Monitor Neural Activity

ABSTRACT The proposed project will build and evaluate the safety and design needs of a new type of intracranial auditory prosthesis that targets the auditory nerve between the cochlea and the brainstem (auditory nerve implant, ANI) in order to substantially improve hearing performance over the current standard of care, the cochlear implant (CI). Current CIs provide crucial speech information to many recipients, but do not restore normal hearing, and are particularly challenged in noisy or complex acoustic environments.

ABSTRACT The goal of this U44 proposal is to develop and test CranialProgrammer, an image-guided programming tool for 2D/3D mapping of disease-related neural signals over patient and device data for more efficient and effective programming of directional deep brain stimulation (DBS) systems. DBS is an established treatment for advanced, refractory movement disorders used in over 150,000 patients.

Project Summary/Abstract Action initiation and withholding are key parts of everyday behavior, and underlying these is action suppression. This includes (1) suppressing competing actions when selecting one action from alternatives (2) suppressing all responses when presented with conflicting information until a proper decision can be made and (3) suppressing a response when the environment rapidly changes indicating a pre-planned response must be stopped. The literature suggests that these three functions are supported by distinct fronto-basal ganglia (BG) circuits.

ABSTRACT In the course of a day we naturally make multiple shifts in our overall cognitive state and in our aims and intents. We go from sleep to awake, from internal dialogue to external communication, from relative immobility to planned complex movements. The neural activity which distinguishes these different high-level states is unknown and yet is a fundamental aspect to understanding overall cognitive processes. It is also a baseline substrate that is adversely impacted by a wide range of neuropsychiatric diseases.

Speech production and control is disrupted in a number of neurological diseases that involve the basal ganglia. Notably, hypophonia and hypokinetic dysarthria (characterized by decreased motor gain) are prevalent in patients with Parkinson's disease (PD). Deep brain stimulation (DBS) of the subthalamic nucleus (STN) produces predictable improvements in other motor symptoms of PD but does not result in consistent improvement in speech and can negatively impact language function. These observations and other accumulating evidence indicate an important role for the basal ganglia in speech.

PROJECT SUMMARY Speaking is one of the most complex actions that we perform, yet nearly all of us learn do it effortlessly. The ability to communicate through speech is often described as the unique and defining trait of human behavior. Despite its importance, the basic neural mechanisms that govern our ability to speak fluently remain unresolved.

Project summary/abstract Reach-to-grasp and hand manipulation will be studied in tetraplegic humans with neural recordings from multielectrode arrays (MEAs) and intracortical microstimulation (ICMS) of somatosensory cortex. Recordings will be performed within the cortical grasp circuit with MEAs implanted in two grasp-related areas, the ventral premotor cortex (PMv) and the anterior intraparietal area (AIP) of the posterior parietal cortex (PPC). ICMS will be delivered to Brodmann's area 1 (BA1) of somatosensory cortex.

ABSTRACT – (Title: Dynamic Neural Mechanisms of Audiovisual Speech Perception) Natural speech perception is multisensory; when conversing with someone that we can see, our brains combine visual (V) information from face, postural and hand gestures with auditory (A) information from the voice. The underlying speech processing is extremely rapid, with incoming AV units (e.g., syllables) arriving every few hundred milliseconds that must be encoded and passed on before the next syllable arrives.

Most current approaches to understanding the neural basis of cognitive processes are severely limited in two respects. First, most commonly used methods do not have the temporal (e.g., fMRI) or spatial (e.g., MEG/ EEG) resolution to capture the relevant dynamics. Second, even methods with high spatio-temporal resolution (intracranial EEG - icEEG) typically approach target cognitive processes in a fragmentary, un- integrated way.

Abstract In this proposal, we will develop next-generation flexible micro-electrocortigraphic (µECoG) and penetrating electrode arrays using active electronics in complementary metal-oxide-semiconductor (CMOS) technology. Active electronics enable amplification and multiplexing directly at each electrode, eliminating the need for implanted electrodes to be individually wired to remote electronics and greatly increasing the number and density of electrodes that can be recorded and stimulated.