Marc Schieber's Lab - Research Projects
Here are some of the projects we are working on now:
- The effects observed in spike-triggered averages of EMG can be narrow or wide (in time). Narrow effects with an appropriate latency after the M1 neuron's spike represent relatively direct synaptic connections from the M1 neuron to the motoneuron pool, and are termed pure post-spike effects. Wide effects, especially if they begin before the M1 spike, indicate that other neurons which also have inputs to the same motoneuron pool are discharging spikes synchronized with the recorded M1 neuron, and are termed synchrony effects. We recently found that synchrony effects were much more common in monkeys trained for a long time than in monkeys trained for a shorter time, implying that learning skilled movements entails increasing the synchronization among neurons that provide input to motoneuron pools. We now are examining the relationship between training and synchrony among motor cortex neurons in greater detail to determine whether the increase in synchrony is related to duration of practice, movement repertoire, etc.
- Every time you use your hand to do something, like pick up a pencil, your brain chooses which hand to use, where to look, and which pencil to pick up. Previously we have found that inactivating a region of the ventral premotor cortex biases the choice of which object (on the right or left) to pick, and which hand to use in getting it. Now we are using neuron recording, intracortical microstimulation, and muscimol inactivation to examine how the premotor cortex contributes to the choices of which way to look, which target to take, and which hand to use.
- We are participating in the Revolutionizing Prosthetics project organized by the Applied Physics Laboratory of Johns Hopkins University. This project aims to develop a neurally driven upper extremity prosthesis with a dexterous hand. Our lab is contributing to development of methods for controlling the dexterous hand from neural signals.
