Textbook Notes (369,137)
Canada (162,407)
Psychology (9,699)
PSYA02H3 (962)
Chapter

PSYA02H3: Ch10-11 (Mtuner 2 Review)

21 Pages
428 Views

Department
Psychology
Course Code
PSYA02H3
Professor
Steve Joordens

This preview shows pages 1,2,3,4. Sign up to view the full 21 pages of the document.
Description
Helen  Li     PSYA02H3   Chapter 11: Hunger and Eating • Motivation: concerns the physiological and psychological processes underlying the initiation of behaviors that direct organisms toward specific goals o Initiating factors/ motives -> thoughts, feelings, sensations, bodily process that lead to goal- directed behavior o Essential to individual’s survival -> contributes to homeostasis: body’s physiological processes that allow it to maintain consistent internal states in response to outer environment ▯ Physiological needs -> appropriate body temp, hunger, thirst ▯ Social in nature -> form social bonds -> achieving success at school or work • Drives: the physiological triggers that tell us we may be deprived of something and cause us to seek out what is needed, such as food • We also respond to incentives (or goals): the stimuli we seek to reduce the drives such as social approval and companionship, food, water, and other needs • Satiation: the point in a meal when we are no longer motivated to eat o Homeostasis of food intake is balanced between hunger motives & satiation Helen  Li     PSYA02H3   • On/ off switches involved in hunger -> hypothalamus o Researches found that electrically stimulating the lateral hypothalamus causes rats to begin to eat -> this structure serves as “on” switch o The ventromedial region of hypothalamus -> serve as “off” switch ▯ Damage to this area -> obesity in lab animals o The paraventricular nucleus of hypothalamus -> signals time to stop eating by inhibiting lateral hypothalamus • Hypothalamus -> doesn’t work alone o Busy hub of activity that sends & receives signals throughout body o When it comes to eating/ hunger -> receives info about tastes, textures, smells through nerves coming from mouth & nose & exchanges this info with front cortex o Monitoring blood chemistry for indicators of levels of sugars & hormones involved in energy ▯ Hypothalamus detects changes in level of glucose: a sugar that serves as a primary energy source for the brain and rest of the body • Vital energy source for human body; it’s levels monitored by nervous system ▯ Highly specialized neurons called glucostats -> can detect glucose levels in fluid outside of cell ▯ When glucose level drops, glucostats signal hypothalamus that energy supplies = low => hunger increases • After food reaches stomach & intestines, sugars absorbed into bloodstream & transported throughout body • Insulin: hormone secreted by the pancreas -> helps cells store this circulating glucose for future use • As insulin level rise in response of meal -> hunger decreases & so does glucose levels -> hunger eventually rises a few hours later • Ghrelin: hormone secreted in stomach that stimulates stomach contractions & appetite o Also released by hypothalamus => functions to decrease appetite • Another key chemical in regulating hunger -> cholecystokinin (CKK) o As intestines expand -> neurons release CKK -> communicates to hypothalamus that it’s time to stop eating Helen  Li     PSYA02H3   • Food can be more powerful reinforcer than highly addictive drugs o Cravings for a “sugar fix” – a term that seems to imply that addiction to candy bars is comparable to an addiction to a drug like heroin ▯ Possible that sugar act like a drug? ▯ Ordinary sucrose- plain white granulated sugar- can stimulate release of neurotransmitter dopamine in nucleus accumbens, brain region associated with reinforcing effects of substances such as amphetamines & cocaine • Taste -> another powerful force to motivate o Eating more than just maintaining homeostasis • Scientists not 100% sure -> we crave fats because we have specialized receptors on the tongue that are sensitive to fat content of food o Experiments -> used brain imaging technology -> participants tasted various substances - > overall; they rated fatty substance favorably & brain scans showed activation in regions of brain associated with pleasure sensations when they tasted fat • Scientific studies -> confirmed health risks brought on by high-fat diets • When chemical receptors in mouth & nose are detecting tastes & smells -> touch receptors in mouth are detecting textures of food & relaying this info to the orbitofrontal cortex -> contributes info to overall sensation of eating o These cells help distinguish runny spaghetti sauce from thick one o Other cells -> between fatty & lean meats -> spicy and bland foods • Tube feeding: technique used with hospitalized patients who cannot chew or swallow on their own o Satisfies body’s nutritional needs by delivering nutrients directly to stomach o Experiment -> even tough the tube-fed volunteers received all the nutrition they needed, they were still motivated to eat Helen  Li     PSYA02H3   • Impression management: Eating less o Sometimes people self-consciously control their behavior so that others will see them a certain way o Eg. Polite to chew with your mouth closed • Minimal eating norm: suggests that another aspect of good manners- some social & cultural settings- is to eat small amounts to avoid seeming rude • Modeling: Eating whatever they eat o Eg. Employee will notice no one eats much & everyone takes their