Brain-state classification and a dual-state decoder dramatically improve the control of cursor movement through a brain-machine interface.

Objective: It is quite remarkable that brain machine interfaces (BMIs) can be used to control complex movements with fewer than 100 neurons. Success may be due in part to the limited range of dynamical conditions under which most BMIs are tested. Achieving high-quality control that spans these conditions with a single linear mapping will be more challenging.

Multimodal decoding and congruent sensory information enhance reaching performance in subjects with cervical spinal cord injury.

Cervical spinal cord injury (SCI) paralyzes muscles of the hand and arm, making it difficult to perform activities of daily living. Restoring the ability to reach can dramatically improve quality of life for people with cervical SCI. Any reaching system requires a user interface to decode parameters of an intended reach, such as trajectory and target.

Benzalkonium chloride-induced denervation of orbicularis oculi muscle in rabbits.

Purpose: To examine the potential for benzalkonium chloride (BAK) to cause denervation of the orbicularis oculi muscle (OOM) in a rabbit model.

Methods: Pigmented rabbits were separated into five groups consisting of five rabbits each. Group 1 was injected with 1 mL of BAK 0.

Functional connectivity and tuning curves in populations of simultaneously recorded neurons.

How interactions between neurons relate to tuned neural responses is a longstanding question in systems neuroscience. Here we use statistical modeling and simultaneous multi-electrode recordings to explore the relationship between these interactions and tuning curves in six different brain areas. We find that, in most cases, functional interactions between neurons provide an explanation of spiking that complements and, in some cases, surpasses the influence of canonical tuning curves.

Continuous movement decoding using a target-dependent model with EMG inputs.

Trajectory-based models that incorporate target position information have been shown to accurately decode reaching movements from bio-control signals, such as muscle (EMG) and cortical activity (neural spikes). One major hurdle in implementing such models for neuroprosthetic control is that they are inherently designed to decode single reaches from a position of origin to a specific target. Gaze direction can be used to identify appropriate targets, however information regarding movement intent is needed to determine when a reach is meant to begin and when it has been completed.

Dealing with noisy gaze information for a target-dependent neural decoder.

We tend to look at targets prior to moving our hand towards them. This means that our eye movements contain information about the movements we are planning to make. This information has been shown to be useful in the context of decoding of movement intent from neural signals.

Statistical assessment of the stability of neural movement representations.

In systems neuroscience, neural activity that represents movements or sensory stimuli is often characterized by spatial tuning curves that may change in response to training, attention, altered mechanics, or the passage of time. A vital step in determining whether tuning curves change is accounting for estimation uncertainty due to measurement noise. In this study, we address the issue of tuning curve stability using methods that take uncertainty directly into account.

Kinematics of electrically elicited eyelid movement.

Electrical stimulation has demonstrated potential for reanimating eye blink following facial paralysis caused by damage to the seventh cranial nerve. This study investigated the kinematics of lid movement caused by electrical stimulation of the orbicularis oculi muscle in both normal rabbit and rabbit with surgically induced seventh nerve lesion.

Development of a BIONic muscle spindle for prosthetic proprioception.

The replacement of proprioceptive function, whether for conscious sensation or feedback control, is likely to be an important aspect of neural prosthetic restoration of limb movements. Thus far, however, it has been hampered by the absence of unobtrusive sensors. We propose a method whereby fully implanted, telemetrically operated BIONs monitor muscle movement, and thereby detect changes in joint angle(s) and/or limb posture without requiring the use of secondary components attached to limb segments or external reference frames.

Electrical stimulation of the paralyzed orbicularis oculi in rabbit.

Dysfunction of the seventh cranial nerve often results in facial paralysis and loss of the ability to blink the eye, which can lead to corneal scarring, diminished vision, and potential loss of the eye. This study investigated the potential of electrical stimulation of the orbicularis oculi muscle as a means of restoring blink function. An animal model of orbicularis paralysis was created by sectioning the seventh cranial nerve in rabbit.

Virtual Visit: improving communication for those who need it most.

We are developing a videoconferencing system designed specifically to cater to the needs of the elderly and their distant friends and family. Focus group research has led to the incorporation of several key features that enhance the usability of the system. Audio and video transmission quality are optimized by separation, using the proven and familiar capability of analog phone for voice and the slightly less reliable, but faster data transmission of broadband Internet for video.