Mechanisms of Motivation and Emotion Chapter 6. Principles of Motivation MOTIVATION: the entire constellation of factors, some inside the organism and.

Mechanisms of Motivation and EmotionChapter 6

Principles of Motivation MOTIVATION: the entire constellation of factors, some

inside the organism and some outside, that cause an individual to behave in a particular way at a particular time DRIVE: or motivational state, an internal, reversible

condition in an individual that orients the individual toward one or another type of goal

DRIVEINCENTIVE HUNGER

Varieties of Drives: Homeostasis

HOMEOSTASIS: the constancy in the body’s internal environment that must be maintained through the expenditure of energy

Regulatory drives help maintain homeostasis (hunger, thirst, sleep)

Nonregulatory drives serve some other purpose

Nonregulatory Drives

• Fear, anger

Safety Drives

• Mating and caring for infants

Reproductive Drives

• Friendship and social acceptance

Social Drives

• Play and exploration

Educative Drives

Drives As States of the Brain

CENTRAL-STATE THEORY OF DRIVES: theory that the most direct physiological bases for drives lie in neural activity in the brain

CENTRAL DRIVE SYSTEM: a set of neurons in the brain that, when active, most directly promotes a specific drive

Three Components of Reward

Medial forebrain bundle neurons whose terminals end in the nucleus accumbens release reward-related neurotransmitters.

Rewards:

1. Things we like (Endorphins)

2. Things we want (Dopamine)

3. Things that serve as reinforcers

(Dopamine and new learning)

Wanting and liking and an element of surprise (new learning).

Dopamine

Endorphin

EndorphinDopamine

Three Components of Reward

Medial forebrain bundle neurons whose terminals end in the nucleus accumbens release reward-related neurotransmitters.

Rewards:

1. Things we like (Endorphins)

2. Things we want (Dopamine)

3. Things that serve as reinforcers

(Dopamine and new learning)

Neural and Hormonal Control of Appetite

Neurons that affect appetite are located in the ARCUATE NUCLEUS

Appetite-stimulating neurons NEUROPEPTIDE Y and appetite-suppressing neurons peptide YY (PYY)

Normal vs. Leptin mice

Fat cells secrete Leptin acts on hypothalamus to suppress appetite

Hormonal Influences on Sex Drive(all hypothalamic)

The primary hormone for male sex drive is testosterone

Testosterone has also been linked to aggression, dominance and preoccupation with social status

Males Females

The primary female hormones for sexual drive are estrogen and progesterone

Sexual Differentiation and Determinants of Sexual Orientation

ACTIVATING EFFECTS have temporary, reversible effects

DIFFERENTIATING EFFECTS create long-lasting structural differences

Females: XX, Males: XY

“Y” testes male genitals/brain change

Congenital adrenal hyperplasia

Identical Twins – 50% heredity of sexual orientation

Fraternal Twins/Siblings – 15%

Male birth order - “maternal memory” for male gestations or births. (Blanchard, 2008; Bogaret, 2006).

Sleep As a Physiological and Behavioral State

SLEEP is a condition of relative unresponsiveness to the environment; influenced by a biological clock that keeps a 24 hour day-night cycle

Dreams and Other Mental Activity During Sleep

TRUE DREAMS: the person feels like it is a real experience and they are sensing the situationREM

SLEEP THOUGHT: tend to involve concerns that happened during the day

• non-REM

THE PRESERVATION AND PROTECTION THEORY

Sleep came about in evolution to preserve energy and protect individuals during that portion of each 24-hour day when there is relatively little value and considerable danger in moving about E.g. herbivores sleep less than carnivores

THE BODY RESTORATION THEORY

The body wears out during the day and sleep is necessary to restore it to normal functioning

• Large sleeping differences between animals?

THE BRAIN MAINTENANCE THEORY OF REM

REM sleep provides regular exercise to groups of neurons in the brain and preserves important neural circuits (Infants vs. Adults)

Mammal Trends Hours

Giant Sloth 20

Opossum, brown bat 19

Giant Armadillo 18

Owl monkey 17

Arctic ground squirrel 16

Tree shrew 15

Cat, golden hamster 14

Mouse, rat, grey wolf 13

Arctic fox, chinchilla, gorilla, raccoon

12

Mountain beaver 11

Rhesus monkey, chimpanzee, baboon

9

Human, rabbit, pig 8

Tree hyrax, rock hyrax 5

Cow, goat, elephant, donkey, sheep

3

Roe deer, horse 2

Individual Variation in the Sleep Drive

NONSOMNIACS need much less sleep than average and still function normally the next day

INSOMNIACS have a normal sleep drive but, for whatever reason, sleep much less than they would like

Brain Mechanisms of the Daily Sleep Cycle

CIRCADIAN RHYTHM: any cyclic physiological or behavioral change in a living thing that has a period of about 1 day even in the absence of external cues signaling the time of day

Suprachiasmatic nucleus (rhythm-generating neurons) Body temperature Melatonin

Ventromedial Preoptic Nucleus

• Activates sleep• Lesions in this area cause permanent sleeplessness

Wake-activating center in the Lateral and Posterior Hypothalamus• Release OREXINS• Leading cause of narcolepsy

The Nature and Value of Emotions

EMOTION: a subjective feeling that is experienced as directed toward some particular object or event

AFFECT: any emotional feeling

MOOD: a free-floating emotional feeling, not directed at a specific object

Plutchik’s Model of Primary Emotions

Effects of Bodily Responses on Emotional Feelings

Emotions are accompanied by peripheral changes Heart rate, blood pressure, diversion of blood, gland activation,

muscle tension, facial expressions

Common sense dictates that our emotions cause these changes…but what if it’s the other way around?

Theories of Emotion The bodily reaction to an emotion-provoking stimulus is

automatic, occurring without thought or feeling at first, and the assessment of one’s emotional state comes later

Emotional state depends on the sensory feedback pertaining to the body’s response as well as the person’s perceptions and thoughts about the environmental event that provoked the response

The Facial Feedback Theory of Emotion

Sensory feedback from facial expressions contributes both to emotional feelings and to the production of the full-body reactions that accompany emotions

Brain Mechanisms of Emotion

The AMYGDALA is the brain’s early warning system

Receives sensory input from: A fast subcortical

route A slower cortical route

The PREFRONTAL CORTEX is essential for conscious experience of emotions