4 3 14 The brain Behavioral neuroscience o o The study of the biological underpinnings of behavior Examples Phineas Gage personality Railroad construction worker Metal rod shot through his left eye and exited his left frontal lob For the most part he was okay but his personality changed from being well mannered to really profane and violent Tan language Nick A memory Lost the ability to pronounce words only used the word tan Frontal lobe was severely damaged Air force technician Fencing foil and was lodged up his nose and up into the middle of his brain Had profound trouble with his memory couldn t make new memories Severe damage to hippocampus Self stimulating rats pleasure Septum was activated Some rats ignored hunger for repeated reward o Basic assumption ALL thought and behavior is a function of the nervous system and most fundamentally the brain Goal of nervous system To collect transform and transmit information Enormous complex system o o Most complex we ve ever known Where does the information come from o o o The external world through your senses The internal world through your viscera From other parts of the nervous system e g your brain talks to itself a lot More interactivity than interpreting information from the outside Your brain is one big information processing system much like a computer is an information processing system A computer simple fast computation Our brains complex simple computations relative to a computer Basic divisions of the nervous system Nervous system o Peripheral nervous system Somatic Link to external world Voluntary muscles Sensory systems Autonomic Link to internal world viscera o o o Involuntary muscles Sympathetic arousal Increase in blood pressure Heart rate increase Dilation of eyes 4 f s Parasympathetic calming Reduced heart rate Reduced blood pressure Constriction of eyes o Central nervous system Brain Spinal cord Microscopic view of the brain Structure and function of neurons including the brain o What do neurons do o Neurons are the functionally important cells which make up the nervous system Collect integrate and transmit information o How many do we have in our brains About 100 billion but you lose about 10 000 every day o How many connections are between neurons About 100 trillion connections between neurons synapses o Parts of a neuron Dendrites receive input from other neurons and from muscles organs etc Cell body integrates information collected from other neurons organs etc Typically integrates thousands of dendritic inputs at any given moment in time Based on the integrated input cell body is constantly deciding whether or not to send a signal to other neurons Axon transmits signals to other neurons or muscles etc Although the cell body is microscopic axons can be up to 3 feet in length Axon terminal location of a synapse which is where neurons communicate Myelin sheath fatty cells wrapped around the axon insulating the axon making information transmission faster and more reliable Not all axons are myelinated For those that are some are more myelinated than others