Methods of studying the Methods of studying the brain: A brief historybrain: A brief history

First… a few more basic facts about your brain!First… a few more basic facts about your brain!

Approximately 3 lbs.; slightly larger than size of Approximately 3 lbs.; slightly larger than size of an adult fistan adult fist

2% of total body weight; burns 70% of your bod2% of total body weight; burns 70% of your bodyy’’s glucoses glucose

100 billion+ neurons; trillions of synapses100 billion+ neurons; trillions of synapses Biochemical signals travel at 220 mphBiochemical signals travel at 220 mph Half of the 30,000 genes are dedicated to the Half of the 30,000 genes are dedicated to the

nervous systemnervous system The brain itself feels no pain, but registers it The brain itself feels no pain, but registers it

from everywhere elsefrom everywhere else

Early 1800sEarly 1800s Phrenology: measuring Phrenology: measuring

the bumps on peoplesthe bumps on peoples’’ headsheads

They were wrong about They were wrong about bumps; right about the bumps; right about the brain having localized brain having localized functions!functions!

http://www.bc.edu/http://www.bc.edu/bc_org/avp/cas/fnart/bc_org/avp/cas/fnart/phrenology/phrenology/phrenology_frames.htmlphrenology_frames.html

1848: Phineas Gage1848: Phineas Gage

http://youtu.be/9QXI_BxlY7M

1930s: Prefrontal lobotomies1930s: Prefrontal lobotomies

Dr. Walter Freeman: surgical disconnection of Dr. Walter Freeman: surgical disconnection of the frontal lobes from the thalamus with an the frontal lobes from the thalamus with an icepick icepick

Eliminated severe behavioral problems; also Eliminated severe behavioral problems; also took away emotions, problem solving, thinkingtook away emotions, problem solving, thinking

By 1949, 5,000 done annuallyBy 1949, 5,000 done annually http://www.pbs.org/wgbh/americanexperience/films/

lobotomist/ http://youtu.be/_0aNILW6ILk

1950s: Electrical Stimulation of the Brain1950s: Electrical Stimulation of the Brain

  1954: James Olds and Peter Milner placed an electrode in 1954: James Olds and Peter Milner placed an electrode in the hypothalamus of the brains of rats by mistake and the hypothalamus of the brains of rats by mistake and discovered the pleasure center of the braindiscovered the pleasure center of the brain

When the rats learned that they could control the When the rats learned that they could control the electrical stimulation by pressing a lever, they pressed it electrical stimulation by pressing a lever, they pressed it 7,000 times an hour (endorphins).  7,000 times an hour (endorphins).  

http://accidentalmind.org/the_discovery_of_brain_plea.html

1969: Jose Delgado1969: Jose Delgado’’s s ““matadormatador”” experiment: stimoceiver experiment: stimoceiver http://wireheading.com/matador.html

Selective lesioningSelective lesioning

Selectively damaging Selectively damaging parts of the brain using parts of the brain using electrical instrumentelectrical instrument

Only used in animals… Only used in animals… obviously.obviously.

Rat hypothalamus studyRat hypothalamus study Accidents and brain Accidents and brain

damage are often studied damage are often studied in human beings.in human beings.

For modern technology!For modern technology!And now…And now…

Electroencephalogram (EEG)Electroencephalogram (EEG)

Computerized Axial Computerized Axial Tomography (CAT)Tomography (CAT)

Positron Emission Positron Emission Tomography (PET)Tomography (PET)

Magnetic Resonance Imaging Magnetic Resonance Imaging (MRI)(MRI)

fMRI ScansfMRI Scans

What love looks like in an What love looks like in an fMRI Scan!fMRI Scan!