The Journal of Neuroscience, August 15, 2007, 27(33):8952-8956; doi:10.1523/JNEUROSCI.2076-07.2007
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Brief Communications
Processing of Abstract Ordinal Knowledge in the Horizontal Segment of the Intraparietal Sulcus
Wim Fias,1,2
Jan Lammertyn,1
Bernie Caessens,1 and
Guy A. Orban3
1Department of Experimental Psychology and 2Ghent Institute for Functional and Metabolic Imaging, Ghent University, 9000 Gent, Belgium, and 3Laboratorium voor Neuro- en Psychofysiologie, Medical School, Katholieke Universiteit Leuven, 3000 Leuven, Belgium
Correspondence should be addressed to Wim Fias, Department of Experimental Psychology, Ghent University, H. Dunantlaan 2, 9000 Gent, Belgium. Email: wim.fias{at}ugent.be
The anterior intraparietal sulcus, and more specifically its horizontal segment (hIPS), is known to play a crucial role in the cognitive representation of numerical quantity. Whether the involvement of hIPS is restricted to the processing of numerical information or generalizes to non-numerical ordinal dimensions remains an open question. Using functional magnetic resonance imaging during comparison tasks, we demonstrate that the hIPS is equally responsive to numbers and letters, indicating that hIPS is also involved in the representation and processing of non-numerical ordinal series. This extends the numerical processing function of IPS into the realm of abstract knowledge processing.
Key words: fMRI; parietal cortex; anterior intraparietal sulcus; ordinality; number processing; abstract cognition
Received May 7, 2007;
revised June 21, 2007;
accepted July 5, 2007.
Correspondence should be addressed to Wim Fias, Department of Experimental Psychology, Ghent University, H. Dunantlaan 2, 9000 Gent, Belgium. Email: wim.fias{at}ugent.be