TV Ban

I need a scientific explanation of how a 4-year-old's brain works, especially regarding it's manifestive behaviour on weekend monrings.

Sienna needs to be waken up every morning during the week days. Yet, when it comes to the weekend morning, as if set by an alarm clock, she wakes up at 7:30 regardless how late she goes to bed the night before. A while back, we were trying not to tell her the weekend was coming up. It didn't work. She was looking forward to the weekend as much as I do.

Last night, in an attempt to break the pattern, we brought her to our bed to sleep. Again she woke up as usual and started wanting the TV. I told her that it was too early for TV. And I told her TV is only a treat, not something that she must have every day. Yesterday she didn't have TV for the whole day -- she didn't argue with my decision. Instead she started playing on a LeapFrog kind of thing that grandma bought her from China. It looks like we need to have a TV ban once in a while. This morning she did wake up late because she knew there was no TV waiting for her. I guess you really don't need science to raise a kid. Common sense is always the best approach.