METHODS & RESOURCES
Magnetoencephalography (MEG)
Our facility houses a 306-channel whole-head MEG system and an expansive collection of magnetically-silent stimulus presentation equipment for cognitive neuroscience type experiments. The Elekta/MEGIN model instrument is equipped with 102 magnetometers and 204 planar-gradiometers (306 independent magnetic sensors), and has the capability for simultaneous acquisition of 64-channel EEG. The instrument is housed within a Lindgren magnetically-shielded room (MSR) that is equipped with special coils within the walls for active shielding (i.e., the MSR responds to environmental perturbations by generating compensatory magnetic fields). Beyond this “smart-shield,” the Nebraska MEG facility is equipped with spatiotemporal Signal Space Separation (tSSS) software for additional noise reduction, along with the latest technology for head motion correction.
Magnetic Resonance Imaging (MRI)
The DICoN Laboratory uses a new 3-Tesla Siemens Prisma MRI scanner. This research-dedicated scanner is equipped with 20-, 32-, and 64-channel head coils, as well as array of other coils for cardiac, spinal, and other types of imaging. The instrument is configured with multiband imaging capabilities for very fast imaging, many experimental, research-only sequences, and all commercial sequences currently offered by Siemens. These include numerous MRI sequences for advanced diffusion, spectroscopy, structural, and functional brain imaging. The system has the [204×64] XR 80/200 gradients, which are the most powerful commercially available gradients for any scanner currently on the market. Finally, the Prisma MRI Suite is also equipped with the necessary peripherals to present experimental stimuli and acquire behavioral responses. This includes the BOLDScreen-32 (a 32” in-room LCD monitor for presenting stimuli), and multiple ergonomic subject response devices.
Brain Stimulation
The DICoN laboratory is also equipped with state-of-the-art electrical brain stimulation equipment, including three Soterix Medical systems that are housed in a brain stimulation suite. The suite includes a general preparation and setup area, as well as two testing/stimulation areas, and can be reserved in one-hour increments. Regarding equipment, the suite includes a standard two-pad tDCS system, a two-pad transcranial electrical stimulation (tES) system, a five-lead multipolar high-definition tDCS system (HD-tDCS), and a five-lead alternating-current stimulation (tACS) system. All of the systems are equipped with settings for sham-stimulation, which allows investigators to use “placebo-controlled” experimental designs. In addition to the stimulators, there is a Polhemus digitizer for coregistering the stimulation sponges or metal electrodes to neuroanatomical images. Users also have access to advanced software for finite-element modeling (FEM) of current flow using the participant’s individual anatomy.
Data Processing
The DICoN laboratory includes a high-performance computing space. This space currently includes 26 dedicated high-performance workstations for data processing, a 36 terabyte (RAID5) storage array for MEG and MRI data, and a video conferencing system for virtual meetings. All of the computers are linked via gigabit connection to the storage array and to a backup server located offsite. Each computer has Matlab and other important software for neuroimaging and statistical analyses, including many free packages such as SPM, FSL, AFNI, FreeSurfer, CONN, R, and other leading toolboxes. Many of the computers are also equipped with the Brain Electrical Source Analysis (BESA) software, BrainVoyager, SPSS, and current-distribution modeling software. The open concept space encourages collaborative programming (e.g., algorithm development) and data processing efforts among students and faculty.
