“Violence Not What Attracts Video Gamers, Says Study” Just a few days after a U.S. congressman proposed legislation that would brand violent video games with a health warning, a new study was released that showed that violence is not what attracts players. The research could be reassuring news for parents.
“Anti-Stress Video Game” A simple video game has been shown to reduce stress. As this ScienCentral News video explains, researchers at McGill University found that playing the game also resulted in increased productivity.
Emotion and Motivation When surgeons removed a noncancerous tumor from Elliot’s brain they could not avoid removing some of the surrounding frontal lobe tissue Elliot’s physical recovery was quick, and he continued to be a reasonable, intelligent, and charming man with a superb memory but no longer experienced emotion after the surgery The absence of emotions sabotaged Elliot’s ability to make rational decisions, even about trivial things, and robbed him of his ability to function as a member of society Imagine living without feelings or aspirations to make something of yourself. What sort of life would that be? How profoundly do your feelings affect what you think and do?
10.1 How Do We Experience Emotions? Distinguish between primary and secondary emotions. Compare and contrast the James-Lange, Cannon- Bard, and Schachter-Singer two-factor theories of emotion. Discuss the roles that the amygdala and prefrontal cortex play in emotional experience. Define misattribution of arousal and excitation transfer. Discuss common strategies that people use to regulate their emotional states.
“Gambling Brain” Whether you’re buying a one-dollar Mega Millions lottery ticket, joining a ten-dollar March Madness office pool, or making a large investment in the stock market, your brain has to predict risk. Now researchers say they can predict how much you would be willing to risk based on your brain patterns. This ScienCentral News video has more.
10.1 How Do We Experience Emotions? The terms emotion and mood are often used interchangeably in everyday language, but it is useful to distinguish between them. – emotion (affect): feelings that involve subjective evaluation, physiological processes, and cognitive beliefs. Emotions typically interrupt whatever is happening, or trigger changes in thought and behavior. subjective experience: feelings that accompany an emotion physical changes: increases in heart rate, in skin temperature, and in brain activation cognitive appraisals: people’s beliefs and understandings about why they feel the way they do – mood: diffuse, long-lasting emotional states. Rather than interrupting what is happening, they influence thought and behavior.
Emotions Have a Subjective Component We experience emotions subjectively; we know we are experiencing emotions because we feel them The intensity of emotional reactions varies but people who are overemotional or underemotional tend to have psychological problems, for example: – mood disorders: such as depression or panic attacks; – alexithymia: This disorder causes people to not experience the subjective components of emotions, e.g. Elliot One cause of alexithymia is that the physiological messages associated with emotions do not reach the brain centers that interpret emotion Damage to certain brain regions, especially the prefrontal cortex, is associated with a loss of emotion’s subjective component
Distinguishing Between Types of Emotions Distinguishing between primary and secondary emotions is conceptually similar to viewing color as consisting of primary and secondary hues: – primary emotions: emotions that are evolutionarily adaptive, shared across cultures, and associated with specific physical states. They include anger, fear, sadness, disgust, happiness, and possibly surprise and contempt. – secondary emotions: blends of primary emotions. They include remorse, guilt, submission, and anticipation At the center of the circumplex model is the intersection of two core dimensions of affect: – Valence indicates how negative or positive emotions are; activation indicates how arousing they are arousal: physiological activation (such as increased brain activity) or increased autonomic responses (such as increased heart rate, sweating, or muscle tension)
Negative Affect and Positive Affect Neurochemical evidence supports the idea that positive affect and negative affect are independent Positive activation states appear to be associated with an increase in dopamine Negative activation states appear to be associated with an increase in norepinephrine Crying results mainly when negative events leave us unable to respond behaviorally to the emotions we are feeling Crying may relieve stress through activation of the parasympathetic nervous system and serve an important social function by bringing sympathy and social support from others
Emotions Have a Physiological Component : James-Lange Theory In 1884, William James asserted that a person’s interpretation of the physical changes in a situation leads that person to feel an emotion A similar theory was independently proposed by the physician and psychologist Carl Lange According to what is called the James-Lange theory of emotion, we perceive specific patterns of bodily responses, and as a result of that perception we feel emotion
