History of Mind

In 1800, Franz Gall suggested that bumps of the skull represented mental abilities. His theory, though incorrect, nevertheless proposed that different mental abilities were diverse.Organizer no. 1

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Phrenology

Neural Communication

The body’s information system is built from billions of interconnected cells called neurons.

Glial cell: this acts as a support system for neurons.

When a neuron fires the first bit of the axon opens its gates, like manhole covers flipping open. Axons are like dominoes falling. This process repeats up to 1,000 times a second. Organizer no. 2

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Neuron Communication

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http://www.youtube.com/watch?v=FR4S1BqdFG4&feature=related

Neuron Nerve cells that connect with synapses. Chemical substances cross the gap from one nerve cell to another sending messages through the body. Organizer no. 3

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Excitatory and Inhibitory Processes Excitatory: signals from

hundreds of neurons to other neurons. Like pushing a accelerator.

Inhibitory: signals from neurons that are like pushing a brake.

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All or None Law

Neuron completely fires or it doesn’t fire at all.

Example: A gun firing. A slap rather than a tap.

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Interneurons

Neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs.

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Parts of a Neuron

Cell Body: Life support center of the neuron.

Dendrites: Branching extensions at the cell body. Receive messages from other neurons.

Axon: Long single extension of a neuron, covered with myelin [MY-uh-lin] sheath layer of fatty tissue that insulates and speed up messages through neurons.Organizer no. 7

Terminal Branches of axon: Branched endings of an axon that transmit messages to other neurons.

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Action Potential

A firing on a neuron. Occurs when a change inside a neuron becomes more positive than the charge

outside.

An impulse travels in a wavelike manner along the axon of a nerve, it causes a localized and switch in electric potential across the cell membrane from.

http://www.youtube.com/watch?v=ifD1YG07fB8

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Neurotransmitters

Neurotransmitters (chemicals) released

from the sending neuron travel across the synapse and bind to receptor sites on

the receiving neuron, thereby influencing it to generate an action

potential.

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Neurotransmitters

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Agonists and Antagonists

Drugs which mimic the activity of neurotransmitters.

Drugs which block the activity of neurotransmitters.

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Neurotransmitters

http://www.youtube.com/watch?v=IeZCmqePLzM&feature=related

http://www.youtube.com/watch?v=u3aOZlgJ3eA

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Reuptake Within 1/10,000th of a second a transmitter

molecule crosses the synaptic gap and binds to receptor sites on the receiving neuron.

Soon after this process the sending neuron reabsorbs the excess neurotransmitters.

SSRI: class of drugs used to relieve anxiety by limiting reuptake of a neurotransmitter.

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Endorphins Morphine within natural

neurotransmitters linked to pain control and pleasure.

Helps explain good feelings such as the runners high, the painkilling effects of acupunture.

http://www.youtube.com/watch?v=XbjJBZIONUc

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The Nervous System

Nervous System: Consists of all the nerve cells. It is the body’s speedy, electrochemical communication system. Delivers messages like email.

Central Nervous System (CNS): the brain and spinal cord.

Peripheral Nervous System (PNS): the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body.

Organizer no. 10

What happens when you burn your hand? The peripheral nervous system would send

impulses through a large number of neurons to

the spinal cord.

A simple reflex action occurs next and the effector neurons would send the message to the arm muscles to jerk your hand back. The spinal cord would simultaneously relay the message of the pattern of stimuli to the brain.

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The Ultimate Brain

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Peripheral Nervous System

Somatic Nervous System: The division of the peripheral nervous system that controls the body’s skeletal muscles.

Autonomic Nervous System: the control system of the body that regulates breathing, heart rate and digestion.

Sympathetic Nervous System: division of the ANS that arouses the body and mobilizes its energy in stressful situations.

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Central Nervous System

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The Spinal Cord and Reflexes

Simple Reflex

The Endocrine System21

The Endocrine System is the body’s “slow” chemical communication system.

Communication is carried out by hormones synthesized by a set of glands.

Speedy nervous system zips messages from the eyes to brain to the hand in a fraction of a

second.

Hormones

Hormones are chemicals synthesized by the endocrine glands that are secreted in the

bloodstream. Hormones affect the brain and many other tissues of the body.

For example, epinephrine (adrenaline) increases heart rate, blood pressure, and feelings of excitement during emergency

situations.

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Pituitary Gland

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Is called the “master gland.” The anterior pituitary lobe releases hormones that

regulate other glands. The posterior lobe regulates water and salt balance.

Adrenal Glands

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•Adrenal glands consist of the adrenal medulla and the cortex. The medulla secretes hormones (epinephrine and norepinephrine) during stressful and

emotional situations, while the adrenal cortex regulates salt and carbohydrate

metabolism.

The Brain

A brain lesion/ablation experimentally destroys

brain tissue to study animal behaviors after

such destruction.

Example: Removal of an area of the temporal

lobe of a monkey to see where different

behaviors originate.

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Studying the Brain

Biggest Distraction for the brainThe brain processes sound 50x faster than

vision.

http://www.youtube.com/watch?v=MBQOghQ4IYg

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Prefrontal Cortex Responsible for decision making and impulse

control. Organizer no. 13.

Not fully developed until around 20 years of age. Reason for impulsive behavior by teens.

Does biological drives overpower reason?

Can too much serotonin cause abnormal behavior among teens?

