Self-regulation of the primary auditory cortex attention via directed attention mediated by real-time fMRI neurofeedback is related to attentional control processes¶
Abstract¶
Real-time fMRI neurofeedback training (fMRI-NFT) has a growing interest in the treatment of abnormal brain function. Chronic tinnitus is associated with hyperactivity of the auditory cortex and decrease attentional control. We have applied fMRI-NFT to teach self-regulation of the primary auditory cortex (A1) using directed attention with the intention to lower A1 hyperactivity. Ten healthy volunteers with normal hearing (no more than 1 frequency >40 dB on a standard audiogram) underwent 5 fMRI-NFT sessions. Each session was composed of a simple auditory fMRI followed by 2 runs of A1 fMRI-NFT. FMRI data was acquired using 2D, single-shot echo planar imaging during all 3 runs using a 3T. The auditory fMRI was comprised of 6 blocks, each containing a 20s period of no auditory stimulation followed by a 20s period of white noise stimulation at 90 dB. A1 activity, defined from a region using the activity during the preceding auditory run, was continuously updated during fMRI-NFT using a simple bar plot, and was accompanied by white noise (90 dB) stimulation for the duration of the scan. Each fMRI-NFT run contained 8 blocks, each separated into a 30s relax period followed by a 30s lower period. Subjects were instructed to watch the bar during the relax condition and actively lower the bar by decreasing A1 activity during the lower condition. Average A1 deactivation was extracted from each fMRI-NFT run, representative of A1 self-regulation performance. Additionally, the continuous performance task (CPT) was conducted outside of the MRI on day 1 prior to entering the MRI and on day 5 after exiting the MRI. Performance on the CPT was computed as the sensitivity index (d’) using signal detection theory. A 5x2 (session by run) ANOVA was carried out on A1 deactivation during fMRI-NFT. There was a significant effect of session (p = 0.0275, sphericity assumed, one-tailed) and a significant interaction effect (p = 0.0395, sphericity assumed, one-tailed). The most successful subjects reportedly adopted mindfulness tasks associated with directed attention during the lower condition. Furthermore, we found a significant positive correlation between the change in A1 deactivation and the change in CPT performance (Pearson’s R = 0.612, p = 0.06, one-tailed) despite a non-significant change in CPT performance for the group (paired t test, p > 0.1, one-tailed). For the first time, fMRI-NFT has been applied to teach A1 self-regulation using more than 1 session and to indicate that A1 control is directly related to attentional behavior. This is important to therapeutic development as it is unlikely a single fMRI-NFT session will provide adequate rehabilitation for tinnitus. More importantly, chronic tinnitus has implications of impaired auditory and attentional networks. Our study indicates that fMRI-NFT may provide an innovative approach to alter of these systems simultaneously, and that this method may apply to similar neurologic disorders such as chronic pain.
Bio¶
Mr. Sherwood received his Bachelor’s and Master’s Degrees in Biomedical Engineering from Wright State University in 2011 and 2013, respectively. His formal training has been concentrated on image processing and analysis. This specialization has provided the foundation for a deep understanding of image analyses that has led to his success. Mr. Sherwood has 5 years of professional experience and currently is the Principal Investigator for 3 Department of Defense contracts with over $1.9M in combined funding. He has pending proposals worth over $600k where he will serve as Principal Investigator. Mr. Sherwood’s work revolves around the execution of MRI scans at local hospitals (Kettering Medical Center and Dayton Children’s Hospital) and physician facilities (Wright State Physicians), which has provided for several collaborative opportunities with industry partners as well as faculty and local hospitals.