Facial Feedback Hypothesis One implication of the counterintuitive James-Lange theory is that if you mold your facial muscles to mimic an emotional state, you activate the associated emotion – Facial expressions trigger the experience of emotions, not the other way around In 1963, Silvan Tomkins proposed this idea as the facial feedback hypothesis In other words, putting on a smile can trigger a happy response
Cannon-Bard Theory Walter B. Cannon, along with Philip Bard, proposed that the mind and body experience emotions independently The mind is quick to experience emotions; the body is much slower, taking at least a second or two to respond According to the Cannon-Bard theory of emotion, the information from an emotion-producing stimulus is processed in subcorticalstructures As a result, we experience two separate things at roughly the same time: an emotion and a physical reaction
The Amygdala The amygdala processes the emotional significance of stimuli, and generates immediate emotional and behavioral reactions This is the brain structure most important for emotional learning, as in the development of classically conditioned fear responses People with damage to the amygdala show fear when confronted with dangerous objects, but they do not develop conditioned fear responses to objects associated with dangerous objects The amygdala is associated with emotional learning, memory of emotional events, and the interpretation of facial expressions of emotion
The Prefrontal Cortex The right and left prefrontal cortices are associated with negative and positive affect, respectively; This pattern is known as cerebral asymmetry People also can be dominant in one hemisphere of their frontal lobes, and that dominant hemisphere can bias their emotions
Emotions Have a Cognitive Component: Schachter-Singer Two-Factor Theory According to the two-factor theory of emotion, a situation evokes a physiological response, such as arousal, and a cognitive interpretation, or emotion label When people experience arousal they initiate a search for its source According to the two-factor theory, whatever the person believes caused the emotion will determine how the person labels the emotion
We Can Misattribute the Sources of Our Emotional States One interesting implication of the two-factor theory is that physical states caused by a situation can be attributed to the wrong emotion When people misidentify the source of their arousal, it is called misattribution of arousal Excitation transfer is a similar form of misattribution; residual physiological arousal caused by one event is transferred to a new stimulus
We Regulate Our Emotional States In our daily lives, circumstances often require us to harness our emotional responses – How do you mask your expression of disgust when you are obligated by politeness to eat something you dislike? Gross outlined the ways we strategically place ourselves in certain situations in order to self-regulate – Can you think of any specific examples? Recent studies have found that engaging in reappraisal changes the activity of brain regions involved in the experience of emotion Not all strategies for regulating emotional states are equally successful
“Moral Dilemma” Brain scans are often used to spot physical ills. But one researcher is using MRI images to map how your brain makes sense of moral problems as well. This ScienCentral News video explains.
Humor Humor increases positive affect and can be used to cope with a difficult situation Research shows that laughter stimulates endocrine secretion, improves the immune system, and stimulates the release of hormones, dopamine, serotonin, and endorphins According to one theory, people sometimes laugh in situations that do not seem very funny (e.g. funerals) to distance themselves from their negative emotions, and strengthen their connections to other people
“Humor and the Sexes” Scientists have confirmed something many of us may have already suspected, that the brains of men and women react differently when we find something funny. As this ScienCentral News video explains, the study could help scientists understand how humor helps us cope with stress.
Thought Suppression and Rumination Through thought suppression, people attempt to not feel or respond to the emotion at all Thought suppression often leads to a rebound effect, in which people think more about something after suppression than before Rumination involves thinking about, elaborating, and focusing on undesired thoughts or feelings Rumination prolongs the mood, and it impedes successful mood regulation strategies, such as distracting oneself or focusing on solutions for the problem
Distraction Distraction involves doing something other than the troubling activity or thinking about something other than the troubling thought By absorbing attention, distraction temporarily helps people stop focusing on their problems Distractions can backfire if people change their thoughts but end up thinking about other problems or engaging in maladaptive behaviors, e.g. overeating or binge drinking
10.2 How Are Emotions Adaptive? Review research on the cross-cultural universality of emotional expressions. Define display rules. Discuss the impact of emotions on decision making and self-regulation. Discuss the interpersonal functions of guilt and embarrassment.