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The Brain

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http://www.youtube.com/watch?v=b2O9Veprz7w&feature=PlayList&p=46DE142CB9C72C3A&index=78

http://www.youtube.com/watch?v=J2YlTVg_7Ko

MRI Scan

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MRI (magnetic resonance imaging) uses magnetic fields and radio waves to produce computer-

generated images that distinguish among

different types of brain tissue. Top images

showenlargement in a schizophrenic patient. Bottom image shows brain regions when a

participants lies.

Both photos from Daniel Weinberger, M.D., CBDB, NIMH

James Salzano/ Salzano Photo Lucy Reading/ Lucy Illustrations

Older Brain Structures

The Brainstem is the oldest part of the brain, beginning where the spinal cord swells and enters the skull. It is responsible for automatic survival

functions.

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Brain StemThe Medulla [muh-DUL-uh] is the base

of the brainstem that controls heartbeat

and breathing.

Reticular Formation is a nerve network in the brainstem that plays an important role in controlling

arousal.Organizer no. 14

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Brain StemThe Thalamus [THAL-uh-

muss] is the brain’s sensory switchboard, located on top of the

brainstem.

It directs messages to the sensory areas in the cerebral cortex and

transmits replies to the cerebellum and medulla.

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CerebellumThe “little brain” attached to the rear of the

brainstem. It helps coordinate voluntary movements, balance and thinking processes.

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http://www.youtube.com/watch?v=n_77-ewz5Ig

The Limbic SystemThe Limbic System is a

doughnut-shaped system of neural structures at the

border of the brainstem and cerebrum.Associated with

emotions such as fear, aggression and drives

for food and sex. It includes the

hippocampus, amygdala, and hypothalamus.

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http://www.youtube.com/watch?v=7Qxu5cvW-ds

Amygdala

The Amygdala [ah-MIG-dah-la] consists of two almond-shaped neural clusters linked to the emotions of fear and

anger.Example: Waterboy.

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http://www.youtube.com/watch?v=UfC4u5GCy3I

HypothalamusThe Hypothalamus lies below the thalamus. It

directs several maintenance activities like eating, drinking,

body temperature, and control of emotions. It

helps govern the endocrine system via the

pituitary gland.

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http://www.youtube.com/watch?v=sG9wqZ7Dtx4&feature=related

The Cerebral CortexInterconnected neural cells that covers the cerebral

hemispheres like bark on a tree. It is the body’s ultimate control and information processing center.

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Glial Cells Cells in the nervous

system that support, nourish, and protect neurons.

Neurons are like queen bees who can’t feed on their own. These cells are the worker bees.

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Structure of the Cortex

Each brain hemisphere is divided into four lobes. Frontal lobe (forehead)-reasoning and personality. Parietal lobe (top to rear head-Responds to touch, heat, cold and pain.Occipital lobe (back head)-vision.Temporal lobe (side of head)-Hearing, language.

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Language

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Aphasia is an impairment of language, usually caused by left hemisphere damage either to Broca’s area or Wernicke’s area.

http://www.youtube.com/watch?v=UyyjU8fzEYU

Paul Broca

Discovered an area in the left frontal lobe of the brain that is critical for the production of spoken language.

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Carl Wernicke

German neurologist and psychiatrist who showed the effects of damage upon a specific area of the temporal lobe.

Disrupts the ability to comprehend or produce spoken or written language.

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Association Areas

Areas of the cerebral cortex found in all four lobes that are involved in higher mental functions such as learning, remembering and speaking.

Link sensory input with stored memories.

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Can a Damaged Brain Reorganize Itself Plasticity: brain’s ability to change during

childhood by reorganizing after damage or by building new pathways based on experience.

Ex. If surgery or injury destroys part of a child’s brain the brain will compensate by putting other areas to work. Organizer no. 20

Neurogenesis: baby neurons that originate deep in the brain and then move elsewhere to form connections with other neurons. Some animals form thousands of new neurons each day.

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Plasticity45

Concussions

http://www.youtube.com/watch?v=f0xJT53SZqQ

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Brain disease

http://www.msnbc.msn.com/id/21134540/vp/44493795#44493795

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Our Divided BrainOur brain is divided

into two hemispheres. The left hemisphere processes reading, writing, speaking, mathematics, and

comprehension skills. In the 1960s, it was

termed as the dominant brain.

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Splitting the BrainA procedure in which the two hemispheres of the brain are isolated by cutting the connecting fibers

(mainly those of the corpus callosum) between them.Organizer no. 21

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Corpus Callosum

Split Brain Patients

With the corpus callosum severed,

objects (apple) presented in the

right visual field can be named. Objects (pencil) in the left visual field cannot.

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http://www.youtube.com/watch?v=UyyjU8fzEYU

Phantom Brain http://www.youtube.com/watch?

v=sq6u4XVrr58&feature=related

http://www.youtube.com/watch?v=wlFi6IV42Ag&feature=related

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Brain Organization & Handedness

Historic studies, as well as modern medical studies, show that the right hand is preferred. This suggests genes and/or prenatal factors influence handedness.

Ultrasound observations of fetal thumb sucking reveal that more than 9 in 10 fetuses suck the right hand’s thumb.

Left-handers: more prone to reading disabilities, allergies, and migraine headaches.

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Left-handed Handedness

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Battle of the Brains

http://www.youtube.com/watch?v=kYexLjWY5KE

http://www.youtube.com/watch?v=4TUkhwV7IQc&feature=related

http://www.youtube.com/watch?v=rPH7JwhsfEo&feature=related

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