2.Accommodation: the process by which the eye's lens changes shape to focus near or far images on the retina.
3.Acetylcholine: neurotransmitter that enables muscle action, learning and memory.
4.Achievement Motivation: desire for accomplishment.
5.Achievement Test: an exam designed to test what a person has earned.
6.Acoustic Encoding: encoding of sound, especially words.
7.Acquisition: the initial stage when one links a neutral stimulus and an unconditioned stimulus.
8.Action Potential: a neural impulse; a brief electrical charge that travels down an axon.
9.Activation Synthesis: theory that REM sleep triggers neural firing that evokes random images, which our sleep brain weaves into stories.
10.Adaptation Level Phenomenon: tendency to form judgements relative to a neutral level defined by our prior experience.
11.Adrenal Glands: a pair of endocrine glands that sit just above the kidneys and secrete hormones that help arouse the body in times of stress.
12.Algorithm: a methodical, logical rule that guarantees solving a particular problem.
13.Alpha Waves: the relatively slow brain waves of an awake, relaxed state.
14.Amnesia: loss of memory.
15.Amphetamines: drugs that stimulate neural activity, causing speeded-up body functions and associated energy and mood changes.
16.Amygdala: two lima bean-sized neural clusters in the limbic system; linked to emotion.
17.Aphasia: impairment of language caused by left hemisphere damage to Broca's area, impairing speaking, or Wernicke's area, impairing understanding.
18.Applied Research: scientific study that aims to solve practical problems
19.Aptitude Test: designed to predict a person's future performance.
20.Association Areas: areas of the cerebral cortex that are not involved in primary or sensory functions but in higher mental functions.
21.Associative Learning: learning that certain events occur together.
22.Automatic