Article

Representation of Number in the Brain

Department of Animal Physiology, University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany.
Annual Review of Neuroscience (Impact Factor: 19.32). 04/2009; 32(1):185-208. DOI: 10.1146/annurev.neuro.051508.135550
Source: PubMed

ABSTRACT

Number symbols have allowed humans to develop superior mathematical skills that are a hallmark of technologically advanced cultures. Findings in animal cognition, developmental psychology, and anthropology indicate that these numerical skills are rooted in nonlinguistic biological primitives. Recent studies in human and nonhuman primates using a broad range of methodologies provide evidence that numerical information is represented and processed by regions of the prefrontal and posterior parietal lobes, with the intraparietal sulcus as a key node for the representation of the semantic aspect of numerical quantity.

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    • "The psychophysical functions that link numbers to subjects' estimates of numerical magnitude are both theoretically and practically important. Of theoretical interest, functions generating young children's numerical magnitude estimates have been observed in non-symbolic number discrimination of a wide range of species (for review, see Nieder and Dehaene, 2009), to change abruptly with limited experience (Opfer & Siegler, 2007; Izard & Dehaene, 2008), and to closely track abilities to deal with numbers in other contexts (Booth & Siegler, 2006; Thompson & Siegler, 2010). Thus, just as animals can better discriminate 1 and 10 objects than 101 and 110 objects, so too do children estimate magnitudes of symbols 1 and 10 to differ more than 101 and 110. "
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    • "However, if the same neurons indeed encode both 144 numerosity and motion direction, then motion direction should affect numerosity perception 145 also in the absence of adaptation. Experiment 3 (Fig. 2d) showed that the interaction between 146 motion direction and numerosity perception was also evident when subjects directly judged the 147 numerosity of coherently moving dots, without a preceding adaptation phase: Rightward 148 motion led to an overestimation of numerosity (a leftward shift of theprocessing is in the intraparietal sulcus (IPS), specifically in areas LIP and VIP (Nieder and 176Dehaene, 2009). Comparing our psychophysical results to the known numerosity tuning 177 functions of these two areas gives a first indication of where and how this cross-adaptation 178 effect may come about (Fig. 3): Because we were able to exert an adaption effect despite afiring rate with the number of items in a display (Roitman et al., 2007) and are also sensitive to motion direction (Fanini and Assad, 2009). "
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    • "Neurological and neuropsychological clinical reports frequently mention acalculia, but specific analyses of acalculia are rather limited. Calculation ability represents an extremely complex cognitive process, which requires multifactorial processes, including verbal, spatial, memory, and executive functions [1] [2]. According to Ardila, Rosselli (2002) aphasia is an impairment of language, affecting the production or comprehension of speech and the ability to read or write. "

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