Activity in the Paracingulate and Cingulate Sulci during Word Generation: An fMRI Study of Functional Anatomy

Abstract

The supracallosal medial frontal cortex can be divided into three functional domains: a ventral region with connections to the limbic system, an anterior dorsal region with connections to lateral prefrontal systems, and a posterior dorsal region with connections to lateral motor systems. Lesion and functional imaging studies implicate this medial frontal cortex in speech and language generation. The current functional magnetic resonance imaging (fMRI) study of word generation was designed to determine which of these three functional domains was substantially involved by mapping individual subjects' functional activity onto structural images of their left medial frontal cortex. Of 28 neurologically normal right-handed participants, 21 demonstrated a prominent paracingu- late sulcus (PCS), which lies in the anterior dorsal region with connections to lateral prefrontal systems. Activity increases for word generation centered in the PCS in 18 of these 21 cases. The posterior dorsal region also demonstrated significant activity in a majority of participants (16/28 cases). Activity rarely extended into the cingulate sulcus (CS) (3/21 cases) when there was a prominent PCS. If there was no prominent PCS, however, activity did extend into the CS (6/7 cases). In no case was activity present on the crest of the cingulate gyrus, which is heavily connected to the limbic system. Thus, current findings suggest that medial frontal activity during word generation reflects cognitive and motor rather than limbic system participation. The current study demonstrates that suitably designed fMRI studies can be used to determine the functional significance of anatomic variants in human cortex.

Three-dimensional locations and boundaries of motor and premotor cortices as defined by functional brain imaging: A meta-analysis

“…For instance, the ventral limit of pre-SMA was at z = 33, the ventral limit where SMA intersects the VCA line was at z = 40, and the ventral limit of SMA proper was at z = 44. Therefore, our data suggest that the ventral limit is more ventral rostrally than it is caudally, and this finding is consistent with previous depictions (in figures) (Crosson et al, 1999;Deiber et al, 1999;Johansen-Berg et al, 2004). It is interesting to note that these values were ventral to the location of the cingulate sulcus in the Talairach and Tournoux atlas (1988).…”

Abnormalities of cingulate gyrus neuroanatomy in schizophrenia

“…The anterior segment of the cingulate gyrus (AC) was divided from the posterior segment (PC) of the structure using a plane passing through the anterior commissure (The plane passes through the anterior commissure at the point where it intersects the interhemisphere plane; this plane also is perpendicular to the line connecting the anterior and posterior commissures.). This border approximates the boundary between Brodmann areas (BA) 24 and 23 (Crosson et al, 1999,Heckers et al, 2004,Yucel et al, 2001). …”

Pitch underlies activation of the vocal system during affective vocalization

“…Previous brain imaging studies of affective vocalization in humans do strongly support the involvement of the ACC in producing affective vocalizations, but do not exclude its involvement in producing non-affective vocalizations (Barrett et al, 2004;Wattendorf et al, 2013). Indeed, the ACC is frequently activated during non-affective speech (Paus et al, 1993;Crosson et al, 1999) and singing (Brown et al, 2009). Hence, the ACC appears to participate in vocalization, affective or otherwise.…”