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After our discussions in class this week I have been pondering the concept of motion sickness, so I decided to do a little research. The best information that I could find matches what we had mentioned in class, with just a few extra details. It appears that the exact nature of motion sickness is not entirely known, but that it seems to arise from a mismatch of various sensory perceptions in the nervous system, including visual sensations, sense of balance in inner ear, and sense of movement in proprioreceptors. In cases of car-sickness, sea-sickness, and related forms, the failure of complete communication between the three of these sensory mechanisms generates confusion in the nervous system, and thus results in what we know as motion sickness.

I continued to explore the various ways in which motion sickness might be further complicated. For example, are blind people more susceptible to motion sickness because they lack the extra visual sensory input to communicate the perception of movement (or lack thereof) to the brain? According to my research, there is no significant increase in the occurrence of motion sickness in those who are blind from birth compared to those with sight, as their sensory mechanisms have adapted to compromised sensory loss...But what about those who become blind later in life? Can they adapt too...or are they forever afflicted?

Additionally, I was wondering about the role of the I-function in motion sickness. I have heard many cases of passengers in planes, cars, and boats who develop motion sickness...but why do I not hear stories of motion sickness on stationary exercise bikes, ellipticals, and treadmills? While I am sure that this occurs to a certain extent, it appears that the sense of sickness decreases if the activity becomes less passive. I can admit that if I am a passenger in a car and I am trying to read, I will feel eventually feel nauseated. However, I can run in place on a treadmill, watch a stationary televison, and feel just fine. The high demand for televisions in the Bryn Mawr gym seems to suggest that my experiences are shared. So, is it possible that one who is actively engaged in manipulating sensory his/her own sensory inputs (visual, inner ear, prorioreceptors) has increased resistance to confusions within the nervous system? And on a slight tangent...if we often perceive ourselves as 'moving' in our dreams, why do we not wake up feeling ill? Might the I-function be responsible in either or both of these situations? I am not sure of the answer...