Thalamus - gatekeeper between cortex and rest of brain and helps with focus and attention
What is midbrain also called? two parts? what is in each part?
1. Tectum - superior (visual) and inferior (auditory) colliculus. NOT reflex. contribute to sensory perception.
2. Tegmentum - sensory and motor neurons (i.e., cranial nerves) and reticular formation
What's in hindbrain? (3)
1. Cerebellum - layered, importnat for motor control (like BG). But BG is responsible for modifying amplitude and direction, while cerebellum is important for modifying plans of movement.
2. Pons - input for cerebellum
3. Medulla LIKE TEGMENTUM - cranial nerve nuclei for both motor and sensory, has important reticular formation. Main function - motor pattern generators for patterened life functions - breathing, heartbeat, etc.
Operational death is brainstem death (death of hindbrain and midbrain).
Even without motor output, people can respond to questions.
Why do we study non-human animals?
What are the methodological concerns? (4)
2. Methodological concerns - possible approaches, convenience of housing, natural experiments (bats with inferior colliculus & giant squid axons), brain evolution.
1. Why do larger bodies need more brains? (4)
1. Same cognition and motor control as smaller animals (neuron:muscle fiber ratio) - so more neurons.
2. More innervation
3. More sensory information
4. Longer extremities = longer axons
What is allometric? What is deviation from the slope in brain weight vs. body weight? Can you use the same line across classes?
Brain size vs. body size - lower slope. Encephalization factor - different mass of brain than expected for body weight --> intelligence.
No. Must ensure level playing field.
Comparing brain size among species?
Role of selective pressures.
Must have experience AND genotype to accommodate experience
Birds that need to store food (higher i mountain) had larger hippocampuses for spatial memory as to where they stored their food. So, here we measured brain region size (hippocampus) vs. telencephalon
Bats have relatively large inferior colliculus size.
Define mosaic and concerted evolution and give examples of each
Mosaic - individual brain regions can evolve independently of rest of brain (inferior colliculus)
Concerted evolution - brain regions evolve together - coordinated changes.Developmental constraint Hippocampus can only get bigger if whole telencephalon gets bigger - basically if it gets to develop later (cells stop proliferating and start differentiating), it'll be disproportionately large. (cortex vs medulla)