Language-making capacity The innate guidelines or operating principles that children bring to the task of learning a language.
Language production What people say, sign, and write, as well as the processes they go through to produce these messages.
Latent content In Freudian dream analysis, the hidden meaning of a dream.
Law of common fate A law of grouping that states that elements moving in the same direction at the same rate are grouped together.
Law of effect A basic law of learning that states that the power of a stimulus to evoke a response is strengthened when the response is followed by a reward and weakened when it is not followed by a reward.
Law of proximity A law of grouping that states that the nearest, or most proximal, elements are grouped together.
Law of similarity A law of grouping that states that the most similar elements are grouped together.
Learned helplessness A general pattern of nonresponding in the presence of noxious stimuli that often follows after an organism has previously experienced noncontingent, inescapable aversive stimuli.
Learning A process based on experience that results in a relatively permanent change in behavior or behavioral potential.
Learning-performance distinction The difference between what has been learned and what is expressed in overt behavior.
Lesions Injuries to or destruction of brain tissue.
Levels-of-processing theory A theory that suggests that the deeper the level at which information was processed, the more likely it is to be retained in memory.
Libido The psychic energy that drives individuals toward sensual pleasures of all types, especially sexual ones.
Life-change units (LCUs) In stress research, the measure of the stress levels of different types of change experienced during a given period.
Lightness constancy The tendency to perceive the whiteness, grayness, or blackness of objects as constant across changing levels of illumination.
Limbic system The region of the brain that regulates emotional behavior, basic motivational urges, and memory, as well as major physiological functions.
Longitudinal design A research design in which the same participants are observed repeatedly, sometimes over many years.
Long-term memory (LTM) Memory processes associated with the preservation of information for retrieval at any later time.
Loudness A perceptual dimension of sound influenced by the amplitude of a sound wave; sound waves with large amplitudes are generally experienced as loud and those with small amplitudes as soft.
Lucid dreaming The theory that conscious awareness of dreaming is a learnable skill that enables dreamers to control the direction and content of their dreams.