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Sophie Rand

Student Engineering, The Cooper Union For The Advancement of Science and Art


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Can we ever know how another person "senses" the world?

In my Bioelectricity class this week, we learned about the cells
in our body that help us sense our environment: chemosensors in our
tongue that help us sense taste, for example, the photoreceptors in
our eye that sense light, and the hair cells in our ears that sense
the mechanical vibrations of sound, to name a few.

As a result, I recently revisited my answer to the age-old question of
“how do I know that the blue I see is the same blue you see?” that was
so startling and exciting to most 3rd graders playing baby Kierkegaard
a little bit differently. An answer could be that we just have to
trust that perception is guided by biology and that humans are
biologically identical to within 80% of our biological systems.

This answer, of course, raises new questions: even if you and I may
perceive the same blue, is that blue "real?" Where does sensation
leave off and perception begin, and how may we trust ourselves as we
try to compare them? Can we ever know how another person "senses" the
world? Would love to hear your thoughts!


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    Feb 18 2012: What if it isn't important if two people perceive two things the same way, but rather that they perceive the difference between two things the same way?

    What I mean to say is that it isn't important if my shade of indigo looks the same as your shade of indigo - what is important, however, is that we both sense the same difference between indigo and blue, which is a product of the physical nature of those colors.

    Additionally, we may not even call two colors the same way, or we may split them up into different categories. Some cultures have only three commonly used color words in their language, whereas some have additional words for certain shades of colors. Even though one may be more sensitive to these difference in experiments, it has been shown empirically that all people are still able to tell the differences between two colors.

    Finally, I'd like to point out that there are many similarities between the mapping of outside sensory stimuli on regions of the brain across individuals. However, the brain exhibits a lot of plasticity, and many differences between people, so certainly there should exist variability among individuals. Until the regions directly implicated with perception are identified and studied, we may not know if these physical differences actually result in different perception.

    My point still remains, however: It is not the perception of point A and of point B that is the same between people; rather, it is the difference between point A and point B that we are all able to perceive similarly. Thus, it doesn't matter if we all see all colors differently because we still have the same perception of them relative to one another!

    Perhaps this logic can be extrapolated to all sensory systems.

    Any thoughts?
    I'm anticipating that color-blindness may be a counter-argument to my claim, but I don't know enough about its neurological basis to comment on it at the moment.

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