Glossary

acoustic phonetics

The study of speech ‘in the air’.

afferent

Said of a connection that reaches inward or towards a central area. Synonym of ascending.

affords

The pivotal verb of ecological psychology, which states the way an aspect of the environment provides the basis for a behavior. The prototypical example is a doorknob, which you can tell that you should grab it with your hand just by looking at it. Thus a doorknob ‘affords’ being grasped by the hand.

agnosia

The inability to process information in a sensory modality despite the perception of the modality being intact.

alexia

A form of receptive aphasia in which the ability to understand written or printed material is lost.

allophones

Phonetic units that are in complementary distribution, such as oral and nasalized vowels in English.

ambiguous

Said of a linguistic form that has more than one interpretation.

anhedonia

The loss of interest in previously pleasurable activities, see for example Anhedonia in Wikipida.

aphasia

The neurological disruption of language. To be diagnosed with aphasia, the other cognitive abilities of a patient should be intact.

aprosodias

Disorders of prosody, thought to be localized to the right hemisphere.

ascending

Said of a connection that reaches inward or towards a central area. Synonym of afferent.

aspiration

The [h]-like puff of air that follows the release of a voiceless stop in English and some other languages.

association areas

Areas of the neocortex where information from different sensory modalities is associated or combined.

articulation

The production of speech.

articulatory phonetics

The study of the production of speech.

audition

The term in the medical sciences for hearing.

auditory verbal agnosia

The inability to understand speech while maintaining normal hearing, speech production, and reading and writing skills.

auditory phonetics

The study of the perception of speech.

axon

The long fiber that extends from the soma at the axon hillock through which action potentials are transmitted to succeeding neurons.

axon hillock

A protuberance at the base of a pyramidal neuron from which the axon sprouts.

basilar membrane

The membrane in the cochlea that lies between the vestibular canal and the tympanic canal and so moves in sympathy with vibrations transmitted from the former to the latter. It constitutes the ‘floor’ of the organ of Corti, in which hair cells transduce vibratory motion into neural signals. Its length is organized by tonotopy from high frequencies at its base to low frequencies at its apex.

cell membrane

The double layer of fats (phosopholipids) that separate animal cells from their environment.

central auditory pathway

TO DO

cerebellum

The roughly spherical structure underneath and at the rear of the cerebrum, usually said to be responsible for fine motor control. Its contribution to language, other than fine control of the muscles of the vocal tract, is unknown.

cerebrum

The large roughly almond-shaped structure that fills most of the skull and that most people take to the ‘brain’.

circumlocution

The tendency of a person with Wernicke’s aphasia to paraphrase or ‘talk around’ a word that he or she cannot recall.

cochlea

The spiral or snail-shaped bony cavity in the inner ear in which acoustic vibrations are transduced into neural signals.

cognition

to do

complementary distribution

The description of allophones as appearing in mutually exclusive contexts, such as oral and nasalized vowels in English.

consonant

A category of speech sounds in which the mouth is partially or completely open or obstructed.

constructivism

A branch of philosophy that holds that the world is independent of human minds, but knowledge of the world is always a human and social construction.

contrastive distribution

The description of phonemes as appearing in the same contexts, such as oral and nasal vowels in French.

convolutions

The folds of the neocortex.

cortical deafness

Inability to ‘hear’ sound despite intact peripheral and central auditory pathways, presumably due to bilateral damage to auditory cortex.

craniotomy

A surgical operation in which part of the skull is removed in order to access the brain.

cycle

The measurement of a wave from peak to peak.

dendrites

The neurites that collect the input signals of a neuron.

diffusion gradient

A difference in chemical concentration between two areas that promotes diffusion of the chemical from the area of high concentration to the area of low concentration.

distal

Far, said of synapses that are far from the soma and so presumably have less influence that ones that are proximal.

dyslexia

An impairment in the ability to recognize visual (written or printed) words.

ecological psychology

A branch of psychology which holds that a particular behavior can only be understood in the context of an environment. Its founder, James Gibson, is famous for saying “Ask not what’s inside your head, but what your head’s inside of.”

efferent

Said of a connection that reaches outward or away from a central area.

electrical gradient

A difference in ionic concentration between two areas that promotes diffusion of the ion from the area of high concentration to the area of low concentration.

empty speech

A synonym of semantic paraphasia.

evolutionary psychology

A branch of psychology which studies behavior as the result of evolutionary pressure.

hertz (Hz)

The measure of frequency as cycles per second.

formants

The bands of energy in a spectrogram that correspond to cavity resonances of the vocal system.

