The anterior cingulate cortex (ACC) plays a key role in cognition, motor function, and emotion processing. However, little is known about how traumatic brain injury (TBI) affects the ACC system. Our purpose was to compare, by functional magnetic resonance imaging (fMRI) studies, the patterns of cortical activation in patients with cognitive impairment after TBI and those of normal subjects. Cortical activation maps of 11 right-handed healthy control subjects and five TBI patients with cognitive impairment were recorded in response to a Stroop task during a block-designed fMRI experiment. Statistical parametric mapping (SPM99) was used for individual subjects and group analysis. In TBI patients and controls, cortical activation, found in similar regions of the frontal, occipital, and parietal lobes, resembled patterns of activation documented in previous neuroimaging studies of the Stroop task in healthy controls. However, the TBI patients showed a relative decrease in ACC activity compared with the controls. Cognitive impairment in TBI patients seems to be associated with alterations in functional cerebral activity, especially less activation of the ACC. These changes are probably the result of destruction of neural networks after diffuse axonal injury and may reflect cortical disinhibition attributable to disconnection or compensation for an inefficient cognitive process.
"This is particularly evident in situations where response conflict is high, and when inappropriate prepotent response tendencies have to be overcome [Larson et al., 2006; Levin et al., 2004; Mecklinger et al., 1999; Perlstein et al., 2006; Seignourel et al., 2005]. A few functional imaging studies have investigated the resolution of interference in the presence of irrelevant stimuli by means of the Stroop task [Mani et al., 2007; Soeda et al., 2005; Tlustos et al., 2011]. These studies give insight into how the ability to ignore distracting information is affected in TBI. "
"For example, Soeda and colleagues (2005) observed reduced ACC activation in TBI patients during completion of a modified Stroop task that elicited a high degree of response conflict, Scheibel and colleagues (2007) observed greater ACC activation in TBI patients during completion of a stimulus-response compatibility cognitive control task. Findings from both studies (Scheibel et al., 2007; Soeda et al. 2005) suggest that neural networks mediating cognitive control and evaluative processes of control are disrupted after brain injury; however, these findings do not account for error-related activity, and methodological limitations (i.e., use of blocked fMRI designs) in the studies described above also preclude full interpretation of results. "
[Show abstract][Hide abstract] ABSTRACT: Continuous monitoring of one's performance is invaluable for guiding behavior towards successful goal attainment by identifying deficits and strategically adjusting responses when performance is inadequate. In the present study, we exploited the advantages of event-related functional magnetic resonance imaging (fMRI) to examine brain activity associated with error-related processing after severe traumatic brain injury (sTBI). fMRI and behavioral data were acquired while 10 sTBI participants and 12 neurologically-healthy controls performed a task-switching cued-Stroop task. fMRI data were analyzed using a random-effects whole-brain voxel-wise general linear model and planned linear contrasts. Behaviorally, sTBI patients showed greater error-rate interference than neurologically-normal controls. fMRI data revealed that, compared to controls, sTBI patients showed greater magnitude error-related activation in the anterior cingulate cortex (ACC) and an increase in the overall spatial extent of error-related activation across cortical and subcortical regions. Implications for future research and potential limitations in conducting fMRI research in neurologically-impaired populations are discussed, as well as some potential benefits of employing multimodal imaging (e.g., fMRI and event-related potentials) of cognitive control processes in TBI.
International journal of psychophysiology: official journal of the International Organization of Psychophysiology 07/2011; 82(1):97-106. DOI:10.1016/j.ijpsycho.2011.06.019 · 2.88 Impact Factor
"H. Kim et al., 1999). Functional neuroimaging studies have found changes in cingulate metabolism following TBI that relate to these cognitive functions in adults (Cohen Kadosh, Cohen Kadosh, Henik, & Linden, 2008; Scheibel et al., 2009; Soeda et al., 2005). An fMRI study of adults with moderate to severe TBI found that greater injury severity, as assessed by the GCS, was associated with increased anterior cingulate activation during stimulus–response incompatibility (Scheibel et al., 2009). "
[Show abstract][Hide abstract] ABSTRACT: Structural damage to the prefrontal-cingulate network has been implicated in cognitive and neurobehavioral deficits associated with traumatic brain injury (TBI). Forty-six children who had sustained moderate-to-severe TBI and 43 children with extracranial injury were imaged using diffusion tensor imaging (DTI). Decreased fractional anisotropy (FA) and increased apparent diffusion coefficient (ADC) values were found in the cingulum bundles bilaterally in the TBI group. Cingulum ADC was related to frontal lesion volume, injury severity, and injury mechanism. Finally, cingulum DTI parameters were related to cognitive control measures. DTI detects TBI-related injury to the cingulum, which may facilitate advances in assessment and treatment.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.