time -> newcomer will see others as models -> later, he may be introduced to friends family reunion where everyone eats more than one plate -> more likely to eat more even if he’s full • In Europe, the typical container of fruit & yogurt is roughly 6 ounces. In the US, the same food item is usually packaged in 8-ounce containers. o The unit bias suggest that a French person in the US would be likely to eat entire container, even tough it contains 25% more than the typical French serving • Obesity: disorder is positive energy balance, in which energy intake exceeds energy expenditure o Epidemic that spread in US -> other parts of world o On major problem -> difficulty in ensuring long-term maintenance of weight loss ▯ E.g. ads tell people that they can lose weight without exercising, just by taking a pill • Hard shedding pounds -> impossible o Several studies shown that girls & adolescents who self-report dieting are heavier later in life o Research studies suggests that people who are obese have an increased sensitivity to food & food- related cutes ▯ Suggest that people with obesity have more intense, rewarding sensory experiences when it comes to food -> but doesn’t tell us whether increased sensitivity to food cues causes obesity, or vice versa ▯ Brain imaging studies show greater activity in obese individuals brains in response to food compared to brains of people of normal weight • In late 1940’s, group of scientists in Minnesota -> young men to participate in extreme food deprivation on physiology & behavior Helen  Li     PSYA02H3   o Not only lost weight -> reduced pulse, respiration & blood pressure o Became depressed, developed abnormal feeding patterns such as binging o Anorexia nervosa: an eating disorder that involves: 1. Self starvation 2. Intense fear of weight gain and distorted perception of body image 3. Denial of serious consequences of severely low weight ▯ Other problems -> female: consecutive loss of menstrual periods (amenorrhea) -> male: loss of sexual motivation ▯ Usually occur during mid- late adolescence & on rise during 20 century • Bulimia nervosa: eating disorder that is characterized by periods of food deprivation, binge- eating and purging o Involves short, but intense episodes of massive calorie consumption marked by lack of regulation of how many calories the body actually needs -> purging (self-induced vomiting, most common type), fasting, laxative or diuretic use, intense exercise o People with anorexia may also purge -> less common than people who have bulimia o More prevalent in late adolescence and young adulthood o Males -> less problems, still develop eating disorders (achieve muscle mass) • One concern to eating disorders -> culture o People with regular exposure to Western culture are more likely to develop bulimia than members without o Exposure to idealized version of body type & thinness -> more likely predictor of someone’s chances of developing eating disorder/ obesity Chapter 11.2: Sexual Motivation • Libido: the motivation for sexual activity and pleasure o Sex drive? o On avg, men more sexually aroused, fantasize more, masturbate more, desire more sexual partners than do women • Sex serves many purposes other than biological purposes o Masturbation occurs in some primate species, bonobo chimpanzee engages in frequent genital contact, touching, other sexual behaviors, without actually copulating • Difficult for psychologists to study -> sex generally happens in private -> interviews & questionnaires are least intrusive techniques (common) • First scientist to tackle human sexual behavior => zoology professor Alfred Kinsey o Fact that Kinsey dared to apply science to sexuality -> offended many people o During time where “sexual orientation” didn’t exist -> he reported 37% of males whom he interviewed had at least 1 homosexual experience resulting in orgasm -> shocking o Believed that heterosexuality and homosexuality fell on continuous scale o His studies opened further opportunities for current researchers to find -> motivate humans o Study conducted by psychologists Cindy Meston & David Buss -> asked more than 1,500 college students to identify reasons for having sex -> reproduction isn’t primary reason to have sex ▯ Physical reasons -> “The person’s physical appearance turned me on” ▯ To help attain a goal -> “I wanted to get a raise” ▯ For emotional reasons -> “I realized I was in love” Helen  Li     PSYA02H3   ▯ Because of insecurity -> “I felt obligated to” • Reasons for avoiding sex -> unplanned/ unwanted effects of sexual behavior such as pregnancy, sexually transmitted diseases or being in relationship that may be abusive or simply too complex for younger person to handle • Starting in 190’s -> William Masters & Virginia Johnson described human sexual response cycle based on their observations of 27 male and 118 female prostitutes who agreed to masturbate/ have intercourse while under observation o Monitored with heart rate & blood pressure equipment o Penile plethysmograph, vaginal photoplethysmograph ▯ Measure blood flow to genitalia in men & women o Sexual response cycle: describes the phases of physiological change during sexual activity, , which comprises four primary stages: excitement, plateau, orgasm, and resolution ▯ Allows researchers to describe cascade of physiological changes that occur during sexual behavior ▯ Applies to men & women • Men usually experience a single orgasm followed by a refractory period: