Mapping the Brain

Pages 128-134

Daily Learning Objectives: THE STUDENT WILL

• Describe why we call them Brain waves• Explain scanning techniques, such as electrode

methods• Compare and Contrast 2 brain scans

Main room in the house= the Brain

• Write Hamlet, discover radium, paper clips• How do we study Brain? • Lesion Method- Damaging or removing

sections of brain in animals then observing the effects

Electrical and Magnetic Detection

• Probed with devices called electrodes• Electrical activity of millions of NEURONS in a

region• Measure Brains, activity, damage• Transfers to machine that turns electrical

energy into wavy lines on piece of paper• As a result called brain waves

electrodes

More electrodes

Electroencephalogram

A recording of neural activity detected by electrodes

chapter 4

EEG

• EEG – electroencephalogram• Brain-wave recording• Standard EEG sounds like outside A.T.&T. park,

hear loud noise but not sure what happened• Needle electrodes are more precise- compare

and contrast elec. currents• Computer technology is almost always

improving so EEG’s analysis is as well

Transcranial magnetic stimulation (TMS)

Involves delivering a large current through a wire coil on a person’s head

Can be used toProduce motor responses

Temporarily inactivate an area of the brain

Treat depression

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TMS

• TMS= transcranial magnetic stimulation• 40,000 times more powerful than Earth’s

natural magnetic field• Virtual lesion method• Neurons fire• Produce motor responses- knee jerk, twitch

thumb• Important findings- TMS show imagine visual

stimulus, the same as seeing a picture

Positron emission tomography

Active areas have increased blood flow.

Sensors detect radioactivity.

Different tasks show distinct activity patterns.

A method for analyzing biochemical activity in the brain, using injections of a glucose-like substance containing a radioactive element

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Scanning the Brain

• PET Scan- 1970’s, Positron-emission tomography• Blood flow, oxygen measures, emotional

disorders, active during emotions, activities• Sad memory, math prob. See pretty girl• Nerve cells convert to glucose• SO inject with glucose like substance and

substance goes to active brain areas• As a result computer processed picture of

biochemical activity on screen

Magnetic resonance imaging (MRI)

Magnetic fields align certain ions and compounds.

When field is removed, these molecules release energy as radio waves.

Computer calculates tissue density from radio waves.

Provides clear 3D images

Method for studying body and brain tissue

chapter 4

MRI

• MRI- magnetic resonance imaging• Allows exploration of inner space• No chemical injection• Magnetic field and radio frequencies• As a result produce vibrations in the nuclei of

atoms• Pick up vibrations, turn into signals, computer

turns into picture.- Functional MRI

Functional MRI

MRI Machine

Summary

• Electrical magnetic scans• VENN DIAGRAM OF 2 SCANS