Motivation

1. Motivation Motivation is defined as the need or desire that energizes and directs behavior. Evolutionary perspective theory focuses on genetically predisposed behaviors. Drive-reduction theory focuses on how our inner pushes and external pulls interact.(m419 f32.1, c405 f11.1) Arousal theory focuses on finding the right level of physiological stimulation. Maslow's Hierarchy of Needs describes how some of our needs take priority over others. (m420 f32.2, c406 f11.2) To qualify as an instinct a complex behavior must have a fixed pattern throughout a species and be unlearned. In humans, a newborn's rooting and sucking behaviors are instinctual.

2. Motivation Drives and Incentives: a physiological need creates an aroused state that drives the organism to reduce the need by a substance transaction, like eating or drinking. Normally this is described as homeostasis. Most Canadians learn this concept by trying to alter their percentage of bodyfat, only to discover that a healthy body resists their attempts at weight loss! Some motivated behaviours increase arousal. Our most common experience of this is curiousity. This is a common trait to all large-brained mammals. Biederman & Vessel (2006) coined the term infovores after identifying brain mechanisms that reward us for acquiring information. (mp420, c406) Maslow (1970) expanded on drive-reduction theory by suggesting that we humans operate on a hierarchy of needs. (m f 32.2, c f 11.2)

3. Hunger Nordgren (2007) found that people in a motivational hot state from fatigue, hunger, or sexual arousal easily recalled such feelings of lack in their own memories and perceived them as driving forces in others' behaviour (m 421 c 407). Precisely what triggers hunger? For example, hunger persists in humans whose ulcerous or cancerous stomachs have been removed. (m 422 f 32.3, c408 f11.3) Washburn showed that stomach contractions accompany (are correlated to) our feelings of hunger. (m 423 f 32.4, c409 f 11.4) The hypothalamus performs various body maintenance functions, including control of hunger. Blood vessels supply the hypothalamus, enabling it to respond to our current blood chemistry as well as to incoming neural information about the body's state. The arcuate nucleus has a center that secretes appetite-stimluating hormones.

4. Physiology of Hunger Another task of the hypothalamus is to monitor levels of hunger-arousing hormones such as ghrelin. Bypass surgery decreases the amount produced, and appetite lessens. (Lemonick 2002, m 423, c 409) Other appetite hormones include leptin and PYY (both decrease hunger) and orexin (which triggers hunger). A complex interaction of appetite hormones and brain activity may help explain the body's apparent predisposition to maintain itself at a particular weight level. This stable weight is called the set point. Only traumatic stress like crash diets or extreme aerobics can alter it; otherwise serious illnesses will change it. None of these approaches is optimum. Our bodies regulate weight through the control of food intake, energy output, and basal metabolic rate (the rate of energy expenditure for maintaining basic body function when the body is at rest.) Slow, sustained changes in body weight can alter one's set point, instead there may be a settling point.(Assanand et al., 1998 m 424 c410).

5. Psychology of Hunger Hot cultures like hot spices: Fig. 32.6 Countries with hot climates, where food spoiled more quickly, feature recipes with bacteria-inhibiting spices. Humans exhibit neophobia, the avoidance of unfamiliar (usually animal-based) foods. Situations control our eating ( m427 f 32.7 c 413 f 11.7): People eat more when eating with others. This is called social facilitation. Our bodies store fat for good reasons. In most of human history (and pre-history) we never had enough to eat, especially a balanced diet. Selection processes created a human who seeks out the most energy-rich foods, such as fat or sugar. This has a cost in our modern environment. As of 2007, one billion people are overweight, and 300 million are clinicallyobese (a body mass index of 30 or more). (m 428 f 32.8 c 414 f 11.8)

6. Psychology of Hunger Significant (clinical) obesity increases the risk of diabetes, high blood pressure, heart disease, gallstones, arthritis, and certain types of cancer. For women, obesity is correlated to late-life cognitive decline, including Alzheimer's disease and brain tissue loss. (Bruce-Keller et al. 2009 m 428 c 414). There are significant social effects of obesity: (m 428 f 32.10 c415 f 11.10) Roehling et al. 2007 (m 429 c 415) reveal that weight discrimination is greater than race or gender discrimination. Another example of separating causation from correlation: (m 429 f 32.11 c 415 f 11.11) Longitudinal studies (a few subjects over an extended period of time) reveal that obesity contributes to depression, and that depression fosters obesity.

7. Physiology of Obesity Logic test: If a pound of fat = 3500 calories, then reducing your food intake by 3500 calories a week (500 a day, a realisitic amount) will make you lose one pound a week. This conclusion is false because of the following realities: Set Point and Metabolism. The body will adapt to the new state of semi-starvation by burning off fewer calories. What will occur: a rigorous diet can produce early rapid losses followed by a plateau. How much is genetic? People's weight resemble those of their biological parents. Identical twins have closely similar weights, even when reared apart. Across studies, their weight correlates by +.74. A variant of the gene FTO nearly doubles the risk of becoming obese ( Fryaling et al., 2007 m 420 c 416.)

