Lateralization of prefrontal activation during internal mental calculation
: a functional magnetic resonance imaging study.
BURBAUD, PIERRE, PHILIPPE DEGREZE, PHILIPPE LAFON, JEAN-MICHEL FRANCONI,
BERTRAND BOULIGAND, BERNARD BIOULAC, JEAN-MARIE CAILLE AND MICHELE ALLARD.
Service de Neuroradiologie, CHU de Bordeaux, + INSERM U.378,
Universit[acute]e de Bordeaux II ; Laboratoire de Neurophysiologie,
Universit[acute]e de Bordeaux II, CNRS URA 1200 ; Soci[acute]et[acute]e
SIEMENS S.A., Paris, France.
APStracts 2:0263N, 1995.
SUMMARY AND CONCLUSIONS
1. Functional magnetic resonance imaging (fMRI) at 1.5 T was used to
investigate the lateralization of prefrontal cortex activity during internal
mental calculation in 16 human volunteers (8 right-handed and 8 left-handed).
Subjects were asked to perform two different tasks : (1) a serial subtraction
of prime numbers and (2) a control task in which they mentally recited
numbers. 2. Signal modifications were regularly observed in the prefrontal
cortex (Brodmann's area 46) during the serial subtraction of prime numbers
whereas the number listing task poorly activated the same areas.
3. In right-handed subjects, activation was clearly lateralized in the left
dorso-lateral prefrontal cortex, whereas a frequent bilateral activation was
found in left-handed subjects. 4. We conclude that prefrontal activation
during mental calculation is lateralized in a manner similar to that reported
during linguistic tasks i.e. a clear lateralization in right-but not in left-
handed subjects.
Received 16 June 1995; accepted in final form 23 August 1995.
APS Manuscript Number J383-5.
Article publication pending J. Neurophysiol.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 23 September 1995.