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Human Brain
the most complex living structure on the universe
ت
ِ س ۡو َرۃ ُ الذّٰ ِر ٰی
ُ -- َْص ُر ۡون
ِ َو ِف ۡۤۡی ا َ ۡنفُ ِس ُك ْمؕ اَفَ ََل تُب
Dr. Abdel Ilah Alshbatat
Tafila Technical University
CONTENTS
1. Facts about Brain
2. Brain Cells
3. Lobes of the brain
4. Synaptic Transmission
5. Right & Left Brain
6. BCI
7.Types of BCI
8. How brain-computer interfaces work
9.EEG
10.Electrode placement
11.Brain waves
12.BCI applications
Facts about Brain
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About 3 pounds (1,300 grams)
78% water, 10% fat, 8% protein
Less than 2.5% of body’s weight
Uses 20% of body’s energy
People only use 10% of their brain
100 billion neurons (Greek word meaning
bowstring)
• 1 trillion glial cells (Greek word meaning glue)
• 1,000 trillion synaptic connection points
• 280 quintillion memories
Facts about Brain
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Brain is modified by environment
Brain is adaptable Plasticity ‘Use it or Lose it’
Left and Right Hemispheres
Left hemisphere for most people is the dominant
hemisphere- responsible for production of
language, mathematical ability, problem solving,
logic
• Right hemisphere thought to be responsible for
creativity and spatial ability
• Everything people have ever experienced is
stored somewhere in their brain
• At birth people have all the neurons that they will
ever have
Two Kinds of Brain Cells
• Glia - (Greek word meaning glue)
– 90% of the brain cells
– Less known about glia cells
– No cell body
– Remove dead brain cells and give structural
support
• Neurons (Greek word meaning bowstring)
– 100 billion neurons in human brain
– Neurons essential to performing the brain's
work
– Consist of a compact cell body, dendrites, and
axons
Neurons
• Neurons (brain cells) make connections between
different parts of the brain.
• Information is carried inside a neuron by electrical
pulses and transmitted across the synaptic gap
from one neuron to another by chemicals called
neurotransmitters.
• Learning is a critical function of neurons.
Dendrites and Axons
• Dendritic branching helps make connections
between cells.
• As cells connect with other cells, synapses
occurs.
• New synapses appear after learning.
• Repeating earlier learning makes neural pathways
more efficient through myelination (fatty
substances formed around axons, Myelination
enables nerve cells to transmit information faster and
allows for more complex brain processes)
Synaptic Density
2
year
old
The nerve cell, or
neuron
6
year
old
ۤۡ
َوہللاُ َخلَقَ ُك ْم ث ُ َّم یَت َ َوفّٰى ُك ْم ۟ۙ َو ِم ۡن ُك ۡم َّم ۡن ی َرد اِ ٰلی اَ ْرذَ ِل ْالعُ ُم ِر ِلک َۡی ََل یَ ْعلَ َم بَ ْعدَ ِع ْل ٍم
س ۡو َرۃ ُ النَّ ۡح ِل
ع ِل ۡی ٌم قَد ِۡی ٌر ُ ---
ہللا َ
ش َۡیئًاؕ اِ َّن َ
Lobes of the Brain
•
•
•
•
Frontal
Parietal
Occipital
Temporal
Lobes of the Brain - Frontal
• The Frontal Lobe of the brain is located deep to the
Frontal Bone of the skull.
• It plays an integral role in the following
functions/actions:
- Memory Formation
- Emotions
- Decision Making/Reasoning
- Personality
Lobes of the Brain - Parietal Lobe
• The Parietal Lobe of the brain is located deep to
the Parietal Bone of the skull.
• It plays a major role in the following functions/actions:
- Senses and integrates sensation(s)
- Spatial awareness and perception
Lobes of the Brain – Occipital Lobe
• The Occipital Lobe of the
Brain is located deep to the
Occipital Bone of the Skull.
• Its primary function is the
processing, integration,
interpretation, etc. of VISION
and visual stimuli.
Lobes of the Brain – Temporal Lobe
• The Temporal Lobes are located on the sides of
the brain, deep to the Temporal Bones of the
skull.
• They play an integral role
in the following functions:
- Hearing
- Organization/Comprehension of
language
- Information Retrieval
(Memory
and Memory Formation)
Right & Left Brain
• Two sides or hemispheres of the brain: LEFT and
RIGHT
• We have two cerebral hemispheres connected
by the corpus callosum. This is a bundle of
nerves that allows each side of the brain to
communicate with each other.
