporal lesions, an unusual tameness
and emotional blunting; a tendency to examine objects with the mouth; and dietary changes.
Korsakoff’s syndrome: Amnesia arising from long-term alcoholism.
Late selection: A theory of attention in which all incoming information is processed up to the level of
meaning (semantics) before being selected for further processing.
Lateral: The outer part (cf. medial).
Lemma: A modality-independent word-level entry that specifies the syntactic components of the word.
Levels-of-processing account: Information that is processed semantically is more likely to be remembered
than information that is processed perceptually.
Lexeme: The phonological code that drives articulation.
Lexical access: The process of matching a perceptual description of a word on to a stored memory
description of that word.
Lexical decision: A two-way forced choice judgment about whether a letter string (or phoneme string) is a
word or not.
Lexicalization: In speech production, the selection of a word based on the meaning that one wishes to
convey.
Limbic system: A region of subcortex involved in relating the organism to its present and past
environment; limbic structures include the amygdala, hippocampus, cingulate cortex and mamillary bodies.
Line bisection: A task involving judging the central point of a line.
Logographs: Written languages based on the one-word–one-symbol principle.
Long-term memory: Memory for information that is stored but need not be consciously accessible; it has
an essentially unlimited capacity.
Long-term potentiation (LTP): An increase in the long-term responsiveness of a postsynaptic neuron in
response to stimulation of a presynaptic neuron.
Loudness: The perceived intensity of the sound.
Malapropisms: A speech error that consists of a word with a similar phonological form to the intended
word.
McGurk illusion: An auditory percept derived from a fusion of mismatching heard speech and seen
speech.
Medulla oblongata: Part of the hindbrain; it regulates vital functions such as breathing, swallowing, heart
rate and the wake–sleep cycle.
Melody: Patterns of pitch over time.
Mental chronometry: The study of the time course of information processing in the human nervous
system.
Mind–body problem: The problem of how a physical substance (the brain) can give rise to our feelings,
thoughts and emotions (our mind).
Mirror neuron: A neuron that responds to goal-directed actions performed by oneself or by others.
Mirror systems: Neural resources that disregard the distinction between self and other.
Mismatch negativity (MMN): An ERP component that occurs when an auditory stimulus deviates from
previously presented auditory stimuli.
Missing fundamental phenomenon: If the fundamental frequency of a complex sound is removed, then
the pitch is not perceived to change (the brain reinstates it).
Modularity: The notion that certain cognitive processes (or regions of the brain) are restricted in the type
of information they process.
Monitoring: The process of relating information currently held in mind back to the task requirements.
Mood: Situations in which a particular emotion occurs frequently or continuously.
Motor programs: Stored routines that specify certain motor parameters of an action (e.g. the relative
timing of strokes).
Multi-cell recordings (or multi-unit recordings): The electrical activity (in terms of action potentials per
second) of many individually recorded neurons.
Multi-tasking: Carrying out several tasks in succession; requires both task switching and maintaining
future goals while current goals are being dealt with.
Myelin: A fatty substance that is deposited around the axon of some neurons that speeds conduction.
Myelination: An increase in the fatty sheath that surrounds axons and increases the speed of information
transmission.
MZ twins (monozygotic): Genetically identical twins caused when a fertilized egg splits in two.
Nativism: In philosophy, the view that at least some forms of knowledge are innate.
Nature–nurture debate: The extent to which cognition and behavior can be attributed to genes or
environment.
N-back task: A working memory task; the participant must decide whether the currently presented
stimulus is the same as the one presented immediately before (1-back) or two items before (2-back) or three
items before (3-back), etc.
Negative priming: If an ignored object suddenly becomes the attended object, then participants are slower
at processing it.
Neglect dyslexia: Reading errors that affect one side of a word.
Neglect: A failure to attend to stimuli on the opposite side of space to the lesion.
Neural network models: Computational models in which information processing occurs using many
interconnected nodes.
Neural tube: The embryo’s precursor to the central nervous system, consisting of a set of cells arranged in
a hollow cylinder.
Neuroblasts: Stem cells for neurons.
Neuroconstructivism: A process of interaction between environment and multiple brain-based constraints
that leads to the mature cognitive system emerging out of transformations of earlier ones.
Neuroeconomics: The use of brain-based methods/theories in order to account for economic decision
making.
Neuron: A type of cell that makes up the nervous system and supports, amongst other things, cognitive
function.
Neurotransmitters: Chemical signals that are released by one neuron and affect the properties of other
neurons.
Nodes: The basic units of neural network models that are activated in response to activity in other parts of
the network.
Non-declarative memory: Memories that cannot be consciously accessed (e.g. procedural memory).
