White matter microstructure between the pre‐SMA and the cingulum bundle is related to response conflict in healthy subjects

Abstract

IntroductionResponse conflict involves selectively attending to relevant information and suppressing distracting, irrelevant information. The medial frontal cortex (MFC) is considered to be involved in response conflict. However, it remains unclear which white matter connectivity is associated with response conflict. This study aimed to delineate the neural connectivity of response conflict in healthy subjects and investigate the association between white matter microstructure and performance of a response conflict task.MethodTwenty‐eight healthy subjects underwent functional magnetic resonance imaging (fMRI) during the Flanker task and diffusion MRI. We identified the presupplementary motor area (pre‐SMA) using fMRI. Furthermore, we delineated the white matter connectivity between the pre‐SMA and the cingulum bundle (CB), which is located in the MFC, using probabilistic tractography. We calculated the mean diffusivity (MD), index of white matter microstructure, of this tract and evaluate the association between MD and performance of the Flanker task.ResultThe mean MD of this tract was significantly and positively associated with performance of the Flanker task.ConclusionThe present study suggests the white matter connectivity between the pre‐SMA and the CB is related to the response conflict in healthy subjects and finer white matter microstructure is associated with smaller response conflict.

The role of the supplementary motor area for speech and language processing

“…In line with these findings, resting state functional connectivity data found pre-SMA to be linked to cognitive processing regions whereas SMA proper exhibited stronger connectivity to motor cortex (Wang et al 2013). Furthermore, pre-SMA shows white matter connectivity to the cingulate cortex via the cingular bundle, which seems to be functionally associated to the processing of response conflicts (Yamamoto et al, 2015). A study on connectivity between basal ganglia and cortical regions during the performance of speech tasks found differential patterns with regard to linked to regions involved in cognitive linguistic processes (pre-SMA, dorsal anterior insula, and inferior frontal gyrus) whereas GPi showed stronger connectivity to regions involved in motor control (middle insula, SMA proper, premotor cortex) (Manes et al, 2014).…”

Attentional control abnormalities in posttraumatic stress disorder: Functional, behavioral, and structural correlates

“…Stroop performance, particularly in the context of positive distractors (Keedwell et al, 2016), has been associated with CB integrity, indicating the functional consequences of these white matter decrements. Other studies have observed that CB integrity is linked to performance on tasks of response conflict and sustained attention (Takahashi et al, 2010; Yamamoto et al, 2015). Injury to this path has been linked to deficits on tasks of executive control e.g., (Cohen et al, 1999; Janer and Pardo, 1991; Kim et al, 2003), and reduced emotional responsivity (Cohen et al, 2001).…”

“…In addition to connecting fronto-parietal control network areas, the limbic aspects of this tract access emotion processing regions. Integrity of the CB has been associated with performance on cognitive control/response inhibition tasks in healthy (Takahashi et al, 2010; Yamamoto et al, 2015) and psychiatric populations (Keedwell et al, 2016; Takei et al, 2009). Stroop performance, particularly in the context of positive distractors (Keedwell et al, 2016), has been associated with CB integrity, indicating the functional consequences of these white matter decrements.…”

Segmentation of the Cingulum Bundle in the Human Brain: A New Perspective Based on DSI Tractography and Fiber Dissection Study

“…This proposition can be supported by some functional studies. For example, white matter connectivity between the pre-SMA and the CB was associated with response conflict in healthy human subjects (Yamamoto et al, 2015 ). Huang et al ( 2013 , 2014 ) also found that the microstructural integrity of the white matter connecting the anterior cingulate area to the precuneus and medial superior frontal areas reflected the level of neurophysiologic dependence in tobacco withdrawal syndrome.…”