An FMRI study of number processing in children with fetal alcohol syndrome.
BACKGROUND
Number processing deficits are frequently seen in children exposed to alcohol in utero.


METHODS
Functional magnetic resonance imaging was used to examine the neural correlates of number processing in 15 right-handed, 8- to 12-year-old children diagnosed with fetal alcohol syndrome (FAS) or partial FAS (PFAS) and 18 right-handed, age- and gender-matched controls from the Cape Coloured (mixed ancestry) community in Cape Town, South Africa, using Proximity Judgment and Exact Addition tasks.


RESULTS
Control children activated the expected fronto-parietal network during both tasks, including the anterior horizontal intraparietal sulcus (HIPS), left posterior HIPS, left precentral sulcus, and posterior medial frontal cortex. By contrast, on the Proximity Judgment task, the exposed children recruited additional parietal pathways involving the right and left angular gyrus and posterior cingulate/precuneus, which may entail verbally mediated recitation of numbers and/or subtraction to assess relative numerical distances. During Exact Addition, the exposed children exhibited more diffuse and widespread activations, including the cerebellar vermis and cortex, which have been found to be activated in adults engaged in particularly challenging number processing problems.


CONCLUSIONS
The data suggest that, whereas control children rely primarily on the fronto-parietal network identified in previous studies to mediate number processing, children with FAS/PFAS recruit a broader range of brain regions to perform these relatively simple number processing tasks. Our results are consistent with structural neuroimaging findings indicating that the parietal lobe is relatively more affected by prenatal alcohol exposure and provide the first evidence for brain activation abnormalities during number processing in children with FAS/PFAS, effects that persist even after controlling statistically for group differences in total intracranial volume and IQ.
Meintjes
Ernesta M
EM
MRC/UCT Medical Imaging Research Unit, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa. ernesta.meintjes@uct.ac.za
Jacobson
Joseph L
JL
Molteno
Christopher D
CD
Gatenby
J Christopher
JC
Warton
Christopher
C
Cannistraci
Christopher J
CJ
Hoyme
H Eugene
HE
Robinson
Luther K
LK
Khaole
Nathaniel
N
Gore
John C
JC
Jacobson
Sandra W
SW
D001921:Brain / Q000502:physiology; D001931:Brain Mapping / Q000379:methods; D002648:Child; D015331:Cohort Studies; D005260:Female; D063647:Fetal Alcohol Spectrum Disorders / Q000453:epidemiology / Q000503:physiopathology / Q000523:psychology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D055641:Mathematical Concepts; D008606:Mental Processes / Q000502:physiology; D011247:Pregnancy; D011597:Psychomotor Performance / Q000502:physiology; D013019:South Africa / Q000453:epidemiology