10.2 How Are Emotions Adaptive? Emotions are adaptive because they prepare and guide successful behaviors. Negative and positive experiences have guided our species to behaviors that increase the probability of our surviving and reproducing. Emotions provide information about the importance of stimuli to personal goals, and then they prepare people for actions aimed at achieving those goals. – goal:a desired outcome, usually associated with some specific object (tasty food) or some future behavioral intention (getting into a doctoral program in psychology)
Facial Expressions Communicate Emotion Charles Darwin argued that expressive aspects of emotion are adaptive because they communicate how we are feeling Facial expressions provide many clues about whether our behavior is pleasing to others or whether it is likely to make them reject, attack, or cheat us Facial expressions, like emotions themselves, provide adaptive information Dunlap demonstrated that the mouth better conveys emotion than the eyes, especially for positive affect Researchers showed identical facial expressions in different contexts and found that the context profoundly altered how people interpreted the emotion
Facial Expressions Across Cultures Research has found general support for cross-cultural congruence in identifying some facial expressions; support is strongest for happiness and weakest for fear and disgust Evidence indicates that some facial expressions are universal and probably have a biological basis Research suggests that pride responses are innate rather than learned by observing them in others In studies of athletes, both sighted and blind winners display similar expressions
Display Rules Differ across Cultures and between the Sexes Display rules govern how and when people exhibit emotions – display rules: rules learned through socialization that dictate which emotions are suitable to given situations Differences in display rules help explain cultural stereotypes From culture to culture, display rules tend to be different for women and men The emotions most closely associated with women are related to caregiving, nurturance, and interpersonal relationships The emotions associated with men are related to dominance, defensiveness, and competitiveness Do sex differences in emotional expression reflect learned patterns of behaviors or biologically based differences? Nature and nurture work together here, so it is difficult — often impossible — to distinguish their effects
Emotions Serve Cognitive Functions Our immediate affective responses arise quickly and automatically and color our perceptions at the very instant we notice an object These instantaneous evaluations subsequently guide decision making, memory, and behavior Our decisions and judgments are affected by our feelings When people are pursuing goals, positive feelings signal that they are making satisfactory progress and thereby encourage additional effort
“Brain Blindness” We all know that seeing something emotional can distract us, but researchers say that it might even blind us—not in our eyes, but in our brains. This ScienCentral news video explains.
Decision Making Emotions influence our decision making in different ways We anticipate our future emotional states, which then serve as a source of information and a guide in decision making. In the face of complex, multifaceted situations, emotions serve as heuristic guides: They provide feedback for making quick decisions Risk judgments are strongly influenced by current feelings, and when emotions and cognitions are in conflict, emotions typically have the stronger impact on decisions According to the affect-as-information theory, posited by Schwarz and Clore, we use our current moods to make judgments and appraisals, even if we do not know the sources of our moods If people are made aware of the sources of their moods (as when the researcher suggests that a good mood might be caused by the bright sunshine), their feelings have less influence over their judgments
“Mood and Money” Feeling sad and bad about ourselves is not only unpleasant, it can also be hard on our wallets. Psychology researchers have found that when you shop while feeling these emotions, you may pay three times more for the same item than when you’re in a better mood, as this ScienCentral News video reports.
Critical Thinking Skill: Recognizing and Correcting for Belief Persistence in Your Own Thinking and in That of Others Belief persistence (my side bias):tendency to hold on to previous ideas even when presented with evidence that the belief is questionable or just plain wrong People tend to believe information consistent with the side of an issue they already believe is true You can be more open to examining all sides of an issue fairly and altering your beliefs when the evidence supports the change To reduce the effects of belief persistence, you should deliberately seek evidence that disconfirms your belief
Somatic Markers According to Domasio’s somatic marker theory, most self- regulatory actions and decisions are affected by bodily reactions called somatic markers – somatic markers: bodily reactions that arise from the emotional evaluation of an action’s consequences Expectation is influenced by your history of performing either that action or similar actions Somatic markers may guide us to engage in adaptive behaviors by using past outcomes to regulate future behavior Damasio has found that patients, such as Elliot, who have damage to the middle of the prefrontal region, often are insensitive to somatic markers When this region is damaged, people still can recall information, but it has lost most of its affective meaning
“Lying Faces” When the stakes are high, emotion in the face and voice may give away hard-to-spot liars. As this ScienCentral News video reports, one researcher studying deception for the military is finding information that may be helpful in love and war.
