Each week the NZ Herald and Newstalk ZB's Cooking The Books podcast tackles a different money problem. Today, it's how shops get into your head, and how to fight back. Hosted by Frances Cook.

We're in the final throes of the season of excess, and New Zealanders like to go out with a bang. 

Right after receiving a bunch of presents for Christmas, many of us like to head out on Boxing Day and get even more stuff. 

It's traditionally the biggest shopping day of the year in New Zealand, and retailers like to step up to the occasion with big sales to make sure they're the ones who get the Christmas cash from your grandma's card. 

But once you're in the store, a weird thing can happen. 

The red discount signs and frenzy from shoppers around you can ruin even the best laid plans. 

You go in for a blender, and walk out with a TV, three pairs of shoes, and a coffee machine that you're sure you need. 

Not that I'm talking from experience or anything. 

For the latest Cooking the Books podcast I talked to AUT lecturer Sommer Kapitan. 

We talked about what those sales signs do to your brain, and how to fight back. For the interview, listen to the episode.