Object constancy: An understanding that objects remain the same, irrespective of differences in viewing
condition.
Object orientation agnosia: An inability to extract the orientation of an object despite adequate object
recognition.
Obsessive-compulsive disorder: An anxiety disorder characterized by repetitive thoughts and/or acts (e.g.
counting, cleaning).
Odema: A swelling of the brain following injury.
Opaque orthography: A system of written language with an irregular (or semi-regular) correspondence
between phonemes and graphemes.
Optic ataxia: A symptom arising from damage to the occipito-parietal junction.
Orofacial dyspraxia: An impaired ability to perform the coordinated movements that are required for
speech.
Papez circuit: A limbic-based circuit that was once thought to constitute a largely undifferentiated
“emotional” brain.
Parabelt region: Part of secondary auditory cortex.
Parallel processing: Different information is processed at the same time (i.e. in parallel).
Parkinson’s disease: A disease associated with the basal ganglia and characterized by a lack of selfinitiated movement.
Parsing: The process of assigning a syntactic structure to words.
Perception: the elaboration and interpretation of a sensory stimulus based on, for example, knowledge of
how objects are structured.
Peripheral dyslexia: Disruption of reading arising up to the level of computation of a visual word form.
Perseveration: Repeating an action that has already been performed and is no longer relevant.
Person identity nodes (PINs): An abstract description of people that links together perceptual knowledge
(e.g. faces) with semantic knowledge.
Phantom limb: The feeling that an amputated limb is still present.
Phobia: A pathological fear of certain stimuli that is out of proportion to the actual threat posed.
Phonological dyslexia: Ability to read real words better than non-words.
Phonological lexicon: A store of the abstract speech sounds that make up known words.
Phonological mediation: The claim that accessing the spoken forms of words is an obligatory component
of understanding visually presented words.
Phrenology: The failed idea that individual differences in cognition can be mapped on to differences in
skull shape.
Pitch: The perceived property of sounds that enables them to be ordered from low to high.
Place cells: Neurons that respond when an animal is in a particular location in allocentric space (normally
found in the hippocampus).
Place value system: A system of writing numbers in which the quantity is determined by its place in the
written string.
Planum temporale: A part of auditory cortex (posterior to primary auditory cortex) that integrates auditory
information with non-auditory information, for example to enable sounds to be separated in space.
Plasticity: The brain’s ability to change as a result of experience.
Pons: Part of the hindbrain; a key link between the cerebellum and the cerebrum.
Pop-out: The ability to detect an object amongst distractor objects in situations in which the number of
distractors presented is unimportant.
Posterior: Towards the back.
Premotor cortex: The lateral area is important for linking action with objects in the environment; the
medial area is known as the supplementary motor area and deals with well-learned actions and action
sequences.
Prepared learning: The theory that common phobias are biologically determined from evolutionary
pressures.
Primary auditory cortex: The main cortical area to receive auditory-based thalamic input.
Primary motor cortex: Responsible for execution of voluntary movements of the body.
Primary visual cortex (or V1): The first stage of visual processing in the cortex; the region retains the
spatial relationships found on the retina and combines simple visual features into more complex ones.
Procedural memory: Memory for skills such as riding a bike.
Proper name anomia: Severe difficulties in retrieving proper names.
Proprioception: Knowledge of the position of the limbs in space.
Prosopagnosia: Impairments of face processing that do not reflect difficulties in early visual analysis (also
used to refer to an inability to recognize previously familiar faces).
Prospective memory: Remembering to do things in the future (e.g. to deliver something or take
medication).
Pseudoneglect: In a non-lesioned brain there is over-attention to the left side of space.
Psychosis: Loss of contact with reality.
Pure alexia: A difficulty in reading words in which reading time increases proportionately to the length of
the word.
Pure insertion (also pure deletion): The assumption that adding a different component to a task does not
change the operation of other components.
Pure tones: Sounds with a sinusoid waveform (when pressure change is plotted against time).
Pure word deafness: Type of auditory agnosia in which patients are able to identify environmental sounds
and music but not speech.
Quadrantanopia: Cortical blindness restricted to a quarter of the visual field.
Radial glial cells: Support cells that guide neurons from the neural tube to final destination.
Rate coding: The informational content of a neuron may be related to the number of action potentials per
second.
Reaction time: The time taken between the onset of a stimulus/event and the production of a behavioral
response (e.g. a button press).
Recall: Participants must produce previously seen stimuli without a full prompt being given (compare
recognition memory).
Receptive field: The region of space that elicits a response from a given neuron.
Recognition memory: A memory test in which participants must decide whether a stimulus was shown on
a particular occasion.
Recollection: Context-dependent memory that involves remembering specific information from the study
episode.