Emotions Strengthen Interpersonal Relations In interacting with others, we use emotional expressions as powerful nonverbal communications Nonverbal displays of emotions signal inner states, moods, and needs Theorists have reconsidered interpersonal emotions in view of humans’ evolutionary need to belong to social groups Survival was enhanced for those who lived in groups; those who were expelled would have been less likely to survive and pass along their genes The fundamental need to belong indicates that people will be sensitive to anything that might lead them to be kicked out of the group, and social emotions may reflect reactions to this possibility
Guilt Strengthens Social Bonds Guilt is a negative emotional state associated with anxiety, tension, and agitation The typical guilt experience occurs when someone feels responsible for another person’s negative affective state Roy Baumeister and colleagues contend that guilt protects and strengthens interpersonal relationships in three ways: – Feelings of guilt discourage people from doing things that would harm their relationships; – Displays of guilt demonstrate that people care about their relationship partners, thereby affirming social bonds; – Guilt is a tactic that can be used to manipulate others Evidence indicates that socialization is more important than biology in determining specifically how children experience guilt Parental warmth is associated with greater guilt in children suggesting that feelings of guilt arise in healthy and happy relationships. As children become citizens in a social world, they develop the capacity to empathize, and they subsequently experience feelings of guilt when they transgress against others
Embarrassment and Blushing A person is likely to feel embarrassed after violating a cultural norm, losing physical poise, being teased, or experiencing a threat to his or her self-image Like guilt, embarrassment may reaffirm close relationships after wrongdoing Recent theory and research suggests that blushing occurs when people believe others view them negatively and that blushing communicates a realization of interpersonal errors This nonverbal apology is an appeasement that elicits forgiveness in others, thereby repairing and maintaining relationships
10.3 How Does Motivation Energize, Direct, and Sustain Behavior? Distinguish between a motive, a need, and a drive. Describe Maslow’s hierarchy of needs. Describe the Yerkes-Dodson law. Distinguish between extrinsic motivation and intrinsic motivation. Discuss the relationships between self-efficacy, the achievement motive, delayed gratification, and goal achievement. Describe needto belong theory.
10.3 How Does Motivation Energize, Direct, and Sustain Behavior? Emotions are a primary source of motivation. – motivation: factors that energize, direct, or sustain behavior Most of the general theories of motivation emphasize four essential qualities of motivational states. Motivational states: – are energizing or stimulating; they activate behaviors; – are directive; they guide behaviors toward satisfying specific goals or specific needs; – help animals persist in their behavior until they achieve their goals or satisfy their needs; – differ in strength, depending on internal and external forces.
Multiple Factors Motivate Behavior Needs lead to goal-directed behaviors; failure to satisfy a particular need leads to psychosocial or physical impairment – need: a state of biological or social deficiency Maslow believed that people are driven by many needs, which he arranged into a need hierarchy – need hierarchy: Maslow’s arrangement of needs, in which basic survival needs must be met before people can satisfy higher needs Maslow’s “need theory” is an example of humanistic psychology because itfocuses on the person in motivation, e.g. it is the person who desires food, not the person’s stomach A state of self-actualization occurs when someone achieves his or her personal dreams and aspirations Maslow’s hierarchy is more useful as an indicator of what might be true about people’s behaviors than of what actually is true about them – For example, some people starve themselves in hunger strikes to demonstrate the importance of their personal beliefs – Others, who have satisfied their physiological and security needs, prefer to be left alone
Drives and Incentives What motivates us to satisfy our needs? – drive: a psychological state that, by creating arousal, motivates an organism to satisfy a need For biological states such as thirst or hunger, basic drives help animals maintain steadiness, or equilibrium – homeostasis: the tendency for bodily functions to maintain equilibrium. The term homeostasis was coined by Walter Cannon Hull proposed that when an animal is deprived of some need (such as water, sleep, or sex) a drive increases in proportion to the amount of deprivation Any behavior that satisfies a need is reinforced and therefore is more likely to recur; if a behavior consistently reduces a drive, it becomes a habit Drive states push us to reduce arousal, but we are also pulled toward certain things in our environments – incentives: external objects or external goals, rather than internal drives, that motivate behaviors Even forces outside our conscious awareness can provide incentives for us to behave in particular ways, e.g. subliminal messages or advertising
Arousal and Performance Yerkes-Dodson law: the psychological principle that performance increases with arousal up to an optimal point, after which it decreases with increasing arousal – For example, As the Yerkes-Dodson law predicts, students perform best on exams when feeling moderate anxiety. Too little anxiety can make them inattentive or unmotivated, while too much anxiety can interfere with their thinking ability. Motivation does not always lower tension and arousal; we are individually motivated to seek an optimal level of arousal
Pleasure Sigmund Freud proposed that drives are satisfied according to the pleasure principle, which drives people to seek pleasure and avoid pain The concept of hedonism refers to humans’ desire for pleasantness From an evolutionary perspective, positive and negative motivations are adaptive – For instance, the motivations to seek out food, sex, and companionship are typically associated with pleasure, whereas the avoidance of dangerous animals is negatively motivated because of the association with pain Animals prefer to eat sweets; sweetness usually indicates that food is safe to eat. By contrast, most poisons and toxins taste bitter, so it is not surprising that animals avoid bitter tastes
“Food Addiction” Obesity researchers have found that the mere presence of food triggers brain regions associated with motivation and pleasure. This ScienCentral report has the skinny on what might be making us fat.
