Transcranial Magnetic Stimulation (TMS) is delivered by a coil on the surface of the head, which generates a brief but powerful magnetic pulse that induces a temporary current in a small area on the surface of the brain. This current can interfere with processing of the brain with high temporal and fair spatial precision. Our facility includes an image-guided neuro-navigation system for the TMS coils that enables us to visualize the precise site of stimulation in the brain.The TMS laboratory, located in PNI room C26A, houses two single pulse, monophasic stimulators (Magstim 200 Mono Pulse). The stimulators are triggered either manually or by the control computer via digital I/O. Users have a choice between two 70-mm double coils and two 90-mm circular coils, capable of a maximum magnetic field of 2.2T and 2.0T, respectively. Each stimulator outputs TTL triggers to a Response Time Box for accurate time stamps.
Coil positioning is performed with image-guided neuro-navigation via a Rogue Research Brainsight 2 system. The coils are tracked with a Northern Digital Polaris Hybrid Position Sensor that communicates with the Brainsight 2 system. Subjects are seated in a specialized Rogue Research Gen 3 TMS chair surrounded by an aluminum frame that supports coil and head positioning. The chair provides a chin rest and forehead rest and allows independent positioning of two coils. The chair may be rotated and reclined back for alternate subject positioning, depending on the needs of the experiment. The Brainsight 2 system also allows for the recording of motor-evoked potentials with a 2-channel built-in EMG device.
The laboratory also houses a 120Hz infrared eye tracker (SMI RED) underneath the stimulus display monitor. The eye tracker is controlled by PC laptop and communicates with the stimulus control desktop computer via Ethernet communication. The TMS lab has a license for the SMI Experiment Suite 360 software. This Windows software suite includes tools for eye data analysis and stimulus display.