title: Cortical volume and speed-of-processing are complementary in prediction of performance intelligence.
abstract: 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.
authors.affiliation: Institute of Psychology, University of Oslo, P.B. 1094, Blindern, 0317 Oslo, Norway. Kristine@walhovd.com
authors.forename: Kristine B
authors.initials: KB
authors.lastname: Walhovd
authors.forename: Anders M
authors.initials: AM
authors.lastname: Fjell
authors.forename: Ivar
authors.initials: I
authors.lastname: Reinvang
authors.forename: Arvid
authors.initials: A
authors.lastname: Lundervold
authors.forename: Bruce
authors.initials: B
authors.lastname: Fischl
authors.forename: David
authors.initials: D
authors.lastname: Salat
authors.forename: Brian T
authors.initials: BT
authors.lastname: Quinn
authors.forename: Nikos
authors.initials: N
authors.lastname: Makris
authors.forename: Anders M
authors.initials: AM
authors.lastname: Dale
mesh_terms: 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