How can we study the human brain?

From

• studies of patients with brain damage.
• functional MRI
• physiology in animals.
• cognitive science
• animal behaviour
• infant cognition

Question: How does the brain work?

• Can approach at multiple levels:
  • molecules and their interactions
  • properties of individual neurons
  • circuits of interacting neurons
  • brain regions and their functions
  • networks of brain regions

How does the brain give rise to the mind?

• What is mind?
• Mental functions included in mind are:
  • Perception
  • Vision
  • Hearing
  • Cognition
  • Language
  • Thinking about
    • people
    • things
• How each mental function
  • works in mind?
  • is computed?
• The basics of the brain.
  • Specialized brain machinery?
  • What, when, and how is information represented?

How to answer these questions?

• Psychophysics
  • By
    • Showing people visual stimuli
    • Playing them sounds
    • Asking them what they see or hear
  • Collect reaction time and accuracy
• Perceptional Illusions
  • Provides information about how the mind works.
• Neuropsychology Patients
• Functional MRI
• Neurophysiology
  • Recording from individual neurons in animal brains and in rare cases even in human brains (ECoG)
• EEG, ERPs
  • Recorded from electrodes on the scalp.
• Magetoencephalography (MEG)
• Diffusion tractography

Functional Organization of the Human Brain

What we knew in 1990

• Primary sensory and motor regions
• Face recognition
  • works somewhere in the back end of the bottom of the right hemisphere
    • How do we know? Because of people who had damage back there and lost their facial recognition ability. Some times preserving their ability to visually recognize words and scenes, and objects, only losing their ability to recognize faces.
• Language regions
  • Known about for nearly 200 years from Broca and Wernicke and others, who had studied patients with damage in those regions and noted that they had problems with language function.
• Attention
  • Also many people had reported that if you have damage up in the parietal lobes, you sometimes lose your ability to direct your attention to different places in the visual scene.

What we know now

We now know the function of dozens of brain regions:

• Places
• Colors
• Words/letters
• Faces, Language
• Grasping
• Multiple Demand
• Reaching
• Bodies
• Motion
• Shape
• Perception
• Pitch
• Music
• Speech
• Other People Thoughts
• Social perception.

Thanks to functional MRI.

• visual perception of color, shape, and motion
• visual recognition of faces, places, bodies, and words
• perceiving scenes and navigation
• representing numerical quantity
• perceiving speech and music
• understanding language
• understanding other minds

For each of these aspects of perception/cognition, ask:

• To what extent is this process implemented in its own specialized brain hardware?
• Do multiple brain regions contribute to this process?
• What does each one do?
• How does this region/system develop?
• Does this region/system have the homologs in other species, or is it uniquely human?

Other questions

• What (if anything) is "special" about the human brain? (comparing to animals)
• Where does knowledge come from?
  • How much genetic, how much experience?
• How plastic are our minds and brains?
  • can we change the structure of our minds/brains?
    • by training?
    • after brain damage?
• Can we think without language?
• Can we perceive/understand/think/decide without awareness?

Other topics

• Motor control
• Subcortical function, basal ganglia, habits, etc.
• Decision-making
• Circuit=level mechanistic explanations of cognition
  • Rarely do we have access to this info in humans.
  • Even in animals actual cases are rare where
    • we can see how the Circuit implements the computation
• Memory/hippocampus
• Reinforcement learning/reward systems
• Attention