Some Behaviors Are Motivated for Their Own Sake Pleasure can be associated with the satisfaction of biological needs and the performance of adaptive behaviors – extrinsic motivation: motivation to perform an activity because of the external goals toward which that activity is directed, e.g. working to receive a paycheck – intrinsic motivation: motivation to perform an activity because of the value or pleasure associated with that activity, rather than for an apparent external goal or purpose, e.g. reading a good novel, listening to music Playful exploration is characteristic of all mammals — especially primates Play helps us learn about the objects in an environment and has survival value, since knowing how things work allows us to use those objects for more serious tasks Creativity is the tendency to generate ideas or alternatives that may be useful in solving problems, communicating, and entertaining ourselves and others Creativity is an important factor in solving adaptive problems
“Teens Reading” Every year, more than a million teens drop out of high school, mostly because they can’t read well. Right now, researchers aren’t sure how to help teens get out of reading trouble. But one things they do know is: they have to figure out how to persuade teenagers to read in the first place. This ScienCentral News video has more.
Self-Determination Theory and Self-Perception Theory Consistent evidence suggests that extrinsic rewards can undermine intrinsic motivation – self-determination theory:People are motivated to satisfy needs for competence, relatedness to others, and autonomy, which is a sense of personal control. Extrinsic rewards may reduce intrinsic value because such rewards undermine people’s feeling that they are choosing to do something for themselves. In contrast, feelings of autonomy and competence make people feel good about themselves and inspire them to do their most creative work (Deci& Ryan, 1987). – self-perception theory: People are seldom aware of their specific motives; they draw inferences about their motives according to what seems to make the most sense (Bem, 1967). Rewarding people for engaging in an intrinsic activity gives them an alternative explanation for engaging in it; the reward replaces the goal of pure pleasure
We Set Goals to Achieve Henry Murray proposed 27 basic psychosocial needs, including the needs for power, autonomy, achievement, and play A key insight in the study of psychosocial needs is that people are especially motivated to achieve personal goals Self-regulation of behavior is the process by which people change their behavior to attain personal goals According to an influential theory developed by Locke and Latham, challenging — but not overly difficult — and specific goals are best Challenging goals encourage effort, persistence, and concentration; goals that are too easy or too hard can undermine motivation and therefore lead to failure Dividing specific goals into concrete steps and focusing on short-term goals facilitates achieving long-term goals
Critical Thinking Skill: Recognizing When Psychological Reactance May Be Influencing Your Thinking Psychological reactance is a motivational state aroused when our feelings of personal freedom are threatened and often affects how we make choices The common notion of reverse psychology is based on psychological reactance, e.g. playing hard to get By noticing if your thinking has been influenced by this potentially irrelevant variable, you will find it easier to make better-informed and more-rational choices
Self Efficacy and the Achievement Motive Bandura argued that people’s personal expectations for success play an important role in motivation Self efficacy is the expectancy that your efforts will lead to success. This expectancy helps mobilize your energies, e.g. not believing your efforts will pay off may discourage you from trying The achievement motive is the desire to do well relative to standards of excellence Individuals high in achievement need set challenging but attainable personal goals, while those low in achievement need set extremely easy or impossibly high goals
Delayed Gratification One common challenge in self-regulation is postponing immediate gratification in the pursuit of long-term goals The ability to delay gratification is predictive of success in life According to Mischel and Metcalf, the most successful strategy to delay gratification involves turning hot cognitions into cold cognitions — mentally transforming the desired object into something undesired – Hot cognitions focus on the rewarding, pleasurable aspects of objects – Cold cognitions focus on conceptual or symbolic meanings Metcalfe and Mischel proposed that this hot/cold distinction is based on how the brain processes the information The amygdala and the nucleus accumbens are important for motivating behavior The prefrontal cortex performs cold-cognitive processes, such as the control of thought and of behavior and helps us make choices that may optimize survival
We Have a Need to Belong Over the course of human evolution, our ancestors who lived with others were more likely to survive and pass along their genes Effective groups shared food, provided mates, and helped care for offspring, including orphans Roy Baumeister and Mark Leary formulated the need to belong theory, which states that the need for interpersonal attachments is a fundamental motive that has evolved for adaptive purposes
