Re: Object Constancy

From: Harnad, Stevan (
Date: Wed Apr 30 1997 - 19:42:23 BST

> From: Taylor, Karl <>
> > (16) Object Constancy is:
> >
> > A. *seeing something as the same whether near or far
> > B. seeing something as the same whether present or absent
> > C. seeing something as the same whether big or small
> > D. all of the above
> > E. none of the above
> I took C. to mean "seeing something as the same whether it's image on
> your retina is big or small" ie. a blow-up of a picture to A3 being the
> same as the original on A4, or whatever. It's a bit confusing. Why is
> C. wrong?

Because object constancy is about seeing something as the same THING
whether near or far, upside down or right-side up, rotated or unrotated,

Seeing a shape as the same shape whether bigger or small is not object
constancy (and actually we would not speak about it as a constancy at
all), because a big thing and a little thing, even if their shape is the
same, is not the same thing. They're only the same KIND or thing (or,
better, the same SHAPE, but not the same thing).

Here are two events that will cast exactly the same "shadow" on your
retina: (1) a faraway sphere, moving closer and closer; (2)
a small sphere, growing bigger and bigger. You would see the first thing
as being the same size, despite the growth of its shadow on your retina,
but you would see the second thing as growing (and that's not a

But because there were other parts of the chapter where we spoke about
shape invariance (which is not the same as object constancy), I did
mention that there are shape properties that are invariant under a
scaling transformation (one that makes them bigger or smaller, but the
same shape). I will scrap this question this time, but make sure you
know what object constancy is, and how it's not quite the same as shape

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