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 (R2=.26 and .40, respectively). The amount of explained variance increased significantly (to R2=.51) when both measures were used as simultaneous predictors. When a path diagram was constructed including age as an exogenous variable, P3a latency and cortical volume both significantly predicted performance intelligence, but were no longer related to one another. The main conclusion from the study is that speed and size are complementary in prediction of performance intelligence, and the theoretical implications are discussed.
Walhovd
Kristine B
KB
Institute of Psychology, University of Oslo, P.B. 1094, Blindern, 0317 Oslo, Norway. Kristine@walhovd.com
Fjell
Anders M
AM
Reinvang
Ivar
I
Lundervold
Arvid
A
Fischl
Bruce
B
Salat
David
D
Quinn
Brian T
BT
Makris
Nikos
N
Dale
Anders M
AM
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000033:anatomy & histology* / Q000502:physiology*; D004569:Electroencephalography / Q000379:methods; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D006801:Humans; D007360:Intelligence / Q000502:physiology*; D007361:Intelligence Tests; D008297:Male; D008875:Middle Aged; D008960:Models, Psychological; D009483:Neuropsychological Tests; D010775:Photic Stimulation / Q000379:methods; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology*; D014705:Verbal Behavior / Q000502:physiology