Neurology

Real Time Functional MRI

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Read more about our research in the MIT Technology Review (11/06/2006) article by Emily Singer: Watching a Single Thought Form in the Brain: New techniques to capture single thought processes open up new possibilities for neuro-imaging.

Functional MRI based on blood-oxygenation-level-dependent (BOLD) contrast is a technology that has found widespread application in cognitive neuroscience. At the same time, the sensitivity of data acquisition methodology has evolved to the point that brain activation can be detected in single trials and there is increasing interest in mapping brain activity in individual subjects for the purpose of understanding inter-individual differences in cognitive processing. Clinical applications for presurgical mapping and interactive brain-imaging-guided exams of patients suffering from psychiatric and neurological disorders are foreseeable.

Real-time fMRI is a variant of fMRI that enables monitoring of changes in brain activation during the ongoing scan. It is characterized by steady-state image reconstruction, preprocessing and statistical analysis in a time frame that is short with respect to the time to acquire a volume fMRI data set, and with a time delay from data acquisition that is shorter than the hemodynamic response delay, which is on the order of several seconds. Real-time fMRI offers new intriguing opportunities for monitoring brain processes related to thoughts and emotions. Using novel highly sensitive real-time data acquisition methods based on multi-echo Echo-Planar-Imaging (EPI) and real-time sliding-window correlation analysis, we have shown that it is possible to monitor dynamic changes in brain activation during brief motor, visual, auditory and cognitive tasks with an effective temporal resolution of just a few seconds. Recent real-time fMRI studies have demonstrated the feasibility of modulating brain activity in localized areas for the purpose of accelerated learning, to develop novel brain-computer interfaces for communication and for controlling pain perception in patients with chronic pain.

Our technology development is aimed at innovative individualized designs of fMRI experiments, which include, but are not limited to, (a) interactive brain-imaging-guided interview of patients suffering from psychiatric and neurological disorders that are refractory to conventional diagnosis and treatment, and (b) individualized training of mental abilities and control of brain activation patterns through the use of experimental feedback. The first approach is of importance in situations where the subject is either unable (e.g., stroke victims, babies and young children, many schizophrenic patients, many patients with major depression) or unwilling (e.g., in situations where deception is used) to accurately report his/her mental experience. The second approach is of interest for developing individually tailored training strategies for operators of complex machine-human interfaces (e.g., automobile driver, pilots) and for developing individually tailored mental learning strategies. Such capabilities would constitute a breakthrough in cognitive neuroscience, because they open the elusive world of human thought processes to rigorous neural systems level analysis.