Page 57 - Mind Games The Aging Brain and How to Keep it Healthy

The Intelligent Mind • 41

hemisphere. (A lot of readers would simply like to know
where the average mathematical skills are based!)
The only available information regarding the location of
mathematical abilities is from observation of those individu-
als who have suffered damage to the brain through an acci-
dent or stroke, or who required surgery. Gerstmann Syndrome
is the designation for damage to the left parietal lobes and
the temporal and occipital association areas adjoining them
(part of the angular gyrus). Damage to these areas reduces
the ability to orient oneself in space, understand certain
grammatical structures (such as prepositional phrases and
passive constructions), tell left from right, and perform nu-
merical calculations. It also creates difficulty in drawing. The
syndrome is characterized by damaging effects to the associ-
ation cortexes in the posterior areas of the dominant hemi-
sphere—those associated with recognizing ordered arrays
and patterns visually (see Figure 2-10).
Deficits in calculation abilities can be grouped into three
main categories:
1. Alexic and agraphic acalculia—difficulty in reading and
writing numbers
2. Spatial acalculia—difficulty in dealing with the spatial
organization of written numbers
3. Anarithmetria—difficulty with the calculation itself

The first two types of deficits (difficulty in visualizing
numbers) are linked to the visual system and/or associative
memory areas. Damage to the posterior portion of the left
hemisphere, near Wernicke’s area, results in the calculation
disability.
Essential to the logical-mathematical ability, the frontal
lobes play an important part in organization skills. The ability
to plan a strategy to achieve a specific goal is housed in this
area. Damage to the frontal lobes leaves an individual with not
only an inability to plan a problem-solving strategy but also the
inability to set goals and follow through in everyday life.