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Cognitive
Psychology PSY 504
VU
Lesson
04
COGNITIVE
NEUROPSYCHOLOGY (CONTINUED)
Cognitive
Neuropsychology describes cognition at
the hardware level to use
the computer
metaphor.
The neural architecture of
cognition is the basis on
which the edifice of the
software
level
is erected.
At
this level it is possible to
explain many visual and
auditory phenomena. Higher
level cognitions,
however,
remain a mystery.
The
Eye
The
following diagram of the Eye
describes its different
parts.
Visual
information passes through
the lens which helps
focus the image on the
retina. The
information
goes from the retina to
the optic nerve which
transmits it to the
brain.
Ibn-al-Haitham
The
following diagram gives us a
glimpse of contributions by Ibn-al-
Haitham, a great
Muslim
scientist,
who had not only
discovered the structure and
the function of the eye
but also how it
links
with the nervous
system.
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Cognitive
Psychology PSY 504
VU
Ibn-al-Haitham
had not only proposed
that the eyes transmit
the information to the brain
via the
optic
nerve but was also
aware of the different
visual fields in the eye
and had also proposed
a
dual
visual pathway system. Among
his other contributions was
the development of
spectacles
and
telescopes.
The
visual pathway
The
visual pathway can be simply
described as starting from
the retina where the
image is
formed
to the optic nerve. From
the Optic nerve the
information goes to the
optic chiasma where
the
visual information from the
two eyes is combined and
then moves on to the lateral
geniculate
nucleus.
The geniculate nucleus
processes information about
colors and details of the
image.
Another
visual pathway takes the
information about global
features such as localization
and
movement
to the superior
colliculus.
There
is by now considerable evidence
that there isn't one
but two different visual
pathways that
take
different features of an image to
different parts of the
brain.
The
Ear
The
following diagram shows
different parts of the
ear:
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Cognitive
Psychology PSY 504
VU
The
auditory information in the
ear comes in the form of
sound waves and impacts
the ear drum.
From
this the information is
transmitted via Cochlea to
the auditory nerve.
The
Auditory Pathway
The
auditory pathway is shown in
the following
diagram:
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Cognitive
Psychology PSY 504
VU
Sound
Localization
The
simple architecture of sound
localization information about
where the sound is coming
from
is described below. There
are delay detectors in the
nervous system. These delay
detectors are
connected
to each ear and process
information about which ear
got the information first
and
which
got it later. Depending on
the delay between the
ears it determines which
direction the
information
came from.
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Cognitive
Psychology PSY 504
VU
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