Exam and Assignment Dates Midterm 1 Feb 3 rd and 4 th Midterm 2 March 9 th and 10 th Final April 20 th and 21 st Idea journal assignment is due on last day of class

Class Web Site Is not on WebCT / Blackboard !! Is actually at: –

To get you thinking… A bit of philosophy, a bit of biology

First, some philosophy I see, I hear, I feel… Who is I - Do you mean my brain sees, hears, and feels or do you mean something else?

First, some philosophy Brains and Minds - Are they the same thing? If not, what is the difference? What is a good analogy?

Philosophy of Mind Monism -

Philosophy of Mind Monism - mind and brain (body and soul) are not different things

Philosophy of Mind Monism - mind and brain (body and soul) are not different things Dualism -

Philosophy of Mind Monism - mind and brain (body and soul) are not different things Dualism - mind and brain are fundamentally different

Philosophy of Mind What might constitute evidence for or against either of these two alternatives?

What are Brains Made Of? About one trillion neurons (1,000,000,000,000) Assorted other cells called “glial cells”

Neurons Have Three Parts (Usually)

Neurons Relay Signals From Other Neurons to Other Neurons

Neurons are Cells with Electrically Charged Membranes membrane channels

Neurons Carry Information as Electrochemical Signals at rest, charges balance each other Axon

Neurons Carry Information as Electrochemical Signals - when stimulated, membrane briefly lets charges switch sides

Neurons Carry Information as Electrochemical Signals - “depolarization” opens channels nearby that allow more charges to switch

Neurons Carry Information as Electrochemical Signals - Chain-reaction, called an action potential, propagates along the axon

Neurons Carry Information as Electrochemical Signals - Chain-reaction, called an action potential, propagates along the axon

Neurons Carry Information as Electrochemical Signals - Chain-reaction, called an action potential, propagates along the axon

Neurons Carry Information as Electrochemical Signals - Chain-reaction, called an action potential, propagates along the axon

Neurons Carry Information as Electrochemical Signals Action potential can travel very fast - on the order of 100 meters per second (360 km/hr !)

Signals Jump from Neuron to Neuron Across Synapses

Neurotransmitter molecules carry signal across synapse What does this have to do with cognition ?

Signals Jump from Neuron to Neuron Across Synapses Neurotransmitter molecules carry signal across synapse The synapse is the site of action of the vast majority of psychoactive drugs!

Optic Nerve Visual Cortex Neurons are linked Together to Form “Pathways” eye

Neurons are Linked Together to Form “Pathways” Different regions are specialized for different functions

Neurons are Linked Together to Form “Pathways” Different regions are specialized for different functions Regions are reciprocally connected

Philosophy of Mind The Hard Problem - How does the movement of sodium and potassium ions across a membrane generate an experience?

Sensation What is sensation?

Sensation What is sensation? Sensation is acquiring information about the outside world.

Perception What is perception?

Perception What is perception? Perception is interpreting information about the outside world.

The Senses Name the “senses”

The Senses Vision Hearing Taste Smell Touch “Conscious Senses” Temperature Balance Body Position “Subconscious Senses (sometimes)”

The Senses All of these senses are really just systems that extract information about how you and the rest of the universe are interacting

The Senses All of these senses are really just systems that extract information about how you and the rest of the universe are interacting What IS sensory information?

Information is Contained in Energy Hearing is the perception of vibrations in the air

Information is Contained in Energy Hearing is the perception of vibrations in the air Vision is the perception of electromagnetic radiation

Information is Contained in Energy Hearing is the perception of vibrations in the air Vision is the perception of electromagnetic radiation Taste and smell are the perceptions of chemicals

Information is Contained in Energy Hearing is the perception of vibrations in the air Vision is the perception of electromagnetic radiation Taste and smell are the perceptions of chemicals Touch is the perception of force on your skin

Sensation Starts with “Receptors” Receptors transduce incoming signals into neural signals to be sent along axons to the brain transduction - converting one type of energy into another type of energy (e.g. mechanical sound energy into electrochemical neural signals)

Next Time: Hearing