a time period during which erection and orgasm are not psychically possible o Some women experience multiple orgasms without refractory period • Stimulation of breasts, nipples & vaginal areas causes sensory nerves to send signals -> hypothalamus -> stimulates pituitary gland to release hormone called oxytocin (plays role in orgasm & post-orgasm physiology) -> oxytocin released during orgasm in males o Dopamine-rich reward centers of brain become highly active during orgasm • If researcher wanted to study how brain activity changes during sexual activity -> use functional MRI scan • In males, erectile dysfunction (ED): inability to achieve or maintain an erection o Caused by cardiovascular problems such as hypertension o Physicians may prescribe Viagra, that enhance blood flow to genitals • For females, physiological problems may lead to lack of arousal or painful intercourse o Estrogen replacement therapy may be of relief • Adolescents may engage in cybersex- use of internet & computer equipment for sending sexually explicit images & messages to a partner o 1/3 adults today engages in cybersex o Unplanned pregnancy & STDs not immediate risk, however people tend to communicate with less inhabitation vid digital media compared to face-to-face encounters ▯ Impulsive behavior, “sexting” (some states consider it form of pornography -> sex offender) • Sexual orientation: a consistent preference for sexual relations with members of opposite sex (heterosexuality), same sex (homosexuality) or either sex (bisexuality) Helen  Li     PSYA02H3   o Current definitions focus on psychological aspects of sexuality (desire, emotion, identification) o E.g. person can have a sexual orientation but never have sexual contact throughout his/her life o Sigmund Freud advanced theory that male homosexuality could be traced to presence of domineering mother and weak father figure o 1987 -> Ellis & Ames argued that homosexuality could be caused by experiencing seduction from older sibling / playmate o Both theories lack scientific evidence to confirm validity o Modern scientific explanations of homosexuality focus on interactions between biological & sociocultural factors • In early 1990’s Simon LeVay compared brains of deceased gay & heterosexual males o Found that area of hypothalamus was, on avg, smaller in gay men compared to heterosexual men o Created storm of controversy among scientists & public ▯ Differences in hypothalamus could have been due to environmental factors- LeVay’s study was not designed to test either conclusion ▯ “Nature vs Nurture” • Modern research on brain show how environmental factors, contribute to anatomical & functional differences in brain • Scientists -> proved difficult to replicate LeVay’s results o Region of hypothalamus was only smaller on avg in gay men vs heterosexuals, & ranges in size were overlapping ▯ Homosexual men whom LeVay studied died associated with HIV (accounted for diff in brain) o Only diff they found between male-preferring & female-preferring rams is a smaller region of the hypothalamus • Homosexual males & heterosexual females show greater activity in the brain’s reward centers when viewing pictures of genitalia of sexually aroused males o Same pattern of brain activity found in homosexual women & heterosexual men viewing pictures of female genitalia • Testosterone: hormone that is involved in development of sex charactertics and motivation of sexual behavior o Found in both men & women, typically higher in males 1. Surges in testosterone are associated with elevated sexual arouse in both males/ females 2. Testosterone has long-term effects on sexual development Helen  Li     PSYA02H3   • Researches long notes that prenatal hormone levels influence sex-specific behavior & sexual preferences in nnd-humth species o During 2 & 5 , months of pregnancy, when fetal brain is developing rapidly- amount of testosterone the fetus encounters influences behavior later in life o If fetus is female -> high testosterone, increased chance of showing male typical behavior & sometimes homosexual orientation o Low circulating levels of testosterone during prenatal development -> feminization o Males exposed to low prenatal testosterone levels more -> feminine pursuits & show homosexual preferences • Heterosexual females tend to have index & ring fingers of equal length • Heterosexual males have longer ring fingers than index fingers • On avg, homosexual males tend to have feminized (equal) ratios & lesbians have masculine ratios o Though not found in all studies o Point here -> finger length has some particular relevance to sexual orientation • Gay males tend to have larger number of older brothers than do heterosexual males o Expecting mother’s immune system o At birth, some mixing of blood between mother & newborn occurs o If newborn is male, mother is thus exposed to proteins that we are specific to males -> triggers an immune response by mother o If subsequent fetuses are male -> maternal immune system may transport the antibodies of her immune system that she built up from previous birth across placenta o Result -> inhabitation of testosterone circulation in developing male o Limited testosterone exposure -> feminized brain o Absence of corresponding birth order effect in lesbians -> affects male fetuses • Sexual orientation may be influenced by combo of genes • Higher for identical twins than fraternal twin pairs Chapter 11.3: Social and Achievement Motivation