This document provides an overview of brain-computer interfaces (BCIs). It discusses the history of BCIs, how they work, different types including invasive, partially invasive and non-invasive BCIs, applications such as assisting those with disabilities and human enhancement, examples of BCI projects, and challenges with the technology such as risks of invasive BCIs and need for training with non-invasive options. The document aims to cover introduction to BCIs, the role of neurons in generating signals, techniques like EEG and applications in areas like restoring vision and movement as well as augmenting cognition.
2. TOPICS TO BE COVERED…
INTRODUCTION
HISTORY
BRAIN
TYPES OF BCIs
BCI WORKING
BCI APPLICATIONS
BCI PROJECTS
BCI DRAWBACKS
3. A Brain Computer Interface creates a direct link
between the brain and a computer. It allows the
computer to be controlled by the brain and in some
cases can also send signals to the brain.
Brain-Computer Interfacing (BCI) can be used for
capturing brain signals and translating them into
commands that allow humans to control (just by
thinking) devices such as computers, robots,
rehabilitation technology and virtual reality
environments.
4. In 1924 Berger was the first one who recorded an EEG
from a human brain. By analyzing EEGs Berger was
able to identify different waves or rhythms which are
present in a brain, as the Alpha Wave (8 – 12 Hz), also
known as Berger's Wave.
The Advanced Research Project Agency (ARPA) of the
government of the United State of America became
interested in this field of research. They had the vision
of increasing the performance of mental high load
tasks by enhancing human abilities with artificial
computer power. But their attempt failed.
5. The first wireless brain-computer interface was build
by Philip Kennedy and his colleagues by implanting
neurotrophic cone electrodes into monkey brains.
By the year 2000, Miguel Nicolelis' group implanted
electrode arrays into multiple brain areas of monkeys.
They built a BCI system that was capable of
reproducing a monkey's movement, while reaching for
food or using a joystick in real time.
6.
7. One of the first persons who benefit from all the years
of BCI research is Matt Nagle. In 2004 an electrode
array was implanted into his brain to restore
functionalities he had lost due to paralysis.
The system required some training but finally he was
able to control the TV, check emails and do basically
everything that can be achieved by using a mouse. He
could also open and close a prosthetic hand.
8.
9. Our brain is the main reason why BCI work.
Our brains are filled with neurons, individual nerve
cells connected to one another by dendrites and axons.
Every time we think, move or feel, our neurons are at
work.
Some kind of electric signals are generated by these
nerves. These signals are generated by differences in
electric potential carried by ions on the membrane of
each neuron.
Scientists can detect those signals, interpret what they
mean and use them to direct a device of some kind.
10. There are three ways in which BCI technology is
implemented on humans. The three ways are:-
INVASIVE BCI
PARTIALLY INVASIVE BCI
NON INVASIVE BCI
11. Invasive BCIs are implanted directly into the grey
matter of the brain during neurosurgery. As they rest
in the grey matter, invasive devices produce the
highest quality signals of BCI devices.
WILLIAM DOBELLE was the first scientist to use BCI
in VISION SCIENCE.
In VISION SCIENCE, direct brain implants have been
used to treat non-congenital (acquired) blindness.
12. In 1998 researchers at Emory University in Atlanta led by
Philip Kennedy and Roy Bakay were first to install a brain
implant in a human that produced signals of high enough
quality to simulate movement.
In 2005, after nine months of human trial Cyberkinetics
Neurotechnology’s BrainGate chip-implant.
This brainGate chip is a technology used to cure patients
suffering with paralysis and locked in kind of syndrome
diseases.
13. Partially invasive BCIs is a milder or scaled down
version of Invasive BCIs.
Partially invasive BCI devices are implanted inside the
skull but rest outside the brain rather than amidst the
grey matter.
Unlike Invasive BCIs these have low risk of formation
of scar tissues in brain.
14. Non-Invasive BCIs rest outside the brain and tries to
capture the signals of the brain.
Although the waves can still be detected it is more
difficult to determine the area of the brain that created
them or the actions of individual neurons.
They produce poor signal resolution because the skull
dampens signals, dispersing and blurring the
electromagnetic waves created by the neurons.
Signals recorded in this way have been used to power
muscle implants and restore partial movement in an
experimental volunteer.
15. It uses following techniques:
Neuro-Imaging
Direct Neural Contact
Electroencephalography (EEG)
Magnetoencephalography (MEG)
Functional Magnetic Resonance Imaging (FMRI)
In these techniques a head cover with installed electrode
is attached to the brain.
16. It is the main technique used in Non-Invasive BCI.
It measures the electrical activity of the brain.
Due to its ease of use, cost and high temporal
resolution this method is the most widely used one in
BCIs nowadays.
DRAWBACKS:-
In practice EEGs are highly susceptible to noise.
Another substantial barrier to using EEG as a brain–
computer interface is the extensive training required
before users can work the technology.
17. MEG is a much newer and more accurate technology.
Instead of measuring the electrical activity in the brain
this technology records magnetic fields produced by
it.
The main drawbacks of this technology are its high
requirements in equipment.
18. This technique measures the haemodynamic response
(blood flow and blood oxygenation) known as
Magnetic Resonance Tomography (MRT).
In contrast to the MRI which studies the brain’s
structure this method studies the brain’s function.
As this method requires MRI technology it needs very
special equipment and thus is quite costly.
19. scientists can implant electrodes directly into the gray
matter of the brain itself, or on the surface of the brain,
beneath the skull.
The electrodes measure minute differences in the
voltage between neurons. The signal is then amplified
and filtered, it is then interpreted by a computer
program.
In the case of a sensory input BCI, the function
happens in reverse. A computer converts a signal, such
as one from a video camera, into the voltages necessary
to trigger neurons.
20.
21. BCI APPLICATIONS
Medical applications
BCIs provide a new and possibly only communication
channel for people suffering from severe physical
disabilities but having intact cognitive functions.
For example these devices could help in treating (or
rather overcoming) paraplegia or amyotrophia, the
most widespread neuroprosthetic is the cochlear
implant or bionic ear. This device can help people with
impaired hearing.
22. BCI APPLICATIONS
Human enhancement
Human enhancement describes any attempt (whether
temporary or permanent) to overcome the current
limitations of human cognitive and physical abilities,
whether through natural or artificial means.
For eg. Brainwave synchronization is the practice to entrain
one's brainwaves to a desired frequency, by means of a
periodic stimulus with corresponding frequency.
An exocortex (speculative) is an external information
processing system that augments, in a subtle and seamless
fashion via a brain-computer interface, the brain's
biological high-level cognitive processes.
24. In case of Invasive BCI there is a risk of formation of scar
tissue.
There is a need of extensive training before user can use
techniques like EEG
BCI techniques still require much enhancement before
they can be used by users as they are slow.
Ethical implications of BCI will arise in future
BCI techniques are costly. It requires a lot of money to
set up the BCI environment.
