Chapter 6 (pg. 185-208) 1. Describe the term motivational state or drive. What are the different drives present in all mammals and what is an example of each? What is the central-state theory of drives? Be sure to describe the role of neurons and the hypothalamus in your response.Motivational State/ Drive: An internal, reversible condition in an individual that orients the individual toward one or another type of goal (such as food or water). This condition is not observed directly but is inferred from the individual’s behavior. - Motivation is a Hypothetical Construct: inferred state from resulting behavior Biological (physiological) - Regulatory Drives: Drives that help maintain some constancy of the body’s internal environment (helping to maintain the body’s homeostasis) that is necessary for survivalo Hunger, Thirst- Safety Drives: drives that motivate an animal to avoid, escape, or fend off dangers such as predators, or enemies. o Fear, AngerPsychological- Social Drives (Relationship): Drives that promote cooperation with others to survive. o Friendship, Acceptance, Approval (in Humans as powerful as Regulatory, safety and reproduction) - Educative Drives (Curiosity): When other drives are not too pressing, this drive comes out and consists mostly of play (to learn) and exploration (to acquire useful info. about environment) o Play, Explore (Curiosity) Species - Reproductive Drives (Sexual): o Sexual, drive to care for young once they are born, sexual jealousyNon-Regulatory Drive: Any motivational state (such as the sex drive) that serves some function other than that of preserving some constancy of the body’s internal environment. Homeostasis: The constancy in the body’s internal environment that must be maintained through the expenditure of energy. Maslow’s Hierchy of Needs: Must first satisfy Physiological needs, then safety needs, belongingness and love needs, esteem needs, self actualization needsCentral State Theory of Drives: The theory that the most direct physiological bases for motivational states, or drives, lay in neural activity in the brain. According to most versions of this theory, different drives correspond to activity in different, localizable sets of neurons.Central Drive System: According to the central state theory of drives, a set of neurons in the brain that, when active, most directly promotes a specific motivational state, or drive. - Different drives correspond to neural activity in different sets of neurons in the brain. Role of Neurons and the Hypothalamus: - Hypothalamus is the hub of many central drive systemso The brain structure is ideally located to play such a role Centered at the base of the brainstem, and is strongly interconnected with higher areas of the brain. Direct connections to nerves that carry input from and autonomic motor output to the body’s internal organs. Connection with pituitary gland controls the release of many hormones.o Has all the inputs and outputs that central drive systems would be expected to have. 2. Differentiate between the liking, wanting, and reinforcement systems of reward. What role does dopamine play in how the liking and wanting systems differ? What role does it play in reinforcement for learning?Three components of Reward: Liking, Wanting, and ReinforcementLiking: the subjective feeling of pleasure, or satisfaction, that occurs when one receives a reward. Occurs when you get what you want. - Endorphins released into the nucleus accumbens are crucial for the immediate pleasure experienced when rewards are received or consumed.Wanting: the desire to obtain a reward. (To want something is to be motivated to get it) Occurs before reward is received. - Dopamine is responsible for wanting.- Release of dopamine into the nucleus accumbens just before animal “pushes lever”, but not after they receive the reward. - Dopamine helps motivate the animal to obtain the reward but is not essential for the pleasure received from obtaining the reward. Reinforcement: the effects that rewards have in promoting learning. (Through effects on the brain reward helps to stamp in or reinforce, the memory of stimuli and actions that occurred just before the reward was received) - Closely related to “wanting” - The release of dopamine into the nucleus accumbens just before animal “pushes lever” is also crucial for their ability to learn to use cues to predict when and where rewards are available. - Dopamine release promotes LTP (long term potential) of neural connections within the nucleus accumbens.- With learning dopamine starts to be released just to stimulus (just to light flashing with no food) Dopamine: One of many neurotransmitter substances in the brain. It is crucial for the “wanting” component of reward. Endorphin: Chemicals produced in the body that acts like morphine in inhibiting pain. (Essential for liking)3. What is hunger an example of? Describe the roles of the arcuate nucleus, hormone PYY, leptin, and sensory stimuli in the control of appetite.Hunger is an example of a regulatory drive for survival Arcuate Nucleus: A nucleus (cluster of neural cell bodies) in the hypothalamus of the brain that plays a critical role in the control of appetite. - Contains two classes of Neurons that have opposite effects on appetite. o 1. Appetite-stimulating neurons o 2. Appetite-suppressing neurons- Exert effects on other brain areas through the release of slow acting neurotransmitters. (Capacity to alter neural activity for long periods of time)Hormone PYY: An appetite-suppressing hormone. - Is produced in by special endocrine cells in the large intestine.- When food enters the intestines after a meal, it stimulates secretion of PYY into the bloodstream. - Internal signals contribute to short term regulation of appetite - Target tissues of PYY is the arcuate nucleus, where the hormone excites appetite-suppressing neurons and inhibits appetite-stimulating neurons. Leptin: Fat cells secrete this hormone at a rate that is directly proportional to the amount of fat that is in the cells. - Leptin is taken up into the brain and acts on neurons in the arcuate nucleus and other parts of the hypothalamus to reduce appetite. - Body is sensitive to not only the amount of food recently eaten (PYY), but also to the amount of fat stored in body Sensory Stimuli: - Hunger is provoked not just by events inside us but also by sensory stimuli in the environment - Evolutionarily makes sense (eat when food
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