Paracingulate asymmetry in anterior and midcingulate cortex: sex differences and the effect of measurement technique

Abstract

Many structural brain asymmetries accompany left hemisphere language dominance. For example, the cingulate sulcus is larger in the medial cortex of the right hemisphere, while the more dorsal paracingulate sulcus is larger on the left. The functional significance of these asymmetries is unknown because fMRI studies rarely attempt to localize activation to specific sulci, possibly due to difficulties in consistent sulcal identification. In medial cortex, for example, there are many regions of partial sulcal overlap where MRI images do not provide sufficient information to unambiguously distinguish a paracingulate sulcus from a displaced anterior cingulate segment. As large samples of postmortem material are rarely available for cytoarchitectural studies of sulcal variation, we have investigated the effect of variation in boundary and sulcal definition on paracingulate asymmetry in the MRI scans of 200 healthy adults (100 men, 100 women). Although women displayed a reliable asymmetry in the size of the paracingulate sulcus, regardless of boundary definition or technique, asymmetry was greatest when (1) the measurement was limited to the midcingulate region between the genu and the anterior commissure; and (2) the more dorsal of two overlapping sulci was always classified as a paracingulate sulcus (rather than as a displaced cingulate segment). The fact that paracingulate asymmetry is maximal in the midcingulate region suggests that this region may play a particular role in hemispheric specialization for language. Future work should investigate the structural and functional correlates of sulcal variation in this region.

Cognitive control deficit in patients with first-episode schizophrenia is associated with complex deviations of early brain development

“…17 Sex was also added a priori as a potential confounding factor, as some studies have reported sex-related differences in ACC asymmetry. [25][26][27] To control for the potential bias effect of psychotic symptoms, we performed our statistical analyses using the total PANSS score as a confounding covariate.…”

Sex differences in cognitive control are associated with midcingulate and callosal morphology

“…Similarly, it is not yet entirely clear whether a more precise definition of the PCS can be achieved by including or excluding fragmented sulci running parallel to the CS (e.g., Leonard et al 2009). Nevertheless, it has already been shown that variations in midcingulate fissurization are indeed associated with differences in performance at both the behavioral (e.g., Fornito et al 2004) and the electrophysiological level (Huster et al 2009).…”

“…It has been shown that a leftward-asymmetric doubling of gyri in the midcingulate region (see, e.g., Vogt et al 1995) is more pronounced in males than females (Huster et al 2007;Paus et al 1996;Yücel et al 2001; but see Leonard et al 2009, for a recent contradictory finding). This suggests a stronger degree of lateralization in men.…”

The Shape of the ACC Contributes to Cognitive Control Efficiency in Preschoolers

“…The sulcal pattern of ACC was visually assessed using 3-D, mesh-based reconstruction of cortical folds to measure the occurrence and extent of local sulci (e.g., Leonard, Towler, Welcome, & Chiarello, 2009;Huster, Westerhausen, Kreuder, Schweiger, & Wittling, 2007;Fornito et al, 2004;Yucel et al, 2001). ACC sulcal pattern was classified as "single" or "double parallel" type (Ono et al, 1990) based on the presence or absence of a PCS (Figure 2).…”

“…The PCS was considered absent if there were no clearly developed horizontal sulcus elements parallel to the cingulate sulcus and extending at least 20 mm (interruptions or gaps in the PCS course was not taken into account for the length measure). The finer distinction between "present" and "prominent" PCS ( Yucel et al, 2001;Paus et al, 1996), leading to three ACC sulcal pattern types, was not used here because this distinction is based on the PCS length of adult brains-that is, greater than 20 mm according to Pausʼs classification (Paus et al, 1996) or greater than 40 mm according to Yucelʼs classification (Yucel et al, 2001) for a prominent PCS (Leonard et al, 2009). Furthermore, the classification of ACC morphology into five categories by grouping the individual measurements of PCS in 15-mm steps was also proposed (Huster et al, 2007).…”