Human Brain

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Human Brain
the most complex living structure on the universe
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Dr. Abdel Ilah Alshbatat Tafila Technical
University
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CONTENTS

• Facts about Brain
• Brain Cells
• Lobes of the brain
• Synaptic Transmission
• Right Left Brain
• BCI
• Types of BCI
• How brain-computer interfaces work
• EEG
• Electrode placement
• Brain waves
• BCI applications

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Facts about Brain

• About 3 pounds (1,300 grams)
• 78 water, 10 fat, 8 protein
• Less than 2.5 of bodys weight
• Uses 20 of bodys 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

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Facts about Brain

• 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

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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

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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.  

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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)

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The nerve cell, or neuron
Synaptic Density
6 year old
2 year old
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Lobes of the Brain

• Frontal
• Parietal
• Occipital
• Temporal

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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
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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

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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.

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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)

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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.

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how the two sides process information that is!

• Left Brain
• Logical
• Sequential
• Rational
• Analytical
• Objective
• Looks at parts

• Right Brain
• Random
• Intuitive
• Holistic
• Synthesizing
• Subjective
• Looks at wholes

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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.

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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

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what information the two sides recognize!

• Left Brain
• Letters
• Numbers
• Words

• Right Brain
• Faces
• Places
• Objects

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Sensory and motor strips
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Auditory Activity
Visual Activity
Thinking Activity
Memory Activity
Motor Activity
Seeing,
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Brain-Computer Interfaces (BCI)
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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.

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WHAT IS BCI?

• Translate your brains electrical activity (EEGs)
  into messages or commands.

• The four BCI components acquisition,
  processing, output, environment.

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WHAT IS BCI?
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TYPES OF BCIs

• Invasive techniques, which implant electrodes
  directly onto a patients brain
• Noninvasive techniques, in which medical scanning
  devices or sensors mounted on caps or headbands
  read brain signals (EEG)

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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)

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HOW BRAIN-COMPUTER INTERFACES WORK
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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.

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PHYSICAL MECHANISMAS

• EEGs require electrodes attached to the scalp
  with sticky gel
• Require physical connection to the machine

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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

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Electrode Placement

• A more detailed view

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Continuous Brain Waves

• Generally grouped by frequency (amplitudes are
  about 100µV max)

Type Frequency Location Use
Delta lt4 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
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BCI APPLICATIONS

• Enabling disabled people
• Vision and hearing
• Paralysis treatment
• Prosthetic devices (legs, hands etc)
• Psychotherapy
• Diagnostics
• Treatment
• Military and civil research
• Making dangerous jobs

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BCI APPLICATIONS CONT

• Provide a means of communication to completely
  paralyzed patients
• Surgically implanted devices used as replacement
  for paralyzed patients
• Allow patients to control a computer by conscious
  changes of brain activity
• Allow those with poor muscle control to
• communicate and control physical devices

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• Thank You!