fMRI is a powerful research tool for studying the functioning human brain that has developed over the last two decades and has truly revolutionized the field of cognitive neuroscience. It utilizes the same magnet as a standard MRI uses to acquire structural images, but through the application of specialized software, information about the location in the brain of subtle changes in blood oxygenation can be now obtained. Since it has been shown that the BOLD (Blood Oxygen Level Dependent) signal is correlated with neural activity, we can use this tool to localize changes in neural activity with a high degree of spatial resolution. Studies can be performed when individuals are lying in the scanner at rest or engaged in a cognitive task. High-resolution structural images and other MRI images (e.g., DTI and FLAIR) can be gathered during the same scanning session. To increase the sophistication of the experiments that can be performed in the scanner, different presentation peripherals (e.g., LCD screen and headphones) and other recording devices (e.g., eye movement tracker, EKG, button response box) are often integrated in the scanner environment.

fMRI experiments in the Gazzaley lab are performed at the UCSF Neuroscience Imaging Center (NIC), a new core facility that is dedicated to functional brain imaging.  The NIC has at its core a Siemens 3 Tesla Trio Tim MRI. The system is state-of-the-art, with two 12-channel head coils, 16-channel parallel imaging, inline diffusion, perfusion, fMRI BOLD imaging, DTI and high-resolution anatomical imaging capabilities.  The facility has hardware and software for presentation of visual and auditory stimuli, as well as the recording of button presses, eye-movements, galvanic skin response, pulse oximetry, respirations and EKG.  A staff physicist oversees all imaging research, a Siemens physicist is present at the site full time and a staff research associate is available to assist with scanner operation. Dr. Gazzaley serves as the director of the NIC.

  

EEG is a tool that has been used both clinically and scientifically to study the brain since the early 1900’s. Its use has continued to expand over the last two decades as  a cognitive neuroscience technique, serving a role as a complementary methodological approach to fMRI. Unlike fMRI, where neural activity is assessed as an indirect correlate of changes in blood flow, EEG permits the direct recording of electrical signatures of neural activity via electrodes positioned over the scalp. Although this technique has poor spatial resolutiuon, it has the advantage of recording very high time-resolution data, on the order of milliseconds, in  contrast to the lower temporal resolution of fMRI. Thus, EEG serves as a powerful research tool to couple with fMRI.

EEG experiments in the Gazzaley Lab are performed at the Mission Bay facility. A waiting room is availble for participants, as well as an area for obtaining research consents. The human neurophysiology suite consists of an acoustic-paneled room with an Active Two 64-channel EEG Acquisition System. The EEG equipment is controlled remotely from an adjoining computer control room.

TMS is another approach to study the functioning human brain that has rapidly developed over the last two decades. Unlike fMRI and EEG which are correlational techniques, TMS allows us to explore the causality and necessity of brain regions for cognitive operations by noninvasively exciting neurons in the brain. This is accomplished via the application of a focal magnetic pulse to the scalp that results in excitation of the underlying cortical neurons. When applied in different stimulation patterns (i.e., repetitive, single pulse or paired pulse), TMS can have either a facilitating or perturbing influence on neural activity. Stereotaxic localization systems can be used to guide TMS pulses to either structurally or functionally defined brain regions. TMS can also be coupled with the other physiological tools, EEG and fMRI, to reveal a more comprehensive picture of how the brain functions. Research has revealed that TMS is a safe technique when used within established guidelines.

TMS experiments are performed at the Gazzaley lab physiology suite located on the Mission Bay campus. The suite has an acoustic-paneled room equipped with a Brainsight Optical Tracking System, Power Mac G5 and a Magstim TMS system with a double 70 mm coil and air-cooled coil for repetitive stimulation. The TMS unit shares  same suite as the EEG system to permit combined TMS-EEG experiments.