8. Food & Activity Factors Children and adults who suffer from sleep loss are more vulnerable to obesity. With sleep deprivation, levels of leptin (which reports bodyfat to the brain) fall, and ghrelin (the appetite-stimulating hormone) rise. Social influence is a factor. We are more likely to become obese if a friend becomes obese. As world economies improve, obesity increases, due both the drop of physical effort (in newer technologies) and easy access to high-energy foods. There can be high levels of heritability (genetic influence on individual differences) without heredity explaining group differences. Genetics mostly determine why one person today is heavier than another. Environment mostly determines why people today are heavier than their counterparts from from fifty years ago.

9. Sexual Motivation Masters and Johnson sexual response cycle: excitement, plateau, orgasm & resolution. This is followed by a refractory period, in which the person is incapable of another orgasm. The pleasure of sex is basically the same for both sexes: Holstege (2003 m 425 c 420) discovered that men and women undergoing PET scans had the same subcortical brain region response. Fisher et al. (2002 m435 c420). Couples passionately in love undergoing fMRI scane while viewing photos of their beloved or a stranger, found similar response patterns to their partner. Sexual disorders are defined as performance problems that consistently impair sexual arousal or functioning. Most commonly reported: erectile dysfunction; premature ejaculation; painful orgasmic dysfunction, low desire (usually in females). Dawood et al. 2005: Women's orgasm frequency is genetically influenced (m 436 c421).

10. Sex Hormones Sex hormones have two major effects: directing the physical development of male and female sex characteristics, and activating sexual behavior in instinct-bound organisms. Estrogens (such as estradiol) peak during ovulation. Male hormones are more constant. In humans, hormones only loosely influence sexual behaviour. Around ovulation, women fantasize more about sex with desirable partners, wear more sexually attractive clothing, and have slightly higher voice pitch. Human female sexuality differs from other mammalian females in being more responsive to to testosterone levels (van Anders & Dunn, 2009 m 437 c422). Fluctuation in male hormones are partly a response to sexual stimulation. (Ronay & von Hippel, 2010 m 437 c 422). Sex,however, is not a need like hunger.

11. The Sexualization of Girls Downs & Smith, 2010 (m 440 c425): An analysis of the 60 top-selling video games found that the female characters were much more likely than the male characters to be 'hypersexualized' --partially nude or revealing clothing, with large breasts and tiny waists. APA, 2007: In experiments, being made self-conscious about one's body, such as wearing a swimsuit, disrupts thinking when doing math computations or logical reasoning. Sexualization also contributes to eating disorders and depression, and unrealistic expectations regarding sexuality. The brain is our most significant sex organ. People who because of a spinal-cord injury, have no genital sensation, can still feel sexual desire. About 95% of men and women have sexual fantasies. Men (gay or straight) prefer less personal and faster-paced sex. (Lietenberg & Henning, 1995 m 439 c 424).

12. Sexual Orientation Defined as: “the enduring sexual attraction toward members of the opposite or of our own sex.” Self perception is important. Most gays or lesbians do not become aware of their preferences until shortly after puberty; and do not think of themselves as gay or lesbian until late in their teens or twenties. Statistically, the most accurate % of the population that is exclusively homosexual is 3% men & 1-2% women. (Chandra et al. 2011 m 442 c 427) Homosexuality, in and of itself, is not associated with mental disorders or emotional problems. (APA, 2007). Compared to men, womens' sexual orientation tends to be more fluid and changing. (Chivers, 2005 m 443 c 428). Women are more likely to feel and act on bisexual attraction. (Mosher et al., 2005). High female sex drive is more likely to be bisexual. (Lippa, 2007 m 443 c428).

13. Sexual Orientation & the Brain Fraternal Birth-Order Effect (Blanchard, 2008): There may be a defensive maternal immune response to foreign substances produced by male foetuses.(m 444 c 429) For each male foetus pregnancy, the maternal antibodies may become stronger and prevent the foetus' brain from developing in a male-typical pattern. The birth-order effect is not found on women with older sisters, fraternal twins male/female or left-handed males (Rose et al. 2002 m444 c429) In gay men and women, the INH4 cluster in the hypothalamus is consistently larger than in heterosexual men. It is a mistake to think of the hypothalamus as a sexual orientation center, rather it is an important part of the neural pathway that results in overt sexual behaviour. Savie et al. 2005: When straight women are given a whiff of a scent derived from men's sweat, their hypothalamus lights up in an area governing sexual arousal (m 445 c 430).

14. Genes & Sexual Orientation Mustanski & Bailey, 2003: Homosexuality does appear to run in families. Twin studies have also established that genes play a substantial role in explaining individual differences in sexual orientation (m 445 c 430). Perhaps the genes that dispose women to be strongly attracted to men and therefore have more children, also dispose some of their male relatives to be attracted to men. (Campero-Ciani, 2009 m 446 c 431) A shared prenatal environment and its attendant hormonal bath also contribute. Pregnant sheep were injected with testosterone during a critical period of foetal development, and their female offspring exhibited homosexual behavior. (Money, 1987 m446 c 431). Rahman et al., 2003: Fig. 33.3 Straight males tend to find 3d spacial orientation puzzles easier to solve than straight females, with gay man and lesbian women somewhere in between (m 448 c 433).