Error-related processing following severe traumatic brain injury: an event-related functional magnetic resonance imaging (fMRI) study

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.

Figure 1

Schematic of the task-switching cued Stroop task. As shown, task trials comprised an instructional cue followed after a delay by a stimulus probe to which the participant responded with a button press.

Figure 2

Behavioral performance on the cued-Stroop task as a function of Group and Congruency. (Left) Error rates; (Right) Reaction times. Error bars reflect standard errors.

Figure 3

Brain regions illustrating error-related activity (incorrect > correct). Results from the between-group analyses showing a significant main effect of accuracy. Statistical maps are superimposed on the three-dimensional structural MRI averaged over all participants. Graphic insert at lower left illustrates beta weights showing the main effect of accuracy in a region of the midline anterior cingulate, F(1,20) = 20.65, p < .0002 which exhibited neither a main effect of group, F(1,20) < 1, p > .40, nor a Group x Accuracy interaction, F(1,20) < 1, p > .94, Error bars reflect standard errors. (L = left; R = right; Talairach coordinates of images shown = -1 26 27).

Figure 4

Brain regions of patients with TBI and healthy comparison participants illustrating significant error-related activity (incorrect > correct). Results from the individual-group analyses: Yellow illustrates significant error-related activity in TBI patients, blue illustrates error-related activity in healthy controls, and green illustrates error-related activity in in which the TBI patients and healthy controls overlap. Results from the between-group analysis: Red illustrates a region of the anterior cingulate cortex (ACC) in which there is a Group x Accuracy interaction; graph insert in lower left illustrates beta weights showing the interaction effect. Error bars reflect standard errors. Statistical maps are superimposed on the three-dimensional structural MRI averaged over all participants. (L = left; R = right; Talairach coordinates of images shown = 18 11 34).

Figure 5

Box plots illustrating the total number of suprathrehold error-related voxels as a function of group as derived from the separate-groups contrast error > correct response. Bottom and top of each box represent the lower and upper quartiles, respectively, and the band near the middle of the box reflects the 50^th percentile (median); upper and lower whiskers reflect the maximum and minimum number of voxels.