Question: I have been wondering if any of you know about dreams. How are they made, what makes them relate to our everyday lives and do they control us in our sleep. Is it to do with our brains and can it be dangerous?

Martha Havenith answered on 13 Jun 2015:

Hiya, this is my first go at an answer, I’ll have to read up on some stuff to give you a fuller answer! Anyways, here goes… Dreams are not dangerous (unless you happen to be a crazy and very unlucky sleep walker I suppose), and they are most definitely down to our brains. It looks like they are a pretty old habit of mammal brains; And one reason we have dreams seems to be that repeating patterns of neuron activity in our sleep makes us ‘learn’ them properly.
For example, when rats have learned to run a certain path through a maze to find food, you can record activity from their hippocampus (one of the main memory centres of the brain, see below), and you can see that the same neurons that were active while the rat was running through the maze are also active during their sleep. It’s really like a replay. The rats who have more of that replay at night remember the maze better the next day. Of course, we don’t know if dreams feel the same to animals as they do to us, but it seems that our dreams are really just a more complicated version of that kind of replay: We don’t just replay ‘places we have been’, but all sorts of experiences that are running around in our brain. That’s also why people say that you can interpret dreams – they may not be logical, but they do relate to stuff that’s ‘on your mind’.

PS – In case you want more details: The hippocampus is a structure in the middle of the brain and it connects to lots of other brain regions (for example the ones that mainly deal with seeing and hearing things). The hippocampus seems to help you form memories by activating neurons together that belong to the same experience (while I saw that person, I heard them say that and the room smelled like vanilla etc…), so that those neurons connect to each other more. That’s probably why we can see and hear things in dreams – the hippocampus replays an ‘experience pattern’, and activates all the neurons that are connected to that pattern.