Neural activations at the junction of the inferior frontal sulcus and the inferior precentral sulcus: Interindividual variability, reliability, and association with sulcal morphology

Abstract

The sulcal morphology of the human frontal lobe is highly variable. Although the structural images usually acquired in functional magnetic resonance imaging studies provide information about this interindividual variability, this information is only rarely used to relate structure and function. Here, we investigated the spatial relationship between posterior frontolateral activations in a taskswitching paradigm and the junction of the inferior frontal sulcus and the inferior precentral sulcus (inferior frontal junction, IFJ) on an individual-subject basis. Results show that, although variable in terms of stereotaxic coordinates, the posterior frontolateral activations observed in task-switching are consistently and reliably located at the IFJ in the brains of individual participants. The IFJ shares such consistent localization with other nonprimary areas as motion-sensitive area V5/MT and the frontal eye field. Building on tension-based models of morphogenesis, this structure-function correspondence might indicate that the cytoarchitectonic area underlying activations of the IFJ develops at early stages of cortical folding.

Magnetic resonance spectroscopy investigations of functionally defined language areas in schizophrenia patients with and without auditory hallucinations

“…Four regions within the cerebral language system were chosen for a neurochemical analysis. However, it is well established that there are crucial neuroanatomical variations across subjects in terms of location and function [2,3] that persist to a substantial degree after normalization into a common anatomical space [33,38,39,40] and that are particularly relevant with respect to the functional specification of cerebral language regions [41]. A possible reason for inconsistencies between functional imaging studies of the language system is the application of group analyses in most of the investigations, which might have resulted in an underestimation of individual differences [41].…”

Prefrontal Cortical Mechanisms Underlying Individual Differences in Cognitive Flexibility and Stability

“…This might account for the lack of IFJ activation in Hedden and Gabrieli (2010). Although the IFJ was found to be reliably involved in task switching , even when individual differences in sulcal anatomy were taken into account (Derrfuss, Brass, von Cramon, Lohmann, & Amunts, 2009), the IFJ seems to be particularly critical for the updating of task rule representations, which is clearly not required when applying the same task rule to global versus local features of the same object.…”

Lost in localization: The need for a universal coordinate database

“…Structure-based and BA-based searches are unsatisfactory because nearby activations might receive different anatomical labels or different BA designations, and activations quite distant from one another might be given identical anatomical labels or BA designations. For example, activations close to the junction of the inferior frontal sulcus and the inferior precentral sulcus Derrfuss et al, 2004Derrfuss et al, , 2005Derrfuss et al, , 2009) might be referred to as lying in the inferior precentral sulcus, the inferior frontal sulcus, the precentral gyrus, the middle frontal gyrus, the inferior frontal gyrus, pars opercularis, Broca's area, the premotor cortex, or the inferior frontal junction. On the other hand, activations in the most ventral and the most dorsal part of the posterior frontal cortex might both receive the label "precentral gyrus" or "BA 6," although these activations might lie as far as 60 mm apart.…”