Oct. 19, 2106
  PSY 101    [Psychology
                Images] Motivation I: Theories & Hunger as Motivated Behavior (Outline)

Motivation => Goal-Directed Behavior

Why do you and I do the things that we do???

Motivational Theories and Concepts

Body temperature as homeostatic1. Drive Theories ("push")
  • homeostasis (balance)
  • allostasis (process of reaching balance by physical or behavioral change)
  • Drive =
  • (a) internal state of tension which
  • (b) motivates an organism
  • (c) to act to reduce the tension
  • 2. Incentive Theories ("pull")

    • Incentive = external goal which can motivate behavior
    3. Evolutionary Theories
    • maximize reproductive success, e.g.,
      • dominance
      • affiliation (need for belonging)

    4. The Two Types of Motivations

     Biological Social

    Originate in bodily need

    • Hunger
    • Thirst
    • Sex
    • Sleep, etc.

     Originate in social experiences

    • Achievement
    • Affiliation
    • Nurturance 
    • Play

     Hunger & Eating

    What can we say about the causes of Homer Simpson's insatiable appetite for doughnuts?

    A very complicated set of interrelated & interacting forces & mechanisms

    Biological Factors

                  Hypothalamus]       hypothalamus     Hypothalamus (Visible Human Female)

    Hypothalamic control of eatingA. Brain: Interconnected neural circuits in the hypothalamus

    • Lateral Hypothalamus (LH): Initiate eating
    • Ventromedial Hypothalamus (VMH): Stop eating
    • Arcuate Nucleus: Dual set of neurons: start & stop
    • Paraventricular Hypothalamus (PVH): modulation of hunger
    • Neurotransmitters:
      • neuropeptide Y (carbs) & serotonin ( fats, food)

    B. Disgestive & Hormonal Regulation


    • Glucostatic Theory & "glucostats"
    • Stomach
      • Stomach distention
      • Ghrelin
      • CCK (cholecystokinin) from duodenum
      • Satiety = Feeling of fullness or satisfaction

    C. Hormones






    [bakery]Environmental Factors

    A. Food Cues: Incentives

    • Attractiveness
    • Good taste
    • Quantity/Availability
    • Sensory-specific satiety

    B. Learning

    • Innate (in-born)
    • Observation of others eating


    This page was originally posted on 10/16/03 and last updated on Oct. 19, 2016