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Dissociation of exact and approximate calculation in severe global aphasia.

Urano M, Yoshino M, Yamamoto M, Mimura M - Open Neurol J (2009)

Bottom Line: Further analyses using specifically designed arithmetic and clock tasks demonstrated a clear dissociation of the patient's abilities between impaired exact calculation and well-preserved approximate calculation.The results support the notion that numerical and arithmetic abilities are heterogeneous in that rote verbal arithmetic facts and quantitative numerical knowledge can be separable.Implications of the present findings for neural correlates of numerical and arithmetic processing suggest that the right hemisphere plays a crucial role in approximate calculation.

View Article: PubMed Central - PubMed

Affiliation: 1Department of Rehabilitation Medicine, Yokohama Stroke and Brain Center, Kanagawa, Japan.

ABSTRACT
We report a 68-year-old patient with severe global aphasia secondary to a large left hemisphere infarction including the parietal lobe. In addition to language and neuroradiological evaluation, the patient was given specifically designed arithmetic and clock tasks requiring either exact calculation or approximate calculation. Despite severe language impairment, the patient showed relatively well-preserved abilities for numerical comprehension and arithmetic operations. Further analyses using specifically designed arithmetic and clock tasks demonstrated a clear dissociation of the patient's abilities between impaired exact calculation and well-preserved approximate calculation. The results support the notion that numerical and arithmetic abilities are heterogeneous in that rote verbal arithmetic facts and quantitative numerical knowledge can be separable. Implications of the present findings for neural correlates of numerical and arithmetic processing suggest that the right hemisphere plays a crucial role in approximate calculation.

No MeSH data available.


Related in: MedlinePlus

Single-photon emission computed tomography demonstrated hypoperfusion specially corresponding to the lesion shown by magnetic resonance imaging.
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Figure 2: Single-photon emission computed tomography demonstrated hypoperfusion specially corresponding to the lesion shown by magnetic resonance imaging.

Mentions: T2-weighted magnetic resonance imaging (MRI) on March 21, 20xx+1 demonstrated a large area of high signal intensity including almost all of the left middle cerebral artery territory (Fig. 1). At the same time point, 99mTc-ECD single-photon emission computed tomography (SPECT) demonstrated significant hypoperfusion of the entire left hemisphere (Fig. 2).


Dissociation of exact and approximate calculation in severe global aphasia.

Urano M, Yoshino M, Yamamoto M, Mimura M - Open Neurol J (2009)

Single-photon emission computed tomography demonstrated hypoperfusion specially corresponding to the lesion shown by magnetic resonance imaging.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2682839&req=5

Figure 2: Single-photon emission computed tomography demonstrated hypoperfusion specially corresponding to the lesion shown by magnetic resonance imaging.
Mentions: T2-weighted magnetic resonance imaging (MRI) on March 21, 20xx+1 demonstrated a large area of high signal intensity including almost all of the left middle cerebral artery territory (Fig. 1). At the same time point, 99mTc-ECD single-photon emission computed tomography (SPECT) demonstrated significant hypoperfusion of the entire left hemisphere (Fig. 2).

Bottom Line: Further analyses using specifically designed arithmetic and clock tasks demonstrated a clear dissociation of the patient's abilities between impaired exact calculation and well-preserved approximate calculation.The results support the notion that numerical and arithmetic abilities are heterogeneous in that rote verbal arithmetic facts and quantitative numerical knowledge can be separable.Implications of the present findings for neural correlates of numerical and arithmetic processing suggest that the right hemisphere plays a crucial role in approximate calculation.

View Article: PubMed Central - PubMed

Affiliation: 1Department of Rehabilitation Medicine, Yokohama Stroke and Brain Center, Kanagawa, Japan.

ABSTRACT
We report a 68-year-old patient with severe global aphasia secondary to a large left hemisphere infarction including the parietal lobe. In addition to language and neuroradiological evaluation, the patient was given specifically designed arithmetic and clock tasks requiring either exact calculation or approximate calculation. Despite severe language impairment, the patient showed relatively well-preserved abilities for numerical comprehension and arithmetic operations. Further analyses using specifically designed arithmetic and clock tasks demonstrated a clear dissociation of the patient's abilities between impaired exact calculation and well-preserved approximate calculation. The results support the notion that numerical and arithmetic abilities are heterogeneous in that rote verbal arithmetic facts and quantitative numerical knowledge can be separable. Implications of the present findings for neural correlates of numerical and arithmetic processing suggest that the right hemisphere plays a crucial role in approximate calculation.

No MeSH data available.


Related in: MedlinePlus