Executive functions in the absence of behavior: functional imaging of the minimally conscious state.

摘要: One of the major challenges in clinical evaluation brain injury survivors is to comprehensively assess level preserved cognitive function order inform diagnostic decisions and suggest appropriate rehabilitation strategies. However, limited (if any) capacity for producing behavior some these patients often limits extent which functions can be explored via standard bedside methods. We present a novel neuroimaging paradigm that allows assessment residual executive without requiring patient produce any behavioral output. In particular, we target processes such as active maintenance information through time willful adoption "mind-sets" have been proposed require conscious awareness. Employing an fMRI block design paradigm, healthy volunteers were presented with series neutral (i.e., not emotionally salient) words, alternatively instructed listen all or count number times given repeated. Importantly, perceptual stimulation passive listening counting tasks was carefully matched. Contrasted listening, task revealed fronto-parietal network previously associated detection working memory. Remarkably, when tested on this same procedure, minimally highly similar pattern activation. Furthermore, activity regions appeared synchronous onset offset blocks. Considering close matching sensory across two tasks, findings strongly could willfully adopt differential condition, actively maintain time. Neither apparent (behaviorally) at bedside. This thus exemplifies potential explore high-level functions, awareness, absence response.