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ROSANA Project
Representation Of Stimuli As Neural
Activity
UCM-UAM-FrI-UPo-UEs
“Perception”
⇩
“Internal Representation” of the external world
Understand the fundaments of perception
Determine the principles of coding of sensory stimuli
Interactions sensory inputs - activity of CNS neurons
we will be able to reproduce the same spatiotemporal
pattern of activity
Lemniscal somatosensory system
500.000
10.000
Our Experiment
State of the project (started May 2002)
•We set-up a complete electrophysiology lab
•We implanted sieve microelectrodes in the peripheral nerve of rats and cats
•We obtained functional regeneration of the sensory nerves
•We recorded the electrical activity of the regenerated nerves
•We recorded electrical activity simultaneously from the regenerated nerve
and from neurons in the CNS
•We developed mathematical and computational models of oscillating neurons
•We deveoped specific microstimulators to control the stimulation
•We are developing new microstimulators to control the stimulation
•We are developing new mathematical and computational models
•We are developing new microelectrodes
•We are setting-up the 140 simultaneous recording procedure
•We are setting-up the new data analysis techniques
B
100
50
50
0
0
0
0.5
1.0 s
0
0.5
C
30
1.0 s
D
250
A
150
150
50
50
B
40
0
10
0
0
0
-40
0.5
1.0 s
0
0.5
1.0 s
0
0
0.05
0.10 s
-1.0
-0.5
0
0.5
1.0 s
30
espigas
esp ig as
80
20
250
espigas
espigas
A
100
D
V
D
20
200
10
0
-0.2
C
600
C
0
-200
0
0.2
0.4 s
-1
0
1s
R
Glomeruli
DENDRITES
Gr
PROJECTION
NEURONS
Cu
Amplitud (mV)
40
0
-40
-80
-30
20
40 s
Amplitud (mV)
0
7,5 HZ
-60
2s
-64
-50
-68
-30
Amplitud (mV)
-70
6,0 Hz
-30
-50
-50
-70
-70
0
Azar
10000
20000
30000
0
10
20
30 s
Problems to be solved
1.
If artificial sensors are to be directly connected to the nerve(s), only a very
low number of fibers can be interfaced
2.
Interfacing of artificial sensors to a sensory nerve will submit to each axon
information concerning different sensory submodalities in an entirely
unpredictable fashion