Reductionism: The belief that mind-based concepts will eventually be replaced by neuroscientific
concepts.
Reference frames: A representational system for coding space (e.g. near versus far space; imaginal versus
external space).
Reinforcer: A stimulus that increases or decreases a particular pattern of behavior.
Repetition priming: A stimulus seen previously will be identified faster on a subsequent occasion.
Representations: Properties of the world that are manifested in cognitive systems (mental representation)
and neural systems (neural representation).
Response conflict: A situation in which a prepotent incorrect response needs to be overcome to perform a
task successfully (as in Stroop color naming).
Retina: The internal surface of the eyes containing photoreceptors that convert light to neural signals.
Retinocentric space: A map of space coded relative to the position of eye gaze.
Retrieval-induced forgetting: Retrieval of a memory causes active inhibition of similar competing
memories.
Retrograde memory: Memory for events that occurred before brain damage.
Reversal learning: The ability to stop responding to a previously rewarded stimulus that is no longer
rewarded.
Ribot’s law: The observation that memories from early in life tend to be preserved in amnesia.
Rod cells: A type of photoreceptor specialized for low levels of light intensity, such as those found at
night.
Saccade: A movement of the eyes.
Schema: An organized set of stored information (e.g. of familiar action routines).
Schizophrenia: A severe disturbance of thought and affect characterized by a loss of contact with reality.
Scotoma: A small region of cortical blindness.
Self-ordered pointing task: A task in which participants must point to a new object on each trial and thus
maintain a working memory for previously selected items.
Semantic dementia: A progressive loss of information from semantic memory.
Semantic memory: Conceptually-based knowledge about the world, including knowledge of people,
places, the meaning of objects and words.
Sensation: the effects of a stimulus on the sensory organs.
Sensitive period: A time window in which appropriate environmental input is particularly important (but
not necessarily essential) for learning to take place.
Sensory–functional distinction: Semantic categories differ in the extent to which functional versus
sensory information is represented.
Sensory-motor transformation: Linking together of perceptual knowledge of objects in space and
knowledge of the position of one’s body to enable objects to be acted on.
Short-term memory: Memory for information currently held “in mind”; it has limited capacity.
Simple cells: In vision, cells that respond to light in a particular orientation.
Simulation theory: The theory that perceiving the actions and emotional expressions of others uses the
same neural and cognitive resources that are used for producing actions and emotional expressions in
oneself.
Simultanagnosia: Inability to perceive more than one object at a time.
Single case studies: In cognitive neuropsychology, the data from different patients are not combined.
Single-cell recordings (or single-unit recordings): Measure the responsiveness of a neuron to a given
stimulus (in terms of action potentials per second).
Single dissociation: A situation in which a patient is impaired on a particular task (task A) but relatively
spared on another task (task B).
Size effect: It is easier to state which number is larger when the numbers are small (e.g. 2 and 4) relative to
large (e.g. 7 and 9) even when the distance between them is the same.
Skin conductance response (SCR): Changes in electrical conductivity on a person’s skin, triggered by
certain stimuli (e.g. emotional or familiar stimuli).
Smoothing: Redistributing brain activity from neighboring voxels to enhance the signal-to-noise ratio.
SNARC effect: If people are asked to make judgments about numbers (e.g. odd/even judgments), they are
faster with their left hand for small numbers but faster with their right hand for large numbers.
Social referencing: The emotional response of another person may lead to avoidance or interaction with a
previously neutral stimulus.
Sociopathy: Irresponsible and unreliable behavior that is not personally advantageous; an inability to form
lasting commitments or relationships; egocentric thinking; and a marked degree of impulsivity.
Somatic markers: Links between previous situations stored throughout the cortex and the “feeling” of
those situations stored in regions of the brain dedicated to emotion and the representation of the body.
Somatosensation: A cluster of perceptual processes that relate to the skin and body, and include touch,
pain, thermal sensation and limb position.
Source monitoring: The process by which retrieved memories are attributed to their original context.
Sparse scanning: In fMRI, a short break in scanning to enable sounds to be presented in relative silence.
Spatial resolution: The accuracy with which one can measure where an event (e.g. a physiological change)
is occurring.
Spectrogram: Plots the frequency of sound (on the y-axis) over time (on the x-axis) with the intensity of
the sound represented by how dark it is.
Split-brain: A surgical procedure in which fibers of the corpus callosum are severed.
Spoonerisms: A speech error in which initial consonants are swapped between words.
Stereotactic normalization: The mapping of individual differences in brain anatomy onto a standard
template.
Strokes: Disruption in the blood supply to the brain; also called cerebrovascular accidents (CVA).
