Imaginary Phantom Limb and Our Delicate Grip on Reality

The brain can be a freaky thing. We live in this illusion of reality created for us by our brains. This is not to say there is no objective external physical reality - there is as far as anyone can tell - but our experience of ourselves and the world is a neurologically generated illusion.

The brain processes sensory information so that it is a useful, and not necessarily accurate, depiction of the world. This sensory input is also highly selective, giving us that slice of reality that proved to be most evolutionarily adaptive. That part of our brain that pays attention then attends to a tiny slice of that highly processed selective sensory information and mostly ignores the rest.

This neurogenic cacophony of data and information processing are woven together into a seamless narrative we experience as our waking consciousness. It is a useful and adaptive approximation of reality - but it is not reality.

I think those words need rereading and digesting. We don't really know what's going on most of the time.

The bulk of the article is about one particular phenomenon that happens when this neurologically manufactured reality breaks down - supernumerary phantom limb. It is one of several types of disordered that have been described after a stroke leading to neglect of the paralysed limb - the lack of recognition the limb. These can include simple lack of recognition that the weak limb belongs to them, the belief that the limb belongs to someone else, or the false belief that the limb is normal and functional.

One striking example of how internalist is our world view comes from the claim that someone scratching an itch with their phantom limb actually relieves that itch! Great article, and worth being reminded of how tenuous our grip on reality really is. The concluding paragraph sums up how this leads to a serious problem when discussing so-called religious, or just plain weird, experiences.

Further, this means that when people have bizarre experiences that are far outside what they are used to, especially when they involve features that are now known to be neurological, it must first be considered that their experiences result from altered brain states - not external reality. However, we seem to have evolved to make the opposite assumption - that whatever we experience is real. This disconnect is one of the primary fuels for belief in the paranormal.

Complete article at Neurologica.