Isolated Acalculia due to Left Parietal Lesion

Takayama, Yoshihiro; Sugishita, Morihiro; Akiguchi, I; Kimura, Jun

doi:10.1001/archneur.1994.00540150084021

Cited by 112 publications

(68 citation statements)

References 15 publications

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“…The lesions that cause acalculia of the Gerstmann's type are typically centred in the depth of the left intraparietal sulcus (Mayer, Martory, Pegna, Landis, Delavelle, & Annoni, 1999;Takayama, Sugishita, Akiguchi, & Kimura, 1994). This is compatible with the above brain-imaging results showing intraparietal activation during various numerical manipulation tasks independently of language.…”

Section: Neuropsychological Evidencesupporting

confidence: 87%

Three Parietal Circuits for Number Processing

Dehaene

Piazza

Pinel

et al. 2003

Cognitive Neuropsychology

2,157

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Did evolution endow the human brain with a predisposition to represent and acquire knowledge about numbers? Although the parietal lobe has been suggested as a potential substrate for a domain-specific representation of quantities, it is also engaged in verbal, spatial, and attentional functions that may contribute to calculation. To clarify the organisation of number-related processes in the parietal lobe, we examine the three-dimensional intersection of fMRI activations during various numerical tasks, and also review the corresponding neuropsychological evidence. On this basis, we propose a tentative tripartite organisation. The horizontal segment of the intraparietal sulcus (HIPS) appears as a plausible candidate for domain specificity: It is systematically activated whenever numbers are manipulated, independently of number notation, and with increasing activation as the task puts greater emphasis on quantity processing. Depending on task demands, we speculate that this core quantity system, analogous to an internal "number line," can be supplemented by two other circuits. A left angular gyrus area, in connection with other left-hemispheric perisylvian areas, supports the manipulation of numbers in verbal form. Finally, a bilateral posterior superior parietal system supports attentional orientation on the mental number line, just like on any other spatial dimension.

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Section: Neuropsychological Evidencesupporting

confidence: 87%

Three Parietal Circuits for Number Processing

Dehaene

Piazza

Pinel

et al. 2003

Cognitive Neuropsychology

2,157

208

2,149

View full text Add to dashboard Cite

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“…The left posterior parietal cortex is important for arithmetical processing (Ingvar et al, 1997) and lesions here are known to invoke acalculia (Henschen, 1919;Takayama et al, 1994). Its function has also been related to the phonological component of working memory (Baddeley, 1991;Paulesu et al, 1993;Petrides et al, 1993;Smith et al, 1996;Zatorre et al, 1992).…”

Section: Discussionmentioning

confidence: 97%

Coexistence of Attention-Based Facilitation and Inhibition in the Human Cortex

et al. 1998

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A key function of attention is to select an appropriate subset of available information by facilitation of attended processes and/or inhibition of irrelevant processing. Functional imaging studies, using positron emission tomography, have during different experimental tasks revealed decreased neuronal activity in areas that process input from unattended sensory modalities. It has been hypothesized that these decreases reflect a selective inhibitory modulation of nonrelevant cortical processing. In this study we addressed this question using a continuous arithmetical task with and without concomitant disturbing auditory input (task-irrelevant speech). During the arithmetical task, irrelevant speech did not affect task-performance but yielded decreased activity in the auditory and midcingulate cortices and increased activity in the left posterior parietal cortex. This pattern of modulation is consistent with a top down inhibitory modulation of a nonattended input to the auditory cortex and a coexisting, attention-based facilitation of taskrelevant processing in higher order cortices. These findings suggest that task-related decreases in cortical activity may be of functional importance in the understanding of both attentional mechanisms and taskrelated information processing. Academic Press

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“…First, patients with parietal lesions consistently show selective impairments in numerical skills (e.g., Dehaene and Cohen, 1997;Denes and Signorini, 2001;Grafman et al, 1982;Takayama et al, 1994;Warrington, 1982;Zorzi et al, 2002), whereas patients with lesions to other brain regions showed preservation of numerical skills (e.g., Butterworth et al, 2001;Cappelletti et al, 2001Cappelletti et al, , 2002Cappelletti et al, , 2005Crutch and Warrington, 2002;Diesfeldt, 1993;Jefferies et al, 2004Jefferies et al, , 2005Lemer et al, 2003;Zamarian et al, 2006). Second, functional MRI studies have systematically shown that numerical processing elicits greater activation in the parietal lobule than does nonnumerical processing (e.g., Ansari et al, 2006;Cappelletti et al, 2010;Eger et al, 2003;Knops et al, 2006;Le Clec'H et al, 2000;Piazza et al, 2004;Thioux et al, 2005;Zago et al, 2008; but see Göbel et al, 2004;Kadosh et al, 2008;Shuman and Kanwisher, 2004).…”

Section: Introductionmentioning

confidence: 99%

Neural correlates of numbers and mathematical terms

2012

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Numerical processing has been demonstrated to be subserved typically by the brain regions around the bilateral intraparietal sulcus (IPS). The goal of the current study was to investigate whether the processing of mathematical terms shared the same brain regions with numerical processing. Healthy adult participants performed semantic distance judgment tasks on five types of materials, including geometric terms, algebraic terms, linguistic terms, words for tools and other common objects, and Arabic numbers. Brain activation was measured with functional magnetic resonance imaging (fMRI). The results showed that geometric terms had greater activation than algebraic terms, linguistic terms and tool words in the horizontal IPS, but algebraic terms did not have greater activation than linguistic terms and tool words in this region. Arabic numbers showed greater activation than non-number materials (including geometric terms, algebraic terms, linguistic terms and tool words) in the bilateral IPS, right inferior frontal gyrus and bilateral middle frontal gyrus, but the non-number materials showed stronger activation in the left inferior frontal gyrus and left middle temporal gyrus. These results suggest that the brain area for the processing of numbers (the left IPS) seems to be involved in semantic processing of geometric terms, but not that of other mathematical terms such as algebraic terms. Both algebraic and geometric terms share similar brain organization with basic semantic processing in the left temporal and frontal regions.

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Isolated Acalculia due to Left Parietal Lesion

Cited by 112 publications

References 15 publications

Three Parietal Circuits for Number Processing

Three Parietal Circuits for Number Processing

Coexistence of Attention-Based Facilitation and Inhibition in the Human Cortex

Neural correlates of numbers and mathematical terms

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