behavioural neuroscience

• Behavioral Neuroscience


  • The study of the biological processes by which the body (brain) generates and controls behavior
  • also called biological psychology
• Assumptions


  • Behavior is generated by the nervous system
  • The mind is embodied in/by the brain
  • Behavior is the result of the patterns of activation within the brain
• • Neurons are too small and fast to see
  • there are about 80 billion of them (in a human)
  • they are in a network
• Some key methods in Behavioral Neuroscience


  • Psychopharmacology
  • Measuring & recording (MRI, fMRI, EEG, MEG, DTI)
  • Studying brain-damaged patients
  • Comparative cognition
• Tinbergen's four questions


  • Mechanism (physiology); explains the processes that control the behaviour
  • Ontogeny (development); explain how the behaviour develops or matters
  • Phylogeny (evolution); explain the steps by which the behaviour evolved
  • Functional (adaptive); explain the adaptive benefits of the behaviour, what is it for
• Neuronal structure


  • Nucleus
  • Soma (body)
  • Axon
  • Dendrite (have spines)
  • Bouton (Axon terminal)
  • Synapse
• Synapse types


  • terminals attach to postsynaptic neurons' dendritic spines or soma
  • Excitatory (when presynaptic cell fires, postsynaptic cell becomes more likely to fire)
  • Inhibitory (when presynaptic cell fires, postsynaptic cell becomes less likely to fire)
• Types of neurons

  
  

  Sensory

  • convey signals from sense organs to brain
  • soma on a seperate stalk, near middle of axon
  • dendrites near or at the sense organ
  • synapses in the spinal cord (mostly)
  • very long

  Motor

  • convey signals from brain to muscles
  • soma and dendrites in or near spinal cord
  • synapses at the muscle (neuro-muscular junction)
  • also very long

  Interneuron (intrinsic)

  • all within one brain (or spinal cord) structure
  • usually very short
  • often inhibitory
• Evolution basics


  Natural selection:

  • more offspring are born than can survive
  • there is heritable variation between individuals
  • individuals better adapted to their environment have higher fitness -> more surviving offspring
  • if we evolved along with other animals, then there is a mental (psychological) continuity as well as a physical one
  • by studying animal behaviour (psychology) we can learn abt human behavioural mechanisms
• Evolution of behaviour

  • is behaviour heritable?
  • Tyrons' maze-bright/maze-dull experiment:
  • group of rats tested on a maze
  • best and worst bred tg
  • performance is heritable
• Big brains


  Do big brains make you smarter?

  • men have larger brains but not higher IQ
  • no correlation between brain size and IQ

  Reasons not to have a big brain:

  • brain tissue is expensive (only consumes glucose (and oxygen), and lots of it)
  • delicate, needs protection (big,heavy skull)
  • grows after birth
  • requires lots of maintenance (clearing away dead neurons)
• cells of the brain


  Neurons

  • sensory, motor, interneuron (intrinsic)
  • pyramidal, Purkinje, spindle, Golgi

  Glia

  • astrocytes, oligodendrocytes, Schwann cells, microglia, radial glia

  Blood vessels

  • blood-brain barrier
• Axons can be

  • afferent: entering a structure
  • efferent: exiting a structure