• Each side of the brain processes things
differently.
how the two sides process information
that is!
Left Brain
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Logical
Sequential
Rational
Analytical
Objective
Looks at parts
Right Brain
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Random
Intuitive
Holistic
Synthesizing
Subjective
Looks at wholes
Left Hemisphere
• processes things more in parts and
sequentially
• recognizes positive emotions
• Identified with practicality and rationality
• Understands symbols and representations
• Processes rapid auditory information faster
than the right (crucial for separating the
sounds of speech into distinct units for
comprehension)
• is responsible for language development. It
develops slower in boys, that is why males
usually develop more language problems than
females.
Right Hemisphere
• Recognizes negative emotions
• High level mathematicians, problem
solvers, and chess players use
• Responds to touch and music (sensory)
• Intuitive
• Responsive to color and shape
• Emotional and originative
what information the two sides
recognize!
Left Brain
• Letters
• Numbers
• Words
Right Brain
• Faces
• Places
• Objects
Sensory and motor strips
Thinking Activity
Visual Activity
Auditory Activity
Memory Activity
Motor Activity
Seeing, ………
Brain-Computer Interfaces (BCI)
WHAT IS BCI?
• A Brain-Computer Interface (BCI) is a device that
enables communication without movement
• BCI can help people with inabilities to control
computers, wheelchairs, televisions, or other
devices with brain activity.
WHAT IS BCI?
• Translate your brain’s electrical activity (EEGs)
into messages or commands.
The four BCI components: acquisition, processing,
output, environment.
WHAT IS BCI?
TYPES OF BCIs
• Invasive techniques, which implant electrodes
directly onto a patient’s brain
• Noninvasive techniques, in which medical
scanning devices or sensors mounted on
caps or headbands read brain signals (EEG)
WHY BCI?
• BCI is a new neuroscience paradigm that
might help us better understand how the
human brain works
• BCI research allows us to develop a new
class of bioengineering control devices and
robots
• BCI hold promise for rehabilitation and
improving performance
• BCI can expand possibilities for advanced
human computer interfaces (HCIs)
HOW BRAIN-COMPUTER INTERFACES WORK
WHAT IS AN EEG?
• An electroencephalogram is a measure of the
brain's voltage fluctuations as detected from
scalp electrodes.
• It is an approximation of the cumulative
electrical activity of neurons.
• EEG measures the electrical activity of the
brain with multiple electrodes placed on the
scalp
• It is portable and relative inexpensive that is
why most noninvasive BCIs are presently
based on EEG.
PHYSICAL MECHANISMAS
• EEGs require electrodes
attached to the scalp with
sticky gel
• Require physical connection
to the machine
Electrode Placement
• Standard “10-20 System”
• Spaced apart 10-20%
• Letter for region
– F - Frontal Lobe
– T - Temporal Lobe
– C - Center
– O - Occipital Lobe
• Number for exact position
– Odd numbers - left
– Even numbers - right
Electrode Placement
• A more detailed view:
Continuous Brain Waves
• Generally grouped by frequency: (amplitudes
are about 100µV max)
Type
Frequency
Location
Use
Delta
<4 Hz
everywhere
occur during sleep, coma
Theta
4-7 Hz
temporal and parietal
correlated with emotional stress
(frustration & disappointment)
Alpha
8-12 Hz
occipital and parietal
reduce amplitude with sensory
stimulation or mental imagery
Beta
12-36 Hz
parietal and frontal
can increase amplitude during
intense mental activity
Mu
9-11 Hz
frontal (motor
cortex)
diminishes with movement or
intention of movement
Lambda
sharp,
jagged
occipital
correlated with visual attention
Vertex
higher incidence in patients with
epilepsy or encephalopathy
BCI APPLICATIONS…
• Enabling disabled people
o Vision and hearing
o Paralysis treatment
o Prosthetic devices (legs, hands etc)
• Psychotherapy
o Diagnostics
o Treatment
• Military and civil research
o Making dangerous jobs
…
BCI APPLICATIONS CONT
o Provide
a means of communication to
completely paralyzed patients
o Surgically
implanted devices used as
replacement for paralyzed patients
o Allow
patients to control a computer by
conscious changes of brain activity
o Allow
those with poor muscle control to
communicate and control physical devices
Thank You!