The four-sided figure (or vowel space) whose points are determined by the vowels with the articulatory positions of tongue high and front, tongue low and front, tongue low and back, and tongue low and high (see figure below). All other vowels are produced within or along the sides of the quadrilateral so defined. Vowel space …
Category Archives: Uncategorized
Arousal
Generally speaking, it is a term used to denote a state of heightened physiological activity in which there is an increased responsiveness to sensory stimulation or excitability. The relationship between such a state and behavior was encapsulated in the so-called Yerkes-Dodson law of arousal: there is an inverted-U relationship between performance and arousal such that …
Articulation
The process of producing and modifying airflow above the larynx and voice tone into distinctive connected speech through coordinating movements of the jaw, mouth, tongue and vocal cords. Air flow through the nose can be altered to vary the manner of articulation (e.g., whether it flows freely as in producing a vowel or is impeded …
Arguments (grammar)
Words that are operated upon by predicates. They typically include nouns and pronouns. See Language development, Predicates (grammar), Quantifier
Arcuate nucleus
An area of the brain stem thought to be responsible among other things for stimulating reactions necessary for waking and arousing from sleep. It is also present as a collection of neurons in the hypothalamus, where it plays an important role in the development of the reproductive system as it releases pulses of the gonadotropin …
Archenteron
A cavity formed during gastrulation by invagination of the vegetal plate cells (in the sea urchin) or involution of cells at the lip of blastopore (in amphibians); it becomes the interior of the primitive gut. See Blastopore, Blastula, Gastrulation, Induction (embryology), Organizer (embryology), Zygote
Arbitrary cross-modal relations
In contrast to amodal properties,arbitrary cross-modal relations are argued to be multisensory properties that specify information in a non-redundant way across the senses (e.g., therelation between the color of a car and the noise it makes). Some arbitrarycross-modal relations are preferred by infants and adults, and may beconsistent in the environment (e.g., the relation between …
Application (education)
Empirical testing of implications with regard both to whether any implication actually does work in educational practice and to the extent to which it amounts to an improvement. See Education, Implication (education)
Apraxia
Also known as dyspraxia, ideomotor apraxia or ideational apraxia and first described in detail by Hugo Karl Liepmann (1836-1925), it is a neurological syndrome involving the loss of the ability to perform complex voluntary movements, despite no obvious impairments in the muscles or sensory organs themselves. It occurs in many forms. Apraxia of speech, for …
Appendicular muscles
Skeletal muscles of the appendicular skeleton (126 bones in the human) that move the appendages or distal parts of the body (fins, limbs, wings). Muscles in general are classified as either extrinsic or intrinsic. Extrinsic (or axial) muscles have their origins on the axial skeleton or fasciae of the trunk (part that is stationary) and …