Helen  Li     PSYA02H3   • Need to belong (sometimes known as affiliation motivation): the motivation to maintain relationships that involve pleasant feelings such as warmth, affection, appreciation and mutual concern for each person’s well-being o Need to have at least few permanent meaningful relationships • Terror management theory: psychological perspective asserting that the human fear of mortality motivates behavior, particularly those that preserve self-esteem and sense of belonging o Suggests that individuals are motivated to belong to families, religious groups, and nationalities as a means to control their death-related anxiety • Mortality salience- an increased awareness of death- with simple reminders o E.g. volunteers may write 1-2 paragraph what happened when people die, while control group write something unpleasant that does not make mortality more apparent (salient) such as discomfort of a root canal or other dental pain ▯ In experiments, simply writing about death is enough to motivate individuals to increasingly defend their own worldview (their spiritual and political beliefs) ▯ Used to reduce impact of mortality salience -> e.g., psychologists followed mortality salience stimulus by asking participants to think positive thoughts about their parents, the effect of mortality salience disappeared ▯ Mortality salience is powerful motivator regardless of one’s nationality/ political persuasion • Maslow (love & belonging; his hierarchy) -> individuals generally must take care of physiological needs first, but must satisfy love & belonging needs before developing healthy self-esteem • Achievement motivation: drive to perform at high levels & accomplish significant goals o Often involves need to compete with & outperform other individuals o Seen in desire to master a task, with or without other incentives or rewards o Can be observes in students approach to school, entrepreneurs desire to build a business, athletes hopes of winning a gold medal • Mastery motives: motives that reflect a desire to understand or overcome a challenge Helen  Li     PSYA02H3   o E.g. desire to master a task • Performance motives: generally those motives that are geared toward gaining rewards/ public recognition • Approach goals: enjoyable & pleasant incentives that we are drawn toward o E.g. praise, or financial reward • Avoidance goals: unpleasant outcomes we try to avoid o E.g. shame, embarrassment, emotional pain • If a student is a pre-med major because he is curious about how the body works & how it recovers from disease, psychologists would say that he has mastery motives -> if student is studying pre-med only because he thinks this major will impress people, then psychologists would say he has performance motives • People are least likely to procrastinate when they are genuinely interested in task & believe they can gain something from it -> master-approach goal • If you are studying math problems because you really want to win an award, psychologists would say you have approach goals; if you are just hoping that you do not get the lowest score in the class, you are exhibiting avoidance goals Chapter 11.4: Emotion • Emotion: psychological experience involving three components: 1. Subjective thoughts & experiences with 2. Accompanying patterns of physical arousal 3. Characteristic behavioral expressions o E.g. anger may involve thoughts & feelings of frustration, aggravation & ill will ▯ Increased heart rate, expressed with clenched teeth & fists, tightly pursed lips & pinched brow Helen  Li     PSYA02H3   • Autonomic arousal prepares body to response to real/ perceived threats • Imagine taking peaceful walk, suddenly -> charging, snarling dog comes at you OR giant auditorium where you have to give a speech o Physiological aspect of this emotional experiences would involve division of ANS called sympathetic nervous system -> increases energy & alertness to enable you to handle frightening/ dangerous situations -> activating fight-or-flight response ▯ Increased heart rate, respiration, sweat, alertness ▯ Draws energy away from bodily functions that can wait until end of emergency, such as immune responses & sexual arousal • Once you finished speech/ dog is gone -> feel calming effects regulated by another division of ANS -> parasympathetic nervous system -> typically uses energy more sparingly, bringing heart rate & respiration back to resting rates & focusing on non- emergency tasks, such as digestion • Polygraph -> “lie detector” -> measures respiration, blood pressure, palm sweat – autonomic nervous system responses that should increase when someone lies o Most U.S courts don’t accept this as valid evidence o Some researchers -> turning to brain imaging in search fro more reliable lie detection methods ▯ Reported that increased brain activity in regions of frontal & parietal lobes when subjects are being deceptive, compared to when they tell truth ▯ E.g. Paul Ekman -> showed that people can be trained to detect very subtle non- verbal “microexpressions” indicative of lying • Limbic system -> critical to emotional processing o Includes hippocampus, hypothalamus, amygdala, & various cortical regions o Amygdala -> interest to
More Less
Unlock Document

Only pages 1,2,3,4 are available for preview. Some parts have been intentionally blurred.

Unlock Document
You're Reading a Preview

Unlock to view full version

Unlock Document

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit