Try this online mind bender, brain teaser!
Free will or synaptic wiring? You be the judge. Check out the following exercise, guaranteed to freak you out. There's no trick or surprise. Just follow these instructions, and answer the questions one at a time and as quickly as you can! Again, as quickly as you can but don't advance until you've done each of them... really. Now, arrow down (but not too fast, you might miss something).......
Now repeat/say the number 6 to yourself as fast as you can for 15 seconds. Then scroll down.