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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 17 2012: I'm going with no only because 'sensing' is a biological function and no two humans are alike (not even identical twins), therefore we all sense things differently.

    Sure we can have some commonalities in the sensory department like, for example, I suppose we can assume that most of us can feel hot and cold on our skin (barring some medical issue that impedes this, of course) but just how sensitive we are to the cold or the heat can vary--hence we cannot ever fully 'sense' exactly how someone else does.
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      Feb 17 2012: I agree with what you say about how everyone is biologically different, but how different are we-- different enough that it would affect our perceptions? and even if we do perceive slightly differently, how would we know? I suggest that maybe the 'error' in the consistency of perception, that is, the differences in our perceptions, are dwarfed by the ambiguousness in how we communicate those perceptions. Basically what I'm trying to say is that the even if we do perceive differently, the differences are so small that they are undetectable or undiscoverable when we try to communicate what we perceive, and to see if we share our perception.
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        Feb 18 2012: hmm
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        Feb 18 2012: Fair enough, however your question was about sensory, not about perception; there is a difference. Sensory pertains to the biological responses to stimuli and perception is about our interpretation of that stimuli.

        So, based on your original question-I stand by my original answer.
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          Feb 18 2012: Hey Estela
          thanks for your comments and response. You're reply highlights a common idea that's been coming up in various ways during this conversation, which is that beyond strict sensory perception, going into the realm of interpreting those perceptions is very clearly subjective and very clearly different between any two people.

          When we talk about perception though, we are talking about the very basic sensory input-- perception is how humans process (not interpret!) stimuli in the environment-- perception is the immediate result of our senses working. So the question is even more nuanced than 'do we interpret the sensations that we perceive differently'-- it is 'do we even perceive sensations the same way?'
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        Feb 18 2012: It being a "function of the mind" does not make it different from a biological function but I see what you mean.

        I differentiate between sensory and perception of that sensory stimuli. See my comment above.
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        Feb 18 2012: Hey brigdet,
        initially iseemed to agree with your comment (probably because we both found points of argument in Estela's argument), but I have to disagree with one part of what you say-- and don't call mea language stickler!-- but I get wary when the discussion starts to involve the word 'interpretation'.

        You talked about the idea of the conscious mind as being the 'center point' in a way of the senses, which is to say that the mind senses stimuli even when the sensory organs (eyes, ears) can't sense. Correct me if that's not what you meant because I had a little trouble understanding what you were trying to say.

        But if this is what you meant, again i must disagree, because even in those without blindness, it is never 'the eyes that do the seeing'. The structures in the retina are basically different types of light filters and polarizers, so when the light gets to the very last set of cells of the retina (retinal ganglion cells), that filter light gets transformed into a nerve signal that then causes the brain to see what the eye filtered.

        So for people who have blindness but can sense, for example, when an object is thrown at them and then they can duck away ( a seemingly magical thing!), it means that some part of the retina in the eyes are still working, and able to send some information to a part of the brain to tell it to get out of the way-- albeit this is not the part of the brain that can take the signal from the retina and transform that into an image of what is in front of the eye. So in this way the physical eyes are doing the seeing-- its just that the pathways in the brain needed to create vision aren't being taken. The reason I make this clarification iss because I'd like to get away from the idea of consciousness (at least in this context) because it makes it seem that there are intentions/interpretations related to how and what we perceive, which is not the case. (of course interpretation comes in later after we've established to ourselves what
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        Feb 18 2012: were seeing and can then form an opinion on it...
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        Feb 18 2012: weve hit on a really interesting and really different question.

        it seems that it boils down to questions of what we perceive, and how we know that weve perceived them-- consciousness enters into the equation when we see ourselves perceiving.
        • Feb 19 2012: Hi, Sophie !

          As to my experience, any question about " out there " inevitably boils down to the question what is " in here" The old age , iconic question " Who am I ? "

          Maybe i will never know how another person ... and I don't have to; I am that "another" person ! :)
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      Feb 20 2012: I agree whit you!

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