Early warnings of a change of state

It’s been wonderful watching Benjamin grow in the last nine and a bit weeks. He’s now become fully interactive – he’ll respond to what we do and what’s going on around him. hearing him ‘talk’ is fun – he can come out with an excited string of goos and gahs when he’s happy. 

Naturally, though, there’s still only a relatively small range of behaviours he exhibits.  Sleeping, feeding, squarking, gazing carefully at something, or goo-ing happily is pretty well the extent of it still. These behaviours are mutually exclusive – he’s only ever in one at a time, and transitions between them many times a day. To be one step ahead of him, we need to pick up the signs of a change of state.

In physics, there’s several ways that can be done. For example, at a first-order phase transition (e.g. water turning to ice) there’s several hallmarks that a change of state is imminent. In particular, the natural variations in the system begin to grow – they get longer and larger. One can measure these to determine just how close to transition a system is. Also, the susceptibility to an external stimulus gets greater – poke the system somehow and its response is larger than if it were further from transition (it is more ‘irritable’). We do this kind of thing with our brain modelling – e.g. look at the transition from deep sleep into REM (rapid-eye-movement) sleep – there are indications that can be picked up through electrical recording from the scalp (the electroencephalogram or EEG) that a state change might be imminent.

 I wonder if we see similar things with baby. For example, as he transitions from squarking to sleeping, the noise he makes does seem to fluctuate more – with loud periods and quiet periods, before ceasing altogether. Of course, anecdote isn’t data, and we certainly haven’t done a scientific analysis of this, but I wonder if it is the case. I certainly think we are better at anticipating what he’s about to do – so maybe there are subtle signs that we’re picking up.

Which brings me to the cat.  He too has only a few modes of behaviour – eating, sleeping, washing, gazing out of the window, being an adorable cuddly purring kitty and then being completely loopy (in this last case you don’t want your arm anywhere near him).  Unfortunately, as is the way with most cats, the transition between these last two states can be very quick indeed. The warm, cuddly, purring moggie can turn into a viscous arm-shredding machine in a couple of seconds. Is there warning? Maybe a couple of tail twitches and a short pause in the purring. One needs to be very clued into phase-transition theory to pick these up.


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