frequency

The number of repetitions of a phenomenon per some unit of time.

fundamental frequency

The lowest or basic frequency of a sound-emitting object, indicated by \(F_0\).

frontal lobe

The division of the cerebrum along the front, behind the forehead. It is responsible for motor planning and ‘executive functions’.

graphemes

The units of written language.

graphemic transcription

A transcription into the standard spelling (or orthography) of a language.

grey matter

The mass of cell bodies that lies along the surface of the cerebrum and has a grey or pinkish-grey color. Also known as (neo)cortex.

gyrus

The peak or upward extent of convolutions.

hair cells

The cells in the organ of Corti whose cilia or ‘hairs’ at the top open ion channels when pressed upon by the tectorial membrane, which can trigger action potentials which are fed into the auditory nerve. They are divided into inner hair cell and outer hair cells.

harmonics

The higher frequencies that are multiples of the fundamental frequency.

hemispheres

The two side-by-side, mirror-image divisions of the cerebrum.

homunculus

A representation of the layout of the body from foot to tongue arrayed along the primary motor and somatosensory cortices.

inner hair cell

The hair cells

integrative neuroscience

An approach to neuroscience that strives to combine descriptions of neural behavior at several scales, from that of the individual neuron to that of a functional brain area.

ion channels

The protein tubes in the cell membrane that allow particular ions to cross between the interior and exterior of a cell.

IPA

The acronym of the International Phonetic Alphabet, a standardized representation of speech in which each grapheme corresponds to a single phone, and each phone corresponds to a single grapheme.

jargon

A description of the speech of people with Wernicke’s aphasia characterized by neologism some extreme that it becomes unintelligible.

laryngeal system

The middle section of the speech production apparatus, which encompasses the larynx which houses the vocal cords.

lateral

The view of the hemispheres from the outside.

lateral inhibition

Inhibition (‘turning off’) of units at the same level of a neural hierarchy.

logorrhea

‘Word diarrhea’ as you may have guessed; the tendency of a person with Wernicke’s aphasia to keep talking far beyond what is relevant or appropriate. A synonym of press of speech.

manner of articulation

One of the three characteristics of consonants, which delineates how the constriction takes place.

medial

The view of the hemispheres from the inside or center line of the cerebrum.

membrane potential

The electrical potential that builds up inside a neuron due to the electrical gradient between its interior and exterior.

minicolumns

The organization of neocortex into functional units in which a group of nearby neurons exite one another yet inhibit their surrounding neighbors.

morphemes

The smallest units of language that have meaning, such as ‘cat’, ‘anti-’, or ‘-ish’. Usually understood as the parts of words, though undecomposable words count, too.

morphology

The study of morphemes.

nasalized

Said of segments, usually vowels, that are normally articulated orally but that can have nasal airflow in certain contexts.

neocortex

The thin layer of cell bodies on the surface of the cerebrum. “Cortex” is the Latin word for the bark of a tree. It is “neo” or new because it expanded tremendously during the evolution of mammals. I usually just call it “cortex”, ignoring the potential for confusion with the cortex of the cerebellum.

neologism

A “new word” in Latin, the term used to describe the invention of novel words in the speech of people with aphasia, especially Wernicke’s aphasia.

neolithic

The new Stone Age, dating approximately from the invention of agriculture to the invention of metal tools.

non-primary auditory pathway

The pathway that connects the cochlea to non-auditory areas of cortex, which ‘ascends’ from the ear through various subcortical organs.

normalization

The process of translating, rotating, scaling, and maybe warping a brain to roughly match a standard template image.

nucleus

In the context of the central auditory pathway, it is a group of anatomically differentiated neurons in some subcortical structure. It is used in contrast to neocortex, which has a different and more uniform structure.

organ of Corti

The structure running the length of the basilar membrane which houses the hair cells which transduce vibratory motion to neural signals.

occipital lobe

The division of the cerebrum at the back. It is responsible for the initial processing of vision.

oscillate

To repeat a cycle.

outer hair cells

The hair cells

paleolithic

The Old Stone Age, dating approximately from the invention of stone tools to the invention of agriculture.

pascal

The unit of pressure in the International System of Units, see Pascal (unit) at Wikipedia.

paraphasia

A linguistic error associated with a neurological disorder.

paraphrased

Restated in a different way, usually to bring out a subtle meaning.

parietal lobe

The division of the cerebrum along the top between all the other lobes. It is responsible for touch and sensory association in general.