Making and Keeping Friends Societies differ in their types of groups, but all societies have some form of group membership Not belonging to a group increases a person’s risk for various adverse consequences, such as illnesses and premature death, and suggests that the need to belong is a basic motive driving behavior Evidence indicates that people feel anxious when facing exclusion from their social groups People who are shy and lonely tend to worry most about social evaluation and pay much more attention to social information
Anxiety and Affiliation Schachter found that increased anxiety led to increased affiliativemotivations According to Schachter, other people provide information that helps us evaluate whether we are acting appropriately According to Festinger’ssocial comparison theory,we are motivated to have accurate information about ourselves and others; we compare ourselves with those around us to test and validate personal beliefs and emotional responses The effect occurs especially when the situation is ambiguous and we can compare ourselves with people relatively similar to us
Psychology: Knowledge You Can Use— How Might Psychology Influence My Working Life? Industrial and Organizational (I-O) psychology applies findings from psychological science to work settings Key challenges in I-O psychology include helping employers deal with employees fairly, helping employers design jobs so that workers find them interesting and satisfying, and helping workers be more productive An important finding in I-O psychology is that satisfied workers are the best workers; people will work hardest when their jobs are meaningful and when they feel they have some control over what they do Assess your strengths and weaknesses and try to develop a general idea of the kind of career you can pursue effectively and are likely to find fulfilling
10.4 What Motivates Eating? Discuss the impact of time, taste, and cultural learning on eating behavior. Identify neural structures associated with eating. Describe the glucostatic and lipostatic theories of eating. Discuss the role that hormones play in regulating eating behavior.
10.4 What Motivates Eating? Eating involves much more than survival. Around the globe, special occasions often involve elaborate feasts, and much of the social world revolves around eating. Common sense dictates that most eating is controlled by hunger and satiety, but the amount an individual consumes can vary from person to person. What complex interactions between biology, cultural influences, and cognition determine our eating behavior?
Time and Taste Set the Stage We have been classically conditioned to associate eating with regular mealtimes The clock indicating mealtime is much like Pavlov’s metronome: It leads to various anticipatory responses that motivate eating behavior and prepare the body for digestion, e.g. an increase in insulin promotes glucose use and increases short- term hunger signals Flavor and variety motivate eating. Animals, including humans, will stop eating relatively quickly if they have just one type of food to eat, but they will continue eating if presented with a different type of food – sensory-specific satiety: Animals eat more when presented with a variety of foods in that they quickly grow tired of any one flavor The region of the frontal lobes that is involved in assessing the reward value of food exhibits decreased activity when the same food is eaten over and over but increased activity when a new food is presented Sensory-specific satiety may be advantageous because animals that eat many types of food are more likely to satisfy nutritional requirements. Eating large meals may have been adaptive when the food supply was scarce or unpredictable
Culture Plays a Role What people will eat is determined by a combination of personal experience and cultural beliefs, and has little to do with logic and everything to do with what we believe is food Unfamiliar foods may be dangerous or poisonous, so avoiding them is adaptive for survival Local norms for what to eat and how to prepare it—guidelines that Rozin calls cuisine — reinforce many food preferences Religious and cultural values often tell people which foods to avoid Taboos on certain types of food may have been adaptive in the past because those foods were likely to contain harmful bacteria Many food taboos and preferences are idiosyncratic and reflect an evolved group preference for specific foods, prepared and eaten in certain ways Culturally transmitted food preferences powerfully affect our diet
Brain Structure, Homeostasis, and Hormones Direct the Action: Neural Processes The hypothalamus integrates the various inhibitory and excitatory feeding messages, and it organizes behaviors involved in eating Damage to the hypothalamus dramatically changes eating behavior and body weight – Ventromedial/middle region (VMH): eat far more than normal; hyperphagialeads to obesity – Lateral/outer region (LH): eat far less than normal; aphagialeads to weight loss and eventual death unless force fed The hypothalamus monitors various hormones and nutrients and operates to maintain a state of homeostasis A region of the prefrontal cortex processes taste cues such as sweetness and saltiness and indicates the potential reward value of particular foods The craving triggered by seeing tasty food is associated with activity in the limbic system Damage to the limbic system or the right frontal lobes sometimes produces gourmand syndrome, in which people become obsessed with the quality and variety of food and how food is prepared
“Taste the Difference” Is it possible that overweight people get more pleasure from eating? As this ScienCentral News video reports, studies indicate this may be why some people overeat.
