All data in the Brain Mapping Laboratory is recorded from human subjects who have provided informed consent as approved by UF Institutional Review Board (UF IRB-01).

Human Systems Neuroscience and Functional Mapping

research1Our research aims to identify neural correlates of behavior and information processing in electrocorticographic signals (ECoG) in humans, which are collected on the surface of the cortex. Studying ECoG enables the investigation of widely spread networks with very high temporal resolution at the system level and facilitates understanding of higher level functions, such as attention and language. ECoG research has very strong clinical ties, as the signals are recorded from patients awaiting surgery for intractable epilepsy. This setting facilitates rare access to the surface of the human cortex and opens unparalleled avenues for human brain research. We collaborate with Dr. Jean E. Cibula of Neurology and Dr. Steve Roper of Neurosurgery to recruit patients for these studies.

Neural Correlates of Tourette’s Syndrome and Responsive Deep Brain Stimulation

xray copyTics are sudden, repetitive motor movements or vocalizations involving discrete muscle groups. In the context of Tourette syndrome, tics are considered “semi-voluntary;” they have been described as voluntary responses to involuntary, irresistible urges. Tourette syndrome (TS) and disorders producing tic behaviors are highly prevalent and are socially embarrassing. Deep brain stimulation (DBS) has emerged as a highly efficacious treatment option for this sub-group of resistant patients. DBS implants also facilitate recording of cortical and subcortical signals. Our goal, in collaboration with Dr. Michael S. Okun and Dr. Kelly Foote of the Center of Movement Disorders and Neurorestoration, is to correlate tic behaviors in TS with network physiology by describing oscillation dynamics in both the thalamus and cortex. We are able to examine emergent phenomena, such as coupling between the regions, that are not evident in recordings from a single region. The study of network activity will move us one step closer to a closed loop, responsive approach to DBS therapy. This work is being sponsored by NSF CAREER (Gunduz) and NIH NINDS R01 grants (Okun & Gunduz).

Brain Computer Interfaces for Neurorehabilitation

research1Rehabilitation of chronically lost or affected motor functions is the ultimate goal in the treatment of stroke survivors. The use of brain-computer interface (BCI) systems is a potential novel approach for the restoration of function and improving the quality of life of these patients. However, there are many unknown factors regarding whether surface-acquired brain signals (electroencephalography (EEG)) over lesional or viable areas can feasibly be trained and used in treatments for recovery of volitional motor control after stroke in humans. These unknown factors include whether brain signals are detectable and can support training strategies; which brain signal features are best suited for use in motor learning and restoring motor functions; how brain signals can be used most effectively; and the most effective format for BCI systems (e.g., what guidance should be provided to the user to maximize training that produces beneficial changes in brain signals). The value of BCI technologies for improving motor function after stroke depends on obtaining adequate answers to these questions. We are currently working on these answers in collaboration with Dr. Janis Daly, Director of the Malcolm Randall VA Hospital Brain Rehabilitation Research Center. This project is funded by the Brain Rehabilitation Research Center through a VA grant.

A Responsive Closed-Loop Approach to Treat Freezing of Gait in Parkinson’s Disease

GPI_PPNWe aim to uncover the neurophysiological changes  within the basal ganglia circuitry in order to alleviate levodopa-resistant posture, gait and freezing symptoms, which are among the most disabling and difficult to treat in people with Parkinson’s disease (PD). In the normal non-PD state, the pedunculopontine nucleus (PPN) provides the “gas pedal” for ambulation, whereas the globus palludus (GPi) provides the “brake”. We implant PD patients with sensing and stimulating electrodes in these two regions in order to (i) understand the underlying mechanisms of freezing of gait (FoG), (ii) detect FoG events in real-time from the recorded signals, and (iii) provide closed-loop responsive stimulation strategies to resolve FoG. Further, this study will provide significant enhancement of our understanding of the basic circuitry underlying gait function in ambulating humans. This project is currently funded by the Michael J. Fox Foundation for Parkinson’s Research under the Improved Neuromodulation Approaches for Parkinson’s Disease Program in collaboration with Dr. Michael S. Okun and Dr. Chris Hass.

IMPRESS: Implantable Multimodal Peripheral Recording and Stimulation System

20150208-619-460-haptixThe nervous system is an intricate, distributed, and hierarchical system that works closely with the motor system to create a perfectly integrated sensory motor loop. Muscles integrate in low-dimensional continuous variables from the high-dimensional spike trains that reach their inputs. The sensory system, which operates in a converse manner, takes a low-dimensional continuous external signal and creates a high-dimensional space of spike trains. In an amputee, the breech of communication between the sensory and the motor systems occurs at the high-dimensional portion of the sensory motor loop. Therefore prosthetics have to deal with the high-dimensional problem of restoring sensing and motor communications. The goal of the IMPRESS project is to overcome this neural-interface-technology challenge through the development of a portable hardware infrastructure that enables restoration of the failed motor/sensor-system communication. This project is currently funded by DARPA under the Hand Proprioception and Touch Interfaces (HAPTIX) Program in collaboration with Drs. Rizwan Bashirullah, Jose C. Principe and Kevin Otto.

Closing the Loop on Tremor: Responsive Deep Brain Stimulation for the Treatment of Essential Tremor

Medtronic Neuromodulation Imagined Coffee Pot Update 033015-01

Essential tremor (ET) is an incurable, degenerative brain disorder that results in increasingly debilitating tremor, and afflicts an estimated 7 million people in the US (2.2% of the population). The tremor associated with ET is typically slow (~5 Hz), involves the hands (and sometimes the head and voice), worsens with intentional movements, and is insidiously progressive over many years. DBS has emerged as a highly effective treatment for intractable, debilitating ET. However, for most patients with ET, tremor is absent at rest and begins at the initiation of goal-directed movement. Hence current DBS systems may be delivering unnecessary current to the brain that increases undesirable side effects such as slurred speech and walking difficulty, and hastens the depletion of device batteries, necessitating more frequent surgical procedures to replace spent pulse generators. Our objective is to provide preliminary data on the safety and efficacy of “closed-loop” DBS for intention tremor using novel DBS devices capable of continuously sensing brain activity and delivering therapeutic stimulation only when necessary to suppress tremor. This project is currently funded by a BRAIN Initiative grant (Gunduz & Foote).