Cortical volume and speed-of-processing are complementary in prediction of performance intelligence

The rationale for the present study was to investigate the relationship between cortical volume, the latency of the ERP component P3a (as a measure of speed-of-processing), and performance intelligence (not adjusted for age differences). Seventy-one participants aged 20-88 years underwent a visual 3-stimuli oddball ERP task, an MRI-scan, and intelligence testing. P3a latency and cortical volume shared 9% variance (p<.05 and="" both="" were="" significantly="" related="" to="" performance="" intelligence="" .40="" respectively="" the="" amount="" of="" explained="" variance="" increased="" r2=".51)" when="" measures="" used="" as="" simultaneous="" predictors.="" a="" path="" diagram="" was="" constructed="" including="" age="" an="" exogenous="" variable="" p3a="" latency="" cortical="" volume="" predicted="" but="" no="" longer="" one="" another.="" main="" conclusion="" from="" study="" is="" that="" speed="" size="" are="" complementary="" in="" prediction="" theoretical="" implications="" discussed.="">