Motivation: a need or desire that energizes and directs behavior.
Instinct: a complex behavior that is rigidly patterned throughout
a species and is unlearned (e.g., imprinting in birds or the return of
salmon to their birthplace to spawn). Reflexes in human infants
are to simple to be considered instincts.
Drive-Reduction Theory: the idea that a physiological
NEED creates an aroused state of tension (DRIVE) that
motivates an organism to satisfy that need.
NEED (for food or water)→DRIVE (hunger or
thirst)→DRIVE-REDUCING BEHAVIORS (eating or drinking).
Drive-Reduction Theory is based on the
Concept of Homeostasis.
tendency to maintain a balanced or constant internal state; the
regulation of any aspect of body chemistry, such as blood glucose,
around a particular level.
Arousal Theory: rather that reducing a physiological need or
tension state, some motivated behaviors increase arousal.
Curiosity-driven behaviors, for example, suggest that too little as well
as too much stimulation can motivate people to seek an optimum level of
Incentive Theory: Theory that even if a need or drive is not
originally present, positive or negative environmental stimuli may
motivate behavior (e.g., after finishing a big meal, and feeling totally
satisfied, we may become hungry again if we see or smell a delicious
Hierarchy of Needs: Maslow's pyramid of human needs, beginning at
the base with physiological needs that must first be satisfied before
higher-level needs become active. SEE
Glucose: the form of sugar that circulates in the blood and provides
the major source of energy for body tissues. When blood glucose
levels are low, we feel hungry.
blood-glucose is low, the lateral hypothalamus releases orexin, which
makes us even more hungry.
Lateral Hypothalamus: the "hunger center" of the brain.
When blood glucose is low, the lateral hypothalamus kicks on, releases
orexin and we feel hungry.
Ventromedial Hypothalamus: the "satiety center" of the brain.
When blood glucose is high (after we have eaten), the ventromedial
hypothalamus kicks in and we no longer feel hungry.
Insulin: Substance released from the pancreas. When blood
glucose rises, insulin is released to allow the glucose to move from the
blood to the tissues of the body.
Set Point: the point at which an individual's "weight thermostat"
is supposedly set. When the body falls below this weight, an increase in
hunger and a lowered metabolic rate may act to restore the lost weight.
Basal Metabolic Rate: the body's resting rate of energy
Anorexia Nervosa: an eating disorder in which a normal-weight
person (usually an adolescent female) diets and becomes significantly
underweight (15% or more), yet, still feeling fat, continues to diet.
Bulimia Nervosa: an eating disorder characterized by episodes of
overeating, usually of high-calorie foods, followed by vomiting,
laxative use, fasting, or excessive exercise. These individuals
are not typically underweight.
Sexual Response Cycle: the four stages of sexual responding
described by Masters and Johnson--excitement, plateau, orgasm, and
Refractory Period: a resting period after orgasm, during which a
man cannot achieve another orgasm.
Sexual Disorder: a problem that consistently impairs sexual
arousal or functioning. They include impotence andpremature
ejaculation in men and orgasmic dysfunction in women.