Download - OBC | Observing the brain to know ourselves
Observing the brain to know ourselves
Sara A. Solla
Northwestern University
The human brain
The human brain
Neurons
About 85 billion neurons,
of which about 15 billion
are in the cortex.
Neurons
Neurons
electrode
Spikes: action potentials
Spikes: from single neurons
to multiple neurons
Multi Electrode Arrays (MEAs)
Reaching tasks
Center out task
MEA recordings: center out task
MEA recordings: multiple targets
Converting thoughts into actions
Nicolelis, Nature Reviews Neuroscience (2003)
Brain machine interfaces Idea first proposed by Edward M. Schmidt in 1980: `Single
neuron recording from motor cortex as a possible source of
signals for control of external devices’.
Schmidt, Annals of Biomedical Engineering (1980)
Multi Electrode Arrays (MEAs)
Truccolo, Hochberg, Donoghue, Nature Neuroscience (2009)
Activity: multiple neurons
110 neurons, M1, hS3
Brain machine interfaces
Neuroprosthesis
Hochberg, Serruya, Friehs, Mukand, et al, Nature (2006)
Neuroprosthesis
MEA recordings: center out task
Target-dependent population activity
fi =ni
D
Here is the number of spikes
emitted by neuron i during a time
bin of duration .
ni
D
Decoding direction of motion
for center out task
Predicting motion from neural activity
Simultaneous recordings of population activity
provide insight on the activity of networks of neurons
and its relation to function.
The ability to simultaneously record and decode the
activity of large populations of neurons provides a tool for
the restoration of function.
The mathematical analysis of neural activity associated
with arm reaches allows us to predict motion trajectory.
• Incorporate realistic limb dynamics into forward pathway
• Incorporate proprioception in feedback pathway
Bidirectional Brain Machine Interface