Single neuron recordings and microstimulation in humans
Event details
| Date | 11.11.2014 |
| Hour | 14:00 › 15:00 |
| Speaker | Dr. Michael R. H. Hill, University of Bonn & California Institute of Technology |
| Location | |
| Category | Conferences - Seminars |
For diagnostic purposes patients suffering from intractable epilepsy are routinely implanted with clinical deep brain recording electrodes. Adding research micro-electrodes to such a setup can provide the rare opportunity to record single neuron responses in awake behaving human subjects. However, trial numbers and the signal-to-noise ratio in such datasets are inherently low due to clinical circumstance. We therefore developed a new algorithm to significantly increase the sensitivity and specificity in the analysis of peristimulus time histogram based data in human as well as non-human research. This algorithm was then applied together with other novel analysis methods to investigate single neuron correlates of social decision making in the human medial prefrontal cortex (mPFC), anterior cingulate cortex (ACC) and amygdala.
In this research project subjects were asked to play a card game in which they could optimize their winnings by observing their own and other players’ decisions and outcomes. We recorded various outcome and learning specific responses including single neuron encoding of amounts in mPFC ($10 vs $100) and single neuron encoding of observed outcomes as well as the encoding of learning while observing other players in the ACC (social reward prediction error).
To move from correlative findings such as these to a direct causal investigation of human neuronal activity we additionally developed chronic microstimulation protocols in humans. Microstimulation allows for precisely targeted modulation of neuronal activity; however, due to increased risk it is rarely applied in human research. We developed new protocols and hardware for safe microstimulation in humans and applied these in a memory encoding and retrieval paradigm. In this ongoing study we were able to show that microstimulation of the entorhinal cortex can significantly decrease memory performance. Through the development of new methods such as these, and their application in various cognitive research paradigms, human intracranial electrophysiology can provide rare insight into the activity of single neurons in awake and behaving humans.
In this research project subjects were asked to play a card game in which they could optimize their winnings by observing their own and other players’ decisions and outcomes. We recorded various outcome and learning specific responses including single neuron encoding of amounts in mPFC ($10 vs $100) and single neuron encoding of observed outcomes as well as the encoding of learning while observing other players in the ACC (social reward prediction error).
To move from correlative findings such as these to a direct causal investigation of human neuronal activity we additionally developed chronic microstimulation protocols in humans. Microstimulation allows for precisely targeted modulation of neuronal activity; however, due to increased risk it is rarely applied in human research. We developed new protocols and hardware for safe microstimulation in humans and applied these in a memory encoding and retrieval paradigm. In this ongoing study we were able to show that microstimulation of the entorhinal cortex can significantly decrease memory performance. Through the development of new methods such as these, and their application in various cognitive research paradigms, human intracranial electrophysiology can provide rare insight into the activity of single neurons in awake and behaving humans.
Links
Practical information
- Informed public
- Free
Organizer
- Center for Neuroprosthetics
Contact
- Aude Rousic