Motivation
Theories of Motivation
Motivation: The force that moves people to behave, think, and feel as they do.
Energizes, directs, and sustains behavior.
Theories of Motivation Overview
Evolutionary Approach
Emphasizes the role of instincts in motivation.
Instincts: Inborn patterns of behavior biologically determined rather than learned.
Assumes people are governed by instincts similar to those of animals.
Drive Reduction Theory
Behavior arises from physiological needs causing internal drives.
Need (physiological): A deprivation that energizes the drive to eliminate or reduce it.
Drive (psychological): Motivational tension or arousal due to need.
Goal: Reduce drive to achieve homeostasis.
Homeostasis: Body's tendency to maintain equilibrium or a steady internal state.
Optimum Arousal Theory
Suggests an optimal level of arousal is necessary for goal attainment.
Yerkes-Dodson Law: Performance is best under moderate arousal conditions rather than low or high.
Internal Regulation
Temperature Regulation
Homeostasis: Maintains certain body variables within a fixed range.
Negative Feedback: Processes reducing discrepancies from the set point.
Allostasis: Adaptive way the body changes set points in response to life changes or environmental stimuli.
Basal Metabolism
Energy used to maintain a constant body temperature while at rest.
Ectothermic/Poikilothermic Animals:
Do not regulate temperature physiologically (body temperature matches environment).
Endothermic/Homeothermic Animals:
Use physiological mechanisms to maintain a constant body temperature over varying environmental temperatures.
Physiological Changes vs. Behavioral Changes
Physiological Changes: Regulate internal states.
Behavioral Changes: Adapt behavior to manage environmental challenges.
Brain Mechanisms in Temperature Regulation
Preoptic Area/Anterior Hypothalamus (POA/AH): Monitors body temperature using information from skin and internal receptors.
Fever: An allostasis mechanism with increased set point for body temperature.
Water Regulation
Thirst
Different species have unique strategies for fluid maintenance depending on their circumstances.
Example: Beavers drink plenty of water; desert animals conserve water.
Types of Thirst
Osmotic Thirst:
Triggered by eating salty foods; differences in osmotic pressure between cells.
Hypovolemic Thirst:
Triggered by fluid loss from bleeding, diarrhea, etc.; linked to sodium-specific hunger.
Digestive System and Food Regulation
Influences food selection and satiety.
Enzyme lactase in baby mammals aids in food selection during weaning.
Oral Factors: Taste contributes to satiety but not solely sufficient.
Stomach & Intestines: Stretching of stomach walls triggers satiety signals; CCK hormone release limits meal size.
Regulation of Feeding Hormones
Leptin: Produced by fat cells, monitors fat levels in the body.
More fat cells → more leptin.
Affected in individuals with the obese gene (lack leptin production).
Brain Regions Involved in Feeding Regulation
Arcuate Nucleus of Hypothalamus: Controls appetite, responds to hunger and satiety signals.
Paraventricular Nucleus of Hypothalamus: Signals satiety; damage leads to overeating.
Lateral Hypothalamus: Facilitates eating behavior; damage leads to refusal of food and water.
Ventromedial Hypothalamus (VMH): Damage causes overeating; increased insulin production leads to more fat storage.
Eating Disorders Overview
Types of Eating Disorders
Obesity:
Genetic component, influenced by environment.
Anorexia Nervosa:
Severe food intake restriction, fear of gaining weight, common in young women.
Bulimia Nervosa:
Binge-purge cycles, often associated with anxiety and depression.
Binge Eating Disorder:
Recurrent eating episodes with a feeling of lack of control; common among obese individuals.
Approaches to Motivation in Everyday Life
Maslow’s Hierarchy of Human Needs
Needs must be satisfied in sequence; self-actualization is the highest motivation.
Self-Determination Theory
Three Basic Needs:
Competence: Self-efficacy, mastery, success expectations.
Relatedness: Warm relationships with others, need for belonging.
Autonomy: Independence and self-reliance.
Intrinsic vs. Extrinsic Motivation
Intrinsic Motivation: Fulfillment from engaging in the activity for its own sake.
Extrinsic Motivation: Engagement motivated by rewards or consequences.
Self-Regulation and Temptation
Self-Regulation: Control over behavior to achieve goals.
Goal Setting: Specific, moderately challenging objectives help achieve long-term and short-term purposes.
Resisting Temptation:
The ability to delay gratification enhances self-control; distraction may assist in resisting immediate pleasures.