The main scanner that the CCBI uses is located at the Scientific Imaging & Brain Research Center, which was established by Carnegie Mellon in the Spring of 2010. This scanner is a 3T Siemens Verio. The Verio has a 32-channel coil that produces excellent fMRI and diffusion results. The Verio has a larger bore than the Trio (70 cm vs. 60), providing substantially more psychological and physical comfort, particularly for children, larger participants, and participants with anxiety.
In most of our studies, we acquire one complete brain image (consisting of 17 5mm brain slices) once every second. The high imaging speed allows us to obtain many observations of the activation level of each voxel in each experimental condition, and to obtain whole-brain scans, so we can have high-resolution imaging of a large volume of brain. The scanner provides outstanding stability and SNR performance, making it relatively easy to see systematic brain activation, and its time course, associated with various cognitive processes. We also use the scanner to run diffusion-weighted imaging scans to assess the structural integrity of white matter in the brain.
An experimental control system (CogLab) synchronizes the acquisition of MR images with the presentation of audio and visual stimuli. A color high-resolution LCD projector projects visual stimuli onto a rear-projection screen in the bore of the magnet. This screen is viewed by the participants (lying on their back) via an angled mirror system. An alternative visual presentation method is via MR-compatible virtual reality goggles. Audio stimuli are transmitted through earphones. Participants' response times are monitored by response buttons and eye movements are monitored by a MR-compatible infra-red eye tracker. The stimuli are presented and the button press responses are recorded by CogLab, which also synchronizes the stimulus presentation with the fMRI scanning.