Ability A general trait or capacity of an individual that is a determinant of a person's achievement potential for the performance of specific skills.
Absolute error (AE) The unsigned deviation from the target or criterion, representing amount of error. A measure of the magnitude of an error without regard to the direction of the deviation.
Acceleration A kinematic measure that describes change in velocity during movement; we derive it from velocity by dividing change in velocity by change in time.
Action effect hypothesis The proposition that actions are best planned and controlled by their intended effects. When related to attentional focus, this hypothesis proposes that the learning and performance of skills are optimized when the performer's attention is directed to the intended outcome of the action rather than on the movements themselves.
Action preparation The activity that occurs between the intention to perform an action and the initiation of that action. Sometimes, the term motor programming is used to refer to this preparation activity.
Actions See motor skills.
Affordance The reciprocal fit between the characteristics of a person and the characteristics of the environment that permit a specific action to occur, such as stairs having the physical characteristics to permit stair climbing.
Arousal The general state of excitability of a person, involving physiological, emotional, and mental systems. Terms such as anxiety and intensity are sometimes used synonymously in psychological contexts.
Ascending tracts Sensory neural pathways in the spinal cord and brainstem that connect with the various sensory areas of the cerebral cortex and cerebellum.
Associative stage The second stage of learning in the Fitts and Posner model. An intermediate stage on the learning stages continuum.
Asymmetric transfer Bilateral transfer in which there is a greater amount of transfer from one limb than from the other limb.
Attention In human performance, characteristics associated with consciousness, awareness, and cognitive effort as they relate to the performance of skills. Of particular interest are limitations associated with these characteristics on the simultaneous performance of multiple skills and the detection of relevant information in the performance environment.
Attentional focus The directing of attention to specific characteristics in a performance environment, or to action preparation activities.
Attractors The stable behavioral steady states of systems. In terms of human coordinated movement, attractors characterize preferred behavioral states, such as the in-phase and antiphase states for rhythmic bimanual finger movements.
Augmented feedback A generic term used to describe information about a performance that supplements the sensory feedback and comes from a source external to the performer; it is sometimes referred to as extrinsic or external feedback.
Automaticity The term used to indicate that a person performs a skill, or engages in certain information-processing activities, with little or ...