Sunday, June 10, 2007

Kinaesthetic sensations

The philosophy of perception has very little to say about kinaesthetic sensations. These sensations tell us about the inertial forces and spatial motion of our bodies. The semicircular canals within the inner ear function as a set of accelerometers in three perpendicular planes. Each canal detects angular acceleration about an axis perpendicular to the plane of the canal. Whilst the semicircular canals detect rotational acceleration, linear acceleration is detected by adjacent organs within the inner ear, called the otoliths. These are small particles of calcium carbonate, suspended in space, which move and deflect sensitive hair cells when we undergo a linear acceleration.

So we know when we're undergoing a linear or rotational acceleration, and we also know our orientation relative to the gravitational field of the Earth: we know when we're upright, or lying horizontal, or hanging upside-down. These kinaesthetic sensations surely have implications for any philosophical claim that space is a merely a geometrical mental construct, rather than something which objectively exists, and defines inertial forces.


Anonymous said...

I tend to think increasingly that nearly everything is a mental construct.
But to be scientific,surely as we have evolved on a planet with gravity, we have evolved with the appropriate sensory devices for coping with gravity, even if it is a shared mental construct

Andrew said...

I'm not sure why the dispute over the existence of space. However the nature of reality and its intrinsic links to consciousness don't seem to be contradicted by the existence of 'external reality.' Physical reality requires consciousness within which to exist- take away the consciousness & you take away everything else.