Instructions and training about the delay, along with scrolling graphs, have been employed to deal with this RXDX-106 challenge.6,12,13 In addition, as noise in the fMRI signal is typically dealt with by traditional approaches of filtering and signal averaging, constant feedback must employ nontraditional approaches to prevent noise from impacting continuous feedback.2,3 Additionally and perhaps most importantly, the visual attention and cognitive load of evaluating feedback while simultaneously
engaged in the experimental paradigm may be confounding and actually distract from the task under primary study. Too much feedback may distract from the main task at hand. Because of these considerations, intermittent feedback may have some advantages over continuous feedback in RTfMRI neurofeedback procedures. By providing feedback at the end of a block of time, the participant does not need to be aware of any hemodynamic delay and more time points are available for filtering and signal averaging. Furthermore, experimental
task performance and the evaluation of feedback are separable in time (and can be more concretely isolated for further whole-brain analysis). In this study, we directly compared a continuous and an intermittent approach to providing RTfMRIf in a movement learn more imagery task. Our primary hypothesis was that intermittent RTfMRIf would be more effective for increasing brain function in a defined region of interest (ROI) than would continuous feedback. We further aimed to explore whole brain differences evaluating feedback continuously versus intermittently, and we used the intermittent paradigm to characterize brain regions involved in evaluating feedback. Healthy nonsmoking, right-handed volunteers, age of 18-60 years, were eligible to participate
in this study. After providing informed consent as approved by the Institutional Review Board of the Medical University of South Carolina, participants were screened for conditions contraindicated to MRI scanning, current DSM-IV Axis 1 psychiatric disorders, substance dependence, substance selleckchem abuse within the past 30 days, and significant medical problems or medications that would interfere with the hemodynamic response. Study subjects participated in six fMRI scans on the same day. Each scan involved a block-design “imagine movement” task. Participants were instructed to imagine moving their right hand when the word “IMAGINE” was visually displayed (imagined activities such as writing, playing a musical instrument, or completing a sports-related movement were suggested), and to engage in nonmovement thoughts when the word “REST” was displayed. A tight, molded foam wrist/hand brace was placed on the participant’s right hand, wrist, and forearm to limit movement during scanning.