Eye movements

Movements of the eyes, which are normally conjugate in that the two eyes move together in an integrated manner, and are controlled by various complex neural systems terminating on the motoneurons of the eye muscle nuclei, thereby enabling the simultaneous control of twelve muscles through six cranial nerves.  There are five types of eye movements …

Extrapyramidal system

The phylogenetically older one of two pyramidal systems that originate in the motor cortex, the other being the pyramidal system (or corticospinal tract).  Together, they are responsible for the control and coordination of voluntary movements, as well as the maintenance of balance and posture.  Thus, they are not functionally independent of each other, and interact …

Extraversion

A broad factor of temperament, including characteristics of gregariousness, assertiveness, activity, excitement-seeking, and positive emotions.  See Five Factor model, Impulsiveness, Impulsivity, Neuroticism, Surgency, Temperament

Extrafusal muscle fibers

The vast majority of skeletal muscle fibers that are not found within muscle spindles at their polar ends and are innervated by alpha motoneurons.  When stimulated by a motoneuron, actin filaments slide to overlap with myosin filaments, resulting in the muscle contracting.  See Actin, Alpha (α) motoneuron, Direct corticospinal connections or tracts, Gamma (γ) motoneuron, …

External validity

The degree to which the results of an experiment or study on particular groups of participants generalise to the population at large.  One way of checking external validity is by means of replicating experiments or studies.  See Community survey, Convergent validity, Construct validity, Discriminant validity, Ecological validity, Experimental method, Generalization, Internal validity, Quantitative research, Validity