Functional rostro-caudal gradient in the human posterior lateral frontal cortex
The present study examined the hypothesis that the posterior motor/premotor region of the lateral frontal cortex is functionally organized along a rostro-caudal axis. During functional magnetic resonance imaging scanning, the subjects performed various tasks assessing basic saccadic eye or hand actions and also tasks requiring the cognitive selection between competing hand or eye movements based on previously learned conditional relations (if A, select movement X, but if B select movement Y). Subject-by-subject analysis demonstrated precise relationships between the foci of functional activity and specific sulci. In agreement with previous reports, basic eye movements activated the Frontal Eye Field (FEF) in the ventral branch of the superior precentral sulcus, but the high-level selection of saccadic eye movements was localized systematically anterior to this region in the superior frontal sulcus. Similarly, basic performance of hand movements activated the primary motor cortex, but the region involved in the high-level selection between competing hand movements was systematically localized within the dorsal branch of the superior precentral sulcus, anterior to the primary motor region. Importantly, there was no overlap between the anterior cognitive selection regions, suggesting an effector specific organization. These results demonstrate a functional rostro-caudal gradient within the posterior lateral frontal cortex reflecting a hierarchical organization of action control.
KeywordsConditional visuo-motor associations Functional gradient fMRI Human
The research was supported by Canadian Institutes of Health Research (CIHR) grant FRN 37753 and FDN-143212 to M. Petrides.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
- Petrides M (2005b) The rostral-caudal axis of cognitive control within the lateral frontal cortex. In: Dehaene S, Duhamel J-R, Hauser MD, Rizzolatti G (eds) From monkey to human brain. MIT, Cambridge, pp 293–314Google Scholar
- Talairach J, Tournoux P (1988) Co-planar stereotaxic atlas of the human brain. Thieme, New YorkGoogle Scholar