Motivation and Hunger

Motives and Motivation

• Motives: Needs, wants, interests, and desires driving behavior towards goals.

• Motivation: Processes initiating, guiding, and maintaining goal-directed behavior.

Drive Theories

• Organisms maintain homeostasis (physiological equilibrium).

• Deviations create internal tension/drives.

• Example: Hunger creates drive to eat.

• Limitations: Doesn't explain complex behaviors like desire for knowledge or eating when not hungry.

Incentive Theories

• External stimuli (incentives) regulate motivational states.

• Incentives: External goals or rewards motivating behavior.

• 'Push' (drive) vs. 'Pull' (incentive) motivations.

• Example: Aroma of bread motivates eating even without hunger.

Evolutionary Theories

• Motives are products of evolution and natural selection.

• Behaviors enhancing reproductive success are favored.

• Examples: Affiliation, achievement, and dominance.

• Adaptive value in solving problems throughout human history.

Diversity of Motives

• Influenced by individual factors and environmental conditions.

• Context plays a vital role.

• Factors: Culture, gender, and age.

• Motivation: Evolving interaction between individuals and environment.

Hunger

• Fundamental, complex motivational system.

• Early theories: Stomach contractions linked to hunger (disproven).

• Current research: Brain, digestive factors, and hormones.

Brain Regulation of Hunger

• Hypothalamus is key area.

• Initial research: Lateral hypothalamus (LH) and ventromedial nucleus of the hypothalamus (VMH) as on/off switches.

• More recent studies: Arcuate nucleus and paraventricular nucleus play nuanced roles.

Digestive and Hormonal Regulation of Hunger

• Digestive system sends signals to the brain.

• Vagus nerve: Communicates stomach fullness.

• Hormones:

  • Ghrelin: Increases hunger.

  • CCK (cholecystokinin): Decreases hunger.

  • Leptin: Produced