Stroop Test: Response interference from naming the ink color of a written color name (e.g. the word
BLUE is printed in red ink and participants are asked to say the ink color, i.e. “red”).
Structural descriptions: A memory representation of the three-dimensional structure of objects.
Structural imaging: Measures of the spatial configuration of different types of tissue in the brain
(principally CT and MRI).
Subitizing: The process of enumerating a small number of objects at a glance.
Sulci (sulcus = singular): The buried grooves of the cortex.
Superior colliculi: A midbrain nucleus that forms part of a subcortical sensory pathway involved in
programming fast eye movements.
Superior: Towards the top.
Supplementary motor area (SMA): Deals with well-learned actions, particularly action sequences that do
not place strong demands on monitoring the environment.
Surface dyslexia: Ability to read non-words and regularly spelled words better than irregularly spelled
words.
Sustained attention: Retaining focus on the task requirements over a period of time.
Synapse: The small gap between neurons in which neurotransmitters are released, permitting signalling
between neurons.
Syndrome: A cluster of different symptoms that are believed to be related in some meaningful way.
Syntax: The order and structure of the words within a sentence.
Talairach coordinates: Locations in the brain defined relative to the atlas of
Talairach and Tournoux.
Task switching: Discarding a previous schema and establishing a new one.
Task-demand artefact: One task is performed worse than another because the task
is performed sub-optimally (but not because some aspect of the task is
compromised).
Task-resource artefact: If two tasks share the same neural/cognitive resource but
one task uses it more, then damage to this resource will affect one task more than
the other.
Temporal coding: The synchrony of firing may be used by a population of neurons
to code the same stimulus or event.
Temporal resolution: The accuracy with which one can measure when an event
(e.g. a physiological change) occurs.
Thalamus: A major subcortical relay center; for instance, it is a processing station
between all sensory organs (except smell) and the cortex.
Theory of mind: The ability to represent the mental states of others (e.g. their
beliefs, desires, intentions).
Timbre: The perceptual quality of a sound enables us to distinguish between
different musical instruments.
Tip-of-the-tongue phenomenon: A state in which a person knows, conceptually,
the word that he or she wishes to say but is unable to retrieve the corresponding
spoken form.
Tone-deafness (or congenital amusia): A developmental difficulty in perceiving
pitch relationships.
Tonotopic organization: Orderly mapping between sound frequency and position
on cortex.
Tool: An object that affords certain actions for specific goals.
Top-down processing: The influence of later stages on the processing of earlier
ones (e.g. memory influences on perception).
Tourette’s syndrome: A neuropsychiatric disorder with an onset in childhood
characterized by the presence of motor and/or vocal tics.
Transcoding: The means by which one symbol is translated into another of a
different type.
Transcranial magnetic stimulation: Non-invasive stimulation of the brain caused
by a rapidly changing electrical current in a coil held over the scalp.
Transparency assumption: Lesions affect one or more components within the preexisting cognitive system but do not result in a completely new cognitive system
being created.
Transparent orthography: A system of written language with a regular
correspondence between phonemes and graphemes.
Turner’s syndrome: A genetic disorder in which there is whole or partial deletion
of one X chromosome.
Uniqueness point: The point at which the acoustic input unambiguously
corresponds to only one known word.
Utilization behavior: Impulsively acting on irrelevant objects in the environment.
V4: A region of extrastriate cortex associated with color perception.
V5 (or MT): A region of extrastriate cortex associated with motion perception.
Ventral: Towards the bottom.
Ventricles: The hollow chambers of the brain that contain cerebrospinal fluid.
Ventriloquist effect: A tendency to mis-localize heard sounds onto a seen source of
potential sounds.
Visual lexicon: A store of the structure of known written words.
Visual search: A task of detecting the presence or absence of a specified target
object in an array of other distracting objects.
Voicing: Vibration of the vocal cords that characterizes the production of some
consonants.
Voxel: A volume-based unit (cf. pixels, which are 2D); in imaging research the brain
is divided into many thousands of these.
Voxel-based morphometry (VBM): A technique for segregating and measuring
differences in white matter and gray matter concentration.
Water maze: A test of spatial memory developed for rodents that requires learning
and retaining the location of a hidden platform submerged in opaque water.
Wernicke’s aphasia: A type of aphasia traditionally associated with damage to
Wernicke’s area and associated with fluent but nonsensical speech, and poor
comprehension.
White matter: Tissue of the nervous system consisting primarily of axons and
support cells.
Wisconsin Card Sorting Test: A test of executive functions involving rule induction
and rule use.
Word superiority effect: It is easier to detect the presence of a single letter
presented briefly if the letter is presented in the context of a word.
Working memory: A system for the temporary storage and manipulation of
information.