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Wake Up and Smell the Caffeine. Psychology 2800. Introduction. The most popular psychoactive drug in North America How many people here DO NOT ingest caffeine?. Introduction. That includes: Coffee 130 mg Tea 40 mg Soft Drinks (colas) 30 – 90 mg Cold and Headache medications 15 – 50 mg
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Wake Up and Smell the Caffeine Psychology 2800 Caffeine
Introduction • The most popular psychoactive drug in North America • How many people here DO NOT ingest caffeine? Caffeine
Introduction • That includes: • Coffee 130 mg • Tea 40 mg • Soft Drinks (colas) 30 – 90 mg • Cold and Headache medications 15 – 50 mg • Rev ?, probably about 100 mg • Chocolate! 50 – 100 mg • Wake up pills 100 – 500 mg Caffeine
Introduction • Almost always taken orally, absorbed in small intestine. • Crosses all barriers • Absorbed more slowly from cold beverages • Less than 2% is excreted Caffeine
Metabolism • Half life is between 30 min and 3.5 hr • Metabolism slowed by birth control pills • Sped up by broccoli! • 2x faster in smokers Caffeine
Metabolism • That was with adults (well not kids anyway) • Different deal in kids and infants • 85% excreted • 4 DAY half life • Different pathways and metabolism than in adults • More similar to non-humans Caffeine
Neurophysiological Effects. • Like alcohol, we don’t know! • Might block adenosine • Neuromodulator that inhibits firing • So, caffeine disinhibits? • High doeses block benzodiazipine receptors Caffeine
Neurophysiological Effects • Might cause release of epinephrine • Causes smooth muscles to relax, striate muscles to contract • Decreases airway resistance • Good for asthma, colds • Constriction of blood vessels to the brain • Dilation other places Caffeine
Neuropshysiological Effects • Not sure if it helps performance • Does reduce drowsiness,boredom. • Increases FA levels, could be performance enhancing, especially for long athletic events. • Controlled substance. • Increases time in light sleep • Stages 1 and 2 • Can counteract barbiturates. Caffeine
Effects on Nonhumans • Small doses increase SMA • Large doses do the opposite • Increases FR responding • Affects timing • Increases suppressed behaviour. • Generalizes to coke, not to amphetamine. Caffeine
But, how does that first cup make you feel? • Humans are great at discriminating • 1.8 mg, about a sip of coffee!! • Caffeine makes us: • Energized • Focused • Motivated • Same in non users • All at low-moderate doses (20-200 mg) • About a cup of coffee. Caffeine
Could I ever use a coffee • Tolerance • Sustained use leads to more adenosine receptors • Whole deal changes if big dose given to non users. • Withdrawal • Headache • Flu like symptoms • Bad attitude in general • 100 mg a day, most all of us! Caffeine
Reinforcing Properties • Hard to get animals to self-administer • Will prime cocaine use • Lots of variation in us • Task demands • Caffeine experience. • Demand is relatively inelastic. • Late 1970s, 6 bucks a pound. Caffeine
Bad Stuff • Cancer? • Caffeinism • OD? • 30-80 cups of coffee • Reproduction • Chromosomal damage? • Toxicity • Cardiac effects? • Depends on method Caffeine