Motivation

• Motivation -- Purpose for or cause of an action:– Energizes behaviors, &– Directs that energy toward a goal

• Human behavior directed by physiological needs and psychological needs/wants– Hunger/thirst– Need for connection/contact/sex?– Need for stimulation/exploration?– Need to improve self? Or to live up to one’s potential?– Hedonic Principle: we are motivated to maximize pleasure

and minimize pain

Abraham Maslow’s theory

• Amidst the festivities of a grand party, a young guy notices a strikingly beautiful girl and is immediately smitten….

• He approaches her and begins to flirt boldly…. She tries to rebuff him but is flattered by his attention and finds him quite attractive…

Love in bloom

• By the time he departs the scene, with a kiss

followed by a second kiss, these two have

exchanged fewer than a hundred words; yet, both are

swooning with sensations of falling, desperately,

in love.

• All mental processes – thinking, planning, goals,

feelings, and motivations – have been suddenly

transformed….these brains have been completely

gripped by this brief encounter.

Romantic feelings kindle rapidly….

• In the hours after this meeting, these two can not stop thinking about each other

• The intensity of desire is so strong that each would happily forego food, sleep, comfort, and all competing pleasures, simply to be in each other’s presence again

Shakespeare (1595) was dramatizing one of the normal tensions of adolescence and development of sexual motivations.

Longing, obsession, and desire…

•GET READY, HERE COMES A GRAPHIC PICTURE OF YOUR SEX ORGAN!!!!!

•Energizing and directing arousal

•Interplay of internal and external stimuli

•Internal: Hormones, brain structures, neurotransmitters, imagined stimuli

•External: Environmental and sociocultural factors

Hormones and Sexual Motivation

•Dihydroepiandosterone (dhea) seems to be involved in initial onset of sexual desire•Both males and females produce testosterone and estrogen• Testosterone: involved in sex drive for both men and women •Estrogen: in female mammals, estrogen levels peak during ovulation, promoting sexual receptivity (but not a major factor in human females)

• Subcortical– Septal region -- Pleasurable response and orgasm– Hypothalamus -- Neuroendocrine and autonomic aspects of

sexual drive, sexual orientation

• Cortical – Frontal lobes -- Motor components of sexual behavior,

control of sexual response (disinhibition)– Parietal lobes -- Genital sensation– Temporal lobes: sexual drive (hypo/hypersexuality,

impotence)

– Baird et al., 2007 J of Neurology, Neurosurgery, and Psychiatry

Key brain regions mediating human sexual behavior

PlateauPlateau OrgasmOrgasm

ResolutionResolutionArousal - ExcitementArousal - Excitement

Desire PhaseDesire Phase

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Motivation for Eating

• As with sex, eating is an interplay of internal and external stimuli– Internal: Hormones, brain

structures, neurotransmitters, imagined stimuli

– External: Environmental and sociocultural factors

• Primary receiver of hunger signals is hypothalamus

Genetic influences on eating

• ob gene– Regulates production of leptin – Leptin is secreted by fat cells and has dual

activity of decreasing food intake and increasing metabolic rate

– Mice born without the ability to make leptin (ob/ob mice) eat without restraint

ob/ob mouse normal mice

ob/ob mouse

ob/ob mouse

ob/ob mouseinjected withleptin

So, just give obese humans leptin!

• In fact, this works in leptin-deficient humans, but…

• 99.99% of obese humans have HIGH levels of leptin, but have become insensitive to it.

• Something else is going on… (obesity trends powerpoint)

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Other kinds of motivation

• Extrinsic motivation

• Intrinsic motivation– extrinsic motivators can harm intrinsic

motivation

• Self-determination theory– Autonomy, competence, and relationship