When you’re not laying out the cold hard cash it seems there is a disconnect in the brain and people are unaware exactly how much they’re spending.

Dozens of studies have shown that consumers using credit cards rather than cash are less likely to remember how much they spent, take less time deciding what to buy, are more willing to pay high prices and make a greater number of purchases. They also exert less self-control, buying more junk food, luxury goods and other impulsive items.

Studies on debit cards and mobile payments show similar results. A recent neuroscience experiment found that spending with credit cards, rather than cash, activates the same reward centers of the brain that are triggered by cocaine and other addictive drugs. If spending cash hurts, perhaps using credit makes you high.

Wall Street Journal