PSYB57H3 Chapter Notes - Chapter 3: Necker Cube, Outline Of Object Recognition, Ventriloquism
Chapter 3: Recognizing Objects
Form Perception: processes that tell us the shape, size and position of objects in front of us
•Vision is the dominant sense in humans; so much brain area is used for vision and we place
our trust in what we see.
•Ventriloquism: we see dummy’s mouth moving while sounds are coming from dummy’s master
•How do you manage to perceive, and then recognize, the objects you see everyday? This is
the problem of form perception: process through which you manage to see the basic shape
and size of an object
•Problem of object recognition: proess through which you identify what the object is
•Object recognition is essential whenever you want to apply your knowledge to the world, and
for learning
•The process of object recognition begins with the detection of simple visual features, but
there’s more to the process
•Gestalt psychologists early in the 20th century noted that our perception of the visual world is
organized in ways that the stimulus is not; the organization must be contributed by the
perceiver and this is why the perceptual whole is often different from the sum of its parts
•Necker Cube: a reversible figure; can be thought to be seen from above or from below
•Figure/ground organization: determination of what is the figure (the depicted object,
displayed against a background) and what is the ground
•All these figures flipping from one perception to another show that information that’s reaching
your eyes is constant. You organize and interpret the image and it changes.
•Your perception goes “beyond the information given”, you most likely think of similar looking
object(s) blocked halfway by another to be the same object, even though it is not guaranteed
•Your perception is guided by proximity and similarity. Closer-together objects are thought to be
parts of the same objects, as with objects that resemble one another. You assume contours to
be smooth, and avoid interpretation that involves coincidences. (An X shape is thought to be
an X rather than two V’s)
•Our interpretation sometimes seems to happen before we start cataloguing inputs basic
features sometimes, not after. So, it is not true that we first collect information about the
stimulus and then interpret it.
•People easily “supply” missing features, emphasizing that the analysis of features depends on
how the overall figure has been interpreted and organized
Object Recognition
•Bottom-up influences: influences coming directly from the stimulus itself; the features that
are in view
•Top-down influences: relying on your own knowledge; going beyond the information given
•Recognition might begin with the identification of visual features in the input pattern: the
vertical lines, curves, diagonals, and so on
•Specialized cells in the visual system do seem to act as “feature detectors”