part of speech

The category of a word. See The Eight Parts of Speech for definitions and examples.

phonagnosia

An impairment in the ability to recognize familiar voices.

phonation

The production of speech.

phonemes

The units of the ‘mental’ representation of speech. They do not depend on a specific phonetic context but rather are learned or generalized from many contexts.

phonemic paraphasia

A sort of paraphasia characterized by the incorrect selection of one or more phonemes.

phonemic transcription

A transcription of phonemes into a standardized alphabet, usually the IPA.

phones

The units of the physical manifestation of speech in a particular phonetic context, either heard or articulated.

phonetic transcription

A transcription of phones into a standardized alphabet, usually the IPA.

photoreceptors

The cells in the retina that transduce light into action potentials.

place of articulation

One of the three characteristics of consonants, which delineates where in the mouth the constriction takes place.

pragmatics

The field of linguistics that deals with the meaning of a form in a specific context.

primary auditory pathway

The pathway that connects the cochlea to primary auditory cortex, which ‘ascends’ from the ear through various subcortical organs.

prosopagnosia

An impairment in the ability to recognize faces, also known as face blindness.

press of speech

A synonym of logorrhea.

prosodic

A synonym of supra-segmental.

proximal

Near, said of synapses that are close to the soma and so presumably have more influence that ones that are distal.

pure word deafness

An impairment in the ability to comprehend speech. Also known as auditory verbal agnosia.

rate code

A type of neural code in which information is transmitted by the average firing rate of a neuron or group of neurons.

receptor potential

The potential produced by sensory transduction.

rods

The type of photoreceptors that are found concentrated on the outer edge of the retina and are sensitive to black and white.

segment

Refers to the units of phonetics and phonology that are approximated by an alphabet.

segmental

Refers to the units of phonetics and phonology that are approximated by a segment.

semantic paraphasia

As a symptom of aphasia, the usage of words incorrectly or the usage of vague or general words like thing for more specific words. Synonym of empty speech.

semantics

The field of linguistics that deals with meaning.

sensorimotor system

to do

soma

The body of a neuron.

somatosensory

In neuroscience, it refers to the parts of the cortex responsible for processing touch or tactile information.

spectrum

The entire range over which some measure can vary.

speech agnosia

An impairment in the ability to recognize speech.

speech perception

The decoding of an acoustic signal as speech.

speech comprehension

The decoding of speech as meaningful communication.

spike train

A sequence of spikes.

stereocilia

The ‘hairs’ on the top of hair cells.

sulcus

The trough or downward extent of convolutions.

superposition

The addition of multiple waves into a single composite wave.

supralaryngeal system

The top section of the speech production apparatus, which encompasses the mouth and nasal cavity.

supra-segmental

Refers to the aspects of phonetics and phonology that are not approximated by an alphabet but rather by punctuation. It encompasses how intonation, loudness and duration are used in a language.

synapses

The gaps where an axon and a dendrite come together, at which an electrical signal from the axon is transformed into a chemical one which crosses the gap and is transformed back into an electrical signal in the dendrite.

syntax

The field of linguistics that deals with word order.

temporal lobe

The oval division of the cerebrum that runs along the bottom center.

thalamus

to do

tonotopy

The state of being organized by tone or frequency, from low to high or vice versa.

transcription

The act of transforming spoken language into a written form.

traveling wave

A wave in which a crest followed by a trough is seen to move across a medium.

unvoiced

Said of phonetic material during which the vocal cords do not vibrate. Synonym of voiceless.

vestibular canal

The fluid-filled canal in the cochlea that receives an incoming acoustic vibration. Also called the scala vestibule.

visual agnosia

An impairment in the ability to recognize familiar (visual) objects.

vocal cords

The twin membranes in the larynx that vibrate when air from the lungs passes through them, creating the human voice.

vocal tract

The mechanism for producing phonation, embracing the laryngeal system and the ‘supralaryngeal system’.

voiced

Said of phonetic material during which the vocal cords vibrate.

voiceless

Said of phonetic material during which the vocal cords do not vibrate. Synonym of unvoiced.

vowel

A category of speech sounds in which the mouth is maximally open or unobstructed.

Wernicke’s aphasia

One of the two main types of aphasia, attendant on damage to Wernicke’s region. Also called receptive or sensory aphasia.

Wernicke’s region

A poorly delimited area of the left lateral posterior temporal lobe which produces the symptoms of Wernicke’s aphasia when damaged.

word blindness

Older term for dyslexia, the loss of the ability to understand written words.


Last edited: Aug 22, 2023