Internal Sensations Contractions and distensions of the stomach can make the stomach growl; however, research has established that these movements are relatively minor determinants of hunger and eating – People who have had their stomachs removed continue to report being hungry The glucostatic theory proposes that the bloodstream is monitored for its glucose levels – Because glucose is the primary fuel for metabolism and is especially crucial for neuronal activity, it makes sense for animals to become hungry when they are deficient in glucose The lipostatic theory proposes a set-point for body fat – When an animal loses body fat, hunger signals motivate eating and a return to the set-point
Hormonal Activity Leptin is associated with long-term body fat regulation, whereas ghrelin motivates eating behavior – leptin: released from fat cells as more fat is stored and travels to the hypothalamus, where it acts to inhibit eating behavior – ghrelin: originates in the stomach; surges before meals, then decreases after people eat — may play an important role in triggering eating
10.5 What Motivates Sexual Behavior? Review the four stages of the sexual response cycle. Discuss the role that hormones play in sexual behavior. Identify the primary neurotransmitters involved in sexual behavior. Discuss sex differences in sexual behavior and in mate preferences. Review contemporary theories of sexual orientation.
10.5 What Motivates Sexual Behavior? Variation in sexual frequency can be explained by individual differences and by society’s dominating influence over how and when individuals engage in sexual activity. Pioneering research by Alfred Kinsey launched the study of human sexual behavior and shattered many myths regarding men’s and women’s sexual lives.
Biology Influences Sexual Behavior Masters and Johnson gained considerable insight into the physiology of human sexual behavior – sexual response cycle: a four-stage pattern of physiological and psychological responses during sexual activity excitement phase: occurs when people contemplate sexual activity or begin engaging in sexual behaviors plateau phase: pulse rate, breathing, and blood pressure increase, as do the various other signs of arousal orgasm phase: involuntary muscle contractions throughout the body, dramatic increases in breathing and heart rate, rhythmic contractions of the vagina for women, and ejaculation of semen for men resolution phase: dramatic release of sexual tension and a slow return to a normal state of arousal
Hormones Hormones are involved in producing and terminating sexual behaviors Hormones influence the development of secondary sex characteristics during puberty and motivate sexual behavior Males have a greater quantity of androgens than females do, and females have a greater quantity of estrogens and progesterone Males need a certain amount of testosterone (a type of androgen) to be able to engage in sex, but they do not perform better if they have more testosterone The more testosterone women have, the more likely they are to have sexual thoughts and desires — although normal females have relatively low levels of testosterone Oxytocin is released during sexual arousal and orgasm Some researchers believe oxytocin may promote feelings of love and attachment between partners; it also seems to be involved in social behavior more generally The hypothalamus is the brain region considered most important for stimulating sexual behavior
“Addicted to Love” Ever wondered what fuels that flame when you fall in love? As this ScienCentral News video reports, brain scientists have found that it’s all in your head.
Neurotransmitters Neurotransmitters, including dopamine, serotonin, and nitric oxide, have also been found to influence sexual functioning Dopamine receptors in the limbic system are involved in the physical experience of pleasure, and dopamine receptors in the hypothalamus stimulate sexual activity The most common pharmacological treatments for depression enhance serotonin function, but they seriously reduce sexual interest, especially for women Sexual stimulation leads to nitric oxide production. The increased nitric oxide promotes blood flow to both the penis and the clitoris and subsequently plays an important role in sexual arousal, especially penile erections.
Variations Across the Menstrual Cycle Women differ from men in how the hypothalamus controls the release of sex hormones In men, hormones are released at the same rate over time In women, the release of hormones varies according to a cycle that repeats itself approximately every 28 days: the menstrual cycle Research has found only minimal evidence that women’s sexual behavior varies across the menstrual cycle; however, women may process social information differently depending on whether they are in a fertile phase of the cycle
“PMS’s Flip Side” PMS may have a flip side. Brain researchers have found that an important brain circuit changes its activity along with women’s fluctuating hormone levels. As this ScienCentral News video explains, it’s the brain circuit that seeks and experiences pleasure.
