Transcript for This Is Your Brain on a Shopping Spree
What's better for you sex or shopping? Don't laugh for many people there are similarities. We see what happens to your brain when you get your fast fashion fix. ? Finding a good deal makes me really happy. Reporter: What woman doesn't love to shop? What if we told you shopping can give you the same pleasure as sex. I love. This I want this dress. Reporter: Do I hear more shopping please? This is adorable. This is totally fun. Reporter: To find out how that is possible, we mounted a go pro on 30-year-old Alex Roberts. I'm excited to be shopping, to be honest. I haven't been to stores since last weekend. Reporter: To see what is going on in her brain as she hunts for her new spring palate. But more on that later. She is one of the millennials growing up where cheap chic is everywhere bringing a new generation of shopaholics. Take Maddie. It is to the pointed toe thing. Reporter: They are a few of the young self-made celebrities who are famous for literally bragging about their scores on you tube in a phenomenon known as haul videos. Racking up millions of views. Stores like H and M, forever 21 and ZARA have made shopping a euphoric, almost addictive experience for many, creating a multibillion dollar industry. On average, Americans buy more than one item of clothing each week. Take a peek in Alex's closet. You shop often. This is your sport? It is. Reporter: So you have tags on them? Yes, I do. Reporter: Buying as fast as you can wear it. Yeah. I feel so excited and pumped up when I do go shopping. Kind of like a drug. Reporter: So is shopping really like a drug? To find out, we followed Alex as she hit up her favorite stores. A new technology called facial tracking should tell us if Alex is experiencing a high-like euphoria while shopping. First stop, ZARA. I love this. This is amazing. It is 169, which isn't bad for a jacket. Reporter: Immediately Alex says she starts to feel like she has to have what she sees. I have been looking for these. Some camo pants. These are awesome. I'm probably going to have to get these. I have been looking for something like this for a year. So it might be my lucky day. Reporter: What is really happening in Alex's brain? According to analysis provided by the fashl tracking company nviso she is on a shopping high. Her eyes are wide and alert, mouth slightly open. These are signs the pleasure center in her brain is lighting up, which experts at the university of Michigan say is comparable to the joy felt after having sex. I just got a pair of camouflage jeans. Reporter: Do you did you feel when you spotted them? I was super excited. And then I was even more excited when I saw they were my size and the price. Reporter: So it was a triple whammy of excitement. It is like this is meant to be. The universe is just, you know. It's right now. I have to get these. A lot of emotions are unconscious and under the surface. Reporter: Scott Rick, a professor of marketing at the university of Michigan and his team of researchers took an even closer look, actually scanning shoppers' brains. We found the more evidence of pleasure were activation in regions that are targeted by dopamine, the more likely they were to buy the good. That is consistent with the notion, a similar brain region that underlies the craving for drugs, sex or friends. Reporter: They were surprised to learn something else. There's this pain that's associated with spending. To the best we can tell, there seems to be a tradeoff. Weighing of pleasure versus pain. Reporter: Yes, according to Rick, spending actually causes us stress. Was that the case for Alex? We turn back to our facial tracking experiment to find out. I definitely find some awesome pieces at forever. So inexpensive I don't look at price tags. I need a denim shirt. Reporter: She seems to be enjoying herself, but her brain is saying something else. Alex's tightening of the lip and scanning items indicates she's disappointed and feeling stress according to facial tracking experts. Thank you. Reporter: Alex scored three items under $90 at forever 21. Makes me feel happy. I feel like I got a good deal for three things. Reporter: The facial tracking shows a higher stress level. Saying she may have felt compelled to buy the clothes because they were so cheap but it goes way beyond just keeping prices low. Retailers use dozens of tricks to lure customers to buy more. Michelle madhok analyzes retail and marketing trends and knows these tactics all too well. These stores are set up to set off your brain in the pleasure center. They are hitting something in our human behavior that gets you to want to buy. We call it you are buying yourself happy. I'm in love with this but it is an extra small. There's lights, music, smells good. It is immersing yourself in the feel-good experience. This is at H and M. You can see they are using the pricing technique to draw you in. Instead of saying $10, it is $9.95 which makes it seem cheaper than it actually is. Uniqlo is their fashion. They are good at limited edition. These are limited edition outfits they are doing with artists right now. Andy Warhol, Keith herring. This is something fashion does to skraet a scarcity and mediascy to buy something. Reporter: Alex says learning the science behind her shopping habits won't deter her from getting that fashion fix. For "Nightline," I'm Mara schiavocampo in New York.
This transcript has been automatically generated and may not be 100% accurate.