Finished the first part. It was interesting to learn about Perturbational Conscious Index (#PCI) or "zap and zip". This is a method of assessing the level of consciousness present by sending a magnetic pulse (#TMS) to an area of the brain and then recording the brain activity as the pulse spreads out. Then the algorithmic complexity of the measured activity is assessed with #LZW compression. Sort of like throwing a rock into a pond and looking at the waves it causes.
In a vegetative state, under anesthesia or in dreamless sleep there is almost no activity resulting from this while the results are very close to equal between a person in REM sleep or fully awake. The method also shows a lower measurement for someone in a minimally conscious state. Psychedelics tend to increase the activity even more compared to a normally functioning, fully awake …
Finished the first part. It was interesting to learn about Perturbational Conscious Index (#PCI) or "zap and zip". This is a method of assessing the level of consciousness present by sending a magnetic pulse (#TMS) to an area of the brain and then recording the brain activity as the pulse spreads out. Then the algorithmic complexity of the measured activity is assessed with #LZW compression. Sort of like throwing a rock into a pond and looking at the waves it causes.
In a vegetative state, under anesthesia or in dreamless sleep there is almost no activity resulting from this while the results are very close to equal between a person in REM sleep or fully awake. The method also shows a lower measurement for someone in a minimally conscious state. Psychedelics tend to increase the activity even more compared to a normally functioning, fully awake brain.
An alternative is to just record the brain activity over time but this is not as useful as PCI in one respect. According to Integrated information theory (#IIT), an important measure besides just the algorithmic complexity (amount of information) is the level of integration of information. PCI is able to measure this in some way while simply recording brain activity is not.