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In-Depth Information
does it manage to do it?' And that 'How?' is
computational.(Boden, 2006, p. 1111)
and calculation (Dehaene, Piazza, Pinel, & Cohen,
2003). Data obtained with the fMRI (functional
magnetic resonance imaging that measures brain
activity by detecting related changes in blood flow)
show that the first structure (horizontal segment
of the intraparietal sulcus) is involved in number
manipulation independent of number notation;
the second one (left angular gyrus area) supports
verbal form of number manipulation, while the
third circuit (bilateral posterior superior parietal
system) supports attention aimed at the mental
and spatial number line.
COGNITION AND SOME OF THE
STRUCTURES OF THE BRAIN
Cerebral hemispheres function alone but with
different abilities. The anterior parts of the left
and right cerebral hemispheres control specific
features of thought, action, and memory. They
process information coming from visual fields
situated on the other side and control movement
of hands and fingers situated on the other side.
Human cognition is assumed to consist of separate
but interconnected verbal and imaginal systems
and the left-right perceptual asymmetries. Ver-
bal, visual, and spatial information is processed
separately: the left hemisphere shows a tendency
toward being dominant for language and speech,
controlling and categorizing information, while
the right hemisphere is better at visual motor tasks;
it is mostly responsive for motor functions in vi-
sion, responses to novel events, and expression of
emotional reactions. The separate processing of
verbal and visual information confirms that verbal
and imaginal symbols are coded independently,
with mental imagery as an important form of
nonverbal processing. It can be seen when cerebral
hemispheres are disconnected in the split-brain
operations. Split-brain research has advanced our
understanding of functional lateralization in the
brain (Gazzaniga, 1997, 2005). Specialization
of hemispheres is present in other than human
vertebrates such as fish, frogs, reptiles, birds, and
mammals; for example, a left hemisphere controls
feeding behavior, while attack and escape depend
on the right hemisphere (Vallortigara & Rogers,
2005). The authors pose that lateralization of func-
tions enhances cognitive capacity and efficiency
of the brain. Moreover, in the parietal region of
the brain that generally integrates sensory infor-
mation, three circuits control organization of the
number-related knowledge, quantity processing
METHODS AND TOOLS
FOR STUDYING NEURAL
STRUCTURES AND FUNCTIONS
Researchers study brain functions and their links
with structures; they also examine links between
brain functions in specified regions and cognitive
activities. Experimental methods include both
animal and human brains, with the use of several
approaches including the
postmortem
(after death)
examinations detecting brain anomalies or lesions
linked to diseases such as Alzheimer's disease (that
causes dementia and memory loss), Parkinson's
degenerative disease (causing movement disor-
der), or the memory and speech problems, and
in vivo
(on living organisms) studies focusing on
functioning of a living brain. Studies of electri-
cal activity of the brain include recordings of the
responses evoked by the electrical or other stimuli,
often involving single cells and their event-related
potentials. Several angiography (arteriograms and
venograms) techniques are aimed at visualizing the
blood vessels' interior, often with the use of cath-
eterization and radio-opaque substances. Results
are often correlated with the static and functional
techniques for imaging the neural structures. With
computing and analyzing electromagnetic changes
in energy of the subatomic particles contained in
the brain molecules researches get metabolic im-
aging, functional patterns, and information about
