Bionics 3
Kevin Warwick
www.kevinwarwick.com
http://en.wikipedia.org/wiki/Kevin_Warwick
Animals & Experiments
• Animal testing/experiments can be
questioned from an ethical viewpoint
• Interested here more in neural aspects
• Not chemical
• Not external
• Behavioural?
• Humans are animals!
Pavlov’s Dogs
• Pavlov performed experiments on
digestion which earned him the 1904
Nobel Prize. These included
surgically extracting portions of the
digestive system from animals,
severing nerve bundles to determine
the effects, and implanting valves
between digestive organs and an
external pouch to examine the
organ's contents.
Pavlov’s Dogs
• Research on reflex actions
involved involuntary reactions to
stress and pain. Pavlov began
the study of transmarginal
inhibition (TMI), the body's
natural response of shutting
down when exposed to
overwhelming stress or pain. His
research showed that all
temperament types responded to
the stimuli the same way, but
different temperaments move
through the responses at
different times. He felt this was
due to a different type of
nervous system.
Pavlov’s Dogs
• It is popularly believed that Pavlov always signalled the
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occurrence of food by ringing a bell. However, his
writings record the use of a wide variety of stimuli,
including whistles, tuning forks and visual stimuli, in
addition to ringing a bell.
Carl Jung continued Pavlov's work on TMI and correlated
the observed shutdown types in animals with his own
introverted and extroverted temperament types in
humans. Introverted persons, he believed, were more
sensitive to stimuli and reached a TMI state earlier.
William Sargent continued the behavioural research in
mental conditioning to achieve memory implantation and
brainwashing.
José Delgado
• Delgado used what he called a stimoceiver, a
radio which joined a stimulator of brain waves
with a receiver which monitored EEG waves
and sent them back on separate radio
channels.
• He said that Radio Stimulation of different
points in the amygdala and hippocampus
produces a variety of effects, including pleasant
sensations, elation, deep, thoughtful
concentration, odd feelings, super relaxation,
coloured visions, and other responses.
José Delgado
• Once Delgado stepped into the ring with a bull which
had had a stimoceiver implanted. The bull charged
Delgado, who pressed a remote control button which
caused the bull to stop. Delgado claimed that the
stimulus caused the bull to lose its aggressive instinct.
• Delgado believed that his experiment with a female
chimpanzee named Paddy was more significant. Paddy
was fitted with a stimoceiver that detected a brain signal
called a spindle. When a spindle was detected, the
stimoceiver responded with a signal to the central gray
area of Paddy's brain, producing an 'aversive reaction'.
Within hours her brain was producing many fewer
spindles.
Cockroach Backpack
• At the University of
Tokyo electrodes
were inserted into
the antennae of a
cockroach – signals
were sent to cause
the cockroach to go
forwards/backwards,
left/right.
Lamprey
• At Northwestern University, Mussa-Ivaldi
built a two-wheeled robot that operated
on the electrical signals of a lamprey’s
brain. The part of the brain used in the
experiment normally keeps the lamprey
upright in the water. When connected up
correctly, the organ can guide the robot
towards a light source.
Miguel Nicolelis
• Miguel Nicolelis at Duke University, North
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Carolina, wired a monkey brain to control a
robot arm that mimicked the motions of its real
arm. "It was an amazing sight to see the robot
in my lab move, knowing that it was being
driven by signals from a monkey brain at Duke,"
said [Massachusetts Institute of Technology's]
Mandayam Srinivasan. "It was as if the monkey
had a 600-mile- (950-km-) long virtual arm.“
KW comment – no direct feedback (only visual).
John Chapin
• Remote controlled rats! Movement signals are
transmitted from a computer to the rat's brain via a radio
receiver strapped to its back. One electrode stimulates
the "feelgood" center of the rat's brain, while two other
electrodes activate the cerebral regions which process
signals from its left and right.
John Chapin II
• In a separate experiment John implanted
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electrodes into the planning area in the brains of
6 rats.
The rats were taught to push a lever to obtain a
liquid treat.
Signals were sent via the implant to cause the
treat to be released without the need for the rat
to actually push the lever.
4 out of 6 rats learned they didn’t need to push
the lever – thinking about pushing it was fine.
Brain Stimulation
• In 1870, two German researchers named Hitzig
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and Fritsch electrically stimulated the brains of
dogs, demonstrating that certain portions of the
brain were the centres of motor function.
Bartholow, within four years, demonstrated that
the same was true of human beings.
By the turn of the [twentieth] century Krause
was able to do a systematic electrical mapping
of the human brain, using conscious patients
undergoing brain surgery.
