2017-02-15 08:36:56

Prelude

Today's topics

  • Wrap-up on systems
  • History of neuroscience

History of neuroscience

  • History of the study of brain and behavior
  • What did humans know about brain and behavior before the emergence of the scientific method?

Why study history?

  • What can observation tell us about brain and behavior?
  • Vital role of tools/methods/techniques in discovery
  • "If I have seen further, it is by standing on the shoulders of giants." – Isacc Newton, 1676

Pre/Early history

Trephining (trepanning)

Trephining

Beer-making (~5,000 BCE)

Egyptians (1,500-3,000 BCE) first written record of the term “brain”

Greek and Roman era

Greeks

Aristotle on the mind and brain

  • mind and body not distinct.
  • brain “cools” the body, heart is the mental organ.

Galen (~177 CE)

Galen and his ideas

  • Physician in Roman Empire, of Greek descent
  • Anatomical reports based on dissection of monkeys, pigs
  • Influenced by Hippocrates notion of human temperaments (~personalities) linked to "humors": blood, black bile, yellow bile, phlegm
  • Speculated that fluid filling the brain cavities called ventricles, circulates through nerves, body
  • Gladiators' head injuries impaired thinking, movement

Ventricles

What did early humans know about the mind and brain?

  • Mental functions controlled by organs in the head, the brain
  • Mental functions can be influenced by exogenous substances
  • Head injury can impair behavior and thinking

What did early humans know about the mind and brain?

  • Brain surgery can (potentially) repair disorders of the brain or behavior
  • Mental functions can be influenced by endogenous substances
  • Ventricles are filled with fluid; something flows from brain to body via nerves.

Why didn't they know more?

  • A. Limited technology.
  • B. Limited cultural support for systematic observation, description. = SCIENCE
  • C. Lack of ability to use knowledge even if it were acquired.

The "dark" ages (in Europe, not elsewhere)

Renaissance and the Enlightenment: New technologies, new ideas

Vesalius (1543)

  • 1st detailed drawings of brain and body anatomy

Vesalius' drawings

Leonardo da Vinci (1504)

  • Wax casts of ventricles
    • fluid filled inner regions of brain
  • Ventricles not spherical!

da Vinci's sketches

The body as machine (René Descartes – mid 1600’s)

Descartes' 'reflexes'

  • Reflexes “reflect” events in the world
  • Not the same as voluntary functions

Descartes' reflexes

Descartes' 'dualism'

  • Reflexes and animal “minds” are physical
  • Human mind is not
    • “Dual” influences on behavior
    • Physical + spiritual
  • Soul controls body via pineal gland
    • Causes muscles to “inflate”

Pineal Gland

Pineal gland

Do you agree with Descartes?

  • A. Yes, human minds are fundamentally different from animal minds. The human mind is influenced by both physical and extraphysical processes.
  • B. No, human minds are similar to animal minds. The human mind arises solely from physical processes.

How would you test Descartes idea about the role of the pineal gland?

Other milestones

The lessons from history

  • Neuroscience shaped by new methods, tools (next time)
  • Neuroscience shaped by great debates
    • Mind vs. brain debate
    • Localist/holist debate
    • Nature of neural communication
  • Forms at multiple levels of analysis contribute to function

Does it matter who did what in science?

Next time…

  • Levels of analysis
  • Neuroscience methods