Automatic and Intentional Number Processing Both Rely on Intact Right Parietal Cortex: A Combined fMRI and Neuronavigated TMS Study

Kadosh, Roi Cohen; Bien, Nina; Sack, Alexander T.

doi:10.3389/fnhum.2012.00002

Cited by 26 publications

(23 citation statements)

References 74 publications

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“…Our finding that the CDE had a significant hemodynamic signature in the right parietal cortex but not in the left parietal cortex is in line with some previous studies (Dehaene, 1996; Andres et al, 2005; Cohen Kadosh et al, 2012). For example, Dehaene (1996) found a right-lateralized parietal dominance for the CDE in an event-related potentials (ERPs) study.…”

Section: Discussionsupporting

confidence: 93%

Different Neural Mechanisms for the Comparison and Priming Distance Effects: An fMRI Study

et al. 2016

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Using functional magnetic resonance imaging, the present study examined whether the comparison distance effect (CDE) and the priming distance effect (PDE) in number processing had the same underlying neural mechanisms. 24 healthy participants completed a number comparison task and a number priming task in the scanner. Imaging data were examined for brain regions selected based on a meta-analysis of previous studies of number processing. Results revealed robust CDE and PDE at both behavioral and neural levels. The CDE had a significant hemodynamic signature in the right parietal cortex but not in the left parietal cortex, although a direct test of this hemispheric laterality did not reach statistical significance. In contrast, the PDE showed significant left-hemisphere laterality with a significant hemodynamic signature in the left parietal cortex but not in the right parietal cortex. These results suggested that the CDE and PDE had different underlying neural mechanisms.

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Section: Discussionsupporting

confidence: 93%

Different Neural Mechanisms for the Comparison and Priming Distance Effects: An fMRI Study

et al. 2016

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“…, which is commonly considered responsible for numerical representation (4,(39)(40)(41)(42)(43)(44)(45)(46)(47)(48)(49)(50)(51)(52)(53), using an established method of functional MRI (fMRI) adaptation for the study of numerosity perception (4). Neural tuning curve shift caused by connectivity in probes.…”

Section: Sulcus (Ips)mentioning

confidence: 99%

Topology-defined units in numerosity perception

Zhou

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

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What is a number? The number sense hypothesis suggests that numerosity is "a primary visual property" like color, contrast, or orientation. However, exactly what attribute of a stimulus is the primary visual property and determines numbers in the number sense? To verify the invariant nature of numerosity perception, we manipulated the numbers of items connected/enclosed in arbitrary and irregular forms while controlling for low-level features (e.g., orientation, color, and size). Subjects performed discrimination, estimation, and equality judgment tasks in a wide range of presentation durations and across small and large numbers. Results consistently show that connecting/ enclosing items led to robust numerosity underestimation, with the extent of underestimation increasing monotonically with the number of connected/enclosed items. In contrast, grouping based on color similarity had no effect on numerosity judgment. We propose that numbers or the primitive units counted in numerosity perception are influenced by topological invariants, such as connectivity and the inside/outside relationship. Beyond the behavioral measures, neural tuning curves to numerosity in the intraparietal sulcus were obtained using functional MRI adaptation, and the tuning curves showed that numbers represented in the intraparietal sulcus were strongly influenced by topology.W hat is a number? The answer to this age-old and fundamental question of philosophy has increasingly benefited from recent scientific investigation using psychology and neuroscience. The number sense hypothesis (1, 2) suggests that a number is "a basic property of the environment" (3) and particularly, because of its remarkable adaptation effect, "a primary visual property" (2), like color, contrast, or orientation (2-8). However, exactly what attribute in the environment is the primary property and determines numbers in the number sense, or more concretely, what is counted in numerosity perception? Consider the invariant nature of numerosity perception. It is self-evident that numerosity is invariant to specific features (e.g., orientation, size, shape, and color) of individual items to be counted. In other words, the primitive units to be counted must be invariant with variation in form dimensions and other visual features (2, 3, 7, 9-11). Then, the critical question becomes how to define precisely such abstract and invariant attributes. ResultsGeneralizing Connection to a Topological Invariant: Connectivity. We designed arbitrary and irregular shapes of connecting line segments (Fig. 1A, Upper) to test the invariant effect of connection on numerosity judgement independent of the concrete forms or manners of connection (12, 13). Three conditions of connection were constructed: zero, one, and two connected pairs of dots in the test patterns (Fig. 1A). A typical numerosity discrimination task was adopted, in which two visual patterns of dots were briefly presented on opposite sides of fixation (one serving as a reference and the other one serving as a test), and subj...

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“…The neurophysiological basis of density coding is not yet clear, but evidence from numerosity studies might provide some hints. Brain imaging studies in both human and monkey show that numerosity information is represented in parietal cortex and lateral prefrontal cortex (Cohen Kadosh, Bien, & Sack, 2012;Dormal, Andres, Dormal, & Pesenti, 2010;Harvey, Klein, Petridou, & Dumoulin, 2013;Nieder, 2012aNieder, , 2012bPiazza & Izard, 2009;Roitman, Brannon, & Platt, 2012;Santens, Roggeman, Fias, & Verguts, 2010;Tudusciuc & Nieder, 2009). Density processing might therefore also occur in these areas, given the close relationship between density and numerosity.…”

Section: Texture Density Versus Numerositymentioning

confidence: 99%

Simultaneous density contrast is bidirectional

2016

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Simultaneous density contrast, or SDC, is the phenomenon in which the perceived density of a textured region is altered by a surround of different density (Mackay, 1973). SDC provides an experimental tool to investigate mechanisms of density coding, yet has not been systematically examined. We measured SDC with a 2AFC staircase procedure in which human observers judged which of two patterns, one with and one without a surround, appeared more dense. We used a range of surround densities varying from very sparse to very dense (0-76.8 dots/deg2), and two center test densities (6.4 and 12.8 dots/deg2). Psychometric functions were used to estimate both the points of subjective equality (PSE) and their precision. Unexpectedly we find a bidirectional SDC effect across the five observers: Not only does a denser surround reduce perceived density of the center, but a sparser surround enhances its perceived density. We also show that SDC is not mediated by either contrast-contrast or spatial-frequency contrast. Our results suggest the presence of multiple channels selective for texture density, with lateral inhibitory interactions between them.

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Automatic and Intentional Number Processing Both Rely on Intact Right Parietal Cortex: A Combined fMRI and Neuronavigated TMS Study

Cited by 26 publications

References 74 publications

Different Neural Mechanisms for the Comparison and Priming Distance Effects: An fMRI Study

Different Neural Mechanisms for the Comparison and Priming Distance Effects: An fMRI Study

Topology-defined units in numerosity perception

Simultaneous density contrast is bidirectional

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