Transcript Document 7303916

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
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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!