Visual Erotic Stimulation Some brain imaging studies indicate that viewing erotica activates reward regions in the brain, such as various limbic structures Hamann and colleagues found that when men and women viewed sexually arousing stimuli, such as film clips of sexual activity or pictures of opposite-sex nudes, men showed more activation of the amygdala Research has shown that women prefer erotica produced specifically for women, which tends to emphasize more of the emotional factors of sexual interaction
Culture Scripts and Cultural Rules Shape Sexual Interactions The depiction of sexual behavior in movies and other media shapes beliefs and expectations about what sexual behaviors are appropriate and when they are appropriate Sexual scripts are cognitive beliefs about how a sexual episode should be enacted The scripts differ in many places in the world, such as in countries where arranged marriages are common
Regulating Sexual Behavior Most of the changes in sexual behaviors must be attributed to changes in cultural pressures and cultural expectations Although sexual customs and norms vary across cultures, all known cultures have some form of sexual morality – For example, one well-known pattern of regulating sexual behavior is the double standard. This unwritten law stipulates that certain activities (such as premarital or casual sex) are morally and socially acceptable for men but not for women. Cultures may seek to restrain and control sex for various reasons, including maintaining control over the birthrate, helping establish paternity, and reducing conflicts
Sex Differences in Sexual Behavior A study of more than 16,000 people from 10 major regions around the world found that the greater male motivation for sexual activity and sexual variety occurs in all cultures Baumeister’s term erotic plasticity refers to the extent that sex drive can be shaped by social, cultural, and situational factors Women’s sexual desires and behaviors depend significantly on social factors such as education and religion, whereas men’s sexuality shows minimal relationships to such influences To account for these differences, the evolutionary psychologist David Buss has proposed the sexual strategies theory – Sexual strategies theory: a theory that maintains that women and men have evolved distinct mating strategies because they faced different adaptive problems over the course of human history. The strategies used by each sex maximize the probability of passing along their genes to future generations. According to the sexual strategies theory, women are more likely to be more cautious about having sex because having offspring is a much more intensive commitment for them than it is for men
Mate Preferences Men and women look for similar qualities in potential partners, but men are more concerned about a potential partner’s attractiveness, and women are more concerned with a potential partner’s status These differences in relative importance may be due to the different adaptive problems the sexes faced over the course of human evolutionary history Both men and women value physical attractiveness highly, but their relative emphases conform to evolutionary predictions Instinctive behaviors are constrained by social context: The frontal lobes work to inhibit people from breaking social rules, which are determined largely by culture These standards shape the context in which men and women view sexual behavior as desirable and appropriate
“The Stud Effect” Is a woman’s choice to mate really a choice? As this ScienCentral news video explains, researchers studying mice have found that alpha males can trigger in females the growth in new brain cells that make them want only alpha males.
We Differ in Our Sexual Orientations Homosexual behavior has been noted in various forms throughout recorded history Until 1973, psychiatrists in Western cultures officially viewed homosexuality as a mental illness Many theories of sexual orientation have emerged, but none has received conclusive support The overwhelming majority of studies have found little or no evidence that how parents treat their children or environmental factors have anything to do with sexual orientation
Biological Factors The best available evidence suggests that exposure to hormones, especially androgens, in the prenatal environment might play some role in sexual orientation Researchers found that altering the expression of a single “master” gene reversed the sexual orientations of male and female flies It remains unclear how human sexual orientation might be encoded in the genes Some research suggests the hypothalamus may be related to sexual orientation
Biology and Environmental Factors Many psychologists believe it is likely that multiple biological and environmental processes affect a person’s sexual orientation in subtle ways Daryl Bem has proposed that feeling different from opposite-sex peers or same-sex peers predicts later sexual orientation Bem’s model is based on the idea of initial biological differences in temperament but then proposes that the social environment shapes what is sexually attractive Bem’s theory is supported by anecdotal evidence, but no concrete evidence supports it
Stability of Sexual Orientation No good evidence exists that sexual orientation can be changed through therapy In some cultures and subcultures, people may engage in same-sex behaviors for a period and then revert to heterosexual behaviors Few psychologists or physicians believe sexual orientation — as opposed simply to sexual activity — is a choice or that it can be changed Homosexuals have always existed, whether or not they were free to be themselves