NEUROFEEDBACK FUNCTIONAL MRI

这个子项目是众多研究子项目之一

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Project Summary The objective of the proposed research is to develop and implement an fMRI method capable of delivering information on anatomically specific brain activities back to a subject in near real-time as biofeedback, thus enabling neurofeedback. Guided by the information on their own cortical activities, the subjects subsequently learn to gain a level of voluntary control in modulating brain activities of auditory and somatomotor areas using cognitive functions such as attention and imagery. The main hypothesis of this study is that the level of attention to auditory stimulation and the content of motor imagery can be voluntarily controlled by the subjects, thus modulating the activities in auditory and somatomotor areas that are characterized by fMRI. The secondary hypothesis is that biofeedback of regionally-specific brain function will assist subjects to achieve a greater degree of modulation compared to subjects without neurofeedback. The tertiary hypothesis is that subjects can retain or further enhance the degree of cortical modulation learned from the initial neurofeedback sessions by mental practice in the absence of additional neurofeedback. Upon the completion of implementation, we will apply the neurofeedback fMRI method to healthy volunteer subjects undergoing auditory attention and motor imagery tasks. We will modulate subjects brain activitites, in terms of an increase/decrease in the size of activation and/or blood-oxygenation-level-dependent signal contrast, in primary and secondary auditory areas during passive auditory stimulation by assigning different degrees of attention/distraction to incoming stimuli. The activities in somatomotor areas will be modualted using motor imagery. The efficacy of the neurofeedback approach will be examined by comparing the functional brain mapping data to that obtained from demographically matched subjects who perform the task without the guidance of neurofeedback. We will also examine whether the degree of modulation achieved from the neurofeedback procedures can be consolidated and retained over time by performing the second fMRI session to measure the degree of modulatory changes learned from the initial neurofeedback sessions. The proposed research consisted of two distinct developmental phases. In the 2005 (Year 1 and ¿ of Year 2), the focus of the research is the development and implementation of the neurofeedback fMRI method in a 3T MRI environment. This phase includes (1) implementation of data processing tools for neurofeedback and (2) the optimization of MRI parameters and determination of design paradigm. We proposed to test the method on twenty volunteer subjects using an auditory attention modulation task. Currently, we have tested the method on 11 volunteer subjects using various mental imagery tasks including both auditory attention and motor imagery tasks. Project Start: 28-SEP-2004 Project End: 30-JUN-2008 Plans going forward We aim to demonstrate the following: (1) that real-time feedback to a stroke patient of his brain function through fMRI during the performance of motor imagery and execution helps that individual to improve hand locomotor function in the affected hand; and (2) that the feedback, combined with training of learned neuro-directed behavior, mediates the neural processes generating the observed motor improvement. We would like to move toward the second phase of the study (R01-level NIH) where we will apply the developed techniques to a group of patients (with selective strokes). Our initial plans are to study stroke patients who have primarily hand motor-deficits. Collaborators (Dr. Joel Stein)in Spaulding Rehabilitation Hospotal (SRH) were contacted, and appropriate IRB application is being filed along with clinical collaborators in Dep of Neurology. Benefits of the Collaboration to the NCIGT As evident from our findings from subject-initiated task and concurrent real-time detection of the brain activity [ Lee JH et al, 2007], the developed method can provide a unique way to monitor cortical activities from the tumor boundaries in high-spatial resolution. It suggests that real-time monitoring of regional BOLD signals can potentially provide alternative non-invasive means to invasive electrical cortical stimulation that requires awake-surgery. Since the technique is non-invasive, a patient may try different tasks to generate significant signal elevation from the regions constituting tumor boundary (analogous to surgeons probing different part of the cortical surface to identify the functional loci of interest). Once the task to activate the regions is isolated, and regular fMRI session may proceed using the same task. The method would not only increase the accuracy of the brain mapping procedures for presurgical planning but also alleviate the ordeal of awake-surgery. Another potential application could be found from the detection and monitoring of the epileptic loci. Detection of the epileptic activity and its spatial localization is considered to be crucial for the surgical intervention and removal. So far, simultaneous recordings of EEG signal in the MRI environment provide the temporal features of seizure-related brain activities. The propose technique, by enabling the display real-time cortical activities, can be readily adapted to detect the irregular and unpredictable BOLD signal signatures, associated with the epileptic discharges. Combined with powerful blind-source localization techniques such as ICA, the temporal features of the detected BOLD signal can be used to localize the epileptic locus. Benefits to the Project The NCIGT is providing comprehensive level of resouces/software to faciliate the real-time data processing of fMRI data. In addition, collaboration with surgical core will be able to allow the method to proceed from a proof-of-concept stage to actual tests in a clinical setting such as rtfMRI for surgical planning and intervention.