IQ-related fMRI differences during cognitive set shifting.
This event-related functional magnetic resonance imaging study compared neural correlates of executive function (cognitive set-shifting) in 28 healthy participants with either high (HIQ) or average (AIQ) intelligence. Despite comparable behavioral performance (except for slower reactions), the AIQ participants showed greater (especially prefrontal) activation during response selection; the HIQ participants showed greater activation (especially parietal) during feedback evaluation. HIQ participants appeared to engage cognitive resources to support more efficient strategies (planning during feedback in preparation for the upcoming response) which resulted in faster responses and less need for response inhibition and conflict resolution. Whether greater intelligence is associated with more or less brain activity (the "neural efficiency" debate) depends therefore on the specific component of the task being examined as well as the brain region recruited. One implication is that caution must be exercised when drawing conclusions from differences in activation between groups of individuals in whom IQ may differ (e.g., psychiatric vs. control samples).
Graham
Steven
S
Functional Brain Imaging Lab, Department of Psychology, National University of Singapore, Singapore 117570. psysg@nus.edu.sg
Jiang
Jiaying
J
Manning
Victoria
V
Nejad
Ayna Baladi
AB
Zhisheng
Koh
K
Salleh
Shan R
SR
Golay
Xavier
X
Berne
Yeh Ing
YI
McKenna
Peter J
PJ
D000328:Adult; D001921:Brain / Q000098:blood supply* / Q000502:physiology*; D001931:Brain Mapping; D056344:Executive Function / Q000502:physiology*; D005246:Feedback; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007360:Intelligence / Q000502:physiology*; D007361:Intelligence Tests; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D011597:Psychomotor Performance; D011930:Reaction Time; D012718:Set, Psychology; D055815:Young Adult
D010100:Oxygen