Hess
• Hess, began his research into Electrical
Stimulation of the Brain in the 1930s,
jolting patients' brains with shocks
administered through tiny needles that
pierced the skull.
• His experiments included the insertion of
fine electrically conductive wires into the
brains of anaesthetized cats.
• Given mild electrical stimulation the cats
went beserk.
Penfield
• During the 1940s and 50s, Penfield
experimented with electrical brain
stimulation on human patients undergoing
surgery.
• One of Penfield's discoveries was that the
application on alert patients could
stimulate the memory of past events.
Pleasure??
• In 1956, Olds reported on research in which he
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had electrically stimulated the brains of rats.
Implanting electrodes in rats' pleasure centre of
the brain, he attached a button that allowed the
rats to activate the electrical impulse
themselves.
The rats were able to choose between food and
immediate pleasure.
Olds found that the rats became so obsessed
with self-stimulation that they would literally
starve themselves to death.
Later repeated with monkeys
Monkeys
• Using high-tech brain scans on monkeys,
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researchers determined that a small clump of
cells are active in the formation of the desire
(plan) to carry out specific body movements.
Armed with this knowledge, researchers at
CALTECH implanted electrodes in the cortex of a
rhesus monkey trained to play a simple video
game.
A computer program, hooked up to the
implanted electrodes then moved a cursor on
the computer screen in accordance with the
monkey's desires - left or right, up or down.
Tipu Aziz/Parkinson
• Tipu’s work involves inducing
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Parkinsonian symptoms in monkeys,
either surgically or chemically, then
switching off the symptoms using
implanted electrodes.
As many as 40,000 PD people around the
world have benefitted from the
technique.
The technique, which Aziz pioneered in
the UK, has been shown to alleviate
symptoms in human sufferers of PD and
dystonia.
Patients have electrodes permanently
implanted in their brains, wires are
attached under the skin to a control chip,
and a battery inserted into the chest.
We will look at this in more depth later in
the course
Cultured Neural Network
• Culture brain cells directly on to a recording
surface and re-embody the ‘brain’ within a robotic
body.
– Multi-Electrode Array (MEA) allows
recording from 128 electrodes
across the entire culture.
200m
TiN Electrodes
30m diameter
Neurone
Embodiment
• Re-embodiment is essential
– Without it the neurones are simply talking to themselves
resulting in no meaningful input / output relationship.
– This can be demonstrated in animals that have developed
in a sensory deprived environment – the relative areas of
the brain simply do not form the appropriate connections
and the animal has limited functionality.
– Embodying the culture with a robot body means that it’s
actions will result in specific sensory input which in
turn should influence future ‘decisions’.
Previous work
Animat (Potter’s group)
Created a closed loop system which
successfully
demonstrated approach / avoidance behaviour.
Used a similar system to fly a simulated
plane.
Angle of roll mapped on to culture, plane
stable in strong
simulated winds.
T. B., Demarse, D. A. Wagenaar, A. W. Blau and S. M. Potter, (2001).
‘The neurally controlled
Methodology
• Culture to Robot Mapping
– How can the activity of the culture be mapped to the robot’s actuators
and the robots sensors on to stimulate the culture.
• Biological Aspects
– The methods behind culturing maintaining and interfacing with
neurones.
• Neural signal interpretation
- Dimensionality reduction and processing before sending to robot.
Culture Protocol
• MEAs coated with PDL (Poly-d-lysine) which allows neurones to adhere
to the surface
• Primary cortical neurones enzymatically dissociated – this breaks down
the connective tissue before trituration which breaks off the axons and
dendrites effectively leaving neural cells in a ‘blank’ state.
• Dissociated cells are suspended in media and added to the MEA
chamber.
• Cells are fed day 1 and every 4 days after with a glucose based media
• After a 1-2 days connections spontaneously reform and begin to resume
activity, initially with single spikes and after roughly a week complex
burst patterns are seen.
Protocol Modifications
• Selective coating allows the neural
density to be increased near the
electrodes
• The use of younger animals may result
in undifferentiated cells that are be able
to adjust to be the most suitable cell
type for the location they land in.
Spike Sorting
• A single electrode may pick up signals from over 100 neurones.
• It is essential to extract the useful signals from the noise and
attempt to separate out the spikes from different neurones.
• Spikes that originate from different neurones have different voltage
profiles (shapes) – although this is not always true.
• Before transmitting this information to the robot - need to apply
some form of dimensionality reduction, possibly involving Principal
Component Analysis (PCA)
3rd Generation (*40 magnification)
200 m